Light Curing of Restorative Materials










e94 CHAPTER 18 Class II Cast-Metal Restorations
e94
18
Class II Cast-Metal Restorations
JOHN R. STURDEVANT
T
he cast-metal restoration is versatile and is especially
applicable to Class II onlay preparations. e process has
many steps, involves numerous dental materials, and requires
meticulous attention to detail. Typically a dental laboratory is
involved, and the dentist and the laboratory technician must be
devoted to perfection. e high degree of satisfaction and service
derived from a properly made cast-metal restoration is a reward
for the painstaking application required.
1
e Class II inlay involves
the occlusal surface and one or more proximal surfaces of a posterior
tooth. When cusp tips are restored, the term onlay is used. e
procedure requires two appointments: the rst for preparing the
tooth and making an impression, and the second for delivering
the restoration to the patient. e fabrication process is referred
to as an indirect procedure because the casting is made on a replica
of the prepared tooth in a dental laboratory.
Material Qualities
Cast-metal restorations can be made from a variety of casting
alloys. Although the physical properties of these alloys vary, their
major advantages are their high compressive and tensile strengths.
ese high strengths are especially valuable in restorations that
rebuild most or all of the occlusal surface.
e American Dental Association (ADA) Specication No. 5
for Dental Casting Gold Alloys requires a minimum total gold-
plus-platinum-metals content of 75 weight percent (wt%). Such
traditional high-gold alloys are unreactive in the oral environment
and are some of the most biocompatible materials available to the
restorative dentist.
2
At present, four distinct groups of alloys are
in use for cast restorations: (1) traditional high-gold alloys, (2)
low-gold alloys, (3) palladium–silver alloys, and (4) base metal
alloys. Each of the alternatives to high-gold alloys has required
some modication of technique or acceptance of reduced perfor-
mance, most commonly related to decreased tarnish resistance and
decreased burnishability.
3
Also they have been associated with higher
incidences of postrestorative allergy, most often exhibited by irritated
soft tissue adjacent to the restoration.
2
Indications
Large Restorations
e cast-metal inlay is an alternative to amalgam or composite
when the higher strength of a casting alloy is needed or when the
superior control of contours and contacts that the indirect procedure
provides is desired. e cast-metal onlay is often an excellent
alternative to a crown for teeth that have been greatly weakened
by caries or by large, failing restorations but where the facial and
lingual tooth surfaces are relatively unaected by disease or injury.
For such weakened teeth, the superior physical properties of a
casting alloy are desirable to withstand the occlusal loads placed
on the restoration; also the onlay can be designed to distribute
occlusal loads over the tooth in a manner that decreases the chance
of tooth fracture in the future. Preserving intact facial and lingual
surfaces is conducive to maintaining the health of the pulp and
the contiguous soft tissue (gingiva). When margins are supragingival
they are easier to inspect for adaptation and seal. When proximal
surface caries is extensive, favorable consideration should be given
to the cast inlay or onlay. e indirect procedure used to develop
the cast restoration allows more control of contours and contacts
(proximal and occlusal).
Endodontically Treated Teeth
A molar or premolar with treatment root canal lling can be
restored with a cast-metal onlay, provided that the onlay has been
thoughtfully designed to distribute occlusal loads in such a manner
as to reduce the chance of tooth fracture.
Teeth at Risk for Fracture
Fracture lines in enamel and dentin, especially in teeth having
extensive restorations, should be recognized as cleavage planes for
possible future fracture of the tooth. Restoring these teeth with a
restoration that braces the tooth against fracture injury may be
warranted sometimes. Such restorations are cast onlays and crowns.
Dental Rehabilitation With Cast-Metal Alloys
When cast-metal restorations have been used to restore adjacent
or opposing teeth, the continued use of the same material
may be considered to eliminate electrical and corrosive activ-
ity that sometimes occurs between dissimilar metals in the
mouth, particularly when they come in contact with each other
(galvanism).
Diastema Closure and Occlusal Plane Correction
Often the cast inlay or onlay is indicated when extension of the
mesiodistal dimension of the tooth is necessary to form a contact
with an adjacent tooth. Cast onlays also can be used to correct
the occlusal plane of a slightly tilted tooth.

CHAPTER 18 Class II Cast-Metal Restorations e95
Control of Contours and Contacts
rough the use of the indirect technique, the dentist has great
control over contours and contacts. is control becomes especially
important when the restoration is larger and more complex.
Disadvantages
Number of Appointments and Higher
Chair Time
e cast inlay or onlay requires at least two appointments and
much more time than a direct restoration, such as amalgam or
composite.
Temporary Restorations
Patients must have temporary restorations between the preparation
and delivery appointments. Temporaries occasionally loosen or
break, requiring additional visits.
Cost
In some instances, cost to the patient becomes a major consider-
ation in the decision to restore teeth with cast-metal restorations.
e cost of materials, laboratory bills, and the time involved
make indirect cast restorations more expensive than direct
restorations.
Technique Sensitivity
Every step of the indirect procedure requires diligence and attention
to detail. Errors at any part of the long, multistep process tend to
be compounded, resulting in less than ideal ts.
Splitting Forces
Small inlays may produce a wedging eect on facial or lingual
tooth structure and increase the potential for splitting the tooth.
Onlays do not have this disadvantage.
Initial Procedures
Occlusion
Before the anesthetic is administered and before preparation of
any tooth, the occlusal contacts of teeth should be evaluated. As
part of this evaluation, the dentist must decide if the existing
occlusal relationships can be improved with the cast-metal restora-
tion. An evaluation should include (1) the occlusal contacts in
maximum intercuspation where teeth are brought into full
interdigitation and (2) the occlusal contacts that occur during
mandibular movements (Fig. 18.1). e pattern of occlusal contacts
inuences the preparation design, selection of interocclusal records,
and type of articulator or cast development needed.
Anesthesia
Local anesthesia of the tooth to be operated on and of adjacent
soft tissue usually is recommended. Anesthesia in these areas
eliminates pain and reduces salivation, resulting in a more pleasant
procedure for the patient and the operator.
Removable Prosthodontic Abutment
Teeth that are to serve as abutments for a removable partial denture
can be restored with cast-metal restorations. e advantages of
cast restorations are as follows: (1) e superior physical properties
of cast-metal alloys allow restorations to better withstand forces
imparted by a partial denture, and (2) rest seats, guiding planes,
and other aspects of contour relating to partial dentures are better
controlled when the indirect technique is used.
Contraindications
High Caries Rate
Facial and lingual (especially lingual) smooth-surface caries indicates
a high caries activity that should be brought under control before
expensive cast-metal restorations are used.
Young Patients
With younger patients, direct restorative materials (e.g., composite
or amalgam) are indicated unless the tooth is severely broken or
endodontically treated. An indirect procedure requires longer and
more numerous appointments, access is more dicult, the clinical
crowns are shorter, and younger patients may neglect oral hygiene,
resulting in additional caries.
Esthetics
e dentist must consider the esthetic impact (display of metal)
of the cast-metal restoration. is factor usually limits the use of
cast-metal restorations to tooth surfaces that are hidden at a
conversational distance. Composite and porcelain restorations are
alternatives in esthetically sensitive areas.
Small Restorations
Because of the success of amalgam and composite, few cast-metal
inlays are done in small Class I and II restorations.
Advantages
Strength
e inherent strength of dental casting alloys allows them to restore
large damaged or missing areas and be used in ways that protect
the tooth from future fracture injury. Such restorations include
onlays and crowns.
Biocompatibility
As previously mentioned, high-gold dental casting alloys are
unreactive in the oral environment. is biocompatibility can be
helpful for many patients who have allergies or sensitivities to
other restorative materials.
Low Wear
Although individual casting alloys vary in their wear resistance,
castings are able to withstand occlusal loads with minimal changes.
is is especially important in large restorations that restore a large
percentage of occlusal contacts.

e96 CHAPTER 18 Class II Cast-Metal Restorations
the area of the defect. An impression is typically made using a
sectional tray (Fig. 18.2A). e tray lled with impression material
is seated (see Fig. 18.2B). After the impression has set, the impression
is removed and examined for completeness (see Fig. 18.2C). Alginate
impressions can distort quickly if they are allowed to gain or lose
moisture, so the impression is wrapped in wet paper towels to
serve as a humidor (see Fig. 18.2D). Preoperative PVS impressions
do not need to be wrapped. e preoperative impression is placed
aside for later use in forming the temporary restoration.
Tooth Preparations for Class II Cast-
Metal Restorations
A small, distal, cavitated caries lesion in the maxillary right rst
premolar is used to illustrate the classic two-surface preparation
Considerations for Temporary Restorations
Before preparation of the tooth, consideration must be given to
the method that will be used to fabricate the temporary restoration.
Most temporary restoration techniques require the use of a preopera-
tive impression to reproduce the occlusal, facial, and lingual surfaces
of the temporary restoration to the preoperative contours.
e technique involves making a preoperative impression with
an elastic impression material. Alginate impression materials may
be used and are relatively inexpensive. e preoperative impression
may be made with a polyvinyl siloxane (PVS) impression material
if additional accuracy, stability, and durability are required. If the
tooth to be restored has large defects such as a missing cusp, an
instrument can be used to carve away impression material in the
area of the missing cusp or tooth structure, to simulate the desired
form for the temporary restoration. Alternatively, a material such
as rope wax can be added to the tooth before the impression in
A
B
C
Fig. 18.1 A–C, Evaluate occlusal relationships in maximum intercuspation (A) and during mandibular
movements (B and C). Be alert for problems with tooth alignment and contact position. Note the amount
of posterior separation provided by the guidance of anterior teeth (working side) and articular eminence
(nonworking side).
D
A
B
C
Fig. 18.2 A, Applying tray adhesive to stock quadrant tray. B, Making preoperative impression. C,
Inspecting preoperative impression for completeness. D, When using alginate, wrap the impression with
wet paper towels to serve as a humidor.

CHAPTER 18 Class II Cast-Metal Restorations e97
Occlusal Step
With the No. 271 carbide bur held parallel to the long axis of the
tooth crown, the dentist enters the fossa or pit closest to the
involved marginal ridge, using a punch cut to a depth of 1.5 mm
to establish the depth of the pulpal wall (
Fig. 18.4A and B). In
the initial preparation, this specied depth should not be exceeded,
regardless of whether the bur end is in dentin, caries, old restorative
material, or air. e bur should be rotating at high speed (with
air-water spray) before application to the tooth and should not
stop rotating until it is removed; this minimizes perceptible vibration
and prevents breakage or chipping of the bur blades. A general
rule is to maintain the long axis of the bur parallel to the long
axis of the tooth crown at all times (see Fig. 18.4B and C). For
mandibular molars and second premolars whose crowns tilt slightly
lingually, this rule dictates that the bur should also be tilted slightly
(5–10 degrees) lingually to conserve the strength of the lingual
cusps (see Fig. 18.4D). When the operator is cutting at high speeds,
a properly directed air-water spray is used to provide the necessary
cooling and cleansing eects.
5
Maintaining the 1.5-mm initial depth and the same bur orienta-
tion, the dentist extends the preparation outline mesially along
the central groove or ssure to include the mesial fossa or pit (see
Fig. 18.4E and F). Ideally, the faciolingual dimension of this cut
should be minimal. e dentist takes care to keep the mesial
marginal ridge strong by not removing the dentin support of the
ridge (see Fig. 18.4F and H). e use of light intermittent pressure
minimizes heat production on the tooth surface and reduces the
incidence of enamel crazing ahead of the bur. Occasionally a ssure
extends onto the mesial marginal ridge. is defect, if shallow,
may be treated with enameloplasty, or it may be included in the
outline form with the cavosurface bevel, which is applied in a later
step in the tooth preparation (see Fig. 18.4G).
Enameloplasty, as presented in earlier chapters, occasionally
reduces extension along the ssures, conserving the tooth structure
vital for pulp protection and the strength of the remaining tooth
crown. e extent to which enameloplasty can be used usually
cannot be determined until the operator is in the process of
for an inlay (Fig. 18.3A). Treatment principles for other defects
are presented later. As indicated previously, few small one-surface
or two-surface inlays are done. Because the description of a small
tooth preparation presents the basic concepts, it is used to illustrate
the technique. More extensive tooth preparations are presented
later.
Tooth Preparation for Class II Cast-Metal Inlays
Initial Preparation
Carbide burs used to develop the vertical internal walls of the
preparation for cast-metal inlays and onlays are plane cut, tapered
ssure burs. ese burs are plane cut so that the vertical walls are
smooth. e side and end surfaces of the bur should be straight to
aid in the development of uniformly tapered walls and smooth pulpal
and gingival walls. Recommended dimensions and congurations
of the burs to be used are shown in Fig. 18.3B. Suggested burs are
the No. 271 and the No. 169L burs (Brasseler USA, Inc., Savannah,
GA). Before using unfamiliar burs, the operator is cautioned to
verify measurements to judge the depth into the tooth during
preparation. e sides and end surface of the No. 271 bur meet in
a slightly rounded manner so that sharp, stress-inducing internal
angles are not formed in the preparation.
4
e marginal bevels are
placed with a slender, ne-grit, ame-shaped diamond instrument
such as the No. 8862 bur (Brasseler USA, Inc.).
roughout the preparation for a cast inlay, the cutting instru-
ments used to develop the vertical walls are oriented to a single
draw” path, usually the long axis of the tooth crown, so that the
completed preparation has draft (no undercuts) (see Fig. 18.3C).
e gingival-to-occlusal divergence of these preparation walls may
range from 2 to 5 degrees per wall from the line of draw. If the
vertical walls are unusually short, a maximum of 2 degrees occlusal
divergence is desirable to increase retention potential. As the
occlusogingival height increases, the occlusal divergence should
increase because lengthy preparations with minimal divergence
(more parallel) may present diculties during the seating and
withdrawal of the restoration.
C
4
x
y
Inlay
Tooth
A B
0.8 mm
0.5 mm
271
169L
8862
Fig. 18.3 A, Proposed outline form for distoocclusal preparation. B, Dimensions and conguration of
No. 271, No. 169L, and No. 8862 instruments. C, Conventional 4-degree divergence from line of draw
(xy).

e98 CHAPTER 18 Class II Cast-Metal Restorations
are not faulty, sucient facial extension in the mesial pit region
should be made to provide this dovetail retention form against
distal displacement. Minor extension in the transverse ridge area
to include any remaining facial or lingual caries may necessitate
additional facial or lingual extension in the mesial pit to provide
this dovetail feature. (During such facial or lingual extensions to
sound tooth structure, the bur depth is maintained at 1.5 mm.)
If major facial or lingual extension is required to remove undermined
occlusal enamel, capping the weak remaining cuspal structure and
additional features in the preparation to provide adequate retention
and resistance forms may be indicated. ese considerations are
discussed in subsequent sections.
Continuing at the initial depth, the occlusal step is extended
distally into the distal marginal ridge suciently to expose the
junction of the proximal enamel and dentin (
Fig. 18.7A and B).
While extending distally, the dentist progressively widens the
preparation to the desired faciolingual width in anticipation of
the proximal box preparation. e increased faciolingual width
extending the preparation wall, when the depth of the ssure in
the enamel wall can be observed (
Fig. 18.5). When enameloplasty
shows a ssure in a marginal ridge to be deeper than one third
the thickness of enamel, the procedures described in the later
section should be used.
Extend to include faulty facial and lingual ssures radiating
from the mesial pit. During this extension cutting, the operator
is cautioned again not to remove the dentin support of the proximal
marginal ridge. To conserve the tooth structure and the strength
of the remaining tooth, the nal extension up these ssures can
be accomplished with the slender No. 169L carbide bur (Fig.
18.6A). e tooth structure and strength can be conserved further
by using (1) enameloplasty of the ssure ends, when possible, and
(2) the marginal bevel of the nal preparation to include (eliminate)
the terminal ends of these ssures in the outline form. e facial
and lingual extensions in the mesial pit region should provide the
desired dovetail retention form, which resists distal displacement
of the inlay (see
Fig. 18.6B). When these facial and lingual grooves
B
C
D
F
G
H
271
Maxillary molar
z
271
271
271
Facial
Lingual
y
x
271
w
Mandibular molar
Facial
Lingual
s
Bevel
Correct Incorrect
A
E
Fig. 18.4 A and B, Bur after punch cut to a depth of 1.5 mm. C, For maxillary posterior teeth, the
long axis of the bur should parallel the long axis of the tooth crown (yz). D, For molar and second premolar
teeth of mandibular dentition, the long axis of the bur should tilt slightly lingually to parallel the long axis
of the tooth crown (wx). E and F, Extending the mesial wall, taking care to conserve dentin that supports
marginal ridge (s). G, The marginal bevel can provide additional extension. H, Improper extension that
has weakened the marginal ridge.

CHAPTER 18 Class II Cast-Metal Restorations e99
be checked with the length of the bur by rst measuring the depth
from the height of the marginal ridge and then removing the bur
and holding it beside the tooth. A periodontal probe also may be
used for this measurement. While penetrating gingivally, the dentist
extends the proximal ditch facially and lingually beyond the caries
to the desired position of the facioaxial and linguoaxial line angles.
If the caries lesion is minimal, the ideal extension facially and
lingually is performed as previously described (see Fig. 18.7F).
Ideal gingival extension of a minimal, cavitated lesion eliminates
caries on the gingival oor and provides a 0.5-mm clearance of
the unbeveled gingival margin with the adjacent tooth. Moderate
to extensive caries on the proximal surface dictates continued
extension of the proximal ditch to the extent of the caries at the
dentinoenamel junction (DEJ), but not pulpally (see Fig. 18.11D
later in the chapter). When preparing the proximal portion of the
preparation, the dentist maintains the side of the bur at the specied
axial wall depth regardless of whether it is in dentin, caries, old
restorative material, or air. e operator should guard against
overcutting the facial, lingual, and gingival walls, which would
not conserve the tooth structure and could result in (1) overextension
of the margins in the completed preparation, (2) a weakened tooth,
enables the facial and lingual walls of the box to project (visually)
perpendicularly to the proximal surface at positions that clear the
adjacent tooth by 0.2 to 0.5 mm (see Fig. 18.7F). e facial and
lingual walls of the occlusal step should go around the cusps in
graceful curves, and the prepared isthmus in the transverse ridge
ideally should be only slightly wider than the bur, thus conserving
the dentinal protection for the pulp and maintaining the strength
of the cusps. If the occlusal step has been prepared correctly, any
caries on the pulpal oor should be uncovered by facial and lingual
extensions to sound enamel (supported by dentin).
Proximal Box
Continuing with the No. 271 carbide bur, the distal enamel is
isolated by cutting a proximal ditch (see Fig. 18.7C–F). e harder
enamel should guide the bur. Slight pressure toward enamel is
necessary to prevent the bur from cutting only dentin. If the bur
is allowed to cut only dentin, the resulting axial wall would be
too deep. e mesiodistal width of the ditch should be 0.8 mm
(the tip diameter of the bur) and prepared approximately two
thirds (0.5 mm) at the expense of dentin and one third (0.3 mm)
at the expense of enamel. e gingival extension of this cut may
A
B
Fig. 18.5 A, Shallow enamel fault that is no deeper than one third the thickness of enamel. B, Using
ne-grit diamond instrument to remove enamel that contains shallow fault.
A
B
x
y
z
Dovetailing
Dovetail
Fig. 18.6 A, Extending up the mesiofacial triangular groove using the slender No. 169L bur. B, Dovetail
retention form is created by extension shown in A. As x ts into y only in one direction resulting in z, simi-
larly dovetail portion of inlay ts into the dovetail portion of the preparation only in an occlusal-to-gingival
direction.

e100 CHAPTER 18 Class II Cast-Metal Restorations
is held. Also the level of the gingival oor is veried by observing
where the end of the bur emerged through the proximal surface.
If indicated, additional gingival extension can be accomplished
while the remaining enamel still serves to guide the bur and to
prevent it from marring the proximal surface of the adjacent tooth.
At this time, however, the remaining wall of enamel often breaks
away during cutting, especially when high speeds are employed.
If the isolated wall of enamel is still present, it can be fractured
out with a spoon excavator (see Fig. 18.7I). At this stage, the
ragged enamel edges left from breaking away the proximal surface
may be touching the adjacent tooth.
Planing the distofacial, distolingual, and gingival walls by hand
instruments to remove all undermined enamel may be indicated
if minimal extension is needed to fulll an esthetic objective.
and (3) possible injury of soft tissue. Because the proximal enamel
diminishes in thickness from the occlusal to gingival level, the end
of the bur is closer to the external tooth surface as the cutting
progresses gingivally. e axial wall should follow the contour of
the tooth faciolingually. Any carious dentin on the axial wall should
not be removed at this stage of the preparation.
With the No. 271 carbide bur, the dentist makes two cuts, one
at the facial limit of the proximal ditch and the other at the lingual
limit, extending from the ditch perpendicularly toward the enamel
surface (in the direction of the enamel rods) (see
Fig. 18.7G).
ese cuts are extended until the bur is nearly through the marginal
ridge enamel (the side of the bur may emerge slightly through the
surface at the level of the gingival oor) as shown in Fig. 18.7H.
is weakens the enamel by which the remaining isolated portion
0.5 mm
0.2 mm
x
x
j
Distal
271
B
D
EF
G
I
x
271
271
j
A
C
H
Fig. 18.7 A, After exposing the junction (j) of proximal enamel and dentin. B, Sectional drawing of
A. C, Cutting the proximal ditch. D, Sectional drawing of C. E, Proximal view of D. F, Occlusal view
of the proximal ditch with proposed ideal clearance with the adjacent tooth. G and H, Proximal ditch
extended distally. x, penetration of enamel by side of bur at its gingival end. I, Breaking away isolated
enamel.

CHAPTER 18 Class II Cast-Metal Restorations e101
intermittent cutting. e operator should avoid unnecessarily
desiccating the exposed dentin during this procedure.
Light-cured glass ionomer cement may be applied with a suitable
applicator to these shallow (or moderately deep) excavated regions
to the depth and form of the ideally prepared surface. Placing the
material takes little time and should be considered because it results
in preparation walls with no undercuts and “ideal” position and
contour. is facilitates making the temporary restoration, and
also applying the light-cured glass ionomer at this time minimizes
additional irritation of the pulp during subsequent procedures
necessary for the completion of the restoration. e material is
applied by conveying small portions on the end of a periodontal
probe and is light-cured when the correct form has been achieved
(see
Fig. 18.9H and I). Any excess cement can be trimmed back
to the ideal form with the No. 271 carbide bur after the cement
has hardened.
If the caries lesion is judged to approach the pulp closely, a
rubber dam should be applied and the soft dentin removed as
indicated (see Chapter 2). Rubber dam provides the optimal
environment for successfully treating a pulp exposure should it
occur. If removal of soft dentin leads directly to a pulpal exposure
(carious pulpal exposure), root canal treatment should be accom-
plished before completing the cast-metal restoration.
If the pulp is inadvertently exposed as a result of operator error
or misjudgment (mechanical pulpal exposure), the operator must
decide whether to proceed with the root canal treatment or to
attempt a direct pulp capping procedure. A clinical evaluation
should be made to determine the health of the pulp. A favorable
prognosis for the pulp after direct pulp capping may be expected
if the following criteria are met:
 <0.5 mm in diameter).
        
pulpitis.
 
 
with little physical irritation to the pulp tissue.
 
using a rubber dam).
If the excavation closely approaches the pulp or if a direct pulp
cap is indicated, the dentist should rst apply a lining of calcium
hydroxide using a ow technique (without pressure). is calcium
hydroxide liner should cover and protect any possible near or
actual exposure and extend over a major portion of the excavated
dentinal surface (Fig. 18.10). Although undetected, an exposed
recessional tract of a pulp horn may exist in any deep excavation.
Calcium hydroxide treatment of an exposed, healthy pulp promotes
the formation of a dentin bridge, which would close the exposure.
3
A resin-modied glass ionomer base should be applied and should
completely cover the calcium hydroxide lining as well as some
peripheral dentin for good adhesion (Fig. 18.11). e base should
be suciently thick in dimension to protect the thin underlying
dentin and the calcium hydroxide liner from subsequent stresses.
Usually good resistance form dictates that the pulpal wall should
not be formed entirely by a base; rather, in at least two regions,
one diametrically across the excavation from the other, the pulpal
wall should be in normal position, at, and formed by sound
dentin (see region S in Fig. 18.11E, which depicts basing in a
mandibular molar). e dentist should consider the addition of
other retention features such as proximal grooves if a major portion
of a proximal axial wall is composed mostly of base because this
base should not be relied on for contributing to retention of the
cast restoration (see
Fig. 18.8F).
Depending on access, the operator can use a No. 15 (width) straight
chisel, bin-angle chisel (
Fig. 18.8), or enamel hatchet. For a right-
handed operator, the distal beveled bin-angle chisel is used on the
distofacial wall of a distoocclusal preparation for the maxillary
right premolar. e dentist planes the wall by holding the instrument
in the modied palm-and-thumb grasp and uses a chisel-like motion
in an occlusal-to-gingival direction (see Fig. 18.8A and B). e
dentist planes the gingival wall by using the same instrument as
a hoe, scraping in a lingual-to-facial direction (see Fig. 18.8C). In
this latter action, the axial wall may be planed with the side edge
(secondary edge) of the blade. e distolingual wall is planed
smooth by using the bin-angle chisel with the mesial bevel (see
Fig. 18.8D). When proximal caries is minimal, ideal facial and
lingual extensions at this step in the preparation result in margins
that clear the adjacent tooth by 0.2 to 0.5 mm.
e experienced operator usually does not use chisel hand
instruments during the preparation for inlays, considering that
the narrow, ame-shaped, ne-grit diamond instrument, when
artfully used, removes ragged, weak enamel during application of
the cavosurface bevel and ares and causes the patient to be less
apprehensive (see Figs. 18.12 and 18.13 later in the chapter). If
the diamond instrument is to be used exclusively in nishing the
enamel walls and margins, this procedure is postponed until after
the removal of soft dentin, old restorative material, or both and
the application of any necessary base. Waiting prevents any hemor-
rhage (which occasionally follows the beveling of the gingival
margin) from hindering (1) the suitable removal of remaining soft
dentin and old restorative material and (2) the proper application
of a necessary base. Hand instruments are more useful on the
mesiofacial surfaces of maxillary premolars and rst molars, where
minimal extension is desired to prevent an unsightly display of
metal.
Shallow (0.3-mm deep) retention grooves may be cut in the
facioaxial and linguoaxial line angles with the No. 169L carbide
bur (see Fig. 18.8E–I). ese grooves are indicated especially when
the prepared tooth is short. When properly positioned, the grooves
are in sound dentin, close to but not contacting the DEJ. e
long axis of the bur must be held parallel to the line of draw.
Preparing these grooves may be postponed until after any required
bases are applied during the nal preparation.
Final Preparation
Removal of Soft Dentin and Pulp Protection
After the initial preparation has been completed, the dentist evaluates
the internal walls of the preparation visually and tactilely (with
an explorer) for indications of any remaining soft dentin. If soft
dentin remains and if it is judged to be shallow or moderate
(1 mm of remaining dentin between the caries and the pulp),
satisfactory isolation for the removal of such caries and the applica-
tion of any necessary base may be attained by reducing salivation
through anesthesia and the use of cotton rolls, a saliva ejector, and
gingival retraction cord. e retraction cord also serves to widen
the gingival sulcus and slightly retract the gingiva in preparation
for beveling and aring the proximal margins (Fig. 18.9; see also
Fig. 18.12A and B). For insertion of the cord, see the sections on
preparation of bevels and ares and tissue retraction. e removal
of the remaining caries and placement of a necessary base can be
accomplished during the time required for the full eect of the
inserted cord. A slowly revolving round bur (No. 2 or No. 4) or
spoon excavator is used to remove soft dentin (see
Fig. 18.9F and
G). If a bur is used, visibility can be improved by using air alone.
is excavation is done just above stall-out speed with light,

e102 CHAPTER 18 Class II Cast-Metal Restorations
169L
FPG
LPG
LPGFPG
A
E
F
G
H
I
BC
D
Fig. 18.8 A–D, Using modied palm-and-thumb grasp (A) to plane distofacial and distolingual walls
(B and D) and to scrape gingival wall (C). E, Before cutting retention grooves. F, Cutting retention grooves.
G and H, Facial proximal groove (FPG) and lingual proximal groove (LPG). I, Section in plane x. Large
arrows depict the direction of translation of the rotating bur.

CHAPTER 18 Class II Cast-Metal Restorations e103
271
y'y
4
c
Correct
Glass ionomer base
A
C
D
B
E
F
G
H
I
Fig. 18.9 Moderately deep caries lesion. A–C, Extending the proximal ditch gingivally (B) to a sound
oor free from caries (C). D, Remaining caries on the axial wall. E, Section of C in plane yy. F, Removing
the remaining soft dentin. c, Inserted retraction cord. G, Section of F. H, Inserting glass ionomer base
with periodontal probe. I, Completed base.
Rubber dam
Calcium hydroxide
A
B
Fig. 18.10 A and B, Deep caries excavations near the pulp are lined with calcium hydroxide. Note
the rubber dam.

e104 CHAPTER 18 Class II Cast-Metal Restorations
and protect the margins and results in a strong enamel margin
with an angle of 140 to 150 degrees. A cavosurface enamel angle
of more than 150 degrees is incorrect because it results in a less-
dened enamel margin (nish line), and the marginal cast-metal
alloy is too thin and weak if its angle is less than 30 degrees.
Conversely, if the enamel margin is 140 degrees or less, the metal
is too bulky and dicult to burnish when its angle is greater than
40 degrees (see Fig. 18.14F later in the chapter).
Usually it is helpful to insert a gingival retraction cord of suitable
diameter into the gingival sulcus adjacent to the gingival margin
and leave it in place for several minutes just before the use of the
ame-shaped diamond instrument on the proximal margins (Fig.
18.12A–C). e cord should be small enough in diameter to
permit relatively easy insertion and to preclude excessive pressure
against the gingival tissue, and yet it should be large enough to
widen the sulcus to about 0.5 mm. Immediately before the ame-
shaped diamond instrument is used, the cord may be removed to
create an open sulcus that improves visibility for beveling the
gingival margin and helps prevent injury and subsequent hemorrhage
of gingival tissue. Some operators prefer to leave the cord in the
sulcus while placing the gingival bevel.
Using the ame-shaped diamond instrument that is rotating
at high speed, the dentist prepares the lingual secondary are (Fig.
18.13A; also see Fig. 18.12D–F). e dentist approaches from the
lingual embrasure (see
Fig. 18.12F), moving the instrument
mesiofacially. e direction of the distolingual wall and the position
of the distolingual margin are compared before and after this
extension (see Figs. 18.8G and 18.13A). e distolingual wall
extends from the linguoaxial line angle into the lingual embrasure
Any remaining old restorative material on the internal walls
should be removed if any of the following conditions are present:
(1) e old material is judged to be thin, nonretentive, or both;
(2) radiographic evidence of a caries lesion under the old material
is present; (3) the pulp was symptomatic preoperatively; or (4)
the periphery of the remaining restorative material is not intact
(i.e., some breach exists in the junction of the material with the
adjacent tooth structure that may indicate a caries lesion under
the material). If none of these conditions is present, the operator
may elect to leave the remaining restorative material to serve as a
base, rather than risk unnecessary removal of sound dentin or
irritation or exposure of the pulp. e same isolation conditions
described previously for the removal of soft dentin also apply for
the removal of old restorative material.
Future root canal therapy is a possibility for any tooth treated
for deep caries that approximates or exposes the pulp. When treating
a tooth that has had such extensive caries, the following should
be considered: (1) reducing all cusps to cover the occlusal surface
with metal, for better distribution of occlusal loads, and (2) adding
skirts to the preparation to augment the resistance form because
teeth are more prone to fracture after root canal therapy.
Preparation of Bevels and Flares
After the base (where indicated) is completed, the slender, ame-
shaped, ne-grit diamond instrument is used to bevel the occlusal
and gingival margins and to apply the secondary are on the
distolingual and distofacial walls. is should result in 30- to
40-degree marginal metal on the inlay (refer to upcoming Figs.
18.12H, 18.13J, and 18.14B). is cavosurface design helps seal
S
S
271
Incorrect
Glass ionomer
Calcium
hydroxide
Glass ionomer
Calcium hydroxide
B
E
C
A
D
Fig. 18.11 A–C, Completed base for the treatment of deep caries. D, Never deepen entire axial wall
with the side of a ssure bur to remove a caries lesion because the pulp would be greatly irritated from
the resulting closeness of the gingivoaxial region of the preparation. E, Base placed deep in the excava-
tion on the mandibular molar. Note the at seats in sound dentin (S) that are desirable for adequate
resistance form.

CHAPTER 18 Class II Cast-Metal Restorations e105
may result. e instrument should be tilted slightly mesially to
produce a gingival bevel with the correct steepness to result in
30-degree marginal metal (see Fig. 18.12C, H, and J). If the
instrument is not tilted in this manner, the bevel is too steep,
resulting in gingival bevel metal that is too thin (<30-degree metal)
and too weak. Although the instrument is tilted mesially, its long
axis must not tilt facially or lingually (see Fig. 18.12G). e gingival
bevel should be 0.5 to 1 mm wide and should blend with the
lingual secondary are.
e operator completes the gingival bevel and prepares the
facial secondary are (see
Fig. 18.13A–F). e long axis of the
instrument during this secondary are is again returned nearly to
in two planes (see
Fig. 18.13A). e rst is termed lingual primary
are; the second is termed lingual secondary are. During this
(secondary) aring operation, the long axis of the instrument is
held nearly parallel to the line of draw, with only a slight tilting
mesially and lingually for assurance of draft (see Fig. 18.12D and
E), and the direction of translation of the instrument is that which
results in a marginal metal angle of 40 degrees (see Figs. 18.12F
and
18.13J).
e dentist bevels the gingival margin by moving the instrument
facially along the gingival margin (see Figs. 18.12G and 18.13A).
While cutting the gingival bevel, the rotational speed should be
reduced to increase the sense of touch; otherwise, overbeveling
A
C
30°
Metal
Retraction cord
0.5-1.0 mm
110°
Incorrect
Metal
0.05 mm
0.05 mm
0.02 mm
30°
Axial wall
0.05 mm
0.05 mm
B
D
E
F
G
H
I
J
K
Fig. 18.12 A and B, The retraction cord is inserted in the gingival sulcus and left for several minutes.
C, An open gingival sulcus after the cord shown in A is removed facilitates beveling the gingival margin
with a diamond instrument. D–F, Diamond instrument preparing lingual secondary are. Large arrow in F
indicates the direction of the translation. G, Beveling the gingival margin. Note in C the mesial tilting of
diamond instrument to produce a bevel that is properly directed to result in 30-degree marginal metal as
shown in H. H, Properly directed gingival bevel resulting in 30-degree marginal metal. I, Failure to bevel
the gingival margin results in a weak margin formed by undermined rods (note the easily displaced wedge
of enamel) and 110-degree marginal metal, an angular design unsuitable for burnishing. J, Lap, sliding
t of prescribed bevel metal decreases the 50-µm error of seating to 20 µm. K, A 50-µm error of seating
produces an equal cement line of 50 µm along the unbeveled gingival margin.

e106 CHAPTER 18 Class II Cast-Metal Restorations
minimal, it is usually desirable to use the lingual-to-facial
direction.
e gingival bevel serves the following purposes:
 
it would be weak if not beveled because of the gingival declina-
tion of the enamel rods (see Fig. 18.12I).
 
die) because of its angular design (see Fig. 18.12H). Bulky
110-degree metal along an unbeveled margin is not burnishable
(see Fig. 18.12I).
 
18.12J). is helps improve the t of the casting in this region.
With the prescribed gingival bevel, if the inlay fails to seat by
50 µm, the void between the bevel metal and the gingival bevel
on the tooth may be 20 µm; however, failure to apply such a
bevel would result in a void (and a cement line) as great as in
the failure to seat (see Fig. 18.12K).
Uninterrupted blending of the gingival bevel into the secondary
ares of the distolingual and distofacial walls results in the disto-
lingual and distofacial margins joining the gingival margin in a
desirable arc of a small circle; also the gingivofacial and gingivo-
lingual line angles no longer extend to the marginal outline. If
such line angles are allowed to extend to the preparation outline,
early failure may follow because of an “open” margin, dissolution
the line of draw, with only a small tilting mesially and facially,
and the direction of translation of the instrument is that which
results in 40-degree marginal metal (see Fig. 18.13E and J). When
the adjacent proximal surface (mesial of the second premolar) is
not being prepared, care must be exercised to avoid abrading the
adjacent tooth and overextending the distofacial margin. To prevent
such abrasion or overextension, the instrument may be raised
occlusally (using the narrower portion at its tip end) to complete
the most facial portion of the wall and margin (see Fig. 18.13D).
Also the more slender No. 169L carbide bur may be used, rather
than the ame-shaped diamond instrument (see Fig. 18.13H).
e No. 169L bur produces an extremely smooth surface to the
secondary are and a smooth, straight distofacial margin. When
access permits, a ne-grit sandpaper disk may be used on the facial
and lingual walls and on the margins of the proximal preparation,
especially when minimal extension of the facial margin is desired
(see Fig. 18.13I). is produces smooth walls and helps create
respective margins that are straight (not ragged) and sound.
In the aring and beveling of the proximal margins, as described
in the previous paragraphs, the procedure began at the lingual
surface and proceeded to the facial surface. e direction may be
reversed, however, starting at the facial surface and moving toward
the lingual surface. On the mesiofacial surface of maxillary premolars
and rst molars where extension of the facial margin should be
LPF
LSF
FPF
FSF
169L
Gold
E
A
G
B
D
C
F
H
J
I
X
40°
40°
Fig. 18.13 A, Occlusal view of Fig. 18.12G. LSF, Lingual secondary are; LPF, lingual primary are.
B–E, Preparing the facial secondary are. Large arrows in B, D, and E indicate the direction of the transla-
tion. F, Completed facial secondary are. FSF, Facial secondary are; FPF, facial primary are. G, Distal
view of F. x, Plane of cross section shown in J. H and I, Preparing the secondary are with the No. 169L
carbide bur (H) or with paper disk (I). J, The secondary ares are directed to result in 40-degree marginal
metal and 140-degree marginal enamel.

CHAPTER 18 Class II Cast-Metal Restorations e107
e ame-shaped, ne-grit diamond instrument also is used
for occlusal bevels. e width of the cavosurface bevel on the
occlusal margin should be approximately one fourth the depth of
the respective wall (Fig. 18.14A and B). e exception to the rule
is when a wider bevel is desired to include an enamel defect (see
Fig. 18.14G and H). e resulting occlusal marginal metal of the
inlay should be 40-degree metal; the occlusal marginal enamel is
140-degree enamel (see Fig. 18.14B and E). Beveling the occlusal
margins in this manner increases the strength of the marginal
enamel and helps seal and protect the margins. While beveling
the occlusal margins, a guide to diamond positioning is to maintain
an approximate 40-degree angle between the side of the instrument
and the external enamel surface; this also indicates when an occlusal
bevel is necessary (see Fig. 18.14A). If the cusp inclines are so
steep that the diamond instrument, when positioned at a 40-degree
angle to the external enamel surface, is parallel with the enamel
preparation wall, no bevel is indicated (see
Fig. 18.14C). By using
this technique, it can be seen that margins on the proximal marginal
ridges always require a cavosurface bevel (see Fig. 18.14D and I).
of exposed cement, and eventual leakage, all potentially resulting
in caries.
e secondary are is necessary for several reasons: (1) e second-
ary flaring of the proximal walls extends the margins into the
embrasures, making these margins more self-cleaning and more
accessible to nishing procedures during the inlay insertion appoint-
ment, and does so with conservation of dentin. (2) e direction of
the are results in 40-degree marginal metal (see
Fig. 18.13J). Metal
with this angular design is burnishable; however, metal shaped at a
larger angle is unsatisfactory for burnishing; metal with an angle less
than 30 degrees is too thin and weak, with a corresponding enamel
margin that is too indenite and ragged. (3) A more blunted and
stronger enamel margin is produced because of the secondary are.
In a later section, the secondary are is omitted for esthetic
reasons on the mesiofacial proximal wall of preparations on pre-
molars and rst molars of the maxillary dentition. In this location,
the wall is completed with minimal extension by using either hand
instruments (straight or bin-angle chisel) followed by a ne-grit
sandpaper disk or very thin rotary instruments.
L
L'
x40°
x'40°
Metal
40°
140°
140°
Metal
40°
Correct
40°
Metal
Incorrect
70°
s
Metal
y
y
A
C
E
H
B
D
G
F
I
Fig. 18.14 A, The diamond instrument beveling the occlusal margin when it is indicated to result in
40-degree marginal metal, as shown in B. Angles x and x are equal because the opposite angles are
equal when two lines (L and L) intersect. The diamond instrument is always directed such that an angle
of 40 degrees is made by the side of the instrument and the external enamel surface. B, Occlusal marginal
metal is approximately 40 degrees in cross section, making the enamel angle 140 degrees. C, When the
cuspal inclines are steep, no beveling is indicated considering that 40-degree metal would result without
beveling. D, Beveling the mesial margin and the axiopulpal line angle. E, The mesial bevel is directed
correctly to result in 40-degree marginal metal. F, An unbeveled mesial margin is incorrect because it
results in a weak enamel margin and unburnishable marginal metal. G, To conserve dentinal support (s),
occlusal defects on the marginal ridge are included in the outline form by applying a cavosurface bevel,
which may be wider than usual, when necessary. H, Occlusal view of G. Preparing a 140-degree cavo-
surface enamel angle at regions labeled y usually dictates that the occlusal bevel be extended over the
marginal ridges into the secondary ares. I, Distal view of H.

e108 CHAPTER 18 Class II Cast-Metal Restorations
Modications in Inlay Tooth Preparations
Because the indications for small inlays are rare, the following
sections provide procedural information that may promote better
understanding of their applications in more complex and larger
inlay or onlay restorations.
Mesioocclusodistal Preparation
If a marginal ridge is severely weakened because of excessive exten-
sion, the preparation outline often should be altered to include
the proximal surface. e distoocclusal preparation illustrated in
the previous section would be extended to a mesioocclusodistal
preparation (Fig. 18.16; see also Fig. 18.15B–D). e decision to
extend the preparation in this manner calls for clinical judgment
as to whether the remaining marginal ridge would withstand occlusal
forces without fracture. A fortunate factor in favor of not extending
the preparation is that such ridge enamel usually is composed of
gnarled enamel and is stronger than it appears. Caries lesions
present on both proximal surfaces would result in a mesioocclu-
sodistal preparation and restoration. e only dierence in technique
as described previously is the inclusion of the other proximal surface.
Modications of Class II Preparation for Esthetics
For esthetic reasons, minimal are is desired for the mesiofacial
proximal wall in maxillary premolars and rst molars in Class II
cast-metal preparations (see Fig. 18.15D). e mesiofacial margin
is minimally extended facially of the contact to such a position
that the margin is barely visible from a facial viewing position. To
accomplish this, the secondary are is omitted, and the wall and
margin are developed with (1) a chisel or enamel hatchet and nal
smoothing with a ne-grit paper disk or (2) a narrow diamond
or bur when access permits.
Facial or Lingual Surface Groove Extension
Sometimes, a faulty facial groove (ssure) on the occlusal surface
is continuous with a faulty facial surface groove (mandibular molars),
or a faulty distal oblique groove on the occlusal surface is continuous
with a faulty lingual surface groove (maxillary molar). is situation
requires extension of the preparation outline to include the ssure
to its termination (Fig. 18.17; see also Fig. 18.19C). Occasionally
the operator may extend further gingivally than the ssure length
to improve retention form. Such groove extensions, when suciently
long, are eective for increasing retention. Likewise, this extension
may be indicated to provide sucient retention form even though
the facial or lingual surface grooves are not ssured.
For extension onto the facial surface, the dentist uses the No.
271 carbide bur held parallel to the line of draw and extends
Failure to apply a bevel in these regions leaves the enamel margin
weak and subject to injury by fracture before the inlay insertion
appointment and during the try-in of the inlay when burnishing
the marginal metal. Also failure to bevel the margins on the marginal
ridges results in metal alloy that is dicult to burnish because it
is too bulky (see Fig. 18.14F). Similarly, the importance of extending
the occlusal bevel to include the portions of the occlusal margin
that cross over the marginal ridge cannot be overemphasized (see
Fig. 18.14H and I). ese margins are beveled to result in 40-degree
marginal metal. Otherwise fracture of the enamel margin in such
stress-vulnerable regions may occur in the interim between the
preparation and the cementation appointment.
e diamond instrument also is used to bevel the axiopulpal
line angle lightly (see Fig. 18.14D). Such a bevel provides a thicker
and stronger wax pattern at this critical region. e desirable metal
angle at the margins of inlays is 40 degrees except at the gingival
margins, where the metal angle should be 30 degrees. e completed
preparation is illustrated in Fig. 18.15A.
A
B
C D
Fig. 18.15 A, Completed distoocclusal preparation for the inlay. B,
Mesioocclusodistal preparation for the inlay on the maxillary right rst
premolar, distoocclusal view. C, Same preparation as in B, mesioocclusal
view. D, Same preparation as in B, occlusal view. Note the absence, for
esthetic reasons, of secondary are on the mesiofacial aspect and minimal
extension of the mesiofacial margin.
A
B
C
Fig. 18.16 Mandibular rst premolar prepared for the mesioocclusodistal inlay. Distal view (A), mesial
view (B), and occlusal view (C).

CHAPTER 18 Class II Cast-Metal Restorations e109
depth gauge for the axial wall, which is in dentin. e blade
portion of the No. 271 bur is 0.8 mm in diameter at its tip end
and 1 mm at the neck; the axial wall depth should approximate
1 mm or slightly more. e bur should be tilted lingually as it is
drawn occlusally, to develop the uniform depth of the axial wall
(see
Fig. 18.17D). e same principles apply for the extension of
a lingual surface groove.
through the facial ridge (see
Fig. 18.17A and B). e depth of the
cut should be 1.5 mm. e oor (pulpal wall) should be continuous
with the pulpal wall of the occlusal portion of the preparation (see
Fig. 18.17D).
With the bur still aligned with the path of draw, the dentist
uses the side of the bur to cut the facial surface portion of this
extension (see Fig. 18.17C). e diameter of the bur serves as a
1.5 mm
D
A
B
C
E
F
G
Fig. 18.17 A–C, Extending to include the occlusal ssure that is continuous with the facial ssure on
the facial surface. D, Section of C. E and F, Beveling the gingival margin (E) and the mesial and distal
margins (F) of ssure extension. G, Beveling completed.

e110 CHAPTER 18 Class II Cast-Metal Restorations
distolingual cusp from subsequent fracture. e distoocclusolingual
preparation requires diligent application to develop satisfactory
retention and resistance forms. Retention form is attained by (1)
creating a maximum of 2-degree occlusal divergence of the vertical
walls, (2) accentuating some line angles, and (3) extending the
lingual surface groove to create an axial wall height in this extension
of at least 2.5 mm occlusogingivally. e proper resistance form
dictates (1) routine capping of the distolingual cusp and (2)
maintaining sound tooth structure between the lingual surface
groove extension and the distolingual wall of the proximal boxing.
To prepare the distoocclusolingual preparation, the operator
rst reduces the distolingual cusp with the side of the No. 271
carbide bur. e cusp should be reduced a uniform 1.5 mm. Next
the operator completes the remaining occlusal step of the preparation
with the No. 271 carbide bur. e operator prepares the proximal
box portion of the preparation. e lingual groove extension is
prepared only after the position of the distolingual wall of the
proximal boxing is established. is permits the operator to judge
the best position of the lingual surface groove extension to maintain
a minimum of 3 mm of sound tooth structure between this exten-
sion and the distolingual wall; if this is not possible because of an
extensive caries lesion, a more extensive type of preparation may
be indicated (one that crosses the oblique ridge). One can use the
side of the No. 271 carbide bur to produce the lingual surface
groove extension (see
Fig. 18.19C). e diameter of the bur is the
gauge for the depth (pulpally) of the axial wall in this extension,
and the occlusogingival dimension of this axial wall is a minimum
of 2.5 mm. With the end of this bur, the operator also establishes
a 2-mm depth to the portion of the pulpal oor that connects the
proximal boxing to the lingual surface groove extension. is
additional depth to the pulpal oor helps strengthen the wax
pattern and casting in later steps of fabrication. is should create
a denite 0.5-mm step from the reduced distolingual cusp to the
pulpal oor. Using the No. 169L carbide bur, the operator increases
retention form in the distoocclusolingual preparation by (1) creating
mesioaxial and distoaxial grooves in the lingual surface groove
extension (see Fig. 18.19D) and (2) preparing facial and lingual
retention grooves in the distal boxing (see Fig. 18.19E).
e dentist uses the ame-shaped, ne-grit diamond instrument
to bevel the proximal gingival margin and to prepare the secondary
ares on the proximal enamel walls and to bevel the lingual margins.
A lingual counterbevel is prepared on the distolingual cusp that
is generous in width and results in 30-degree metal at the margin
(see Fig. 18.19F). Occlusion should be checked at this point because
the counterbevel should be suciently wide to extend beyond any
occlusal contacts, either in maximum intercuspation or during
mandibular movements. e bevel on the gingival margin of the
lingual extension should be 0.5 mm wide and should provide for
a 30-degree metal angle. e bevels on the mesial and distal margins
of the lingual extension also are approximately 0.5 mm wide and
result in 40-degree marginal metal.
Fissures in the Facial and Lingual Cusp Ridges or
Marginal Ridges
In the preparation of Class II preparations for inlays, facial and
lingual occlusal ssures may extend nearly to, or through, the
respective facial and lingual cusp ridges but not onto the facial or
lingual surface. e proper outline form dictates that the preparation
margin should not cross such ssures but should be extended to
include them. For the occlusal step portion of the preparation,
the dentist initially extends along the lingual ssure with the No.
271 carbide bur until only 2 mm of tooth structure remains between
When a facial or lingual groove is included, it also must be
beveled. With the ame-shaped, ne-grit diamond instrument,
the operator bevels the gingival margin (using no more than one
third the depth of the gingival oor) to provide for 30-degree
marginal metal (see Fig. 18.17D). e operator applies a light
bevel on the mesial and distal margins that is continuous with the
occlusal and gingival bevels and results in 40-degree metal at these
margins (see Fig. 18.17F and G). e bevel width around the
extended groove is approximately 0.5 mm.
Class II Preparation for Abutment Teeth and Extension
Gingivally to Include Root-Surface Lesions
Extending the facial, lingual, and gingival margins may be indicated
on the proximal surfaces of abutments for removable partial dentures
to increase the surface area for the development of guiding planes.
In addition, the occlusal outline form must be wide enough facio-
lingually to accommodate any contemplated rest preparation without
involving the margins of the restoration. ese extensions may be
accomplished by simply increasing the width of the bevels.
e following modied preparation is recommended when
further gingival extension is indicated to include a root lesion on
the proximal surface. e gingival extension should be accomplished
primarily by lengthening the gingival bevel, especially when prepar-
ing a tooth that has a longer clinical crown than normal as a result
of gingival recession. It is necessary to extend (gingivally) the gingival
oor only slightly, and although the axial wall consequently must
be moved pulpally, this should be minimal. If additional extension
of the gingival oor is necessary, it should not be as wide pulpally
as when the oor level is at a normal position (Fig. 18.18A). ese
considerations are necessary because of the draft requirement and
because the tooth is smaller apically. Extending the preparation
gingivally without these modications would result in a dangerous
encroachment of the axial wall on the pulp (see Fig. 18.18B).
Maxillary First Molar With Unaected, Strong Oblique Ridge
When a maxillary rst molar is to be restored, consideration should
be given to preserving the oblique ridge if it is strong and unaected,
especially if only one proximal surface is carious. A mesioocclusal
preparation for an inlay is illustrated in Fig. 18.19A and B. If a
distal surface lesion appears subsequent to the insertion of a
mesioocclusal restoration, the tooth may be prepared for a distooc-
clusolingual inlay (see Fig. 18.19H and I). e distoocclusolingual
restoration that caps the distolingual cusp is preferable to the
distoocclusal restoration because it protects the miniature
Correct Incorrect
AB
Fig. 18.18 Modications of the preparation when extending to include
the proximal root-surface lesions after moderate gingival recession. A,
Correct. B, Incorrect. Note the decreased dentinal protection of the pulp
compared with the management depicted in A.

CHAPTER 18 Class II Cast-Metal Restorations e111
may be wider than conventional if the remaining ssure can be
eliminated by such a wider bevel (see
Fig. 18.20C). Enameloplasty
sometimes may eliminate the end portion of the ssure and provide
a smooth enamel surface where previously a fault was present, thus
reducing the extent of the required extension (see Fig. 18.20D).
the bur and the lingual surface of the tooth. Additional lingual
extension at this time is incorrect because it may remove the
supporting dentin unnecessarily (Fig. 18.20A and B). If this
extension almost includes the length of the ssure, additional
extension is achieved later by using the occlusal bevel; this bevel
A
B
C
D
E
F
G
H
I
Fig. 18.19 A and B, Mesioocclusal preparation on the maxillary molar having an unaffected oblique
ridge. C, Preparing the lingual groove extension of the distoocclusolingual preparation. D and E, Cutting
retention grooves in the lingual surface extension (D) and the distal box (E). F and G, Completed distooc-
clusolingual preparation on the maxillary molar having an unaffected oblique ridge. H and I, Preparations
for treating both proximal surfaces of the maxillary molar having a strong, unaffected oblique ridge.

e112 CHAPTER 18 Class II Cast-Metal Restorations
271 carbide bur (see Fig. 18.20F and G). e dentist bevels the
margins of the extension with the ame-shaped, ne-grit diamond
instrument to provide for the desired 40-degree marginal metal
on the occlusal, mesial, and distal margins and for 30-degree
marginal metal on the gingival margin (see Fig. 18.20C, D, I, and
J). In the same manner, the operator should manage the ssures
that may extend into or through a proximal marginal ridge, assuming
that the proximal surface otherwise was not to be included in the
outline form and that such ssure management does not extend
the preparation outline near the adjacent tooth contact. is
treatment particularly applies to a mesial ssure of the maxillary
If possible, the ssure should be included in the preparation outline
without extending the margin to the height of the ridge. If the
occlusal bevel places the margin on the height of the ridge, however,
the marginal enamel likely is weak because of its sharpness and
because of the inclination of the enamel rods in this region. e
preparation outline should be extended just onto the facial or
lingual surface (see
Fig. 18.20I and J). Such extension onto the
facial or lingual surface also would be indicated if the ssure still
remains through the ridge after enameloplasty (see Fig. 18.20E).
When necessary, extension through a cusp ridge is accomplished
by cutting through the ridge at a depth of 1 mm with the No.
s
2 mm
Correct Incorrect
B
H
x
y
A
D
C
E
F
G
I
J
Fig. 18.20 A, Extending to include the lingual (occlusal) ssure. B, Section of A. The dentinal support
(s) of the lingual cusp ridge should not be removed. A bevel can provide additional extension to include
the ssure that does not extend to the crest of the ridge. C, Completed preparations with standard width
bevel (x) and with wider bevel to include a groove defect that nearly extends to the ridge height (y). D,
Completed preparation illustrating enameloplasty for the elimination of a shallow ssure extending to or
through the lingual ridge height. (Compare the smooth, saucer-shaped lingual ridge contour with C, in
which no enameloplasty has been performed.) E, Fissure remaining through the lingual ridge after unsuc-
cessful enameloplasty. This indicates procedures subsequently illustrated. F and G, Extending the prepa-
ration if enameloplasty has not eliminated the ssure in the lingual ridge (F) or the facial ridge (G). H,
Section of F. I and J, Completed preparations after beveling the margins of the extensions through the
lingual ridge (I) and the facial ridge (J).

CHAPTER 18 Class II Cast-Metal Restorations e113
If only one of the two lingual cusps of a molar is reduced for
capping, the reduction must extend to include just the lingual
groove between the reduced and unreduced cusps. is reduction
should terminate with a distinct vertical wall that has a height that
is the same as the prescribed cusp reduction. Applying the bur
vertically (see
Fig. 18.22F) should help establish a vertical wall of
proper depth and direction. Similar principles apply when only
one of the facial cusps is to be reduced (see Figs. 18.22L and
18.23B).
A bevel of generous width is prepared on the facial (lingual)
margin of a reduced cusp with the ame-shaped, ne-grit diamond
instrument (with the exception of esthetically prominent areas).
is bevel is referred to as reverse bevel or counterbevel. e width
varies because it usually should extend beyond any occlusal contact
with opposing teeth, either in maximum intercuspation or during
mandibular movements (see Fig. 18.24C later in the chapter). It
should be at an angle that results in 30-degree marginal metal (see
Fig. 18.22G and H). e exception is the facial margin on maxillary
premolars and the rst molar, where esthetic requirements dictate
only a blunting and smoothing of the enamel margin (a stub
margin) by the light application of a ne-grit sandpaper disk or
the ne-grit diamond instrument (ame-shaped) held at a right
angle to the facial surface (see Fig. 18.23C). Any sharp external
corners should be rounded slightly to strengthen them and reduce
the problems they may generate in future steps (see Fig. 18.22J
and K).
Cusp reduction appreciably decreases the retention form because
it decreases the height of the vertical walls. erefore proximal
retention grooves usually are recommended (see Fig. 18.22I). It
may be necessary to increase the retention form by extending facial
and lingual groove regions of the respective surfaces or by collar
and skirt features (see later). ese additional retention features
also provide the desired resistance form against forces tending to
split the tooth (see Fig. 18.22K; see also Fig. 18.28 later in the
chapter).
e principles stated in the preceding paragraphs may be applied
in the treatment of the distal cusp of the mandibular rst molar
when preparing a mesioocclusodistal preparation (see Fig. 18.23D).
Proper extension of the distofacial margin usually places the occlusal
margin in a region subjected to heavy masticatory forces and wear.
Satisfactory treatment usually dictates either extending the distofacial
margin (and wall) slightly mesial of the distofacial groove (see Fig.
18.23E) or capping the remaining portion of the distal cusp (see
Fig. 18.23F).
After cusp reduction, the dentist visually veries that the occlusal
clearances are sucient. A wax interocclusal record is helpful when
checking the occlusal clearances, especially in areas that are dicult
to visualize, for example, in the central groove and lingual cusp
regions. To make a wax “bite,” the dentist rst dries the preparation
free of any visible moisture; however, dentin should not be desiccated
(Fig. 18.24A). Next the dentist lightly presses a portion of softened,
low-fusing inlay wax over the prepared tooth; the dentist imme-
diately requests the patient to close into the soft wax and slide the
teeth in all directions (see Fig. 18.24B–F). During the mandibular
movements, the dentist observes to verify that (1) the patient
performs right lateral, left lateral, and protrusive movements; (2)
the adjacent unprepared teeth are in contact with the opposing
teeth; (3) the wax in the preparation is stable (not loose and rocking);
and (4) the wax is not in infraocclusion. e dentist cools the wax
and carefully removes it, holds it up to a light, and notes the degree
of light transmitted through it. With experience, this is a good
indicator of the thickness of the wax. An alternative method is to
rst premolar (Fig. 18.21). If this procedure extends the margin
near or into the contact, the outline form on the aected proximal
surface must be extended to include the contact, as for a conven-
tional proximal surface preparation.
Cusp-Capping Partial Onlay
e term partial onlay is used when a cast-metal restoration covers
and restores at least one but not all of the cusp tips of a posterior
tooth (Fig. 18.22). e facial and lingual margins on the occlusal
surface frequently must be extended toward the cusp tips to the
extent of the existing restorative materials and to uncover a caries
lesion (see Fig. 18.22B and C). Undermined occlusal enamel should
be removed because it is weak; removing such enamel provides access
for the proper excavation of the lesion. When the occlusal outline
is extended up, the cusp slopes more than half the distance from
any primary occlusal groove (central, facial, or lingual) to the cusp
tip, covering (capping) the cusp should be considered. If the prepara-
tion outline is extended two thirds of this distance or more, capping
the cusp is usually necessary to (1) protect the weak, underlying
cuspal structure from fracture caused by masticatory force and (2)
remove the occlusal margin from a region subjected to heavy stress
and wear (see Fig. 18.22A and B). At this point in the preparation
of the pulpal oor, depth can be increased from 1.5 mm to 2 mm.
is additional pulpal depth ensures sucient reduction in an area
that is often underreduced and results in imparting greater strength
and rigidity to the wax pattern and cast restoration.
Reduce the cusps for capping as soon as the indication for
such capping is determined because this improves access and
visibility for the subsequent steps in the preparation. If a cusp is
in infraocclusion of the desired occlusal plane before reduction,
the amount of cusp reduction is less and needs to be only that
which provides the required clearance with the desired occlusal
plane. Before reducing the surface, the operator prepares depth
gauge grooves (depth cuts) with the side of the No. 271 carbide
bur (see Fig. 18.22D). Such depth cuts should help to prevent thin
spots in the restoration. With the depth cuts serving as guides, the
operator completes the cusp reduction with the side of the carbide
bur (see Fig. 18.22E). e reduction should provide for a uniform
1.5 mm of metal thickness over the reduced cusp. On maxillary
premolars and rst molars, the reduction should be minimal (i.e.,
0.75–1 mm) on the facial cusp ridge to decrease the display of metal.
is reduction should increase progressively to 1.5 mm toward the
center of the tooth to help impart rigidity to the capping metal
(
Fig. 18.23A and C).
A
B
Fig. 18.21 The ssure that remains on the mesial marginal ridge after
unsuccessful enameloplasty (A) is treated (B) in the same manner as
lingual or facial ridge ssures (see Fig. 18.20I and J).

e114 CHAPTER 18 Class II Cast-Metal Restorations
interocclusal record will not oer as much information as would
the softened inlay wax technique, since the lateral and protrusive
paths are not registered in the former.
Including Portions of the Facial and Lingual Smooth Surfaces
Aected by Caries or Other Injury
When portions of a facial (lingual) smooth surface and a proximal
surface are aected by caries or some other factor (e.g., fracture)
use wax calipers or to section the wax to verify its thickness.
Insucient thickness calls for more reduction in the indicated area
before proceeding. As an alternative to wax, an interocclusal record
can be made in maximum intercuspation with a quick-setting PVS
impression material. Once set, this interocclusal record can be
measured with wax calipers to evaluate the reduction. If wax calipers
are not available, the interocclusal record can be sectioned with a
knife to see the thickness in cross section. However, a PVS
30°
f' fll'
A
B
H
C
D
E
F
G
I J
K
L
Fig. 18.22 A, When the extension of the occlusal margin is one half the distance from any point on
the primary grooves (cross) toward the cusp tip (dot), capping of the cusp should be considered; when
this distance is two thirds or more, capping of the cusp is usually indicated. B, l is midway between the
central groove and the lingual cusp tip; f is midway between the central groove and the facial cusp tip.
When enamel at l and f is undermined by a caries lesion, the respective walls must be extended to the
dotted lines l and f to uncover the lesion. Cusps should be reduced for capping. C, Extension to uncover
the caries lesion indicates that the mesiolingual cusp should be reduced for capping. D, Depth cuts.
E, Reduced mesiolingual cusp. The caries lesion has been removed, and the base has been placed.
F, Applying the bur vertically helps establish the vertical wall that barely includes the lingual groove. G,
Counterbeveling reduced cusp. H, Section of the counterbevel. I, Improving the retention form by cutting
the proximal retention grooves. J and K, The preparation is complete except for the rounding of the
axiopulpal line angle (J) and the rounding of the junction of the counterbevel and the secondary are (K).
Facial surface groove extension improves the retention and resistance forms. L, Preparation when reduc-
ing one of two facial cusps on the mandibular molar.

CHAPTER 18 Class II Cast-Metal Restorations e115
aected area (see Fig. 18.25D). is instrument also is used to
terminate the facial surface reduction in a denite facial margin
running gingivoocclusally and in a manner to provide for 40-degree
metal at this margin (see Fig. 18.25E).
If the distofacial defect is more extensive and deeper into the
tooth (see Fig. 18.25I), eliminating the opportunity for an eective
distal box or groove (no facial wall possible), the No. 271 carbide
bur should be used to cut a gingival shoulder extending from the
distal gingival oor around to include the aected facial surface.
is shoulder partially provides the desired resistance form. (A
gingival oor, perpendicular to occlusal force, has been provided
in lieu of the missing pulpal wall in the distofacial cusp region.)
e No. 271 bur is used to create a nearly vertical wall in the
remaining facial enamel (see Fig. 18.25J). e width of the shoulder
should be the diameter of the end of the cutting instrument. e
vertical walls should have the appropriate degree of draft to
contribute to retention form. en the faciogingival and facial
margins are beveled with the ame-shaped, ne-grit diamond
instrument to provide 30-degree metal at the gingival margin (see
Fig. 18.25K) and 40-degree metal along the facial margin (see Fig.
18.25L). ese two bevels should blend together (see x in Fig.
18.25M), and the faciogingival bevel should be continuous with
the gingival bevel on the distal surface. Additional retention and
(
Fig. 18.25A and I), the treatment may be a large inlay, an onlay,
a three-quarter crown, a full crown, or multiple amalgam or
composite restorations. Generally, if carious portions are extensive,
the choice between the previously listed cast-metal restorations is
determined by the degree of tooth circumference involved. A full
crown is indicated if the lingual and the facial smooth surfaces are
defective, especially if the tooth is a second or third molar. When
only a portion of the facial smooth surface is carious, and the
lingual surfaces of the teeth are conspicuously free of caries, a
mesioocclusal, distofacial, and distolingual inlay or onlay with a
lingual groove extension is chosen over the crown because the
former is more favorable to the health of the gingival tissues and
more conservative in the removal of tooth structure. Often this is
the treatment choice for the maxillary second molar, which may
exhibit a caries lesion on the distofacial surface as a result of poor
oral hygiene (owing to poor access) in this region.
In the preparation of the maxillary molar referred to in the
preceding paragraph, the mesiofacial and distolingual cusps and
the distofacial cusp are usually reduced for capping. If the distofacial
cusp defect is primarily shallow decalcication, the ame-shaped
diamond instrument is used to reduce the involved facial surface
and distofacial corner approximately to the depth of enamel and
to establish the gingival margin of this reduction apical to the
C
A
B
D
E
F
Fig. 18.23 A and B, Capping one of two facial cusps on the maxillary molar. C, Blunting the margin
of the reduced cusp when esthetics is a major consideration. D–F, The margin shown crossing the distal
cusp in D indicates treatment illustrated in E or F.

e116 CHAPTER 18 Class II Cast-Metal Restorations
of the tooths status. Sometimes the diagnosis is deferred until the
extension of the occlusal step of an inlay preparation facially and
lingually to the limits of the caries lesion shows that cusp reduction
is mandatory. e mandibular rst molar is used to illustrate one
mesioocclusodistal preparation for a full cast-metal onlay.
Initial Preparation
Occlusal Reduction
As soon as the decision is made to restore the tooth with a full
cast-metal onlay, the cusps should be reduced because this improves
the access and the visibility for subsequent steps in tooth preparation.
With the cusps reduced, the eciency of the cutting instrument
and the air-water cooling spray is improved. Also when the cusps
are reduced, it is easier to assess the height of the remaining clinical
crown of the tooth, which determines the degree of occlusal divergence
necessary for adequate retention form. Using the No. 271 carbide
bur held parallel to the long axis of the tooth crown, a 2-mm deep
pulpal oor is prepared along the central groove (Fig. 18.26A). To
verify the preoperative diagnosis for cusp reduction, this occlusal
preparation is extended facially and lingually just beyond the caries
to sound tooth structure (see Fig. 18.26B). e groove should not
be extended farther, however, than two thirds the distance from the
central groove to the cusp tips because the need for cusp reduction
is veried at this point. With the side of the No. 271 carbide bur,
uniform 1.5-mm deep depth cuts are prepared on the remaining
occlusal surface (see
Fig. 18.26C and D). Depth cuts usually are
placed on the crest of the triangular ridges and in the facial and
lingual groove regions. ese depth cuts help prevent thin spots in
resistance forms are indicated for this preparation and can be
developed by an arbitrary lingual groove extension (see
Fig. 18.25N)
or a distolingual skirt extension (see Fig. 18.25O and P). ese
preparation features resist forces normally opposed by the missing
distofacial wall and help protect the restored tooth from fracture
injury.
Tooth Preparation for Full Cast-Metal Onlays
e preceding sections have presented basic tooth preparation
principles and techniques for small, simple cast-metal inlays and
for partial onlays that cap less than all the cusps. is section
presents the tooth preparation principles and techniques for full
onlay restorations that cover the entire occlusal surface. Onlay
restorations have many clinical applications and may be desired
by many patients. ese restorations have a well-deserved reputation
for providing excellent service.
e cast-metal onlay restoration spans the gap between the
inlay, which is primarily an intracoronal restoration, and the full
crown, which is a totally extracoronal restoration. e full onlay
by denition caps all of the cusps of a posterior tooth and can be
designed to help strengthen a tooth that has been weakened by
caries or previous restorative experiences. It can be designed to
distribute occlusal loads over the tooth in a manner that greatly
decreases the chance of future fracture.
4,6
It is more conservative
of the tooth structure than the full crown preparation, and its
supragingival margins, when possible, are less irritating to the
gingiva. Usually an onlay diagnosis is made preoperatively because
A
B
C
D
E
F
Fig. 18.24 Verifying sufcient cusp reduction by forming a wax interocclusal record. A, The walls of
the preparations (distoocclusal for the second premolar, and mesioocclusodistal for the rst molar) are
air-dried of visible moisture. The low-fusing inlay wax that is the same length as the mesiodistal length of
the inlay preparations is softened and pressed over the prepared teeth. B–E, The patient moves the
mandible into all occlusal positions, left lateral (B), through maximum intercuspation (C), to right lateral
(D), and protrusive (E). F, Completed interocclusal record.

CHAPTER 18 Class II Cast-Metal Restorations e117
y
z
z
y
x
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Fig. 18.25 A, Maxillary molar with caries lesions on the distofacial corner and the mesial surface. B
and C, Completed mesioocclusal, distofacial, and distolingual inlay for treating lesions shown in A, facio-
occlusal view (B) and distolinguoocclusal view (C). D–H, Preparation for treating caries lesions illustrated
in A, distoocclusal view with diamond instrument being applied (D), occlusal view (E), distal view (F),
distolinguoocclusal view (G), and mesioocclusal view (H). I, Maxillary molar with a deeper caries lesion on
the distofacial corner and with a mesial caries lesion. J, Preparation (minus bevels and ares) for mesiooc-
clusal, distofacial, and distolingual inlay to restore the carious molar shown in I. A No. 271 carbide bur is
used to prepare the gingival shoulder and the vertical wall. K and L, Beveling margins. M and N, Com-
pleted preparation for treating the caries lesion shown in I. Gingival and facial bevels blend at x, and y is
the cement base. O and P, When the lingual surface groove has not been prepared and when the facial
wall of the proximal box is mostly or totally missing, forces directed to displace the inlay facially can be
opposed by lingual skirt extension (z).

e118 CHAPTER 18 Class II Cast-Metal Restorations
271
1 mm
0.8 mm
D
jj
A
B
C
E
F
G
Fig. 18.26 A, Cutting a 2-mm deep central groove. B, Extending the central groove cut facially and
lingually to verify any need for cusp capping. C, Depth cuts. D, Section of C. E, Completion of cusp
reduction. Small portions of the mesial and distal marginal ridges are left unreduced to avoid scarring the
adjacent teeth. F, The occlusal step is extended facially and lingually past any carious areas and is
extended to expose the proximal dentinoenamel junction (DEJ) (j) in anticipation of proximal boxing. G,
Preparation with proximal boxes prepared. Note the clearances with the adjacent teeth.

CHAPTER 18 Class II Cast-Metal Restorations e119
Final Preparation
Removal of Infected Carious Dentin and Defective
Restorative Materials and Pulp Protection
If the occlusal step and the proximal boxes have been extended
properly, any carious dentin or previous restorative materials
remaining on the pulpal and axial walls should be visible. ey
should be removed as described previously.
Preparation of Bevels and Flares
After the cement base (when indicated) is completed (
Fig. 18.27A),
the slender, ame-shaped, ne-grit diamond instrument is used
to place counterbevels on the reduced cusps, to apply the gingival
bevels, and to create secondary ares on the facial and lingual walls
of the proximal boxes. First a gingival retraction cord is inserted,
as described in the previous inlay section. During the few minutes
required for the cord’s eect on the gingival tissues, the diamond
instrument is used to prepare the counterbevels on the facial and
lingual margins of the reduced cusps. e bevel should be of
generous width and should result in 30-degree marginal metal.
e best way to judge this is to always maintain a 30-degree angle
between the side of the instrument and the external enamel surface
beyond the counterbevel (see Fig. 18.27B and C). e counterbevel
usually should be wide enough so that the cavosurface margin is
beyond (gingival to) any contact with the opposing dentition. If
a facial (lingual) surface ssure extends slightly beyond the normal
position of the counterbevel, it may be included (removed) by
deepening the counterbevel in the region of the ssure (see Fig.
18.27D). If the ssure extends gingivally more than 0.5 mm,
however, the ssure is managed as described later.
A counterbevel is not placed on the facial cusps of maxillary
premolars and rst molars where esthetic considerations may dictate
using a stubbed margin by blunting and smoothing the enamel
margin by the light application of a ne-grit sandpaper disk or
the ne-grit diamond instrument (ame-shaped) held at a right
angle to the facial surface (see Fig. 18.23C). e surface created
by this blunting should be approximately 0.5 mm in width. For
beveling the gingival margins and aring (secondary) the proximal
enamel walls, refer to the inlay section.
After beveling and aring, any sharp junctions between the
counterbevels and the secondary ares are rounded slightly (see
Fig. 18.27E). e ne-grit diamond instrument also is used to
bevel the axiopulpal line angles lightly (see Fig. 18.27F). Such a
bevel produces a stronger wax pattern at this critical region by
increasing its thickness. Any sharp projecting corners in the
preparation are rounded slightly because these projections are
dicult to reproduce without voids when developing the working
cast and often cause diculties when seating the casting. e
desirable metal angle at the margins of onlays is 40 degrees except
at the gingivally directed margins, where the metal angle should
be 30 degrees.
When deemed necessary, shallow (0.3-mm deep) retention
grooves may be cut in the facioaxial and the linguoaxial line angles
with the No. 169L carbide bur (see Fig. 18.27G). ese grooves
are especially important for retention when the prepared tooth is
short, which is often the case after reducing all the cusps. When
properly positioned, the grooves are entirely in dentin near the
DEJ and do not undermine enamel. e direction of cutting
(translation of the bur) is parallel to the DEJ. e long axis of the
No. 169L bur must be held parallel to the line of draw, and the
tip of the bur must be positioned in the gingival box internal point
angles. If the axial walls are deeper than ideal, however, the correct
the nal restoration. If a cusp is in infraocclusion of the desired
occlusal plane before reduction, the amount of cusp reduction is
less and needs only that which provides the required clearance with
the desired occlusal plane. Carious dentin and old restorative material
that is deeper in the tooth than the desired clearance are not removed
at this step in preparation.
With the depth cuts serving as guides for the amount of reduc-
tion, the cusp reduction is completed with the side of the No.
271 bur. When completed, this reduction should reect the general
topography of the original occlusal surface (see Fig. 18.26E). e
operator should not attempt to reduce the mesial and distal marginal
ridges completely at this time to avoid hitting an adjacent tooth.
e remainder of the ridges are reduced in a later step when the
proximal boxes are prepared.
roughout the next steps in the initial preparation, the cutting
instruments used to develop the vertical walls are oriented continu-
ally to a single draw path, usually the long axis of the tooth crown,
so that the completed preparation has draft (i.e., no undercuts).
For mandibular molars and second premolars whose crowns tilt
slightly lingually, the bur should be tilted slightly (5–10 degrees)
lingually to help preserve the strength of the lingual cusps (see
Fig. 18.4D). e gingival-to-occlusal divergence of these preparation
walls may range from 2 to 5 degrees from the line of draw, depending
on their heights. If the vertical walls are unusually short, a minimum
of 2 degrees occlusal divergence is desirable for retentive purposes.
Cusp reduction appreciably decreases the retention form because
it decreases the height of the vertical walls, so this minimal amount
of divergence is often indicated in the preparation of a tooth for
a cast-metal onlay. As the gingivoocclusal height of the vertical
walls increases, the occlusal divergence should increase, allowing
5 degrees in the preparation of the greatest gingivoocclusal length.
e latter preparations present diculties during pattern withdrawal,
trial seating and withdrawal of the casting, and cementing, unless
this maximal divergence is provided.
Occlusal Step
After cusp reduction, a 0.5-mm deep occlusal step should be present
in the central groove region between the reduced cuspal inclines
and the pulpal oor. Maintaining the pulpal depth (0.5 mm) of
the step, it is extended facially and lingually just beyond any carious
areas, to sound tooth structure (or to sound base or restorative
material if certain conditions, discussed subsequently, have been
met). Next the operator extends the step mesially and distally far
enough to expose the proximal DEJ (see Fig. 18.26F). e step
is extended along any remaining facial (and lingual) occlusal ssures
as far as they are faulty (ssured). e facial and lingual walls of
the occlusal step should go around the cusps in graceful curves,
and the isthmus should be only as wide as necessary to be in sound
tooth structure or sound base or restorative material. Old restorative
material or caries that is deeper pulpally than this 0.5-mm step is
not removed at this stage of tooth preparation.
As the occlusal step approaches the mesial and distal surfaces,
it should widen faciolingually in anticipation of the proximal box
extensions (see Fig. 18.26F). is 0.5-mm occlusal step contributes
to the retention of the restoration and provides the wax pattern
and cast-metal onlay with additional bulk for rigidity.
7
Proximal Box
Continuing with the No. 271 carbide bur held parallel to the long
axis of the tooth crown, the proximal boxes are prepared as described
in the inlay section. Fig. 18.26G illustrates the preparation after
the proximal boxes are prepared.

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e94 CHAPTER 18 Class II Cast-Metal Restorationse9418 Class II Cast-Metal RestorationsJOHN R. STURDEVANTThe cast-metal restoration is versatile and is especially applicable to Class II onlay preparations. e process has many steps, involves numerous dental materials, and requires meticulous attention to detail. Typically a dental laboratory is involved, and the dentist and the laboratory technician must be devoted to perfection. e high degree of satisfaction and service derived from a properly made cast-metal restoration is a reward for the painstaking application required.1 e Class II inlay involves the occlusal surface and one or more proximal surfaces of a posterior tooth. When cusp tips are restored, the term onlay is used. e procedure requires two appointments: the rst for preparing the tooth and making an impression, and the second for delivering the restoration to the patient. e fabrication process is referred to as an indirect procedure because the casting is made on a replica of the prepared tooth in a dental laboratory.Material QualitiesCast-metal restorations can be made from a variety of casting alloys. Although the physical properties of these alloys vary, their major advantages are their high compressive and tensile strengths. ese high strengths are especially valuable in restorations that rebuild most or all of the occlusal surface.e American Dental Association (ADA) Specication No. 5 for Dental Casting Gold Alloys requires a minimum total gold-plus-platinum-metals content of 75 weight percent (wt%). Such traditional high-gold alloys are unreactive in the oral environment and are some of the most biocompatible materials available to the restorative dentist.2 At present, four distinct groups of alloys are in use for cast restorations: (1) traditional high-gold alloys, (2) low-gold alloys, (3) palladium–silver alloys, and (4) base metal alloys. Each of the alternatives to high-gold alloys has required some modication of technique or acceptance of reduced perfor-mance, most commonly related to decreased tarnish resistance and decreased burnishability.3 Also they have been associated with higher incidences of postrestorative allergy, most often exhibited by irritated soft tissue adjacent to the restoration.2IndicationsLarge Restorationse cast-metal inlay is an alternative to amalgam or composite when the higher strength of a casting alloy is needed or when the superior control of contours and contacts that the indirect procedure provides is desired. e cast-metal onlay is often an excellent alternative to a crown for teeth that have been greatly weakened by caries or by large, failing restorations but where the facial and lingual tooth surfaces are relatively unaected by disease or injury. For such weakened teeth, the superior physical properties of a casting alloy are desirable to withstand the occlusal loads placed on the restoration; also the onlay can be designed to distribute occlusal loads over the tooth in a manner that decreases the chance of tooth fracture in the future. Preserving intact facial and lingual surfaces is conducive to maintaining the health of the pulp and the contiguous soft tissue (gingiva). When margins are supragingival they are easier to inspect for adaptation and seal. When proximal surface caries is extensive, favorable consideration should be given to the cast inlay or onlay. e indirect procedure used to develop the cast restoration allows more control of contours and contacts (proximal and occlusal).Endodontically Treated TeethA molar or premolar with treatment root canal lling can be restored with a cast-metal onlay, provided that the onlay has been thoughtfully designed to distribute occlusal loads in such a manner as to reduce the chance of tooth fracture.Teeth at Risk for FractureFracture lines in enamel and dentin, especially in teeth having extensive restorations, should be recognized as cleavage planes for possible future fracture of the tooth. Restoring these teeth with a restoration that braces the tooth against fracture injury may be warranted sometimes. Such restorations are cast onlays and crowns.Dental Rehabilitation With Cast-Metal AlloysWhen cast-metal restorations have been used to restore adjacent or opposing teeth, the continued use of the same material may be considered to eliminate electrical and corrosive activ-ity that sometimes occurs between dissimilar metals in the mouth, particularly when they come in contact with each other (galvanism).Diastema Closure and Occlusal Plane CorrectionOften the cast inlay or onlay is indicated when extension of the mesiodistal dimension of the tooth is necessary to form a contact with an adjacent tooth. Cast onlays also can be used to correct the occlusal plane of a slightly tilted tooth. CHAPTER 18 Class II Cast-Metal Restorations e95 Control of Contours and Contactsrough the use of the indirect technique, the dentist has great control over contours and contacts. is control becomes especially important when the restoration is larger and more complex.DisadvantagesNumber of Appointments and Higher Chair Timee cast inlay or onlay requires at least two appointments and much more time than a direct restoration, such as amalgam or composite.Temporary RestorationsPatients must have temporary restorations between the preparation and delivery appointments. Temporaries occasionally loosen or break, requiring additional visits.CostIn some instances, cost to the patient becomes a major consider-ation in the decision to restore teeth with cast-metal restorations. e cost of materials, laboratory bills, and the time involved make indirect cast restorations more expensive than direct restorations.Technique SensitivityEvery step of the indirect procedure requires diligence and attention to detail. Errors at any part of the long, multistep process tend to be compounded, resulting in less than ideal ts.Splitting ForcesSmall inlays may produce a wedging eect on facial or lingual tooth structure and increase the potential for splitting the tooth. Onlays do not have this disadvantage.Initial ProceduresOcclusionBefore the anesthetic is administered and before preparation of any tooth, the occlusal contacts of teeth should be evaluated. As part of this evaluation, the dentist must decide if the existing occlusal relationships can be improved with the cast-metal restora-tion. An evaluation should include (1) the occlusal contacts in maximum intercuspation where teeth are brought into full interdigitation and (2) the occlusal contacts that occur during mandibular movements (Fig. 18.1). e pattern of occlusal contacts inuences the preparation design, selection of interocclusal records, and type of articulator or cast development needed.AnesthesiaLocal anesthesia of the tooth to be operated on and of adjacent soft tissue usually is recommended. Anesthesia in these areas eliminates pain and reduces salivation, resulting in a more pleasant procedure for the patient and the operator.Removable Prosthodontic AbutmentTeeth that are to serve as abutments for a removable partial denture can be restored with cast-metal restorations. e advantages of cast restorations are as follows: (1) e superior physical properties of cast-metal alloys allow restorations to better withstand forces imparted by a partial denture, and (2) rest seats, guiding planes, and other aspects of contour relating to partial dentures are better controlled when the indirect technique is used.ContraindicationsHigh Caries RateFacial and lingual (especially lingual) smooth-surface caries indicates a high caries activity that should be brought under control before expensive cast-metal restorations are used.Young PatientsWith younger patients, direct restorative materials (e.g., composite or amalgam) are indicated unless the tooth is severely broken or endodontically treated. An indirect procedure requires longer and more numerous appointments, access is more dicult, the clinical crowns are shorter, and younger patients may neglect oral hygiene, resulting in additional caries.Estheticse dentist must consider the esthetic impact (display of metal) of the cast-metal restoration. is factor usually limits the use of cast-metal restorations to tooth surfaces that are hidden at a conversational distance. Composite and porcelain restorations are alternatives in esthetically sensitive areas.Small RestorationsBecause of the success of amalgam and composite, few cast-metal inlays are done in small Class I and II restorations.AdvantagesStrengthe inherent strength of dental casting alloys allows them to restore large damaged or missing areas and be used in ways that protect the tooth from future fracture injury. Such restorations include onlays and crowns.BiocompatibilityAs previously mentioned, high-gold dental casting alloys are unreactive in the oral environment. is biocompatibility can be helpful for many patients who have allergies or sensitivities to other restorative materials.Low WearAlthough individual casting alloys vary in their wear resistance, castings are able to withstand occlusal loads with minimal changes. is is especially important in large restorations that restore a large percentage of occlusal contacts. e96 CHAPTER 18 Class II Cast-Metal Restorationsthe area of the defect. An impression is typically made using a sectional tray (Fig. 18.2A). e tray lled with impression material is seated (see Fig. 18.2B). After the impression has set, the impression is removed and examined for completeness (see Fig. 18.2C). Alginate impressions can distort quickly if they are allowed to gain or lose moisture, so the impression is wrapped in wet paper towels to serve as a humidor (see Fig. 18.2D). Preoperative PVS impressions do not need to be wrapped. e preoperative impression is placed aside for later use in forming the temporary restoration.Tooth Preparations for Class II Cast- Metal RestorationsA small, distal, cavitated caries lesion in the maxillary right rst premolar is used to illustrate the classic two-surface preparation Considerations for Temporary RestorationsBefore preparation of the tooth, consideration must be given to the method that will be used to fabricate the temporary restoration. Most temporary restoration techniques require the use of a preopera-tive impression to reproduce the occlusal, facial, and lingual surfaces of the temporary restoration to the preoperative contours.e technique involves making a preoperative impression with an elastic impression material. Alginate impression materials may be used and are relatively inexpensive. e preoperative impression may be made with a polyvinyl siloxane (PVS) impression material if additional accuracy, stability, and durability are required. If the tooth to be restored has large defects such as a missing cusp, an instrument can be used to carve away impression material in the area of the missing cusp or tooth structure, to simulate the desired form for the temporary restoration. Alternatively, a material such as rope wax can be added to the tooth before the impression in ABC• Fig. 18.1 A–C, Evaluate occlusal relationships in maximum intercuspation (A) and during mandibular movements (B and C). Be alert for problems with tooth alignment and contact position. Note the amount of posterior separation provided by the guidance of anterior teeth (working side) and articular eminence (nonworking side). DABC• Fig. 18.2 A, Applying tray adhesive to stock quadrant tray. B, Making preoperative impression. C, Inspecting preoperative impression for completeness. D, When using alginate, wrap the impression with wet paper towels to serve as a humidor. CHAPTER 18 Class II Cast-Metal Restorations e97 Occlusal StepWith the No. 271 carbide bur held parallel to the long axis of the tooth crown, the dentist enters the fossa or pit closest to the involved marginal ridge, using a punch cut to a depth of 1.5 mm to establish the depth of the pulpal wall (Fig. 18.4A and B). In the initial preparation, this specied depth should not be exceeded, regardless of whether the bur end is in dentin, caries, old restorative material, or air. e bur should be rotating at high speed (with air-water spray) before application to the tooth and should not stop rotating until it is removed; this minimizes perceptible vibration and prevents breakage or chipping of the bur blades. A general rule is to maintain the long axis of the bur parallel to the long axis of the tooth crown at all times (see Fig. 18.4B and C). For mandibular molars and second premolars whose crowns tilt slightly lingually, this rule dictates that the bur should also be tilted slightly (5–10 degrees) lingually to conserve the strength of the lingual cusps (see Fig. 18.4D). When the operator is cutting at high speeds, a properly directed air-water spray is used to provide the necessary cooling and cleansing eects.5Maintaining the 1.5-mm initial depth and the same bur orienta-tion, the dentist extends the preparation outline mesially along the central groove or ssure to include the mesial fossa or pit (see Fig. 18.4E and F). Ideally, the faciolingual dimension of this cut should be minimal. e dentist takes care to keep the mesial marginal ridge strong by not removing the dentin support of the ridge (see Fig. 18.4F and H). e use of light intermittent pressure minimizes heat production on the tooth surface and reduces the incidence of enamel crazing ahead of the bur. Occasionally a ssure extends onto the mesial marginal ridge. is defect, if shallow, may be treated with enameloplasty, or it may be included in the outline form with the cavosurface bevel, which is applied in a later step in the tooth preparation (see Fig. 18.4G).Enameloplasty, as presented in earlier chapters, occasionally reduces extension along the ssures, conserving the tooth structure vital for pulp protection and the strength of the remaining tooth crown. e extent to which enameloplasty can be used usually cannot be determined until the operator is in the process of for an inlay (Fig. 18.3A). Treatment principles for other defects are presented later. As indicated previously, few small one-surface or two-surface inlays are done. Because the description of a small tooth preparation presents the basic concepts, it is used to illustrate the technique. More extensive tooth preparations are presented later.Tooth Preparation for Class II Cast-Metal InlaysInitial PreparationCarbide burs used to develop the vertical internal walls of the preparation for cast-metal inlays and onlays are plane cut, tapered ssure burs. ese burs are plane cut so that the vertical walls are smooth. e side and end surfaces of the bur should be straight to aid in the development of uniformly tapered walls and smooth pulpal and gingival walls. Recommended dimensions and congurations of the burs to be used are shown in Fig. 18.3B. Suggested burs are the No. 271 and the No. 169L burs (Brasseler USA, Inc., Savannah, GA). Before using unfamiliar burs, the operator is cautioned to verify measurements to judge the depth into the tooth during preparation. e sides and end surface of the No. 271 bur meet in a slightly rounded manner so that sharp, stress-inducing internal angles are not formed in the preparation.4 e marginal bevels are placed with a slender, ne-grit, ame-shaped diamond instrument such as the No. 8862 bur (Brasseler USA, Inc.).roughout the preparation for a cast inlay, the cutting instru-ments used to develop the vertical walls are oriented to a single “draw” path, usually the long axis of the tooth crown, so that the completed preparation has draft (no undercuts) (see Fig. 18.3C). e gingival-to-occlusal divergence of these preparation walls may range from 2 to 5 degrees per wall from the line of draw. If the vertical walls are unusually short, a maximum of 2 degrees occlusal divergence is desirable to increase retention potential. As the occlusogingival height increases, the occlusal divergence should increase because lengthy preparations with minimal divergence (more parallel) may present diculties during the seating and withdrawal of the restoration.C4xyInlayToothA B0.8 mm0.5 mm271169L8862• Fig. 18.3 A, Proposed outline form for distoocclusal preparation. B, Dimensions and conguration of No. 271, No. 169L, and No. 8862 instruments. C, Conventional 4-degree divergence from line of draw (xy). e98 CHAPTER 18 Class II Cast-Metal Restorationsare not faulty, sucient facial extension in the mesial pit region should be made to provide this dovetail retention form against distal displacement. Minor extension in the transverse ridge area to include any remaining facial or lingual caries may necessitate additional facial or lingual extension in the mesial pit to provide this dovetail feature. (During such facial or lingual extensions to sound tooth structure, the bur depth is maintained at 1.5 mm.) If major facial or lingual extension is required to remove undermined occlusal enamel, capping the weak remaining cuspal structure and additional features in the preparation to provide adequate retention and resistance forms may be indicated. ese considerations are discussed in subsequent sections.Continuing at the initial depth, the occlusal step is extended distally into the distal marginal ridge suciently to expose the junction of the proximal enamel and dentin (Fig. 18.7A and B). While extending distally, the dentist progressively widens the preparation to the desired faciolingual width in anticipation of the proximal box preparation. e increased faciolingual width extending the preparation wall, when the depth of the ssure in the enamel wall can be observed (Fig. 18.5). When enameloplasty shows a ssure in a marginal ridge to be deeper than one third the thickness of enamel, the procedures described in the later section should be used.Extend to include faulty facial and lingual ssures radiating from the mesial pit. During this extension cutting, the operator is cautioned again not to remove the dentin support of the proximal marginal ridge. To conserve the tooth structure and the strength of the remaining tooth, the nal extension up these ssures can be accomplished with the slender No. 169L carbide bur (Fig. 18.6A). e tooth structure and strength can be conserved further by using (1) enameloplasty of the ssure ends, when possible, and (2) the marginal bevel of the nal preparation to include (eliminate) the terminal ends of these ssures in the outline form. e facial and lingual extensions in the mesial pit region should provide the desired dovetail retention form, which resists distal displacement of the inlay (see Fig. 18.6B). When these facial and lingual grooves BCDFGH271Maxillary molarz271271271FacialLingualyx271wMandibular molarFacialLingualsBevelCorrect IncorrectAE• Fig. 18.4 A and B, Bur after punch cut to a depth of 1.5 mm. C, For maxillary posterior teeth, the long axis of the bur should parallel the long axis of the tooth crown (yz). D, For molar and second premolar teeth of mandibular dentition, the long axis of the bur should tilt slightly lingually to parallel the long axis of the tooth crown (wx). E and F, Extending the mesial wall, taking care to conserve dentin that supports marginal ridge (s). G, The marginal bevel can provide additional extension. H, Improper extension that has weakened the marginal ridge. CHAPTER 18 Class II Cast-Metal Restorations e99 be checked with the length of the bur by rst measuring the depth from the height of the marginal ridge and then removing the bur and holding it beside the tooth. A periodontal probe also may be used for this measurement. While penetrating gingivally, the dentist extends the proximal ditch facially and lingually beyond the caries to the desired position of the facioaxial and linguoaxial line angles. If the caries lesion is minimal, the ideal extension facially and lingually is performed as previously described (see Fig. 18.7F). Ideal gingival extension of a minimal, cavitated lesion eliminates caries on the gingival oor and provides a 0.5-mm clearance of the unbeveled gingival margin with the adjacent tooth. Moderate to extensive caries on the proximal surface dictates continued extension of the proximal ditch to the extent of the caries at the dentinoenamel junction (DEJ), but not pulpally (see Fig. 18.11D later in the chapter). When preparing the proximal portion of the preparation, the dentist maintains the side of the bur at the specied axial wall depth regardless of whether it is in dentin, caries, old restorative material, or air. e operator should guard against overcutting the facial, lingual, and gingival walls, which would not conserve the tooth structure and could result in (1) overextension of the margins in the completed preparation, (2) a weakened tooth, enables the facial and lingual walls of the box to project (visually) perpendicularly to the proximal surface at positions that clear the adjacent tooth by 0.2 to 0.5 mm (see Fig. 18.7F). e facial and lingual walls of the occlusal step should go around the cusps in graceful curves, and the prepared isthmus in the transverse ridge ideally should be only slightly wider than the bur, thus conserving the dentinal protection for the pulp and maintaining the strength of the cusps. If the occlusal step has been prepared correctly, any caries on the pulpal oor should be uncovered by facial and lingual extensions to sound enamel (supported by dentin).Proximal BoxContinuing with the No. 271 carbide bur, the distal enamel is isolated by cutting a proximal ditch (see Fig. 18.7C–F). e harder enamel should guide the bur. Slight pressure toward enamel is necessary to prevent the bur from cutting only dentin. If the bur is allowed to cut only dentin, the resulting axial wall would be too deep. e mesiodistal width of the ditch should be 0.8 mm (the tip diameter of the bur) and prepared approximately two thirds (0.5 mm) at the expense of dentin and one third (0.3 mm) at the expense of enamel. e gingival extension of this cut may AB• Fig. 18.5 A, Shallow enamel fault that is no deeper than one third the thickness of enamel. B, Using ne-grit diamond instrument to remove enamel that contains shallow fault. ABxyzDovetailingDovetail• Fig. 18.6 A, Extending up the mesiofacial triangular groove using the slender No. 169L bur. B, Dovetail retention form is created by extension shown in A. As x ts into y only in one direction resulting in z, simi-larly dovetail portion of inlay ts into the dovetail portion of the preparation only in an occlusal-to-gingival direction. e100 CHAPTER 18 Class II Cast-Metal Restorationsis held. Also the level of the gingival oor is veried by observing where the end of the bur emerged through the proximal surface. If indicated, additional gingival extension can be accomplished while the remaining enamel still serves to guide the bur and to prevent it from marring the proximal surface of the adjacent tooth. At this time, however, the remaining wall of enamel often breaks away during cutting, especially when high speeds are employed. If the isolated wall of enamel is still present, it can be fractured out with a spoon excavator (see Fig. 18.7I). At this stage, the ragged enamel edges left from breaking away the proximal surface may be touching the adjacent tooth.Planing the distofacial, distolingual, and gingival walls by hand instruments to remove all undermined enamel may be indicated if minimal extension is needed to fulll an esthetic objective. and (3) possible injury of soft tissue. Because the proximal enamel diminishes in thickness from the occlusal to gingival level, the end of the bur is closer to the external tooth surface as the cutting progresses gingivally. e axial wall should follow the contour of the tooth faciolingually. Any carious dentin on the axial wall should not be removed at this stage of the preparation.With the No. 271 carbide bur, the dentist makes two cuts, one at the facial limit of the proximal ditch and the other at the lingual limit, extending from the ditch perpendicularly toward the enamel surface (in the direction of the enamel rods) (see Fig. 18.7G). ese cuts are extended until the bur is nearly through the marginal ridge enamel (the side of the bur may emerge slightly through the surface at the level of the gingival oor) as shown in Fig. 18.7H. is weakens the enamel by which the remaining isolated portion 0.5 mm0.2 mmxxjDistal271BDEFGIx271271jACH• Fig. 18.7 A, After exposing the junction (j) of proximal enamel and dentin. B, Sectional drawing of A. C, Cutting the proximal ditch. D, Sectional drawing of C. E, Proximal view of D. F, Occlusal view of the proximal ditch with proposed ideal clearance with the adjacent tooth. G and H, Proximal ditch extended distally. x, penetration of enamel by side of bur at its gingival end. I, Breaking away isolated enamel. CHAPTER 18 Class II Cast-Metal Restorations e101 intermittent cutting. e operator should avoid unnecessarily desiccating the exposed dentin during this procedure.Light-cured glass ionomer cement may be applied with a suitable applicator to these shallow (or moderately deep) excavated regions to the depth and form of the ideally prepared surface. Placing the material takes little time and should be considered because it results in preparation walls with no undercuts and “ideal” position and contour. is facilitates making the temporary restoration, and also applying the light-cured glass ionomer at this time minimizes additional irritation of the pulp during subsequent procedures necessary for the completion of the restoration. e material is applied by conveying small portions on the end of a periodontal probe and is light-cured when the correct form has been achieved (see Fig. 18.9H and I). Any excess cement can be trimmed back to the ideal form with the No. 271 carbide bur after the cement has hardened.If the caries lesion is judged to approach the pulp closely, a rubber dam should be applied and the soft dentin removed as indicated (see Chapter 2). Rubber dam provides the optimal environment for successfully treating a pulp exposure should it occur. If removal of soft dentin leads directly to a pulpal exposure (carious pulpal exposure), root canal treatment should be accom-plished before completing the cast-metal restoration.If the pulp is inadvertently exposed as a result of operator error or misjudgment (mechanical pulpal exposure), the operator must decide whether to proceed with the root canal treatment or to attempt a direct pulp capping procedure. A clinical evaluation should be made to determine the health of the pulp. A favorable prognosis for the pulp after direct pulp capping may be expected if the following criteria are met: <0.5 mm in diameter).         pulpitis.  with little physical irritation to the pulp tissue. using a rubber dam).If the excavation closely approaches the pulp or if a direct pulp cap is indicated, the dentist should rst apply a lining of calcium hydroxide using a ow technique (without pressure). is calcium hydroxide liner should cover and protect any possible near or actual exposure and extend over a major portion of the excavated dentinal surface (Fig. 18.10). Although undetected, an exposed recessional tract of a pulp horn may exist in any deep excavation. Calcium hydroxide treatment of an exposed, healthy pulp promotes the formation of a dentin bridge, which would close the exposure.3 A resin-modied glass ionomer base should be applied and should completely cover the calcium hydroxide lining as well as some peripheral dentin for good adhesion (Fig. 18.11). e base should be suciently thick in dimension to protect the thin underlying dentin and the calcium hydroxide liner from subsequent stresses. Usually good resistance form dictates that the pulpal wall should not be formed entirely by a base; rather, in at least two regions, one diametrically across the excavation from the other, the pulpal wall should be in normal position, at, and formed by sound dentin (see region S in Fig. 18.11E, which depicts basing in a mandibular molar). e dentist should consider the addition of other retention features such as proximal grooves if a major portion of a proximal axial wall is composed mostly of base because this base should not be relied on for contributing to retention of the cast restoration (see Fig. 18.8F).Depending on access, the operator can use a No. 15 (width) straight chisel, bin-angle chisel (Fig. 18.8), or enamel hatchet. For a right-handed operator, the distal beveled bin-angle chisel is used on the distofacial wall of a distoocclusal preparation for the maxillary right premolar. e dentist planes the wall by holding the instrument in the modied palm-and-thumb grasp and uses a chisel-like motion in an occlusal-to-gingival direction (see Fig. 18.8A and B). e dentist planes the gingival wall by using the same instrument as a hoe, scraping in a lingual-to-facial direction (see Fig. 18.8C). In this latter action, the axial wall may be planed with the side edge (secondary edge) of the blade. e distolingual wall is planed smooth by using the bin-angle chisel with the mesial bevel (see Fig. 18.8D). When proximal caries is minimal, ideal facial and lingual extensions at this step in the preparation result in margins that clear the adjacent tooth by 0.2 to 0.5 mm.e experienced operator usually does not use chisel hand instruments during the preparation for inlays, considering that the narrow, ame-shaped, ne-grit diamond instrument, when artfully used, removes ragged, weak enamel during application of the cavosurface bevel and ares and causes the patient to be less apprehensive (see Figs. 18.12 and 18.13 later in the chapter). If the diamond instrument is to be used exclusively in nishing the enamel walls and margins, this procedure is postponed until after the removal of soft dentin, old restorative material, or both and the application of any necessary base. Waiting prevents any hemor-rhage (which occasionally follows the beveling of the gingival margin) from hindering (1) the suitable removal of remaining soft dentin and old restorative material and (2) the proper application of a necessary base. Hand instruments are more useful on the mesiofacial surfaces of maxillary premolars and rst molars, where minimal extension is desired to prevent an unsightly display of metal.Shallow (0.3-mm deep) retention grooves may be cut in the facioaxial and linguoaxial line angles with the No. 169L carbide bur (see Fig. 18.8E–I). ese grooves are indicated especially when the prepared tooth is short. When properly positioned, the grooves are in sound dentin, close to but not contacting the DEJ. e long axis of the bur must be held parallel to the line of draw. Preparing these grooves may be postponed until after any required bases are applied during the nal preparation.Final PreparationRemoval of Soft Dentin and Pulp ProtectionAfter the initial preparation has been completed, the dentist evaluates the internal walls of the preparation visually and tactilely (with an explorer) for indications of any remaining soft dentin. If soft dentin remains and if it is judged to be shallow or moderate (≥1 mm of remaining dentin between the caries and the pulp), satisfactory isolation for the removal of such caries and the applica-tion of any necessary base may be attained by reducing salivation through anesthesia and the use of cotton rolls, a saliva ejector, and gingival retraction cord. e retraction cord also serves to widen the gingival sulcus and slightly retract the gingiva in preparation for beveling and aring the proximal margins (Fig. 18.9; see also Fig. 18.12A and B). For insertion of the cord, see the sections on preparation of bevels and ares and tissue retraction. e removal of the remaining caries and placement of a necessary base can be accomplished during the time required for the full eect of the inserted cord. A slowly revolving round bur (No. 2 or No. 4) or spoon excavator is used to remove soft dentin (see Fig. 18.9F and G). If a bur is used, visibility can be improved by using air alone. is excavation is done just above stall-out speed with light, e102 CHAPTER 18 Class II Cast-Metal Restorations169LFPGLPGLPGFPGAEFGHIBCD• Fig. 18.8 A–D, Using modied palm-and-thumb grasp (A) to plane distofacial and distolingual walls (B and D) and to scrape gingival wall (C). E, Before cutting retention grooves. F, Cutting retention grooves. G and H, Facial proximal groove (FPG) and lingual proximal groove (LPG). I, Section in plane x. Large arrows depict the direction of translation of the rotating bur. CHAPTER 18 Class II Cast-Metal Restorations e103 271y'y4cCorrectGlass ionomer baseACDBEFGHI• Fig. 18.9 Moderately deep caries lesion. A–C, Extending the proximal ditch gingivally (B) to a sound oor free from caries (C). D, Remaining caries on the axial wall. E, Section of C in plane yy. F, Removing the remaining soft dentin. c, Inserted retraction cord. G, Section of F. H, Inserting glass ionomer base with periodontal probe. I, Completed base. Rubber damCalcium hydroxideAB• Fig. 18.10 A and B, Deep caries excavations near the pulp are lined with calcium hydroxide. Note the rubber dam. e104 CHAPTER 18 Class II Cast-Metal Restorationsand protect the margins and results in a strong enamel margin with an angle of 140 to 150 degrees. A cavosurface enamel angle of more than 150 degrees is incorrect because it results in a less-dened enamel margin (nish line), and the marginal cast-metal alloy is too thin and weak if its angle is less than 30 degrees. Conversely, if the enamel margin is 140 degrees or less, the metal is too bulky and dicult to burnish when its angle is greater than 40 degrees (see Fig. 18.14F later in the chapter).Usually it is helpful to insert a gingival retraction cord of suitable diameter into the gingival sulcus adjacent to the gingival margin and leave it in place for several minutes just before the use of the ame-shaped diamond instrument on the proximal margins (Fig. 18.12A–C). e cord should be small enough in diameter to permit relatively easy insertion and to preclude excessive pressure against the gingival tissue, and yet it should be large enough to widen the sulcus to about 0.5 mm. Immediately before the ame-shaped diamond instrument is used, the cord may be removed to create an open sulcus that improves visibility for beveling the gingival margin and helps prevent injury and subsequent hemorrhage of gingival tissue. Some operators prefer to leave the cord in the sulcus while placing the gingival bevel.Using the ame-shaped diamond instrument that is rotating at high speed, the dentist prepares the lingual secondary are (Fig. 18.13A; also see Fig. 18.12D–F). e dentist approaches from the lingual embrasure (see Fig. 18.12F), moving the instrument mesiofacially. e direction of the distolingual wall and the position of the distolingual margin are compared before and after this extension (see Figs. 18.8G and 18.13A). e distolingual wall extends from the linguoaxial line angle into the lingual embrasure Any remaining old restorative material on the internal walls should be removed if any of the following conditions are present: (1) e old material is judged to be thin, nonretentive, or both; (2) radiographic evidence of a caries lesion under the old material is present; (3) the pulp was symptomatic preoperatively; or (4) the periphery of the remaining restorative material is not intact (i.e., some breach exists in the junction of the material with the adjacent tooth structure that may indicate a caries lesion under the material). If none of these conditions is present, the operator may elect to leave the remaining restorative material to serve as a base, rather than risk unnecessary removal of sound dentin or irritation or exposure of the pulp. e same isolation conditions described previously for the removal of soft dentin also apply for the removal of old restorative material.Future root canal therapy is a possibility for any tooth treated for deep caries that approximates or exposes the pulp. When treating a tooth that has had such extensive caries, the following should be considered: (1) reducing all cusps to cover the occlusal surface with metal, for better distribution of occlusal loads, and (2) adding skirts to the preparation to augment the resistance form because teeth are more prone to fracture after root canal therapy.Preparation of Bevels and FlaresAfter the base (where indicated) is completed, the slender, ame-shaped, ne-grit diamond instrument is used to bevel the occlusal and gingival margins and to apply the secondary are on the distolingual and distofacial walls. is should result in 30- to 40-degree marginal metal on the inlay (refer to upcoming Figs. 18.12H, 18.13J, and 18.14B). is cavosurface design helps seal SS271IncorrectGlass ionomerCalciumhydroxideGlass ionomerCalcium hydroxideBECAD• Fig. 18.11 A–C, Completed base for the treatment of deep caries. D, Never deepen entire axial wall with the side of a ssure bur to remove a caries lesion because the pulp would be greatly irritated from the resulting closeness of the gingivoaxial region of the preparation. E, Base placed deep in the excava-tion on the mandibular molar. Note the at seats in sound dentin (S) that are desirable for adequate resistance form. CHAPTER 18 Class II Cast-Metal Restorations e105 may result. e instrument should be tilted slightly mesially to produce a gingival bevel with the correct steepness to result in 30-degree marginal metal (see Fig. 18.12C, H, and J). If the instrument is not tilted in this manner, the bevel is too steep, resulting in gingival bevel metal that is too thin (<30-degree metal) and too weak. Although the instrument is tilted mesially, its long axis must not tilt facially or lingually (see Fig. 18.12G). e gingival bevel should be 0.5 to 1 mm wide and should blend with the lingual secondary are.e operator completes the gingival bevel and prepares the facial secondary are (see Fig. 18.13A–F). e long axis of the instrument during this secondary are is again returned nearly to in two planes (see Fig. 18.13A). e rst is termed lingual primary are; the second is termed lingual secondary are. During this (secondary) aring operation, the long axis of the instrument is held nearly parallel to the line of draw, with only a slight tilting mesially and lingually for assurance of draft (see Fig. 18.12D and E), and the direction of translation of the instrument is that which results in a marginal metal angle of 40 degrees (see Figs. 18.12F and 18.13J).e dentist bevels the gingival margin by moving the instrument facially along the gingival margin (see Figs. 18.12G and 18.13A). While cutting the gingival bevel, the rotational speed should be reduced to increase the sense of touch; otherwise, overbeveling AC30°MetalRetraction cord0.5-1.0 mm110°IncorrectMetal0.05 mm0.05 mm0.02 mm30°Axial wall0.05 mm0.05 mmBDEFGHIJK• Fig. 18.12 A and B, The retraction cord is inserted in the gingival sulcus and left for several minutes. C, An open gingival sulcus after the cord shown in A is removed facilitates beveling the gingival margin with a diamond instrument. D–F, Diamond instrument preparing lingual secondary are. Large arrow in F indicates the direction of the translation. G, Beveling the gingival margin. Note in C the mesial tilting of diamond instrument to produce a bevel that is properly directed to result in 30-degree marginal metal as shown in H. H, Properly directed gingival bevel resulting in 30-degree marginal metal. I, Failure to bevel the gingival margin results in a weak margin formed by undermined rods (note the easily displaced wedge of enamel) and 110-degree marginal metal, an angular design unsuitable for burnishing. J, Lap, sliding t of prescribed bevel metal decreases the 50-µm error of seating to 20 µm. K, A 50-µm error of seating produces an equal cement line of 50 µm along the unbeveled gingival margin. e106 CHAPTER 18 Class II Cast-Metal Restorationsminimal, it is usually desirable to use the lingual-to-facial direction.e gingival bevel serves the following purposes: it would be weak if not beveled because of the gingival declina-tion of the enamel rods (see Fig. 18.12I). die) because of its angular design (see Fig. 18.12H). Bulky 110-degree metal along an unbeveled margin is not burnishable (see Fig. 18.12I). 18.12J). is helps improve the t of the casting in this region. With the prescribed gingival bevel, if the inlay fails to seat by 50 µm, the void between the bevel metal and the gingival bevel on the tooth may be 20 µm; however, failure to apply such a bevel would result in a void (and a cement line) as great as in the failure to seat (see Fig. 18.12K).Uninterrupted blending of the gingival bevel into the secondary ares of the distolingual and distofacial walls results in the disto-lingual and distofacial margins joining the gingival margin in a desirable arc of a small circle; also the gingivofacial and gingivo-lingual line angles no longer extend to the marginal outline. If such line angles are allowed to extend to the preparation outline, early failure may follow because of an “open” margin, dissolution the line of draw, with only a small tilting mesially and facially, and the direction of translation of the instrument is that which results in 40-degree marginal metal (see Fig. 18.13E and J). When the adjacent proximal surface (mesial of the second premolar) is not being prepared, care must be exercised to avoid abrading the adjacent tooth and overextending the distofacial margin. To prevent such abrasion or overextension, the instrument may be raised occlusally (using the narrower portion at its tip end) to complete the most facial portion of the wall and margin (see Fig. 18.13D). Also the more slender No. 169L carbide bur may be used, rather than the ame-shaped diamond instrument (see Fig. 18.13H). e No. 169L bur produces an extremely smooth surface to the secondary are and a smooth, straight distofacial margin. When access permits, a ne-grit sandpaper disk may be used on the facial and lingual walls and on the margins of the proximal preparation, especially when minimal extension of the facial margin is desired (see Fig. 18.13I). is produces smooth walls and helps create respective margins that are straight (not ragged) and sound.In the aring and beveling of the proximal margins, as described in the previous paragraphs, the procedure began at the lingual surface and proceeded to the facial surface. e direction may be reversed, however, starting at the facial surface and moving toward the lingual surface. On the mesiofacial surface of maxillary premolars and rst molars where extension of the facial margin should be LPFLSFFPFFSF169LGoldEAGBDCFHJIX40°40°• Fig. 18.13 A, Occlusal view of Fig. 18.12G. LSF, Lingual secondary are; LPF, lingual primary are. B–E, Preparing the facial secondary are. Large arrows in B, D, and E indicate the direction of the transla-tion. F, Completed facial secondary are. FSF, Facial secondary are; FPF, facial primary are. G, Distal view of F. x, Plane of cross section shown in J. H and I, Preparing the secondary are with the No. 169L carbide bur (H) or with paper disk (I). J, The secondary ares are directed to result in 40-degree marginal metal and 140-degree marginal enamel. CHAPTER 18 Class II Cast-Metal Restorations e107 e ame-shaped, ne-grit diamond instrument also is used for occlusal bevels. e width of the cavosurface bevel on the occlusal margin should be approximately one fourth the depth of the respective wall (Fig. 18.14A and B). e exception to the rule is when a wider bevel is desired to include an enamel defect (see Fig. 18.14G and H). e resulting occlusal marginal metal of the inlay should be 40-degree metal; the occlusal marginal enamel is 140-degree enamel (see Fig. 18.14B and E). Beveling the occlusal margins in this manner increases the strength of the marginal enamel and helps seal and protect the margins. While beveling the occlusal margins, a guide to diamond positioning is to maintain an approximate 40-degree angle between the side of the instrument and the external enamel surface; this also indicates when an occlusal bevel is necessary (see Fig. 18.14A). If the cusp inclines are so steep that the diamond instrument, when positioned at a 40-degree angle to the external enamel surface, is parallel with the enamel preparation wall, no bevel is indicated (see Fig. 18.14C). By using this technique, it can be seen that margins on the proximal marginal ridges always require a cavosurface bevel (see Fig. 18.14D and I). of exposed cement, and eventual leakage, all potentially resulting in caries.e secondary are is necessary for several reasons: (1) e second-ary flaring of the proximal walls extends the margins into the embrasures, making these margins more self-cleaning and more accessible to nishing procedures during the inlay insertion appoint-ment, and does so with conservation of dentin. (2) e direction of the are results in 40-degree marginal metal (see Fig. 18.13J). Metal with this angular design is burnishable; however, metal shaped at a larger angle is unsatisfactory for burnishing; metal with an angle less than 30 degrees is too thin and weak, with a corresponding enamel margin that is too indenite and ragged. (3) A more blunted and stronger enamel margin is produced because of the secondary are.In a later section, the secondary are is omitted for esthetic reasons on the mesiofacial proximal wall of preparations on pre-molars and rst molars of the maxillary dentition. In this location, the wall is completed with minimal extension by using either hand instruments (straight or bin-angle chisel) followed by a ne-grit sandpaper disk or very thin rotary instruments.LL'x40°x'40°Metal40°140°140°Metal40°Correct40°MetalIncorrect70°sMetalyyACEHBDGFI• Fig. 18.14 A, The diamond instrument beveling the occlusal margin when it is indicated to result in 40-degree marginal metal, as shown in B. Angles x and x′ are equal because the opposite angles are equal when two lines (L and L′) intersect. The diamond instrument is always directed such that an angle of 40 degrees is made by the side of the instrument and the external enamel surface. B, Occlusal marginal metal is approximately 40 degrees in cross section, making the enamel angle 140 degrees. C, When the cuspal inclines are steep, no beveling is indicated considering that 40-degree metal would result without beveling. D, Beveling the mesial margin and the axiopulpal line angle. E, The mesial bevel is directed correctly to result in 40-degree marginal metal. F, An unbeveled mesial margin is incorrect because it results in a weak enamel margin and unburnishable marginal metal. G, To conserve dentinal support (s), occlusal defects on the marginal ridge are included in the outline form by applying a cavosurface bevel, which may be wider than usual, when necessary. H, Occlusal view of G. Preparing a 140-degree cavo-surface enamel angle at regions labeled y usually dictates that the occlusal bevel be extended over the marginal ridges into the secondary ares. I, Distal view of H. e108 CHAPTER 18 Class II Cast-Metal RestorationsModications in Inlay Tooth PreparationsBecause the indications for small inlays are rare, the following sections provide procedural information that may promote better understanding of their applications in more complex and larger inlay or onlay restorations.Mesioocclusodistal PreparationIf a marginal ridge is severely weakened because of excessive exten-sion, the preparation outline often should be altered to include the proximal surface. e distoocclusal preparation illustrated in the previous section would be extended to a mesioocclusodistal preparation (Fig. 18.16; see also Fig. 18.15B–D). e decision to extend the preparation in this manner calls for clinical judgment as to whether the remaining marginal ridge would withstand occlusal forces without fracture. A fortunate factor in favor of not extending the preparation is that such ridge enamel usually is composed of gnarled enamel and is stronger than it appears. Caries lesions present on both proximal surfaces would result in a mesioocclu-sodistal preparation and restoration. e only dierence in technique as described previously is the inclusion of the other proximal surface.Modications of Class II Preparation for EstheticsFor esthetic reasons, minimal are is desired for the mesiofacial proximal wall in maxillary premolars and rst molars in Class II cast-metal preparations (see Fig. 18.15D). e mesiofacial margin is minimally extended facially of the contact to such a position that the margin is barely visible from a facial viewing position. To accomplish this, the secondary are is omitted, and the wall and margin are developed with (1) a chisel or enamel hatchet and nal smoothing with a ne-grit paper disk or (2) a narrow diamond or bur when access permits.Facial or Lingual Surface Groove ExtensionSometimes, a faulty facial groove (ssure) on the occlusal surface is continuous with a faulty facial surface groove (mandibular molars), or a faulty distal oblique groove on the occlusal surface is continuous with a faulty lingual surface groove (maxillary molar). is situation requires extension of the preparation outline to include the ssure to its termination (Fig. 18.17; see also Fig. 18.19C). Occasionally the operator may extend further gingivally than the ssure length to improve retention form. Such groove extensions, when suciently long, are eective for increasing retention. Likewise, this extension may be indicated to provide sucient retention form even though the facial or lingual surface grooves are not ssured.For extension onto the facial surface, the dentist uses the No. 271 carbide bur held parallel to the line of draw and extends Failure to apply a bevel in these regions leaves the enamel margin weak and subject to injury by fracture before the inlay insertion appointment and during the try-in of the inlay when burnishing the marginal metal. Also failure to bevel the margins on the marginal ridges results in metal alloy that is dicult to burnish because it is too bulky (see Fig. 18.14F). Similarly, the importance of extending the occlusal bevel to include the portions of the occlusal margin that cross over the marginal ridge cannot be overemphasized (see Fig. 18.14H and I). ese margins are beveled to result in 40-degree marginal metal. Otherwise fracture of the enamel margin in such stress-vulnerable regions may occur in the interim between the preparation and the cementation appointment.e diamond instrument also is used to bevel the axiopulpal line angle lightly (see Fig. 18.14D). Such a bevel provides a thicker and stronger wax pattern at this critical region. e desirable metal angle at the margins of inlays is 40 degrees except at the gingival margins, where the metal angle should be 30 degrees. e completed preparation is illustrated in Fig. 18.15A.ABC D• Fig. 18.15 A, Completed distoocclusal preparation for the inlay. B, Mesioocclusodistal preparation for the inlay on the maxillary right rst premolar, distoocclusal view. C, Same preparation as in B, mesioocclusal view. D, Same preparation as in B, occlusal view. Note the absence, for esthetic reasons, of secondary are on the mesiofacial aspect and minimal extension of the mesiofacial margin. ABC• Fig. 18.16 Mandibular rst premolar prepared for the mesioocclusodistal inlay. Distal view (A), mesial view (B), and occlusal view (C). CHAPTER 18 Class II Cast-Metal Restorations e109 depth gauge for the axial wall, which is in dentin. e blade portion of the No. 271 bur is 0.8 mm in diameter at its tip end and 1 mm at the neck; the axial wall depth should approximate 1 mm or slightly more. e bur should be tilted lingually as it is drawn occlusally, to develop the uniform depth of the axial wall (see Fig. 18.17D). e same principles apply for the extension of a lingual surface groove.through the facial ridge (see Fig. 18.17A and B). e depth of the cut should be 1.5 mm. e oor (pulpal wall) should be continuous with the pulpal wall of the occlusal portion of the preparation (see Fig. 18.17D).With the bur still aligned with the path of draw, the dentist uses the side of the bur to cut the facial surface portion of this extension (see Fig. 18.17C). e diameter of the bur serves as a 1.5 mmDABCEFG• Fig. 18.17 A–C, Extending to include the occlusal ssure that is continuous with the facial ssure on the facial surface. D, Section of C. E and F, Beveling the gingival margin (E) and the mesial and distal margins (F) of ssure extension. G, Beveling completed. e110 CHAPTER 18 Class II Cast-Metal Restorationsdistolingual cusp from subsequent fracture. e distoocclusolingual preparation requires diligent application to develop satisfactory retention and resistance forms. Retention form is attained by (1) creating a maximum of 2-degree occlusal divergence of the vertical walls, (2) accentuating some line angles, and (3) extending the lingual surface groove to create an axial wall height in this extension of at least 2.5 mm occlusogingivally. e proper resistance form dictates (1) routine capping of the distolingual cusp and (2) maintaining sound tooth structure between the lingual surface groove extension and the distolingual wall of the proximal boxing.To prepare the distoocclusolingual preparation, the operator rst reduces the distolingual cusp with the side of the No. 271 carbide bur. e cusp should be reduced a uniform 1.5 mm. Next the operator completes the remaining occlusal step of the preparation with the No. 271 carbide bur. e operator prepares the proximal box portion of the preparation. e lingual groove extension is prepared only after the position of the distolingual wall of the proximal boxing is established. is permits the operator to judge the best position of the lingual surface groove extension to maintain a minimum of 3 mm of sound tooth structure between this exten-sion and the distolingual wall; if this is not possible because of an extensive caries lesion, a more extensive type of preparation may be indicated (one that crosses the oblique ridge). One can use the side of the No. 271 carbide bur to produce the lingual surface groove extension (see Fig. 18.19C). e diameter of the bur is the gauge for the depth (pulpally) of the axial wall in this extension, and the occlusogingival dimension of this axial wall is a minimum of 2.5 mm. With the end of this bur, the operator also establishes a 2-mm depth to the portion of the pulpal oor that connects the proximal boxing to the lingual surface groove extension. is additional depth to the pulpal oor helps strengthen the wax pattern and casting in later steps of fabrication. is should create a denite 0.5-mm step from the reduced distolingual cusp to the pulpal oor. Using the No. 169L carbide bur, the operator increases retention form in the distoocclusolingual preparation by (1) creating mesioaxial and distoaxial grooves in the lingual surface groove extension (see Fig. 18.19D) and (2) preparing facial and lingual retention grooves in the distal boxing (see Fig. 18.19E).e dentist uses the ame-shaped, ne-grit diamond instrument to bevel the proximal gingival margin and to prepare the secondary ares on the proximal enamel walls and to bevel the lingual margins. A lingual counterbevel is prepared on the distolingual cusp that is generous in width and results in 30-degree metal at the margin (see Fig. 18.19F). Occlusion should be checked at this point because the counterbevel should be suciently wide to extend beyond any occlusal contacts, either in maximum intercuspation or during mandibular movements. e bevel on the gingival margin of the lingual extension should be 0.5 mm wide and should provide for a 30-degree metal angle. e bevels on the mesial and distal margins of the lingual extension also are approximately 0.5 mm wide and result in 40-degree marginal metal.Fissures in the Facial and Lingual Cusp Ridges or Marginal RidgesIn the preparation of Class II preparations for inlays, facial and lingual occlusal ssures may extend nearly to, or through, the respective facial and lingual cusp ridges but not onto the facial or lingual surface. e proper outline form dictates that the preparation margin should not cross such ssures but should be extended to include them. For the occlusal step portion of the preparation, the dentist initially extends along the lingual ssure with the No. 271 carbide bur until only 2 mm of tooth structure remains between When a facial or lingual groove is included, it also must be beveled. With the ame-shaped, ne-grit diamond instrument, the operator bevels the gingival margin (using no more than one third the depth of the gingival oor) to provide for 30-degree marginal metal (see Fig. 18.17D). e operator applies a light bevel on the mesial and distal margins that is continuous with the occlusal and gingival bevels and results in 40-degree metal at these margins (see Fig. 18.17F and G). e bevel width around the extended groove is approximately 0.5 mm.Class II Preparation for Abutment Teeth and Extension Gingivally to Include Root-Surface LesionsExtending the facial, lingual, and gingival margins may be indicated on the proximal surfaces of abutments for removable partial dentures to increase the surface area for the development of guiding planes. In addition, the occlusal outline form must be wide enough facio-lingually to accommodate any contemplated rest preparation without involving the margins of the restoration. ese extensions may be accomplished by simply increasing the width of the bevels.e following modied preparation is recommended when further gingival extension is indicated to include a root lesion on the proximal surface. e gingival extension should be accomplished primarily by lengthening the gingival bevel, especially when prepar-ing a tooth that has a longer clinical crown than normal as a result of gingival recession. It is necessary to extend (gingivally) the gingival oor only slightly, and although the axial wall consequently must be moved pulpally, this should be minimal. If additional extension of the gingival oor is necessary, it should not be as wide pulpally as when the oor level is at a normal position (Fig. 18.18A). ese considerations are necessary because of the draft requirement and because the tooth is smaller apically. Extending the preparation gingivally without these modications would result in a dangerous encroachment of the axial wall on the pulp (see Fig. 18.18B).Maxillary First Molar With Unaected, Strong Oblique RidgeWhen a maxillary rst molar is to be restored, consideration should be given to preserving the oblique ridge if it is strong and unaected, especially if only one proximal surface is carious. A mesioocclusal preparation for an inlay is illustrated in Fig. 18.19A and B. If a distal surface lesion appears subsequent to the insertion of a mesioocclusal restoration, the tooth may be prepared for a distooc-clusolingual inlay (see Fig. 18.19H and I). e distoocclusolingual restoration that caps the distolingual cusp is preferable to the distoocclusal restoration because it protects the miniature Correct IncorrectAB• Fig. 18.18 Modications of the preparation when extending to include the proximal root-surface lesions after moderate gingival recession. A, Correct. B, Incorrect. Note the decreased dentinal protection of the pulp compared with the management depicted in A. CHAPTER 18 Class II Cast-Metal Restorations e111 may be wider than conventional if the remaining ssure can be eliminated by such a wider bevel (see Fig. 18.20C). Enameloplasty sometimes may eliminate the end portion of the ssure and provide a smooth enamel surface where previously a fault was present, thus reducing the extent of the required extension (see Fig. 18.20D). the bur and the lingual surface of the tooth. Additional lingual extension at this time is incorrect because it may remove the supporting dentin unnecessarily (Fig. 18.20A and B). If this extension almost includes the length of the ssure, additional extension is achieved later by using the occlusal bevel; this bevel ABCDEFGHI• Fig. 18.19 A and B, Mesioocclusal preparation on the maxillary molar having an unaffected oblique ridge. C, Preparing the lingual groove extension of the distoocclusolingual preparation. D and E, Cutting retention grooves in the lingual surface extension (D) and the distal box (E). F and G, Completed distooc-clusolingual preparation on the maxillary molar having an unaffected oblique ridge. H and I, Preparations for treating both proximal surfaces of the maxillary molar having a strong, unaffected oblique ridge. e112 CHAPTER 18 Class II Cast-Metal Restorations271 carbide bur (see Fig. 18.20F and G). e dentist bevels the margins of the extension with the ame-shaped, ne-grit diamond instrument to provide for the desired 40-degree marginal metal on the occlusal, mesial, and distal margins and for 30-degree marginal metal on the gingival margin (see Fig. 18.20C, D, I, and J). In the same manner, the operator should manage the ssures that may extend into or through a proximal marginal ridge, assuming that the proximal surface otherwise was not to be included in the outline form and that such ssure management does not extend the preparation outline near the adjacent tooth contact. is treatment particularly applies to a mesial ssure of the maxillary If possible, the ssure should be included in the preparation outline without extending the margin to the height of the ridge. If the occlusal bevel places the margin on the height of the ridge, however, the marginal enamel likely is weak because of its sharpness and because of the inclination of the enamel rods in this region. e preparation outline should be extended just onto the facial or lingual surface (see Fig. 18.20I and J). Such extension onto the facial or lingual surface also would be indicated if the ssure still remains through the ridge after enameloplasty (see Fig. 18.20E).When necessary, extension through a cusp ridge is accomplished by cutting through the ridge at a depth of 1 mm with the No. s2 mmCorrect IncorrectBHxyADCEFGIJ• Fig. 18.20 A, Extending to include the lingual (occlusal) ssure. B, Section of A. The dentinal support (s) of the lingual cusp ridge should not be removed. A bevel can provide additional extension to include the ssure that does not extend to the crest of the ridge. C, Completed preparations with standard width bevel (x) and with wider bevel to include a groove defect that nearly extends to the ridge height (y). D, Completed preparation illustrating enameloplasty for the elimination of a shallow ssure extending to or through the lingual ridge height. (Compare the smooth, saucer-shaped lingual ridge contour with C, in which no enameloplasty has been performed.) E, Fissure remaining through the lingual ridge after unsuc-cessful enameloplasty. This indicates procedures subsequently illustrated. F and G, Extending the prepa-ration if enameloplasty has not eliminated the ssure in the lingual ridge (F) or the facial ridge (G). H, Section of F. I and J, Completed preparations after beveling the margins of the extensions through the lingual ridge (I) and the facial ridge (J). CHAPTER 18 Class II Cast-Metal Restorations e113 If only one of the two lingual cusps of a molar is reduced for capping, the reduction must extend to include just the lingual groove between the reduced and unreduced cusps. is reduction should terminate with a distinct vertical wall that has a height that is the same as the prescribed cusp reduction. Applying the bur vertically (see Fig. 18.22F) should help establish a vertical wall of proper depth and direction. Similar principles apply when only one of the facial cusps is to be reduced (see Figs. 18.22L and 18.23B).A bevel of generous width is prepared on the facial (lingual) margin of a reduced cusp with the ame-shaped, ne-grit diamond instrument (with the exception of esthetically prominent areas). is bevel is referred to as reverse bevel or counterbevel. e width varies because it usually should extend beyond any occlusal contact with opposing teeth, either in maximum intercuspation or during mandibular movements (see Fig. 18.24C later in the chapter). It should be at an angle that results in 30-degree marginal metal (see Fig. 18.22G and H). e exception is the facial margin on maxillary premolars and the rst molar, where esthetic requirements dictate only a blunting and smoothing of the enamel margin (a stub margin) by the light application of a ne-grit sandpaper disk or the ne-grit diamond instrument (ame-shaped) held at a right angle to the facial surface (see Fig. 18.23C). Any sharp external corners should be rounded slightly to strengthen them and reduce the problems they may generate in future steps (see Fig. 18.22J and K).Cusp reduction appreciably decreases the retention form because it decreases the height of the vertical walls. erefore proximal retention grooves usually are recommended (see Fig. 18.22I). It may be necessary to increase the retention form by extending facial and lingual groove regions of the respective surfaces or by collar and skirt features (see later). ese additional retention features also provide the desired resistance form against forces tending to split the tooth (see Fig. 18.22K; see also Fig. 18.28 later in the chapter).e principles stated in the preceding paragraphs may be applied in the treatment of the distal cusp of the mandibular rst molar when preparing a mesioocclusodistal preparation (see Fig. 18.23D). Proper extension of the distofacial margin usually places the occlusal margin in a region subjected to heavy masticatory forces and wear. Satisfactory treatment usually dictates either extending the distofacial margin (and wall) slightly mesial of the distofacial groove (see Fig. 18.23E) or capping the remaining portion of the distal cusp (see Fig. 18.23F).After cusp reduction, the dentist visually veries that the occlusal clearances are sucient. A wax interocclusal record is helpful when checking the occlusal clearances, especially in areas that are dicult to visualize, for example, in the central groove and lingual cusp regions. To make a wax “bite,” the dentist rst dries the preparation free of any visible moisture; however, dentin should not be desiccated (Fig. 18.24A). Next the dentist lightly presses a portion of softened, low-fusing inlay wax over the prepared tooth; the dentist imme-diately requests the patient to close into the soft wax and slide the teeth in all directions (see Fig. 18.24B–F). During the mandibular movements, the dentist observes to verify that (1) the patient performs right lateral, left lateral, and protrusive movements; (2) the adjacent unprepared teeth are in contact with the opposing teeth; (3) the wax in the preparation is stable (not loose and rocking); and (4) the wax is not in infraocclusion. e dentist cools the wax and carefully removes it, holds it up to a light, and notes the degree of light transmitted through it. With experience, this is a good indicator of the thickness of the wax. An alternative method is to rst premolar (Fig. 18.21). If this procedure extends the margin near or into the contact, the outline form on the aected proximal surface must be extended to include the contact, as for a conven-tional proximal surface preparation.Cusp-Capping Partial Onlaye term partial onlay is used when a cast-metal restoration covers and restores at least one but not all of the cusp tips of a posterior tooth (Fig. 18.22). e facial and lingual margins on the occlusal surface frequently must be extended toward the cusp tips to the extent of the existing restorative materials and to uncover a caries lesion (see Fig. 18.22B and C). Undermined occlusal enamel should be removed because it is weak; removing such enamel provides access for the proper excavation of the lesion. When the occlusal outline is extended up, the cusp slopes more than half the distance from any primary occlusal groove (central, facial, or lingual) to the cusp tip, covering (capping) the cusp should be considered. If the prepara-tion outline is extended two thirds of this distance or more, capping the cusp is usually necessary to (1) protect the weak, underlying cuspal structure from fracture caused by masticatory force and (2) remove the occlusal margin from a region subjected to heavy stress and wear (see Fig. 18.22A and B). At this point in the preparation of the pulpal oor, depth can be increased from 1.5 mm to 2 mm. is additional pulpal depth ensures sucient reduction in an area that is often underreduced and results in imparting greater strength and rigidity to the wax pattern and cast restoration.Reduce the cusps for capping as soon as the indication for such capping is determined because this improves access and visibility for the subsequent steps in the preparation. If a cusp is in infraocclusion of the desired occlusal plane before reduction, the amount of cusp reduction is less and needs to be only that which provides the required clearance with the desired occlusal plane. Before reducing the surface, the operator prepares depth gauge grooves (depth cuts) with the side of the No. 271 carbide bur (see Fig. 18.22D). Such depth cuts should help to prevent thin spots in the restoration. With the depth cuts serving as guides, the operator completes the cusp reduction with the side of the carbide bur (see Fig. 18.22E). e reduction should provide for a uniform 1.5 mm of metal thickness over the reduced cusp. On maxillary premolars and rst molars, the reduction should be minimal (i.e., 0.75–1 mm) on the facial cusp ridge to decrease the display of metal. is reduction should increase progressively to 1.5 mm toward the center of the tooth to help impart rigidity to the capping metal (Fig. 18.23A and C).AB• Fig. 18.21 The ssure that remains on the mesial marginal ridge after unsuccessful enameloplasty (A) is treated (B) in the same manner as lingual or facial ridge ssures (see Fig. 18.20I and J). e114 CHAPTER 18 Class II Cast-Metal Restorationsinterocclusal record will not oer as much information as would the softened inlay wax technique, since the lateral and protrusive paths are not registered in the former.Including Portions of the Facial and Lingual Smooth Surfaces Aected by Caries or Other InjuryWhen portions of a facial (lingual) smooth surface and a proximal surface are aected by caries or some other factor (e.g., fracture) use wax calipers or to section the wax to verify its thickness. Insucient thickness calls for more reduction in the indicated area before proceeding. As an alternative to wax, an interocclusal record can be made in maximum intercuspation with a quick-setting PVS impression material. Once set, this interocclusal record can be measured with wax calipers to evaluate the reduction. If wax calipers are not available, the interocclusal record can be sectioned with a knife to see the thickness in cross section. However, a PVS 30°f' fll'ABHCDEFGI JKL• Fig. 18.22 A, When the extension of the occlusal margin is one half the distance from any point on the primary grooves (cross) toward the cusp tip (dot), capping of the cusp should be considered; when this distance is two thirds or more, capping of the cusp is usually indicated. B, l is midway between the central groove and the lingual cusp tip; f is midway between the central groove and the facial cusp tip. When enamel at l and f is undermined by a caries lesion, the respective walls must be extended to the dotted lines l and f to uncover the lesion. Cusps should be reduced for capping. C, Extension to uncover the caries lesion indicates that the mesiolingual cusp should be reduced for capping. D, Depth cuts. E, Reduced mesiolingual cusp. The caries lesion has been removed, and the base has been placed. F, Applying the bur vertically helps establish the vertical wall that barely includes the lingual groove. G, Counterbeveling reduced cusp. H, Section of the counterbevel. I, Improving the retention form by cutting the proximal retention grooves. J and K, The preparation is complete except for the rounding of the axiopulpal line angle (J) and the rounding of the junction of the counterbevel and the secondary are (K). Facial surface groove extension improves the retention and resistance forms. L, Preparation when reduc-ing one of two facial cusps on the mandibular molar. CHAPTER 18 Class II Cast-Metal Restorations e115 aected area (see Fig. 18.25D). is instrument also is used to terminate the facial surface reduction in a denite facial margin running gingivoocclusally and in a manner to provide for 40-degree metal at this margin (see Fig. 18.25E).If the distofacial defect is more extensive and deeper into the tooth (see Fig. 18.25I), eliminating the opportunity for an eective distal box or groove (no facial wall possible), the No. 271 carbide bur should be used to cut a gingival shoulder extending from the distal gingival oor around to include the aected facial surface. is shoulder partially provides the desired resistance form. (A gingival oor, perpendicular to occlusal force, has been provided in lieu of the missing pulpal wall in the distofacial cusp region.) e No. 271 bur is used to create a nearly vertical wall in the remaining facial enamel (see Fig. 18.25J). e width of the shoulder should be the diameter of the end of the cutting instrument. e vertical walls should have the appropriate degree of draft to contribute to retention form. en the faciogingival and facial margins are beveled with the ame-shaped, ne-grit diamond instrument to provide 30-degree metal at the gingival margin (see Fig. 18.25K) and 40-degree metal along the facial margin (see Fig. 18.25L). ese two bevels should blend together (see x in Fig. 18.25M), and the faciogingival bevel should be continuous with the gingival bevel on the distal surface. Additional retention and (Fig. 18.25A and I), the treatment may be a large inlay, an onlay, a three-quarter crown, a full crown, or multiple amalgam or composite restorations. Generally, if carious portions are extensive, the choice between the previously listed cast-metal restorations is determined by the degree of tooth circumference involved. A full crown is indicated if the lingual and the facial smooth surfaces are defective, especially if the tooth is a second or third molar. When only a portion of the facial smooth surface is carious, and the lingual surfaces of the teeth are conspicuously free of caries, a mesioocclusal, distofacial, and distolingual inlay or onlay with a lingual groove extension is chosen over the crown because the former is more favorable to the health of the gingival tissues and more conservative in the removal of tooth structure. Often this is the treatment choice for the maxillary second molar, which may exhibit a caries lesion on the distofacial surface as a result of poor oral hygiene (owing to poor access) in this region.In the preparation of the maxillary molar referred to in the preceding paragraph, the mesiofacial and distolingual cusps and the distofacial cusp are usually reduced for capping. If the distofacial cusp defect is primarily shallow decalcication, the ame-shaped diamond instrument is used to reduce the involved facial surface and distofacial corner approximately to the depth of enamel and to establish the gingival margin of this reduction apical to the CABDEF• Fig. 18.23 A and B, Capping one of two facial cusps on the maxillary molar. C, Blunting the margin of the reduced cusp when esthetics is a major consideration. D–F, The margin shown crossing the distal cusp in D indicates treatment illustrated in E or F. e116 CHAPTER 18 Class II Cast-Metal Restorationsof the tooth’s status. Sometimes the diagnosis is deferred until the extension of the occlusal step of an inlay preparation facially and lingually to the limits of the caries lesion shows that cusp reduction is mandatory. e mandibular rst molar is used to illustrate one mesioocclusodistal preparation for a full cast-metal onlay.Initial PreparationOcclusal ReductionAs soon as the decision is made to restore the tooth with a full cast-metal onlay, the cusps should be reduced because this improves the access and the visibility for subsequent steps in tooth preparation. With the cusps reduced, the eciency of the cutting instrument and the air-water cooling spray is improved. Also when the cusps are reduced, it is easier to assess the height of the remaining clinical crown of the tooth, which determines the degree of occlusal divergence necessary for adequate retention form. Using the No. 271 carbide bur held parallel to the long axis of the tooth crown, a 2-mm deep pulpal oor is prepared along the central groove (Fig. 18.26A). To verify the preoperative diagnosis for cusp reduction, this occlusal preparation is extended facially and lingually just beyond the caries to sound tooth structure (see Fig. 18.26B). e groove should not be extended farther, however, than two thirds the distance from the central groove to the cusp tips because the need for cusp reduction is veried at this point. With the side of the No. 271 carbide bur, uniform 1.5-mm deep depth cuts are prepared on the remaining occlusal surface (see Fig. 18.26C and D). Depth cuts usually are placed on the crest of the triangular ridges and in the facial and lingual groove regions. ese depth cuts help prevent thin spots in resistance forms are indicated for this preparation and can be developed by an arbitrary lingual groove extension (see Fig. 18.25N) or a distolingual skirt extension (see Fig. 18.25O and P). ese preparation features resist forces normally opposed by the missing distofacial wall and help protect the restored tooth from fracture injury.Tooth Preparation for Full Cast-Metal Onlayse preceding sections have presented basic tooth preparation principles and techniques for small, simple cast-metal inlays and for partial onlays that cap less than all the cusps. is section presents the tooth preparation principles and techniques for full onlay restorations that cover the entire occlusal surface. Onlay restorations have many clinical applications and may be desired by many patients. ese restorations have a well-deserved reputation for providing excellent service.e cast-metal onlay restoration spans the gap between the inlay, which is primarily an intracoronal restoration, and the full crown, which is a totally extracoronal restoration. e full onlay by denition caps all of the cusps of a posterior tooth and can be designed to help strengthen a tooth that has been weakened by caries or previous restorative experiences. It can be designed to distribute occlusal loads over the tooth in a manner that greatly decreases the chance of future fracture.4,6 It is more conservative of the tooth structure than the full crown preparation, and its supragingival margins, when possible, are less irritating to the gingiva. Usually an onlay diagnosis is made preoperatively because ABCDEF• Fig. 18.24 Verifying sufcient cusp reduction by forming a wax interocclusal record. A, The walls of the preparations (distoocclusal for the second premolar, and mesioocclusodistal for the rst molar) are air-dried of visible moisture. The low-fusing inlay wax that is the same length as the mesiodistal length of the inlay preparations is softened and pressed over the prepared teeth. B–E, The patient moves the mandible into all occlusal positions, left lateral (B), through maximum intercuspation (C), to right lateral (D), and protrusive (E). F, Completed interocclusal record. CHAPTER 18 Class II Cast-Metal Restorations e117 yzzyxABCDEFGHIJKLMNOP• Fig. 18.25 A, Maxillary molar with caries lesions on the distofacial corner and the mesial surface. B and C, Completed mesioocclusal, distofacial, and distolingual inlay for treating lesions shown in A, facio-occlusal view (B) and distolinguoocclusal view (C). D–H, Preparation for treating caries lesions illustrated in A, distoocclusal view with diamond instrument being applied (D), occlusal view (E), distal view (F), distolinguoocclusal view (G), and mesioocclusal view (H). I, Maxillary molar with a deeper caries lesion on the distofacial corner and with a mesial caries lesion. J, Preparation (minus bevels and ares) for mesiooc-clusal, distofacial, and distolingual inlay to restore the carious molar shown in I. A No. 271 carbide bur is used to prepare the gingival shoulder and the vertical wall. K and L, Beveling margins. M and N, Com-pleted preparation for treating the caries lesion shown in I. Gingival and facial bevels blend at x, and y is the cement base. O and P, When the lingual surface groove has not been prepared and when the facial wall of the proximal box is mostly or totally missing, forces directed to displace the inlay facially can be opposed by lingual skirt extension (z). e118 CHAPTER 18 Class II Cast-Metal Restorations2711 mm0.8 mmDjjABCEFG• Fig. 18.26 A, Cutting a 2-mm deep central groove. B, Extending the central groove cut facially and lingually to verify any need for cusp capping. C, Depth cuts. D, Section of C. E, Completion of cusp reduction. Small portions of the mesial and distal marginal ridges are left unreduced to avoid scarring the adjacent teeth. F, The occlusal step is extended facially and lingually past any carious areas and is extended to expose the proximal dentinoenamel junction (DEJ) (j) in anticipation of proximal boxing. G, Preparation with proximal boxes prepared. Note the clearances with the adjacent teeth. CHAPTER 18 Class II Cast-Metal Restorations e119 Final PreparationRemoval of Infected Carious Dentin and Defective Restorative Materials and Pulp ProtectionIf the occlusal step and the proximal boxes have been extended properly, any carious dentin or previous restorative materials remaining on the pulpal and axial walls should be visible. ey should be removed as described previously.Preparation of Bevels and FlaresAfter the cement base (when indicated) is completed (Fig. 18.27A), the slender, ame-shaped, ne-grit diamond instrument is used to place counterbevels on the reduced cusps, to apply the gingival bevels, and to create secondary ares on the facial and lingual walls of the proximal boxes. First a gingival retraction cord is inserted, as described in the previous inlay section. During the few minutes required for the cord’s eect on the gingival tissues, the diamond instrument is used to prepare the counterbevels on the facial and lingual margins of the reduced cusps. e bevel should be of generous width and should result in 30-degree marginal metal. e best way to judge this is to always maintain a 30-degree angle between the side of the instrument and the external enamel surface beyond the counterbevel (see Fig. 18.27B and C). e counterbevel usually should be wide enough so that the cavosurface margin is beyond (gingival to) any contact with the opposing dentition. If a facial (lingual) surface ssure extends slightly beyond the normal position of the counterbevel, it may be included (removed) by deepening the counterbevel in the region of the ssure (see Fig. 18.27D). If the ssure extends gingivally more than 0.5 mm, however, the ssure is managed as described later.A counterbevel is not placed on the facial cusps of maxillary premolars and rst molars where esthetic considerations may dictate using a stubbed margin by blunting and smoothing the enamel margin by the light application of a ne-grit sandpaper disk or the ne-grit diamond instrument (ame-shaped) held at a right angle to the facial surface (see Fig. 18.23C). e surface created by this blunting should be approximately 0.5 mm in width. For beveling the gingival margins and aring (secondary) the proximal enamel walls, refer to the inlay section.After beveling and aring, any sharp junctions between the counterbevels and the secondary ares are rounded slightly (see Fig. 18.27E). e ne-grit diamond instrument also is used to bevel the axiopulpal line angles lightly (see Fig. 18.27F). Such a bevel produces a stronger wax pattern at this critical region by increasing its thickness. Any sharp projecting corners in the preparation are rounded slightly because these projections are dicult to reproduce without voids when developing the working cast and often cause diculties when seating the casting. e desirable metal angle at the margins of onlays is 40 degrees except at the gingivally directed margins, where the metal angle should be 30 degrees.When deemed necessary, shallow (0.3-mm deep) retention grooves may be cut in the facioaxial and the linguoaxial line angles with the No. 169L carbide bur (see Fig. 18.27G). ese grooves are especially important for retention when the prepared tooth is short, which is often the case after reducing all the cusps. When properly positioned, the grooves are entirely in dentin near the DEJ and do not undermine enamel. e direction of cutting (translation of the bur) is parallel to the DEJ. e long axis of the No. 169L bur must be held parallel to the line of draw, and the tip of the bur must be positioned in the gingival box internal point angles. If the axial walls are deeper than ideal, however, the correct the nal restoration. If a cusp is in infraocclusion of the desired occlusal plane before reduction, the amount of cusp reduction is less and needs only that which provides the required clearance with the desired occlusal plane. Carious dentin and old restorative material that is deeper in the tooth than the desired clearance are not removed at this step in preparation.With the depth cuts serving as guides for the amount of reduc-tion, the cusp reduction is completed with the side of the No. 271 bur. When completed, this reduction should reect the general topography of the original occlusal surface (see Fig. 18.26E). e operator should not attempt to reduce the mesial and distal marginal ridges completely at this time to avoid hitting an adjacent tooth. e remainder of the ridges are reduced in a later step when the proximal boxes are prepared.roughout the next steps in the initial preparation, the cutting instruments used to develop the vertical walls are oriented continu-ally to a single draw path, usually the long axis of the tooth crown, so that the completed preparation has draft (i.e., no undercuts). For mandibular molars and second premolars whose crowns tilt slightly lingually, the bur should be tilted slightly (5–10 degrees) lingually to help preserve the strength of the lingual cusps (see Fig. 18.4D). e gingival-to-occlusal divergence of these preparation walls may range from 2 to 5 degrees from the line of draw, depending on their heights. If the vertical walls are unusually short, a minimum of 2 degrees occlusal divergence is desirable for retentive purposes. Cusp reduction appreciably decreases the retention form because it decreases the height of the vertical walls, so this minimal amount of divergence is often indicated in the preparation of a tooth for a cast-metal onlay. As the gingivoocclusal height of the vertical walls increases, the occlusal divergence should increase, allowing 5 degrees in the preparation of the greatest gingivoocclusal length. e latter preparations present diculties during pattern withdrawal, trial seating and withdrawal of the casting, and cementing, unless this maximal divergence is provided.Occlusal StepAfter cusp reduction, a 0.5-mm deep occlusal step should be present in the central groove region between the reduced cuspal inclines and the pulpal oor. Maintaining the pulpal depth (0.5 mm) of the step, it is extended facially and lingually just beyond any carious areas, to sound tooth structure (or to sound base or restorative material if certain conditions, discussed subsequently, have been met). Next the operator extends the step mesially and distally far enough to expose the proximal DEJ (see Fig. 18.26F). e step is extended along any remaining facial (and lingual) occlusal ssures as far as they are faulty (ssured). e facial and lingual walls of the occlusal step should go around the cusps in graceful curves, and the isthmus should be only as wide as necessary to be in sound tooth structure or sound base or restorative material. Old restorative material or caries that is deeper pulpally than this 0.5-mm step is not removed at this stage of tooth preparation.As the occlusal step approaches the mesial and distal surfaces, it should widen faciolingually in anticipation of the proximal box extensions (see Fig. 18.26F). is 0.5-mm occlusal step contributes to the retention of the restoration and provides the wax pattern and cast-metal onlay with additional bulk for rigidity.7Proximal BoxContinuing with the No. 271 carbide bur held parallel to the long axis of the tooth crown, the proximal boxes are prepared as described in the inlay section. Fig. 18.26G illustrates the preparation after the proximal boxes are prepared. e120 CHAPTER 18 Class II Cast-Metal Restorations30°30°CABDEFGHI• Fig. 18.27 A, The caries lesion has been removed, and the base has been inserted. B, Counterbevel-ing facial and lingual margins of reduced cusps. C, Section of B. D, The ssure that extends slightly gingival to the normal position of the counterbevel may be included by slightly deepening the counterbevel in the ssured area. E, The junctions between the counterbevels and the secondary ares are slightly rounded. F, The axiopulpal line angle is lightly beveled. G, Improving the retention form by cutting proximal grooves. H, Completed mesioocclusodistal onlay preparation. I, Completed mesioocclusodistofacial onlay preparation showing the extension to include the facial surface groove or ssure. CHAPTER 18 Class II Cast-Metal Restorations e121 grooves for additional retention with the No. 169L bur. e linguogingival and lingual margins are beveled with the ame-shaped, ne-grit diamond instrument to provide 30-degree metal at the gingival margin (see Fig. 18.28C) and 40-degree metal along the lingual margin (see Fig. 18.28D).ese two bevels should blend together (see x in Fig. 18.28E), and the linguogingival bevel is continuous with the gingival bevel on the mesial surface. Additional features to improve the retention and resistance forms are indicated and can be developed by a mesiofacial skirt extension or by a facial groove extension. ese preparation features (discussed in the following section) improve the retention form, resist forces normally opposed by the missing mesiolingual wall, and help protect the restored tooth from further fracture injury.Enhancement of Resistance and Retention FormsWhen the tooth crown is short (which is often the case when all cusps are reduced), the operator must strive to maximize the retention form in the preparation. Retention features that already have been presented are as follows:1. Minimal amount of taper (2 degrees per wall) on the vertical walls of the preparation2. Addition of proximal retention grooves3. Preparation of facial (or lingual) surface groove extensionsIn the preparation of a tooth that has been grossly weakened by caries or previous lling material and is judged to be prone to fracture under occlusal loads, the resistance form that cusp capping provides should be augmented by the use of skirts, collars, or facial (lingual) surface groove extensions. When properly placed, these features result in onlays that distribute the occlusal forces over most or all of the tooth and not just a portion of it, reducing the reference for placing retention grooves is just inside the DEJ to minimize pulpal impacts but avoids undermining enamel. e model showing the completed preparation is illustrated in Fig. 18.27H.Modications in Full Onlay Tooth PreparationsFacial or Lingual Surface Groove ExtensionA facial surface ssure (mandibular molar) or a lingual surface ssure (maxillary molar) is included in the outline in the same manner as described in the section on inlays. is extension sometimes is indicated to provide additional retention form, even though the groove is not faulty. A completed mesioocclusodistofacial onlay preparation on a mandibular rst molar is illustrated in Fig. 18.27I.Inclusion of Portions of the Facial and Lingual Smooth Surfaces Aected by Caries, Fractured Cusps, or Other InjuryFor inclusion of shallow to moderate lesions on the facial and lingual smooth surfaces, refer to the section on inlays. A mandibular molar with a fractured mesiolingual cusp is used to illustrate the treatment of a fractured cusp of a molar (Fig. 18.28). e dentist uses a No. 271 carbide bur to cut a shoulder perpendicular to occlusal force by extending the proximal gingival oor (adjacent to the fracture) to include the aected surface. is shoulder partially provides the desired resistance form by being perpendicular to gingivally directed occlusal force. is instrument also is used to create a vertical wall in the remaining lingual enamel (see Fig. 18.28B). e width of the gingival oor should be the diameter of the end of the cutting instrument. e vertical walls should have the degree of draft necessary for the retention form. If the clinical crown of the tooth is short, it is advisable to cut proximal xyABCDEFGH• Fig. 18.28 A, Mandibular rst molar with large mesioocclusodistal amalgam and fractured mesiolingual cusp. B, Preparation (minus bevels and ares) for mesioocclusal, distofacial, and distolingual onlay to restore the fractured molar shown in A. A No. 271 carbide bur is used to prepare the gingival shoulder and the vertical lingual wall. Reducing cusps for capping and extending out the facial groove improve the retention and resistance forms. C and D, Beveling of margins. E and F, Completed preparation. The gingival and lingual bevels blend at x, and y is the base. G and H, Completed onlay. e122 CHAPTER 18 Class II Cast-Metal Restorationse addition of skirt extensions also is recommended when the proximal surface contour and contact are to be extended more than the normal dimension to develop a proximal contact. Extending these proximal margins onto the respective facial and lingual surfaces aids in recontouring the proximal surface to this increased dimen-sion. Also, when improving the occlusal plane of a mesially tilted molar by a cusp-capping onlay, reshaping the mesial surface to a satisfactory contour and contact is facilitated when the mesiofacial and mesiolingual margins are extended generously.Skirting also is recommended when splinting posterior teeth together with onlays. e added retention and resistance forms are desirable because of the increased stress on each unit. Because the facial and lingual proximal margins are extended generously, the ease of soldering the connector and nishing of the proximal margins is increased.A disadvantage of skirting is that it increases the display of metal on the facial and lingual surfaces of the tooth. For this reason, skirts are not placed on the mesiofacial margin of maxillary premolars and rst molars. Skirting the remaining three line angles of the tooth provides ample retention and resistance forms.e preparation of a skirt is done entirely with the slender, ame-shaped, ne-grit diamond instrument. Skirt preparations follow the completion of the proximal gingival bevel and primary ares. Experienced operators often prepare the skirt extensions at the same time that the gingival bevel is placed, however, working from the lingual toward the facial or vice versa. Maintaining the long axis of the instrument parallel to the line of draw, the operator translates the rotating instrument into the tooth to create a denite vertical margin, just beyond the line angle of the tooth, providing at the same time a 140-degree cavosurface enamel angle (40-degree metal angle) (see Fig. 18.30D–F). e occlusogingival length of this entrance cut varies, depending on the length of the clinical likelihood of fractures of teeth (Fig. 18.29A and B). e lingual “skirt” extension (see Fig. 18.29C–E), the lingual “collar” preparation (see Fig. 18.29F), or the lingual surface groove extension on a maxillary molar protects the facial cusps from fracture. e facial skirt extension, the facial collar preparation, or the facial surface groove extension on a mandibular molar protects the lingual cusp from fracture.Skirt PreparationSkirts are thin extensions of the facial or lingual proximal margins of the cast-metal onlay that extend from the primary are to a termination just past the transitional line angle of the tooth. A skirt extension is a conservative method of improving the retention and resistance forms of the preparation. It is relatively atraumatic to the tooth because it involves removing very little (if any) dentin. Usually the skirt extensions are prepared entirely in enamel.When the proximal portion of a Class II preparation for an onlay is being prepared and the lingual wall is partially or totally missing, the retention form normally provided by this wall can be developed with a skirt extension of the facial margin (Fig. 18.30A–C). Similarly, if the facial wall is not retentive, a skirt extension of the lingual margin supplies the desired retention form (see Fig. 18.25O and P). When the lingual and facial walls of a proximal box are inadequate, skirt extensions on the respective lingual and facial margins can satisfy the retention and resistance form requirements. e addition of properly prepared skirts to three of four line angles of the tooth virtually eliminates the chance of postrestorative fracture of the tooth because the skirting onlay is primarily an extracoronal restoration that encompasses and braces the tooth against forces that might otherwise split the tooth. e skirting onlay is often used successfully for many teeth that exhibit split-tooth syndrome.xpxxxsssssACDBEF• Fig. 18.29 The large cement base x indicates severely weakened tooth crown. Occlusal force (thick arrow) may fracture the facial cusp (A) or the lingual cusp (B), which may expose the pulp (p). C and D, Skirt extensions (s) on the mesiolingual, distolingual, and distofacial transitional line angles prevent the fractures shown in A and B. Esthetic consideration contraindicates skirting the mesiofacial line angle. E, Distal view of the preparation shown in D. Skirt extensions are prepared with a ne-grit diamond instru-ment. F, A collar preparation around the lingual cusp prevents the fracture shown in A. CHAPTER 18 Class II Cast-Metal Restorations e123 HxxIJxxxxKLDEFGAxByxCxy• Fig. 18.30 A, When the lingual wall of the proximal box is inadequate or missing, the retention form can be improved by facial skirt extension (x). B, Facioocclusal view of A. Maximal resistance form is developed by skirting the distofacial (y) and mesiofacial (x) transitional line angles. C, Occlusal view of B. D–F, The initial cut for the skirt is placed just past the transitional line angle of the tooth. G and H, Blending the skirt into the primary are. I, Occlusal view showing the mesiolingual and distolingual skirts. Caution is exercised to prevent the overreduction of transitional line angles (x). Facial surface groove extension also improves the retention and resistance forms. J, The junction of the skirt and the counterbevel is slightly rounded. K, Skirt-ing all four transitional line angles of the tooth further enhances the retention and resistance forms. Caution is exercised to prevent the overreduction of transitional line angles (x). L, Mesial and facial views of the preparation shown in K. e124 CHAPTER 18 Class II Cast-Metal Restorationsthickness of metal, the occlusal 1 mm of this reduction should be prepared to follow the original contour of the tooth (see Fig. 18.31C), and any undesirable sharp line angle formed by the union of the prepared lingual and occlusal surfaces should be rounded. is aspect of the preparation is completed by lightly beveling the gingival margin of the shoulder with the ame-shaped, ne-grit diamond instrument to achieve a 30-degree metal angle at the margin (see Fig. 18.31D).Slot PreparationOccasionally the use of a slot in dentin is helpful in creating the necessary retention form. An example is the mandibular second molar that has no molar posterior to it and requires a mesioocclusal onlay restoration that caps all of the cusps (Fig. 18.32A–C). e distal, facial, and lingual surfaces are free of caries or other injury, and these surfaces also are judged not to be prone to caries. After cusp reduction, the vertical walls of the occlusal step portion of the preparation have been reduced so as to provide very little retention form. e necessary retention can be achieved by cutting a distal slot. Such a slot is preferred over preparing a box in the distal surface because (1) the former is more conserving of the tooth structure and of the strength of the tooth crown, and (2) the linear extent of marginal outline is less.To form this slot, the dentist uses a No. 169L carbide bur with its long axis parallel to the line of draw (this must be reasonably close to a line parallel with the long axis of the tooth) (see Fig. 18.32A). e slot is cut in dentin so that it would pass midway between the pulp and the DEJ if it were to be extended gingivally (see Fig. 18.32C). e position and direction of the slot thus avert (1) the exposure of the pulp, (2) the removal of the dentin sup-porting the distal enamel, and (3) the perforation of the distal surface of the tooth at the gingival termination of the slot. e slot should have the following approximate dimensions: (1) the width (diameter) of the bur mesiodistally, (2) 2 mm faciolingually, and (3) a depth of 2 mm gingival of the normally positioned crown and the amount of extracoronal retention and resistance forms desired. Extending into the gingival third of the anatomic crown is usually necessary for an eective resistance form. In most instances the gingival margin of the skirt extension is occlusal to the position of the gingival bevel of the proximal box (see Fig. 18.30H and L).e operator should use less than half the tip diameter of the ame-shaped diamond instrument to avoid creating a ledge at the gingival margin of the skirt extension. Using high speed and maintaining the long axis of the diamond instrument parallel with the line of draw, the operator translates the instrument from the entrance cut toward the proximal box to blend the skirt into the primary are and the proximal gingival margin (see Fig. 18.30G and H). e operator must ensure that the line angle of the tooth is not overreduced when preparing skirt extensions (see x in Fig. 18.30I and K). If the line angle of the tooth is overreduced, the bracing eect of the skirt is diminished. Holding the diamond instrument at the same angle that was used for preparing the counterbevel, the operator rounds the junction between the skirt and the counterbevel (see Fig. 18.30J). Any sharp angles that remain after preparation of the skirt need to be rounded slightly because these angles often lead to diculties in the subsequent steps of the restoration.Collar PreparationTo increase the retention and resistance forms when preparing a weakened tooth for a mesioocclusodistal onlay to cap all cusps, a facial or lingual “collar” or both may be provided (Fig. 18.31). To reduce the display of metal, however, the facial surfaces of maxillary premolars and rst molars usually are not prepared for a collar. e operator uses a No. 271 carbide bur at high speed parallel to the line of draw to prepare a 0.8-mm–deep shoulder (equivalent to the diameter of the tip end of the bur) around the lingual (or facial) surface to provide for a collar about 2 to 3 mm high occlusogingivally (see Fig. 18.31A and B). To provide for a uniform C232712711ADEFB• Fig. 18.31 A, First position of the bur in preparing for the lingual collar on a weakened maxillary premolar. B and C, Section drawings of the rst position of the bur (B) and the second and third positions (C). D, Beveling the lingual margin. Note the distofacial skirt extension. E, Completed preparation. F, Completed onlay. CHAPTER 18 Class II Cast-Metal Restorations e125 secondary are is omitted, and the wall and margin are developed with a chisel or enamel hatchet. Final smoothing with the ne-grit paper disk is recommended when access permits. e cavosurface margin should result in a gold angle of 40 to 50 degrees, if possible.When more than ideal extension of the mesiofacial margin is necessary because of a caries lesion or previous restoration, and as dictated by the esthetic desires of the patient, the operator may choose to place a composite insert at this margin. is is a more conservative option than preparing the tooth to receive a porcelain-veneered metal crown. When preparing the mesiofacial margin, no attempt is made to develop a straight mesiofacial wall past the point of ideal extension. After caries lesion excavation, a resin-modied glass ionomer base is inserted to temporarily form the missing portion of the wall. e base is contoured to the ideal form, and the preparation can continue, terminating the mesiofacial onlay margin in the ideal position in the base. After placement, the operator removes (with small round burs) the glass ionomer material to a depth of 1 mm for a composite insert. Small undercuts should be prepared in the wall formed by the cast-metal onlay (see Fig. 18.57A later in the chapter). (It is best to carve the undercut in the wall formed by the onlay during the wax pattern stage.) After beveling the enamel cavosurface margin and preparing a gingival retention groove where, and if, enamel is thin or missing, the composite veneer is inserted (see Fig. 18.62A later in the chapter).Endodontically Treated TeethRoutinely, teeth that have had endodontic treatment are weak and subject to fracture from occlusal forces. ese teeth require restora-tions designed to provide protection from this injury (see Fig. 18.30K and L). is particularly applies to posterior teeth, which are subjected to greater stress. e need for such protection is accentuated when much of the strength of the tooth has been lost pulpal wall. To be eective, the mesial wall of the slot must be in sound dentin; otherwise, the retention form obtained is insucient.A comparable situation occurs occasionally: e maxillary rst premolar requires a distoocclusal onlay restoration to cap the cusps, and the mesial surface is noncarious and deemed not prone to caries (see Fig. 18.32D–F). To reduce the display of metal and to conserve the tooth structure, a slot similar to that described in the preceding paragraph (except that it is mesially positioned and 1.5 mm wide faciolingually) may be used for the production of adequate retention. e mesioocclusal marginal outline in this preparation should be distal of the height of the mesial marginal ridge.Modications for Esthetics on Maxillary Premolars and First MolarsTo minimize the display of metal on maxillary premolars and rst molars, several modications for esthetics are made to the basic onlay preparation. On the facial cusps of maxillary premolars and on the mesiofacial cusp of the maxillary rst molar, the occlusal reduction should be only 0.75 to 1 mm on the facial cusp ridge to minimize the display of metal. is thickness should increase progressively to 1.5 mm toward the center of the tooth to provide rigidity to the capping metal. ese cusps do not receive a coun-terbevel but are “stubbed” or blunted by the application of a sandpaper disk or the ne-grit diamond instrument held at a right angle to the facial surface (see Fig. 18.23C). e surface created by this blunting should be approximately 0.5 mm in width.To further decrease the display of metal on maxillary premolars and rst molars, the mesiofacial margin is minimally extended facially of the contact to such a position that the margin is barely visible from a facial viewing position. To accomplish this, the xxxxBCDEFxxA• Fig. 18.32 A and B, Cutting a distal slot for the retention for the mesioocclusal onlay to treat the terminal molar having a large base (x) resulting from extensive occlusal and mesial caries. C, Section of A. D and E, Preparing a mesial slot for the retention for the distoocclusal onlay to treat the maxillary rst premolar that has a large base (x). F, Section of D. e126 CHAPTER 18 Class II Cast-Metal Restorationstooth structure by preparing facial and lingual skirt extensions on the respective proximal margins, which improves retention and resistance forms. In contrast, achieving extension by preparing the mesiofacial and mesiolingual walls facially and lingually does not improve retention or resistance forms and is less conservative of the tooth structure. Verication of appropriate cusp reduction is the same as presented for the inlay tooth preparation, as illustrated in Fig. 18.24.Restorative Techniques for Cast- Metal RestorationsInterocclusal RecordBefore preparation of the tooth, the occlusal contacts in maximum intercuspation and in all lateral and protrusive movements should have been carefully evaluated. If the patient has sucient canine guidance to provide disocclusion of posterior teeth, the necessary registration of the opposing teeth can be obtained by (1) making a maximum intercuspation interocclusal record with commercially available bite registration pastes or (2) making full-arch impressions and mounting the casts made from these impressions on a simple hinge articulator. e interocclusal record works well when preparing one tooth; the full-arch casts are preferred when two or more prepared teeth are involved.e maximum intercuspation interocclusal record can be made from one of several commercially available bite registration pastes. e most commonly used bite registration pastes are composed of heavily lled PVS impression materials. Several materials are available in cartridge systems that automatically mix the base and accelerator pastes together as they are expressed through a special disposable mixing tip (Fig. 18.34A). e mixed impression material is dispensed directly onto the prepared teeth and their opponents, then the patient closes completely (see Fig. 18.34B and C). e dentist observes teeth not covered by the bite registration paste to verify that teeth are in maximum intercuspation. When the material has set, the dentist removes the interocclusal record and inspects it for completeness. When held up to a light, areas where the because of extensive caries or previous restorations. When the facial and lingual surfaces of an endodontically treated tooth are sound, it is more conservative, for the health of the facial and lingual gingival tissue, to prepare the tooth not for a full crown, but for a full occlusal coverage onlay that has been designed with adequate resistance form to prevent future tooth fracture. Such features include skirt extensions and collar preparations. ese features make the onlay more of an extracoronal restoration that encompasses the tooth such that the tooth is better able to resist lateral forces that otherwise might fracture the tooth.Before starting the preparation of an endodontically treated posterior tooth, the pulp chamber should be excavated to the chamber oor and usually into the canals (1–2 mm), and an amalgam or composite foundation should be placed; this gives the onlay a rm base on which to rest. In the preparation of an endodontically treated premolar that has had extensive damage, the root canal may be prepared for a cast-metal or ber-reinforced composite post, which is cemented before the onlay preparation is completed. is post helps the tooth resist forces that otherwise might cause a horizontal fracture of the entire tooth crown from the root. e post should extend roughly two thirds the length of the root and should terminate, leaving at least 5 mm of the root canal lling material at the apical portion of the root.Restoring the Occlusal Plane of a Tilted MolarAn onlay is excellent for restoring the occlusal plane of a mesially tilted molar (Fig. 18.33). When the unprepared occlusal surface (mesial portion) is less than the desired occlusal plane, a correspond-ing decrease in occlusal surface reduction is indicated. To facilitate increasing the height of the tooth, while maintaining the desirable faciolingual dimension of the restored occlusal surface and good contour of the facial and lingual surfaces, the counterbevels on the latter surfaces often should be extended gingivally more than usual (see Fig. 18.33B).Often the mesiofacial and mesiolingual margins (on the “submerged” proximal surface) should be well extended onto the respective facial and lingual surfaces to help in recontouring the mesial surface to desirable proximal surface contour and contact. is extension can be accomplished with a minimal loss of the ABC• Fig. 18.33 A, The mandibular second and third molars being tilted mesially often is the result of failure to replace a lost rst molar by bridgework. Note the poor contact relationship between the molars and between the molar and the second premolar. B, The second premolar is prepared for an inlay, and the molars are prepared for onlays. The margins of the preparations are well extended on the facial and lingual surfaces to aid in recontouring teeth to improve the occlusal relationship and to improve the proximal contours and contacts. C, Completed restorations. Note the improvement in the occlusal plane and in the proximal contacts. CHAPTER 18 Class II Cast-Metal Restorations e127 much more information about the general occlusal scheme, pathways of cusps, opposing cusp steepness and groove direction, and the anatomy of other teeth in the mouth. e technique uses a full-arch tray when making the nal impression, which requires mixing more material, especially when using stock trays. e opposing arch is impressed with impression material, and the appropriate mandibular movement and face-bow transfer records are made. e reader is referred to Chapter 1 for principles regarding the use of the semiadjustable articulator in developing proper occlusal relationships for cast-metal restorations.Temporary RestorationBetween the time the tooth is prepared and the cast-metal restoration is delivered, it is important that the patient be comfortable and the tooth be protected and stabilized with an adequate temporary restoration. e temporary restoration should satisfy the following requirements:1. It should be nonirritating and protect the prepared tooth from injury.2. It should protect and maintain the health of the periodontium.3. It should maintain the position of the prepared, adjacent, and opposing teeth.adjacent unprepared teeth have penetrated through the material should be seen (see Fig. 18.34D). e interocclusal record is set aside for later use in the laboratory.e maximum intercuspation interocclusal records described in the previous paragraph provide information on the shape and position of the opposing teeth in maximum intercuspation. Such records give the laboratory technician some information about how to form the occlusal surface and position the occlusal contacts on the restoration, but they supply no data on how these structures and contacts might function during mandibular movements. is is also true when full-arch casts are mounted on a simple hinge articulator. Cast-metal restorations made with these simple bite registration techniques often require adjustments in the mouth to alleviate interferences during mandibular movements.If information is desired in the laboratory about the pathways of cusps during mandibular movements (such as when the tooth is to be restored in group function), an excellent technique involves making full-arch impressions and mounting casts from these impressions on a properly adjusted semiadjustable articulator (Fig. 18.35). e use of full-arch casts mounted on a semiadjustable articulator is recommended when restoring a large portion of the patient’s posterior occlusion with cast-metal restorations. It involves only a little extra chair time and gives the laboratory technician ABCD• Fig. 18.34 Maximum intercuspation interocclusal record made with PVS bite registration paste. A, One of many commercially available bite registration materials used in this technique. B, Using a car-tridge dispenser and a disposable automixing tip, the base and accelerator pastes are automatically mixed and applied to the prepared teeth, their neighbors, and the opposing teeth. C, Have the patient close into maximum intercuspation position. Be sure that the adjacent unprepared teeth are touching in their normal relationships. D, Remove the maximum intercuspation interocclusal record carefully after it has set, and inspect it for completeness. Areas where the adjacent, unprepared teeth have penetrated through paste should be seen. e128 CHAPTER 18 Class II Cast-Metal Restorationspostoperative cast of the prepared teeth (indirect technique). e indirect technique is not as popular as the direct technique because of the increased number of steps and complexity in the former; however, it is useful when making temporaries that might become “locked on” (e.g., intracoronal inlays) when using the direct technique.Technique for Indirect Temporary Restoratione indirect temporary technique has the following advantages:1. e indirect technique avoids the possibility of “locking on” the set temporary material into undercuts on the prepared tooth or the adjacent teeth.2. e indirect technique avoids placing polymerizing temporary material directly on freshly prepared dentin and investing soft tissue, reducing potential irritation to these tissues.8-103. e postoperative cast made in the indirect technique aords an opportunity to evaluate the preparation (before the nal impression) and serves as an excellent guide when trimming and contouring the temporary restoration.4. Fabrication of the temporary restoration can be delegated to a well-trained dental auxiliary.To form the indirect temporary, rst an impression of the prepared tooth is made with fast-setting impression material. A stock, plastic impression tray that has been painted with tray adhesive is used (Fig. 18.36A). If using alginate, it is ensured that teeth are slightly moistened by saliva, then some alginate is applied over and into the preparation with a ngertip to avoid or to minimize trapping air (see Fig. 18.36B); then the tray is seated over the region (see Fig. 18.36C). After the material has become elastic, the impression is removed with a quick pull in the direction of the draw of the preparation and is inspected for completeness (see Fig. 18.36D). e impression is poured with fast-setting plaster or stone (see Fig. 18.36E).As soon as the postoperative cast has been recovered from the impression, the dentist inspects the cast for any negative or positive defects (see Fig. 18.36F). Small voids on the cast may be lled in 4. It should provide for esthetic, phonetic, and masticatory function, as indicated.5. It should have adequate strength and retention to withstand the forces to which it will be subjected.When properly made, the custom temporary restoration can satisfy these requirements and is the preferred temporary restoration. Temporaries can be fabricated intraorally directly on the prepared teeth (direct technique) or outside of the mouth using a • Fig. 18.35 Full-arch casts mounted via a facebow transfer on a semi-adjustable articulator provide maximal information in the laboratory on how to position cusps to prevent undesirable contacts. ABCDEF• Fig. 18.36 Making a postoperative plaster cast for indirectly forming a temporary restoration. A, The interior of the tray is coated with alginate tray adhesive. B, Some alginate is applied over and into the preparations with the ngertip to avoid trapping air. C, Alginate-lled tray in place. D, Alginate impression. E, The alginate impression is poured with fast-setting plaster. F, Plaster cast of the preparations shown in Fig. 18.24A. CHAPTER 18 Class II Cast-Metal Restorations e129 the preoperative impression in the area of the prepared teeth (see Fig. 18.37G). When adjacent teeth are prepared, the temporary material may be continuous from one tooth to the next. e cast is seated into the preoperative impression (see Fig. 18.37H). e formed temporary restoration is shown in Fig. 18.37I.With suitable burs the excess temporary material along the facial and lingual margins is trimmed away. e red line previously placed helps in the trimming, especially if it is performed by an auxiliary (Fig. 18.38A). On multiple-unit temporary restorations, a thin diamond instrument or the slender No. 169L bur or diamond can be used to rene the interproximal embrasures (see Fig. 18.38B). After the excess temporary material has been removed from the facial and lingual embrasures, a cut is made through the adjacent unprepared tooth 1 mm away from the proximal contact (see Fig. 18.38C). A knife is inserted into the cut and the temporary restora-tion is pried o from the cast. Access to improve the contour of the proximal surface that will contact the adjacent unprepared with utility wax. Large voids indicate repouring the impression. Positives (blebs) on the cast should be removed carefully with a suitable instrument.e postoperative cast is seated into the preoperative impression (Fig. 18.37A–D). e thin edges of the postoperative impression material that record the gingival sulcus can be cut away for more thickness of the temporary in this area (see Fig. 18.37A). e postoperative cast is trial-seated into the preoperative impression to verify that it seats completely. Soft tissue around the perimeter of the impression or the cast, or in both areas, may have to be relieved to allow full seating (see Fig. 18.37B and C).When satised that the gypsum cast seats completely in the preoperative impression (see Fig. 18.37D), the dentist removes the cast and marks the margins of the preparations on the cast with a red pencil to facilitate trimming (see Fig. 18.37E). A release agent is brushed on the preparations and adjacent teeth (see Fig. 18.37F). Tooth-colored temporary resin is mixed and inserted into ABCDEFGHI• Fig. 18.37 Forming indirect temporary restorations for the preparations initially shown in Fig. 18.24A. A, Thin edges of the preoperative impression material that record the gingival sulcus should be cut away because these are apt to tear when seating the postoperative cast in the impression. B and C, Trimming away much of the soft tissue areas recorded by the impression and the cast also facilitates seating. D, Trial seating the postoperative cast into the preoperative impression. E, Marking the margins with red pencil. F, Applying the release agent to the cast. G, Filling the preoperative impression with temporary material in the area of the tooth preparation. H, Seating the cast into impression, taking care not to overseat or tilt the cast. I, Formed temporary restoration. e130 CHAPTER 18 Class II Cast-Metal Restorationsin the preparation should be “blocked out” using a resin-modied glass ionomer base (see Fig. 18.39B). A light lm of a water-based lubricant over any exposed base prevents adherence and facilitates removal.When using the direct technique with inlay and onlay prepara-tions (preparations that gain their retention primarily through internal retention features), it is helpful to select temporary material systems that become elastic before the nal set, allowing removal from undercuts without permanent distortion. e temporary material is mixed, following the manufacturer’s instructions. Temporary materials that use automixing tips are especially con-venient (see Fig. 18.39C). e dentist places the material into the preoperative impression in the area of the prepared tooth, taking care not to entrap any air (see Fig. 18.39D). e impression is placed on teeth, and the dentist ensures that it seats completely (see Fig. 18.39E). e manufacturer’s instructions for gauging the setting time should be followed. Most temporary systems recom-mend monitoring the setting by rolling some excess material into a small ball and holding it between two ngers. When the temporary material has set to a rm stage, the impression is removed. When the material is suciently strong, the operator removes it from the tooth (see Fig. 18.39F). Excess material is trimmed away (see Fig. 18.39G). e cavosurface margins of the preparation can be seen inside the temporary restoration and are used as a guide for trimming the critical external areas near the margins (see Fig. 18.39H). e techniques for try-in, adjustment, and nishing the direct temporary restoration are identical to those described in the previous section (see Fig. 18.39I).Final ImpressionFabrication of cast-metal restorations occurs in dental laboratories using replicas of the prepared and adjacent unprepared teeth. Classic tooth is now available (see Fig. 18.38D). e contact area on the temporary restoration that was accurately formed should not be disturbed.Trial-t the temporary restoration on the patient’s teeth (see Fig. 18.38E). It should t well, make desirable contact with the adjacent teeth, and meet occlusal requirements with minimal adjustments (see Fig. 18.38F). If occlusal adjustments are indicated, the prematurities are marked with articulating paper and reduced with an appropriate rotary instrument. After correcting the occlu-sion, any roughness or undesirable sharp edges are smoothed with a rubber point or wheel. e temporary restoration is removed from the mouth and set aside for cementation with temporary cement after the nal impression has been made.Technique for Direct Temporary Restoratione direct temporary technique involves forming the temporary restoration directly on the prepared tooth and has the following advantages (Fig. 18.39): (1) e direct technique involves fewer steps and materials because no postoperative impression and gypsum cast are required, and (2) it is much faster than the indirect technique. e main disadvantages of the direct temporary technique include the following: (1) ere is a chance of locking hardened temporary materials into small undercuts on the prepared tooth and the adjacent teeth, (2) the marginal t may be slightly inferior to the indirect technique, and (3) it is more dicult to contour the temporary restoration without the guidelines oered by the postoperative cast.11Forming the temporary restoration directly on the prepared tooth requires the preoperative impression (see Fig. 18.2C). Trial-tting seats the preoperative impression onto teeth to verify that it seats completely. Because a potential for locking the temporary restoration on the tooth exists, it is necessary to eliminate undercuts in the preparation and occasionally in the proximal areas. Undercuts ABCDEF• Fig. 18.38 Trimming and adjusting the indirect temporary restorations. A, Trimming the excess material back to the accessible facial and lingual margins (marked by red line on the plaster cast). B, On multiple-unit temporaries, a slender bur or diamond instrument can be used to rene the interproximal embrasure form. C, On the cast, any tooth adjacent to the temporary restoration is cut away. D, Trimming the proximal surface of the temporary restoration to the proper contour. Care should be taken to avoid removing the proximal contact (arrow). E and F, After the nal impression is made, the temporary restoration is cemented with temporary cement. Note the anatomic contour and t (E) and the functional occlusion of the tem-porary restoration (F). CHAPTER 18 Class II Cast-Metal Restorations e131 IHGFcCDABfgiE• Fig. 18.39 Forming the direct temporary restoration with preoperative impression. Mesioocclusodisto-facial onlay preparation for the mandibular rst molar is used for illustration. A, Preoperatively, this patient had symptoms indicating an incomplete fracture of a vital tooth. B, After preparation for an onlay, an incomplete fracture (f) of dentin is seen extending mesiodistally along the pulpal oor. To maximize the retention and resistance forms, all the cusps are reduced for capping, a facial surface groove extension is prepared, and all four transitional line angles have skirt extensions. Resin-modied glass ionomer bases are inserted into excavations on axial walls (gi). Bases should have a light coat of water-soluble lubricant to prevent adhesion. C, Automixing the temporary resin material. D, The mixed temporary material is poured into the preoperative impression of the prepared tooth. E, The preoperative impression is seated with the temporary material onto the prepared tooth. F, The formed temporary restoration is removed from the preparation (note the contact area c, which must not be removed during trimming). G, Thin excess can be removed by using scissors. H, The internal surface of the temporary restoration has record of the cavosurface margin that is used as guide for nal trimming. I, After the nal impression is made, the temporary restoration is cemented with temporary cement. The temporary material over the skirt extensions is left slightly overcontoured for additional strength. e132 CHAPTER 18 Class II Cast-Metal Restorationssevere cardiovascular disease, uncontrolled hyperthyroidism, or diabetes and patients taking drugs such as β-blockers, monoamine oxidase inhibitors, or tricyclic antidepressants.12All sensory nerves to the region should be anesthetized, cotton rolls applied, and the saliva ejector inserted. Profound local anesthesia substantially reduces salivation to facilitate a dry eld and allows tissue retraction without causing discomfort to the patient. e dentist selects and cuts a retraction cord of suitable diameter that is slightly longer than the length of the gingival margin. e cord may be cut long enough to extend from one gingival margin to another if they are on the same tooth or on adjacent teeth. In Fig. 18.41A and B, the cord is inserted into the gingival sulcus only in areas where the cavosurface margin is prepared subgingivally. Using the edge of a paddle-tipped instrument or the side of an explorer, one end of the cord is gently placed into the sulcus, about 2 mm facial to the point where the facial margin passes under the free gingiva. en the cord is inserted progressively into the remainder of the sulcus, with the end of the cord left exposed, to be grasped with tweezers later in the technique (see Fig. 18.41A–C, H). e cord is placed to widen the sulcus and not to depress soft tissue gingivally (although some temporary retraction does occur apically).Occasionally when the gingival margin is deep, it is helpful to insert a second cord of the same or larger diameter over the rst. When the free gingiva is thin and the sulcus is narrow (e.g., facial surface of the maxillary or mandibular canine), a cord of very small diameter must be selected to prevent undue trauma to the tissue. In instances when a small diameter cord is used, layering a second cord on top of the rst may be necessary to keep the sulcus from narrowing at the gingival crest.In Fig. 18.41D, the cord is incorrectly placed because it is tucked too deeply into the sulcus, as its depth permitted such positioning. When the cord is withdrawn before the injection of the impression material, the sulcus is wide at the bottom but narrow at the top. If the impression material is injected successfully into such a sulcus, the material is likely to tear in the region of x during the removal of the impression from the mouth. Correct application of the retraction cord is shown in Fig. 18.41C.Occasionally the retraction cord becomes displaced from the sulcus during its insertion in the presence of slight hemorrhage or seepage, but this can be controlled if an assistant repeatedly touches the cord with dry cotton pellets or dries the area with a gentle stream of air. When excessive hemorrhage from the interproximal tissue occurs, rst a cotton pellet is moistened with aqueous aluminum chloride solution, and the pellet is wedged between teeth so that it presses on the bleeding tissue. is pellet is left in for several minutes before it is removed and the cord is inserted. e widening or opening of the gingival sulcus by the earlier insertion of the retraction cord before the beveling of the gingival margin also should minimize or eliminate hemorrhage of the gingiva. For retracting a large mass of tissue, rst a suitably shaped, large diameter cotton pack is made by rolling cotton bers between ngertips, and the pack is then moistened with a drop or two of aqueous aluminum chloride and inserted into the sulcus.e cords remain in place for several minutes. When hemorrhage or excessive tissue is present, more time is recommended. e region must remain free of saliva during this interval, and the patient should be cautioned not to close or allow the tongue to wet the teeth. Placing cotton rolls over teeth and having the patient close lightly to relax while the teeth remain isolated is sometimes helpful.techniques involving impressions and gypsum casts are described in this chapter. e reader is referred to Chapter 12 for alternative methods in digital dentistry.e material used for the nal impression should have the following qualities:1. It must become elastic after placement in the mouth because it must be withdrawn from undercut regions that usually exist on the prepared and adjacent teeth. Note the shaded portions in Fig. 18.40, which are undercut areas with regard to the line of draw of the preparation. A satisfactory impression must register some of this undercut surface to delineate the margin sharply and to signify the desirable contour of the restoration in regions near the margin.2. It must have adequate strength to resist breaking or tearing on removal from the mouth.3. It must have adequate dimensional accuracy, stability, and reproduction of detail so that it is an exact negative imprint of the prepared and adjacent unprepared teeth.4. It must have handling and setting characteristics that meet clinical requirements.5. It must be free of toxic or irritating components.6. It must be possible to disinfect it without distorting it.In addition to the absolute requirements listed, the choice of impression material is usually made by comparisons of cost; ease of use; working time; shelf life; and pleasantness of odor, taste, and color. e most common impression material used for the indirect casting technique is PVS. e technique for the use of this material is discussed in detail in the following sections.Tissue RetractionFinal impression materials make accurate impressions only of tooth surfaces that are visible, clean, and dry. When margins are sub-gingival, retraction cords can be used to displace the free gingiva temporarily away from the tooth and to control the ow of any gingival hemorrhage and sulcular uids. e objective of gingival retraction is to widen the gingival sulcus to provide access for the impression material to reach the subgingival margins in adequate bulk to resist tearing during impression withdrawal (see Fig. 18.40). e objective of control of hemorrhage and moisture is met by the use of retraction cord impregnated with appropriate styptics (e.g., aluminum chloride), vasoconstrictors (e.g., epinephrine), or both. e use of vasoconstrictors in retraction cord is contraindicated in some patients, especially those who have cardiac arrhythmias, hux• Fig. 18.40 The shaded area on the prepared tooth is undercut in relation to the line of withdrawal of the impression. The impression material that is in the position of greatest undercut (u) must be withdrawn in the direction of the vertical arrow and exed over the greatest heights of contour (h). The position of the gingival attachment is indicated by x. CHAPTER 18 Class II Cast-Metal Restorations e133 CDCorrectCordIncorrectCordxABEHFG• Fig. 18.41 A and B, Inserting the retraction cord to widen the gingival sulcus to expose the gingival margin. Separate lengths of cord can be inserted (one for each gingival margin) (A), or a cord long enough to run from one gingival margin to another can be inserted (B). Where the margin is not subgingival, as on the lingual surface of the molar, the cord should not be in the sulcus. C, Correct application of the retraction cord. D, Incorrect application of the retraction cord causing the impression material to tear at x. E, Maxillary quadrant before preparing teeth for onlays. Note the fracture of the mesiofacial cusp of the molar. F, Facial view of E. G, Bitewing radiograph of E. H, Teeth prepared for onlays and ready for making the nal impression. The lingual and distofacial transitional line angles of premolars are prepared for skirting. e134 CHAPTER 18 Class II Cast-Metal Restorationsdisposable automixing tip ts onto the end of each cartridge (see Fig. 18.43C). e light-bodied mixing tip has an accessory curved tip that is small enough to gain access to the smallest, most remote areas of the preparation (see Fig. 18.43D).e rst dispenser is used to mix and ll the impression tray with the heavy-bodied impression material (see Fig. 18.43E). e dispensing tip should be kept embedded in the impression material as it is expressed into the tray so that the chance of trapping air is decreased. e second dispenser is then used to mix and inject the light-bodied impression material on the prepared teeth (see Fig. 18.43F). Teeth should be examined to ensure that the eld is still clean and dry. Any visible moisture on teeth is removed with compressed air. e retraction cord is gently removed with operative pliers. All preparation surfaces should be clean, dry, and exposed to view. Next the opened gingival sulci and preparations are deliberately and progressively (moving from distal to mesial) lled over and beyond the margins with material from the syringe. To avoid trapping air, the tip is kept directly on the gingival and pulpal walls, lling the preparations from the gingival to the occlusal aspect, and the ow is regulated so that the material is not extruded too fast ahead of the tip. Light-bodied material also is injected on the occlusal surfaces of the unprepared adjacent teeth to eliminate the trapping of air on the occlusal grooves.After lling and covering teeth with material from the syringe, the cotton rolls are immediately removed and the loaded tray seated over the region. e manufacturer’s product instructions should be followed with regard to how long the material should be allowed to set before removal. As an additional safeguard, the operator should test the set of the impression material wherever it is accessible at the periphery of the tray. When it recovers elastically from an indentation made by the tips of the operative pliers, it is ready for removal (see Fig. 18.43G).Removing and Inspecting the ImpressionAfter the PVS impression has properly polymerized, it is removed from the mouth by a quick, rm pull that is directed as much as possible in line with the draw of the preparation. Removal is aided by inserting a ngertip at the junction of the facial border of the impression and the vestibule fornix, disrupting the vacuum that occasionally occurs during withdrawal, especially with full-arch impressions. e impression should be inspected carefully with good lighting and magnication. It should register every detail of the teeth and the preparation (Fig. 18.44).Fig. 18.41 E-H illustrates correct use of gingival retraction on the maxillary quadrant.Polyvinyl Siloxane Impressione PVS impression is discussed in detail here because it is widely used, and the technique for its use can be readily applied to most other impression materials. PVS impression materials have many advantages over other impression materials used for nal impressions. ey have excellent reproduction of detail and dimensional stability over time. ey are user friendly because they are easy to mix and have no unpleasant odor or taste. PVS impressions can withstand disinfection routines without signicant distortion. ese impression materials come in the form of two pastes (base and catalyst) that are mixed in disposable, automix, cartridge-dispensing systems. ese automix systems provide excellent mixing of the accelerator and base pastes (Fig. 18.42A).Tray Selection and Preparatione impression tray must be suciently rigid to avoid deformation during the impression technique. If the tray bends or exes at any time, the accuracy of the impression may be aected. Two types of trays, commercial stock and custom made, are suitable. Use of stock plastic trays is convenient and saves time. e custom resin tray made over a 2- to 3-mm wax spacer on the study cast is an excellent tray. A thickness of impression material greater than 3 mm increases shrinkage and the chance of voids; a thickness less than 2 mm may lead to distortion or tear of the impression material or to breakage of narrow or isolated teeth on the cast during withdrawal from the impression. Adequate bonding of impression material to the tray is accomplished with the application of a special adhesive to the tray (see Fig. 18.42B).Impression TechniqueMost dental manufacturers oer their PVS impression materials in automix dispensing systems. e automixing systems have many advantages, including (1) speed, (2) consistent and complete mixing of accelerator and base pastes, and (3) incorporation of very few air voids during mixing and delivery to teeth. e technique demonstrated illustrates the use of two viscosities of impression material, a light-bodied material to inject around the preparation and a heavy-bodied material to ll the tray. Two dispensing guns are needed (Fig. 18.43A). e dispensers are loaded with cartridges that contain the accelerator and base pastes (see Fig. 18.43B). A BA• Fig. 18.42 A, Light-bodied (low viscosity), heavy-bodied (high-viscosity) polyvinyl siloxane impression materials; dispensers, automixing tips. B, Painting adhesive on stock tray. CHAPTER 18 Class II Cast-Metal Restorations e135 DEFGABC• Fig. 18.43 A, One dispenser is loaded with light-bodied impression material and the other dispenser is loaded with heavy-bodied impression material. B, The disposable automixing tip ts onto the end of the cartridge. C, An accessory curved tip is added to the end of the automixing tip for the light-bodied material. D, The impression tray is lled with heavy-bodied material. E, The retraction cord is removed, and the opened sulci and preparations are progressively lled over and beyond the cavosurface margins without trapping air. The occlusal surfaces of the adjacent unpre-pared teeth are covered with light-bodied impression material. F, The cotton rolls are removed, and the impression tray is seated. G, Completed automixed polyvinyl siloxane impression. e136 CHAPTER 18 Class II Cast-Metal Restorationsof the die segment is at, the sides closer to the facial and lingual aspects of teeth should be trimmed (see Fig. 18.46B). Deep scratches left by the model trimmer are removed by wet sanding the base of the die segment with 220-grit wet or dry sandpaper.General rule: Teeth that will be removable are the prepared teeth with proximal gingival margins and any unprepared teeth adjacent to the prepared proximal surfaces. e two main advantages to making removable dies of unprepared teeth adjacent to prepared proximal surfaces are as follows: (1) e adjacent tooth will not interfere with removing the die that has the preparation, as occasion-ally may happen otherwise; and (2) adjusting the contacts is easier and more accurate when waxing and nishing the castings.One dowel pin usually is placed in each prepared tooth and each adjacent tooth. When long sections of teeth are to be remov-able, the operator may wish to place more than one pin to increase stability and prevent rotation of the die. e cast is placed on the Pindex drilling machine, and one hole is drilled into the die base precisely in the middle of each tooth that is to be removable (see Fig. 18.46C and D). A small light beam helps position the cast correctly. When all the holes are drilled, a small drop of cyanoacrylate glue is placed in each hole, and a dowel pin is inserted (see Fig. 18.46E and F). e cast must be dry before cementing the pins, or the cement may not adhere. Any excess glue should be removed, and the operator should ensure that the dowel pins are parallel to one another (see Fig. 18.46G). To prevent rotation of the dies on the model base, small dimples may be placed just facial and lingual to each dowel pin with one third the diameter of a No. 6 round bur (see Fig. 18.46H). A bead of rope wax is placed around the die segment level with the base of the dies (see Fig. 18.46I). en boxing wax is added around this to form a container for the base pour (see Fig. 18.46J). A separating medium is applied on the die segment, and a mix of dental stone is vibrated into the boxing wax container (see Fig. 18.46K). At least 1 mm of the ends of the dowel pins should be allowed to protrude. To provide adequate strength, the base of the cast should not be less than 10 mm thick.After the stone has hardened, the boxing and rope wax are removed. en the cast is removed from the impression (see Fig. 18.46L). e operator taps the end of each dowel pin lightly with the end of an instrument handle until a dierent sound is heard; this indicates that the die segment has moved slightly from its seating (see Fig. 18.46M). Next the ends of the pins are carefully pushed conjointly, causing the die segment to move equally away from its seating (see Fig. 18.46N). After the die segment is removed in this manner, the teeth that are to be individually removable Working Casts and Diese working cast is an accurate replica of the prepared and adjacent unprepared teeth that allows the cast-metal restoration to be fabricated in the laboratory. During this fabrication procedure, it is most helpful if the replicas of the prepared teeth and of the adjacent unprepared teeth, called dies, are individually removable. e most used methods for creating a working cast with removable dies from an elastic impression require two pours. e rst pour is made to produce the removable dies and the second pour is made to establish intraarch relationships. Working casts made in this manner are called split casts. Several satisfactory methods are available for making a split cast with removable dies. e Pindex system (Coltene/Whaledent Inc., Cuyahoga Falls, OH) is illustrated because it oers many advantages, as follows:1. e rst pour becomes the die segment and can be made quickly and easily.2. Dowel pins can be positioned precisely, where needed.3. Dowel pins are automatically positioned parallel, which facilitates die removal.Pouring the Final ImpressionA mix of high-strength die stone is made using a vacuum mechanical mixer, and the dies are poured with the aid of a vibrator and a No. 7 spatula. e rst increments are applied in small amounts, allowing the material to ow into the remote corners and angles of the preparation without trapping air. Surface tension–reducing agents that allow the stone to ow more readily into the deep, internal corners of the impression are available. e impression should be suciently lled so that the dies are approximately 15 to 20 mm tall occlusogingivally after trimming. is may require surrounding the impression with boxing wax before pouring. After the die stone has set, the cast is removed from the impression and inspected for completeness (Fig. 18.45). is rst pour (die segment) becomes the removable dies.Completing the Working Caste base of the die segment is trimmed at on a model trimmer (Fig. 18.46A). is trimming is approximately parallel to the occlusal surfaces of teeth. e operator must take care while doing this so that no grinding slurry is allowed to splash onto the dies. e dies should be approximately 15 mm occlusogingivally. When the base gftsgbgm• Fig. 18.44 Close-up view of the impression shows sharp details of record of the gingival oor (gf), gingival bevel (gb), and margin (gm) and a small amount of unprepared tooth surface (ts) beyond the margin. • Fig. 18.45 Cast poured from the die stone is inspected for completeness. IJG HE FC DAB• Fig. 18.46 A, The base of the die segment is trimmed at and approximately parallel to the occlusal surfaces with a model trimmer. Dies should be approximately 15 mm high occlusogingivally. B, The die segment is trimmed on the facial and lingual surfaces to reduce the need for trimming in later steps. C, The die segment on the Pindex machine, ready to drill hole for rst molar die. A small red dot of light helps position the cast. D, Holes drilled for removable dies. E, A drop of cyanoacrylate glue is poured into each hole. The cast must be dry for the glue to adhere. F, Immediately insert a dowel pin into the hole, being sure it is fully seated. G, The dowel pins must be parallel to one another and fully seated, and no excess glue must be present. H, To aid in indexing, small dimples are cut in the base of the dies, using one third the diameter of a large (No. 6) round bur. Typically these are positioned facial and lingual to the dowel pin. I, Rope wax is placed around the cast, ush with the die bases. J, Boxing wax is placed around the rope wax to create a container for the base pour. A separating agent must be painted on the die bases to prevent adherence to the base pour. e138 CHAPTER 18 Class II Cast-Metal RestorationsSTRQPOMNK LK, Base pour is completed. At least 1 mm of the dowel pin should be left protrud-ing. L, Cast after removing boxing and rope wax. M, Tapping on the end of each dowel pin until the die segment moves. N, Removing the die segment from base. O, The dies are carefully cut apart by using a saw, bur, or thin diamond abrasive disk. Eye protection and dust collection are essential. P, Excess die stone around the gingival margins usually prevents good access for later steps in fabrication. Q, Removing the excess die stone with a large crosscut carbide bur in a slow-speed handpiece. Trimming across slightly gingival of the recorded gingival contour of the tooth weakens the excess, causing it to fall away. R, Final trimming is completed with a sharp scalpel. S, Cast completed, lingual view. Note how each prepared tooth and the adjacent unprepared teeth are removable now. T, Cast completed, facial view. Note the full seating of the dies. • Fig. 18.46, cont’d CHAPTER 18 Class II Cast-Metal Restorations e139 the risk of proximal drifting of teeth, shifting occlusion, food impaction, and damage to the supporting tissues. Total lack of a proximal contact is often referred to as an open contact and is to be avoided.Drawings of two maxillary premolars (see Fig. 18.50) are used to illustrate forms of contact and mesiodistal widths of interproximal spaces. Fig. 18.50A–C shows normal conditions. In Fig. 18.50A, the position of the contact is marked with an x, the area of near-approach of the two surfaces is indicated with a broken line, and the position of the crest of the gingiva is indicated with a continuous line. Fig. 18.50B is a mesiodistal section through teeth at the point of contact, and Fig. 18.50C is an occlusal view.A broad contact faciolingually is illustrated in Fig. 18.50D–F. In the proximal view (see Fig. 18.50D), the position of a normal contact is marked x, the contact of this tooth is the outlined oblong area, and the area of near approach is the broken line. e crest of the gingiva is less arched, being almost horizontal along the area of near-approach. Viewed from the facial in the mesiodistal section (see Fig. 18.50E), the contact appears to be the same as in Fig. 18.50B, but a comparison of the occlusal views (see Fig. 18.50F and C) shows the extra breadth of this contact at the expense of the lingual embrasure. Fig. 18.50H shows a contact that is too far to the gingival. Its position in comparison with normal is shown by the relation of the circle to the x in Fig. 18.50G. e problem with such a contact is in the inclinations of the proximal surfaces from the occlusal marginal ridges to the contact. Stringy food is likely to become packed into this space, and the contact may impinge on the interproximal tissue.See Fig. 18.50I and J for an illustration of a contact too close to the occlusal. is form is frequently observed in restorations (especially amalgams), seldom in virgin teeth. Such a contact allows food to ll the gingival embrasure and invites proximal caries.A contact that is too broad in the occlusogingival direction, but narrow faciolingually, is illustrated in Fig. 18.50K and L. e principal objections to this form of contact are that stringy foods are likely to be caught and held; also, if proximal recurrent caries occurs, it is farther to the gingival, requiring a tooth preparation close to the cementoenamel junction (CEJ). In cases of excessive proximal wear of teeth, the condition of the contact areas is similar to the combination of the areas illustrated in Fig. 18.50D and K, resulting in a facet of considerable dimensions.Forming the Occlusal SurfacePayne developed the fundamental principles in the following method of waxing.7 e technique is particularly applicable when capping cusps. With practice, it has proven to be faster than the old method of building up wax, cutting away, building up again, and so on. e amount of wax desired is added in steps until the occlusal surface of the pattern is completed (Fig. 18.51).To obtain the faciolingual position of the cusp tips, the facio-lingual width of the tooth is divided in quarters. Facial cusps are located on the rst facial quarter line. Lingual cusps fall on the rst lingual quarter line (see Fig. 18.51B). To obtain the mesiodistal position of the cusp tips, one notes the regions in the opposing tooth that should receive the cusp tips. e operator waxes small cones of inlay wax to the pattern to establish the cusp tips one at a time (see Fig. 18.51C and D). Next the operator waxes the inner and outer aspects of each cusp, being careful not to generate premature occlusal contacts (see Fig. 18.51D–F). It is suggested that only one aspect of each cusp be waxed into occlusion at a time. On the maxillary molar (illustrated in Fig. 18.51D), where all of the cusps are being restored, each of the nine aspects present must be cut apart from one another (see Fig. 18.46O). is requires the use of a saw, bur, or disk. To aid in carving the wax pattern and polishing the casting, the gingival aspect of the dies is carefully trimmed to expose the gingival margins properly (see Fig. 18.46P–R). e trimmed dies should have a positive and complete seating in the base portion of the cast (see Fig. 18.46S and T).Caution: Do not allow any debris between the die portion and the base, or the accuracy will be compromised. is is especially true for the walls of the dowel pin holes. A small bit of wax or gypsum can be carelessly pressed onto the wall and prevent complete seating of the pin. Such debris is dicult to detect and remove to regain accuracy.Use of Interocclusal RecordsA maximum intercuspation interocclusal record is made before making the nal impression. From this interocclusal record, a gypsum cast of the opposing teeth is made; this cast can be related accurately to the working cast, when forming the occlusal surface of the wax pattern. is step can be omitted if full-arch casts are to be used in waxing. See Chapter 1 for the principles of developing occlusion when using full-arch casts.When using this type of interocclusal record, the working cast is mounted on a simple hinge articulator. e working cast is attached to one member of the articulator with fast-setting plaster. e interocclusal record is carefully tted on the dies of the working cast (Fig. 18.47A and B). e interocclusal record should seat completely without rocking. Interocclusal bite records must never touch the registrations of soft tissue areas on the cast because these contacts usually interfere with complete seating. Such areas of contact on the interocclusal record can be trimmed away easily with a sharp knife. After ensuring that the interocclusal record is completely seated, lute the record adjacent to the unprepared teeth with sticky wax to prevent dislodgment when dental stone is poured into the record. Dental stone is then poured into the record (see Fig. 18.47C). is gypsum is attached to the opposite arm of the hinge articulator (see Fig. 18.47D), it is allowed to set, and then the interocclusal record is removed (see Fig. 18.47E–G).Wax PatternsForming the Pattern Basee operator lubricates the die and incrementally adds liquid wax from a No. 7 wax spatula by the “ow and press” method to form the proximal, facial, and lingual surface aspects of the pattern. A thin layer of wax should be added on the occlusal surface (Fig. 18.48A). Wax shrinks as it cools and hardens and tends to pull away from the die. is eect can be minimized and pattern adaptation improved by applying nger pressure for at least several seconds on each increment of wax soon after surface solidication and before any subsequent wax additions (see Fig. 18.48B). In this incremental technique, the wax that is owed on the previously applied wax must be hot enough, as otherwise voids are formed.Forming the Proximal Contour and Contacte proximal contour and contact of the pattern are now formed on the pattern base (Figs. 18.49 and 18.50). e normal proximal contact relationship between teeth is that of two curved surfaces touching one another. e contact on each curved proximal surface is a point inside a small area of near-approach. Soon after eruption and the establishment of proximal contact, wear of the contact point from physiologic movements of teeth creates a contact surface. Lack of a proximal contact is usually undesirable because it creates e140 CHAPTER 18 Class II Cast-Metal RestorationsEFGABCD• Fig. 18.47 Pouring the interocclusal record made with bite registration paste. A, Trimming away some of the interocclusal record (on the preparation side) with a sharp knife is often necessary to allow complete seating on the working cast. B, Fastening the seated interocclusal record to the working cast of prepara-tions rst shown in Fig. 18.33A with small amounts of sticky wax. C, Pouring stone into the interocclusal record. D, Attaching gypsum to the upper member of the hinge articulator. E–G, Three views of the completed mounting. CHAPTER 18 Class II Cast-Metal Restorations e141 proper occlusion before adding another, which simplies the procedure. Building the occlusal aspect by such small increments should help develop a pattern with minimal stress and distortion. Whenever a large portion of wax is added, it creates a potential for pattern distortion caused by the large shrinkage of such an addition.For establishing stable occlusal relationships, the operator should take care to place the cusp tips against at plateaus or into fossae on the stone cast of the opposing teeth. In other areas, the wax is shaped to simulate normal tooth contours, using adjacent teeth as references. Some relief between the opposing cusp inclines should be provided because these incline contacts often interfere during mandibular movements. e maximum intercuspation record provides only information regarding the position of the opposing teeth in maximum intercuspation. Some adjustment to the casting may be necessary in the mouth to eliminate interferences during mandibular movements. See Chapter 1 for the principles of cusp and fossa placement when using full-arch casts mounted on a semiadjustable articulator.Finishing the Wax PatternCareful attention to good technique is required for waxing the margins of the wax pattern. ere must be a continuous adaptation of wax to the margins, with no voids, folds, or faults. If adaptation is questionable, the marginal wax should be remelted to a distance into the pattern of approximately 2 mm. Finger pressure is applied immediately after surface solidication and before subsequent cooling of the wax, with pressure maintained for at least 4 seconds. is nger pressure helps develop close adaptation to the die by osetting the cooling shrinkage of the wax. Additional wax should be added during the remelting procedure to ensure a slight excess of contour and extension beyond the margin.Wax that is along the margins is now carved back to the cavosurface outline with a warmed No. 7 wax spatula (Fig. 18.52A–E). is warming of the spatula permits carving of the marginal wax with light pressure so that the stone margins are not damaged. A little practice helps the operator determine how much to heat the instrument for easy and eective carving. e No. 7 spatula should not have sharp edges; when it touches the die lightly, it should not abrade or injure the die surface. e operator uses the die surface just beyond the cavosurface margin to guide the position and direction of the carving instrument. e direction of the instrument movement is not dictated by the margin but by the contour of the unprepared tooth (die) surface just beyond the margin. e instrument blade is held parallel to this surface and used as a guide for the contour of the pattern near the margin; this should result in a continuity of contour across the margin. is principle of carving is too often neglected, resulting in the contour errors (see x in Fig. 18.52B–D); correct application of are waxed one at a time. e operator should follow the proper angle on the inner and outer aspects (see Fig. 18.51E).Next the distal slopes of the cusps are waxed (one at a time) into occlusal relation with the opposing teeth. e mesial slopes of the cusps are waxed next (one at a time) (see Fig. 18.51G). After the cusps are formed, the operator waxes in the proximal marginal ridge areas (see Fig. 18.51H). e same level to adjacent proximal marginal ridges should be developed, even though occasionally this may sacrice a contact on one of the two ridges. Restor-ing marginal ridges to the same level avoids a “food trap” that otherwise would be created. e mesial and distal pit regions also should be carved enough to have them deeper than the respective marginal ridges. is provides appropriate spillways for the removal of food from the occlusal table and helps prevent food impaction in the occlusal embrasure area of the proximal surface.To complete the occlusal wax-up, wax is added (where appropri-ate) to the fossae until they contact the opposing centric-holding cusps (see Fig. 18.51I). Spillways for the movement of food are established by carving appropriately placed grooves. Flat-plane occlusal relationships are not desired.is technique is a systematic and practical method of waxing the occlusal aspect of the pattern into proper occlusion. Forming one small portion at a time results in waxing each portion into AB• Fig. 18.48 To ensure optimal wax adaptation to the preparation walls, a thin layer of wax is rst poured (A), and then nger pressure is applied for several seconds while the wax cools (B). ogfi• Fig. 18.49 Measuring the diameters of the proximal contact faciolin-gually (l) and occlusogingivally (og) with dental oss. Two parallel strands should not be more than 1 to 2 mm apart. (Modied from Black GV: Operative dentistry, vol 2, ed 8, Woodstock, IL, 1947, Medico-Dental.) e142 CHAPTER 18 Class II Cast-Metal RestorationsSpruing, Investing, and CastingIf a delay of several hours or more occurs between the forming of the wax pattern and the investing procedure, the pattern should remain on the die and the margins should be inspected carefully again before spruing and investing. When such a delay is contem-plated, it is suggested that the sprue be added to the pattern before the delay period. If the addition of the sprue caused the induction of enough stress to produce pattern distortion, such a condition is more evident after the rest period, and corrective waxing can be instituted before investing. e reader is referred to textbooks on dental materials for the principles and techniques of spruing, investing, casting, and cleaning the casting.Seating, Adjusting, and Polishing the CastingIt is crucial to examine the casting closely, preferably under magnication, before testing the t on the die. e internal and external surfaces should be examined with good lighting to identify any traces of investment, positive defects (blebs), or negative defects (voids). Voids in critical areas indicate rejection of the casting, unless they can be corrected by soldering. Any small positive defects on the internal surface should be carefully removed with an appropriately sized round bur in the high-speed handpiece.e casting is then trial-tted on the die before removing the sprue and sprue button, which serve as a handle to remove the the carving instrument results in correct contours (exemplied by y). e completed patterns are shown in Fig. 18.52F–I.On accessible surfaces of the carved pattern, satisfactory smooth-ness can be imparted by a few strokes with the end of a nger if surfaces have been carefully carved with the No. 7 spatula. Rubbing with cotton that has been twisted onto a round toothpick may smooth less accessible surfaces such as grooves.Initial Withdrawal and Reseating of the Wax PatternCare must be exercised when initially withdrawing the wax pattern from the die. e wax can be dislodged by holding the die and pattern as shown in Fig. 18.53. When the pattern has been dis-lodged, it should be removed gently from the preparation. e operator should inspect the preparation side of the pattern to see if any wrinkles or holes are present. Such voids indicate poor wax adaptation and should be corrected if they are (1) in critical regions of the preparation designed to provide the retention form, (2) numerous, or (3) closer than 1 mm to the margin. To eliminate these voids, the operator rst relubricates the die and reseats the pattern on the die. en a hot instrument is passed through the wax to the unadapted area. is usually results in the air (void) rising through the liquid wax to the pattern’s surface as the wax takes the place of the air. A consequence of this correcting procedure on the occlusal surface is the obliteration of the occlusal carving in the aected region, requiring the addition of wax, recarving, and rechecking the occlusion.ABCDEFGHIJKLxxxx• Fig. 18.50 A–C, Correct contact. Note the position and form of the contact and the form of the embrasures around the contact. The mesial and distal pits are below (gingival of) the proximal marginal ridges. D–F, Contact too broad faciolingually. G and H, Contact positioned too far gingivally. I and J, Contact too close to the occlusal surface. K and L, Contact too broad occlusogingivally. (Modied from Black GV: Operative dentistry, vol 2, ed 8, Woodstock, IL, 1947, Medico-Dental.) CHAPTER 18 Class II Cast-Metal Restorations e143 should be left) (see Fig. 18.54B). If the cut is made completely through, control of the disk is sometimes lost, often resulting in damage to the casting or to the operator’s ngers. e uncut portion should be so small that bending with the ngers breaks it with very little eort (see Fig. 18.54C).Having seated the casting on the die, the technician hand burnishes the marginal metal using a ball or beaver-tail burnisher (see Fig. 18.54D). An area approximately 1 mm in width is burnished, using strokes that increasingly approach the marginal metal and are directed parallel to the margin. Burnishing improves marginal adaptation and begins the smoothing process, almost imparting a polish to this rubbed surface. While burnishing, the adaptation of the casting along the margin is continually assessed by using magnication, as needed, to see any marginal opening 0.05 mm in size. Moderate pressure during burnishing is indicated casting, if removal is necessary. e casting should seat with little or no pressure (Fig. 18.54A). Ideally when being placed on the die, it should have the same feel as that of the wax pattern when it was seated on the die. If the casting fails to seat completely, it should be removed and the die surface should be inspected for small scratches to see where it is binding. Usually failure to seat is caused by small positive defects not seen on the rst inspection. Attempts at forcing the casting into place cause irreparable damage to the die and diculties when trial-seating the casting in the mouth.After the accuracy of the casting is found to be satisfactory, the casting is separated from the sprue as close to the inlay as possible using a carborundum separating disk. e cut should be made twice as wide as the thickness of the disk to prevent binding and should not cut completely through the sprue (a small uncut portion BACDEFGHICone tipOuteraspectOuteraspectCone tipInneraspectDistal viewOcclusal viewInner aspectOuter aspectDistal slopeMesial slope• Fig. 18.51 A, The pattern base is completed and ready for waxing two reduced cusps (distolingual and distal) into occlusion by using Payne’s waxing technique. B, The facial cusps are located on the rst facial quarter line, and the lingual cusps fall on the rst lingual quarter line. C, The distolingual and distal cusp tips are waxed into occlusion in the form of small cones. D, Cone tips and inner and outer aspects. E, Cone tips and inner and outer aspects of the cusps of teeth. F, The inner and outer aspects of the distolingual and distal cusps have been added to the pattern base. G, The mesial and distal slopes of the cusps of teeth. H, Marginal ridges of teeth. I, After the marginal ridge is added to the pattern base, fossae are waxed in and grooves are carved to complete the wax pattern. (Modied from Payne E: Reproduction of tooth form, Ney Tech Bull 1, 1961.) e144 CHAPTER 18 Class II Cast-Metal RestorationsBCDxNo. 7yyxNo. 7No. 7xyAEFHIG• Fig. 18.52 A, Wax is carved to margins with a warm No. 7 spatula. B–D, Incorrect application of No. 7 spatula to carve the contour of the marginal wax is shown by x; the correct manner is labeled y. E, Carving the occlusal groove and pit anatomy. F, The adjacent marginal ridges should be on the same level as much as possible. G, Occlusal view of completed patterns. Note the shape of the facial and lingual embrasures and the position of the contact. H and I, Facial view of the completed patterns. Note the gingival and occlusal embrasures and the position of the contact. CHAPTER 18 Class II Cast-Metal Restorations e145 e technician brushes the occlusal surface of the casting with a soft bristle disk and tripoli (or bung bar compound [BBC]) (Bung Bar Compound; Heraeus Kulzer Inc., Armonk, NY) polishing compound, running the disk parallel with the grooves (see Fig. 18.55D). A small felt wheel with polishing compound should be used on the proximal and other accessible surfaces (see Fig. 18.55E). e metal should be so smooth before this application of polishing compound that a beautiful luster should develop in a few seconds. A high sheen may be imparted, if desired, with a felt or chamois wheel and rouge (see Fig. 18.55F and G). As in the application of tripoli/BBC, only a few seconds of rouge applica-tion should be required. If more time were expended in the application of these polishing compounds, overpolishing (polishing away) of the margins and die would result. Also such overuse of polishing compounds is often an unsuccessful attempt to mask the fact that the preliminary stages of polishing were not thoroughly completed.e technician cleans the polished casting of polishing com-pounds by immersing the die with its inlay in a suitable solvent for 1 or 2 minutes or by scrubbing with a soft brush and soap and water. e technician rinses and removes the casting from the die. No polishing compounds should be found on the preparation side of the casting or on the preparation walls of the die. e presence of such materials on these surfaces indicates that marginal adaptation on the die is not as good as it should be.Trying-in the CastingPreparing the MouthLocal anesthesia of the tooth may be necessary before removal of the temporary restoration and the try-in of the casting on the tooth. Anesthesia blocks stimuli from inducing pain and salivation, neither of which is conducive to the best results, particularly in cementation. When teeth are not particularly sensitive, however, an option is to delay or eliminate administering the anesthetic because the patient can tell better if the proximal contacts are tight or if the occlusion is high. e temporary restoration is removed, ensuring that all the temporary cement has been dislodged from the preparation walls and cleared away. To improve visualization, the region is isolated with cotton rolls. Saliva is removed from the tooth operated on and from the adjacent teeth with the air syringe.Seating the Casting and Adjusting the Proximal Contactse operator conrms the t of the casting on the tooth. A 7.5 × 7.5 cm gauge sponge should be placed as a “throat screen” to catch the casting if it is accidentally dropped (see Fig. 18.60A later in the chapter). e dentist tries the casting on the tooth, using light pressure. Do not force the casting on the tooth. If the casting does not seat completely, the most likely cause is an overcontoured proximal surface. Using the mouth mirror, where needed, one views into the embrasures from the facial, lingual, and occlusal aspects. e dentist judges where the proximal contour needs adjustment to allow nal seating of the casting, producing at the same time the correct position and form to the contact. Passing dental oss through the contact indicates tightness and position, helping the trained operator identify the degree of excess contact and its location. e dentist applies the oss at an angle and with secure nger-bracing to pass it gently through the contact and not with a snap that is likely to injure interproximal soft tissue. If the oss cannot enter or if it tears on entering, the contact is excessive. during closure of small marginal gaps. When the casting is well adapted, pressure is reduced to a gentle rubbing for continued smoothing of the metal surface. At this stage, marginal openings and irregularities should not be detectable even under (1.5× or 2×) magnication (see Fig. 18.54E and F). Care must be taken not to overburnish the metal because this can crush and destroy the underlying die surface. Overburnished metal prevents complete seating of the casting on the prepared tooth. Proper burnishing usually improves the retention of the casting on the die so that the casting does not come loose during subsequent polishing steps. A casting must not be loose on the die if the inlay is to be polished properly.e remaining sprue metal is carefully removed with a heat-less stone or a carborundum disk (see Fig. 18.54G and H). e grooves are accentuated by lightly applying a dull No. 1 round bur (see Fig. 18.54I) or other appropriate rotary instrument. Next a knife-edge rubber polishing wheel is used on accessible surfaces (see Fig. 18.54J) (Flexie rubber disk, Dedico International Inc., Long Eddy, NY). e operator should guard against the polish-ing wheel touching the margins and the die because both can be unknowingly and quickly polished away, resulting in “short” margins on the tooth. Also at this time, the proximal contacts are adjusted one at a time. If the distal surface of a mesioocclusodistal casting on the rst molar is being adjusted, only the rst and second molar dies are on the cast. Proximal contacts are deemed correct when they are the correct size, correctly positioned, and passive. If a temporary restoration was made properly, these contact relationships would be the same in the mouth as on the cast. Chair time can be reduced by carefully nishing the contacts on the cast.e occlusion of the castings is checked by marking the occlusal contacts with articulating paper. Any premature contacts are cor-rected, and their locations are rened by selective grinding. Often prematurities occur where the sprue was attached and insucient sprue metal was removed. e operator applies a smaller rubber, knife-edge wheel, which should reach some of the remaining areas not accessible to the larger disk (Fig. 18.55A and B). e grooves, fossae, and other most inaccessible regions are smoothed by rubber, abrasive points (Browne and Greenie rubber points; Shofu Dental Corp., San Marcos, CA) (see Fig. 18.55C). Care should be exercised when using the rubber disks and points so that the die surface is not touched and anatomic contours are not destroyed by overpolish-ing. When nished with the rubber abrasives, the surface of the casting should have a smooth, satin nish. It should be ensured that the contact relationships with the adjacent and opposing teeth have the correct size, position, and intensity.• Fig. 18.53 Removing the wax pattern by using indirect nger pressure. Arrows indicate the direction of the pressure. Care must be exercised not to squeeze and distort the wax pattern as it is initially withdrawn. e146 CHAPTER 18 Class II Cast-Metal RestorationsABCDEFGHIJ• Fig. 18.54 A, Cleaned casting should be tried on the die to determine if it has a satisfactory t. B and C, To remove sprue, a cut that is not quite complete and twice the width of the disk is rst made (B), and then the slim, uncut portion is bent and broken (C). D, The inlay is burnished with a No. 2 bur-nisher along a 1-mm path that is parallel with and adjacent to the margin. E, Magnied view of the casting before burnishing. F, Magnied view of the same marginal region shown in E after burnishing. G and H, Removing the remaining sprue metal with heatless stone (G) or with a carborundum disk (H). I, Accentuat-ing the grooves with a dull No. 1 round bur. J, Smoothing the surfaces accessible to the rubber polishing wheel. CHAPTER 18 Class II Cast-Metal Restorations e147 patient should not be aware of any pressure between teeth after the nal adjustment of contacts.Proper proximal contact occurs when a visual inspection conrms that the adjacent proximal surfaces are touching and that the position and form of the contact relationship are correct. e correct “tightness” of the contacts is best judged with dental oss. is contact should be passive because any pressure between teeth would resolve soon and disappear in unwanted tooth movement.If the contact is open (short of touching the adjacent tooth), a new contact area must be soldered to the casting. An open contact is best detected by visual inspection with the aid of the mouth mirror. e region must be isolated with cotton rolls and dried with the air syringe. Selection of the proper horizontal viewing angle usually discloses the spaces between teeth. Such an open contact permits the passage of food, which aects and irritates the interproximal gingiva.When satised that the proximal contacts are correct when hand pressure rst positions the casting to within 0.2 mm of seating (Fig. 18.56A), the dentist removes the 7.5 × 7.5 cm gauze sponge and ensures that the casting completely seats on the tooth by the Caution: When adjusting a mesioocclusodistal restoration, only one excess contact should be adjusted at a time (the stronger one) before trying again on the tooth and evaluating, unless both contacts feel equally strong. is is done because one excessively strong contact can cause the other to feel strong, when in actuality the latter contact may be correct or even found to be weak (short of contact) after the excessively strong contact is adjusted properly.A rubber wheel abrasive is used to adjust the proximal contour and to correct the contact relationship; this often requires several trials on the tooth, but it is best not to remove too much at a time. After each trial and removal, the position of contact is visible in the form of a bright spot on the satiny surface left on the casting from previous surfacing by the rubber wheel. By noting the position of this bright spot in conjunction with observation in the mouth of the contact relationship, the contact position and form can be judged, and the operator can determine whether additional adjust-ment should be made to alter this position and form. (For retrieval of the casting after each trial on the tooth, see the section on Removing the Casting.)Often the patient is able to indicate whether the contact is strong, particularly when an anesthetic has not been given. e ABCDEFG• Fig. 18.55 A and B, Using a small knife-edge rubber disk on the areas of the occlusal surface that are accessible to this wheel (A) and on proximal surfaces (B). C, Polishing the grooves and other relatively inaccessible areas with a rubber point. D, Applying tripoli/BBC to the occlusal surface using a bristle disk. E, Applying tripoli/BBC to the proximal surfaces using a felt wheel. F, Imparting luster by using a chamois wheel and rouge. G, Polished castings. e148 CHAPTER 18 Class II Cast-Metal Restorationsthe metal, and vice versa, with barely a catch or a bump (Fig. 18.57; see also Fig. 18.56C). Some operators recommend the use of a cotton roll or a piece of wood for the patient to bite on for seating pressure (see Fig. 18.56D and E). e cotton roll may be too large and too soft to be eective for seating inlays, however, and the piece of wood may not distribute the pressure properly, resulting in less eective seating or tooth fracture. Fig. 18.57 shows the castings tried on the teeth that were rst shown in Fig. 18.41H.Occluding the CastingWhen the proximal contacts have been adjusted and the casting is satisfactorily seated on the tooth, the patient is asked to close application of masticatory pressure. is use of masticatory pressure should be a routine procedure. It is accomplished by positioning a small rubber polishing disk (unmounted) on the occlusal of the restoration and requesting the patient to bite rmly; the patient also is asked to move the jaw slightly from side to side while maintaining this rm pressure (see Fig. 18.56B). At this time, the operator must judge whether the restoration is satisfactory or should be rejected and another casting made. When evaluating the t (seating) of the casting, the operator should view particularly the margins that are horizontally directed (i.e., margins that are per-pendicular to the line of draw). Along at least half the marginal outline, the tip of the explorer tine should move from tooth onto CABIncorrectDIncorrectE• Fig. 18.56 A, Hand pressure is used initially to seat the casting on the tooth by applying a ball bur-nisher in the pit anatomy. B, If the casting ts to within 0.2 mm of the seating, complete seating is ensured by using masticatory pressure when the patient closes on the rubber polishing wheel interposed between the casting and the opposing tooth. C, The marginal t of the tried-in inlay is inspected. D and E, A cotton roll (D) or piece of wood (E) should not be used in lieu of the rubber polishing wheel method (B). ABC• Fig. 18.57 A–C, Castings tried on teeth. These photographs were taken immediately after the restora-tions were rst seated on teeth before any dressing down or burnishing of margins. Neither occlusal adjustment nor contact adjustment was required. Extension of the mesiofacial margin of the second premolar was necessary because of extension of a previous amalgam restoration; extension of the disto-facial margins of premolars is caused by skirting (or bracing), which provides maximal resistance form to these weak teeth. Note the area on the mesiofacial margin of the rst molar that is to have a composite insert placed after cementation. CHAPTER 18 Class II Cast-Metal Restorations e149 intercuspation should be composed of supporting cusp tips placed against at or smoothly concave surfaces (or into fossae) for stability. e force vector of occlusal contacts should be one that parallels the long axis of the tooth (see Fig. 18.58C). Contacts on inclines tend to deect the tooth and are less stable (see Fig. 18.58D). e use of articulating paper and the stone is continued until (1) the heavy markings are no longer produced, (2) the contacts on the restoration have optimal position and form, and (3) an even distribu-tion of contacts exists on the casting and the adjacent teeth. Visual inspection should verify that the adjacent unprepared teeth are absolutely touching.Care must be exercised not to overreduce the occlusal contacts. In the nal phase of equilibration, the strength of the occlusal contacts can be tested by using thin plastic shim stock (0.013 mm thick) (Artus Corp., Englewood, NJ) as a “feeler gauge.” e dentist tests the intensity of the occlusal contacts of the casting and the adjacent unprepared teeth to see if they hold the shim stock equally (see Fig. 18.58E). It may be helpful to test the occlusal contacts of the adjacent unprepared teeth with the casting out of the mouth for comparison.When the occlusal contacts have been adjusted in maximum intercuspation, the casting is checked for contacts that occur during into maximum intercuspation, and the dentist inspects the unpre-pared adjacent teeth to see if any space exists between the opposing wear facets. Usually the patient can indicate correctly if the casting needs occlusal adjustment; however, the dentist should verify the occlusal relationship objectively. After drying the teeth of saliva, the dentist inserts a strip of articulating paper and requests the patient to close and tap the teeth together (in maximum intercuspa-tion) several times. e dentist removes the paper and examines it by holding it up toward the light for evidence of any areas of penetration caused by the restoration. Any holes can be matched with heavy markings on the casting, and shiny, metal-colored spots may be present in the center of the marks (Fig. 18.58A). Such heavy contacts should be reduced with suitable abrasive stones, while carefully observing the following fundamental concepts for equilibration of occlusion. e space observed between the opposing wear facets of the adjacent unprepared teeth (when the teeth are “closed”) is an indication of the maximal amount of vertical reduc-tion of the casting required. Often the “high” occlusal contacts are very broad and extend onto the cusp or ridge slopes. When this occurs, the dentist should grind away the most incorrect portion of the incline contact (a deective contact), leaving the most correct portion intact (see Fig. 18.58B). Occlusal contacts in maximum CDAB• Fig. 18.58 Occluding the casting. A, The initial occlusal contact is high and produces a heavy mark with a metal-colored center. Note the corresponding perforation in the articulating paper. B, When adjust-ing occlusal contacts, the most incorrect portion of the contact is removed, leaving the most correct portion intact. C, The proper occlusal contacts in maximum intercuspation are composed of cusp tips placed against at or smoothly concave surfaces (or fossae) for stability. D, Incline contacts are less stable and tend to deect the tooth. e150 CHAPTER 18 Class II Cast-Metal RestorationsFGEE, Testing the intensity of the occlusal contacts with a thin (0.013-mm thick) shim stock used as a feeler gauge. F, Removing the undesirable contact (Zone 1, see Chapter 1) that may occur on the working side during lateral mandibular movement. G, Removing the undesirable contact (Zone 3) that may occur on the nonworking side during lateral mandibular movement. • Fig. 18.58, cont’d lateral mandibular movements. Lateral working (functional) contacts on the casting are marked by (1) inserting a strip of articulator paper over the quadrant with the casting, (2) having the patient close into maximum intercuspation, and (3) “sliding” the teeth toward the side of the mouth where the casting is located. Contacts between the lingual inclines of the maxillary lingual cusps and facial inclines of the mandibular lingual cusps are considered unusually stressful and should be eliminated (see Fig. 18.58F). Contacts between the lingual inclines of the maxillary facial cusps and the facial inclines of the mandibular facial cusps should remain only if they are passive and a group function pattern of occlusion is desired (see Chapter 1 for further discussion on the implications of various occlusal relationships).e dentist inserts a strip of articulating paper over the teeth with the castings and has the patient close into maximum intercuspa-tion and slide the teeth laterally toward the opposite side. is action marks any lateral nonworking (nonfunctional) contacts on the restoration. In a normal arrangement of teeth, contacts that might occur during the nonworking pathway are positioned on the facial inclines of the maxillary lingual cusps and the lingual inclines of the mandibular facial cusps. ese nonworking contacts must be removed with a suitable stone (see Fig. 18.58G). Complete elimination of nonworking contacts can be veried by using the plastic shim stock. A strip of shim stock is inserted over the casting, and the patient bites together rmly. As soon as the patient begins sliding the mandible toward the opposite side, the shim stock should slip out from between teeth. e dentist examines the casting for interferences in protrusive mandibular movements using the shim stock and articulating paper. e areas that may have to be adjusted to prevent contact are the distal inclines of maxillary teeth and the mesial inclines of mandibular teeth.Finally, interferences that occur on the casting between centric occlusion and maximum intercuspation are identied and removed. Most patients have a small discrepancy between centric occlusion and maximum intercuspation. Such a “skid” is considered normal for most patients, but the operator should ensure that the casting does not have premature contact at any point between centric occlusion and maximum intercuspation. e preferred technique for manipulating the mandible into centric relation and making teeth touch in centric occlusion is credited to Dawson.13 When teeth have been marked in centric occlusion, the dentist observes them to ensure that the casting does not have premature contacts in centric occlusion and that it does not exacerbate any centric occlusion–maximum intercuspation skid. If it does, the mesial inclines of maxillary restorations and the distal inclines of mandibular restorations are the areas that may need adjustment.Improving Marginal Adaptatione next step is to “dress down” the margins, that is, to adapt the metal as closely as possible to the margins of the tooth. Regardless of how accurately a casting may seat in the preparation, the t usually can be improved by using the following procedures. With a ball or beaver-tail burnisher, the operator improves marginal adaptation by burnishing the marginal metal with strokes that parallel the margin except for the gingival margin (Fig. 18.59A). CHAPTER 18 Class II Cast-Metal Restorations e151 other portions of accessible margins where a slight excess of metal is present. When burnishing the casting on the tooth, the dentist should ensure that the casting is fully seated. Otherwise burnishing may bend the marginal metal, keep the casting from seating, and result in the rejection of the casting.If necessary, the marginal adaptation and continuity can be improved further by the application of a pointed, ne-grit carbo-rundum stone, especially where the marginal enamel is slightly If the margin is inaccessible to the ball or beaver-tail burnisher (as sometimes occurs at the termination of the casting in groove regions where possibly more enameloplasty or extension could have been employed), the edge of the discoid-type hand instrument serves well as a burnisher. e discoid instrument is held perpendicular to the margin and is moved parallel with the margin (see Fig. 18.59B). e sharp edges of the instrument also trim away any slight excess of metal at the margin. e operator continues on ABCDEFG• Fig. 18.59 A, Burnishing the margins with a No. 27 ball burnisher. The burnisher is moved parallel with the margin. B, Using a discoid instrument on the margins that are inaccessible to the ball burnisher. It is moved parallel with the margins. (Note the small metal scrapings made by this instrument.) C, Dressing down the margins with a small carborundum stone, which is rotating from the metal to the tooth. D, Applying a ne-grit sandpaper disk to the accessible supragingival proximal margins. The disk rotates, wher-ever possible, from the metal to the tooth. E, On the facial or lingual margins on the proximal surface that are inaccessible to the paper disk, a gingival margin trimmer is used to remove any slight excess of metal. F, Using a rubber point to smooth the metal and the tooth of any scratches left by the carborundum stone. G, Completed inlays ready for cementation. e152 CHAPTER 18 Class II Cast-Metal Restorationsocclusal embrasure if the casting is a mesioocclusodistal restoration. is should initiate the displacement of the casting, making complete removal thereafter easy.CementationCement Selectione selection of cement for permanent cementation is crucial to the success of the nal restoration. A discussion of the advantages and disadvantages of each cement can be found in Chapter 13. No cement is without shortcomings. Each product has specic requirements with regard to tooth surface conditioning, casting surface conditioning, and manipulation techniques. To obtain optimal performance from the cement, the dentist should carefully follow the manufacturer’s instructions for dispensing, mixing, and application.Cementation TechniqueBefore cementing the casting, the tooth is isolated from saliva with the aid of cotton rolls (and saliva ejector, if necessary) (Fig. 18.61A). With the air syringe, the dentist dries the preparation but does not desiccate it. e cement is mixed according to the manufacturer’s instructions. With the cement mix applied generously to the preparation side of the casting (see Fig. 18.61B), the dentist starts to place the casting with the ngers or with operative pliers. Next the dentist places the ball burnisher in the pit areas (rst one and then another), exerting rm pressure to seat the casting (see Fig. 18.61C). e dentist places a small exible rubber polishing disk over the casting, removes the saliva ejector, and requests the patient to close and exert biting force (see Fig. 18.61D and E). e patient also is asked to move the mandible slightly from side to side, while continuing to exert pressure. A few seconds of this pressure is sucient. When the disk is removed, much of the occlusal area should be clean of the cement mix and easier to inspect and to verify complete seating of the casting. When the cusps are capped, complete seating of the casting is veried by inspection of the facial and lingual margins after wiping the excess cement away (see Fig. 18.61F). While the cement is still soft, all accessible margins are burnished. e saliva ejector is replaced in the mouth and the region kept dry during the setting of the cement. Excess moisture during this setting reaction can weaken many types of cement.After the cement has hardened, any excess is cleaned o with an explorer and air-water spray. Dental oss should be passed “high” and should be reduced or where more than just a slight amount of excess metal should be removed (see Fig. 18.59C). is stone should be used at low speed with light pressure and should rotate either parallel with the margin or from metal to tooth across the margin (never from tooth to metal). After this procedure, the margins are burnished again to enhance marginal adaptation and to smooth the marginal metal.Another instrument that can be used to improve marginal t in accessible areas (e.g., the occlusal two thirds of the proximal margins) is a ne-grit paper disk. Wherever possible, the disk should be revolved in a direction from the metal toward the tooth (see Fig. 18.59D). Sometimes these margins are inaccessible to the disk, and a gingival margin trimmer, a gold le, or a cleoid instrument may be helpful to remove a slight excess of metal (see Fig. 18.59E). It is moved in a scraping motion parallel to the margin and burnishes and trims the metal.e experienced operator, with proper use of the elastic impres-sion material, can produce restoration margins that require little or no burnishing or dressing down. One of the signicant advantages of the indirect procedure, when correctly applied, is the high degree of accuracy of the gingival margin adaptation.e margins should now be such that the explorer tip can pass across the margins smoothly without jumping or catching. e operator should use rubber polishing points of increasing neness at low speed to smooth and polish the accessible areas of roughness left from adjusting procedures (see Fig. 18.59F and G). An attempt should be made to preserve the anatomic contour and detail. e operator should take care to use light, intermittent pressure when using rubber points to avoid overheating the tooth. e casting surface should be cleaned and dried to verify that it is smooth and free of scratches.Removing the CastingWhen preparing to remove a casting from a tooth, the dentist rst places a 7.5 cm × 7.5 cm gauze sponge throat screen to prevent the patient from swallowing or aspirating the casting in the event that it is accidentally mishandled (Fig. 18.60A). If the casting is highly retentive, the dentist rst initiates removal with the aid of a sharp Black spoon (15-8-14). e tip of the spoon is inserted as deep as possible in the occlusal embrasure with the back of the spoon resting against the marginal ridge of the adjacent tooth (see Fig. 18.60B). With the tip of the spoon rmly seated against the metal casting, the spoon is pivoted using the adjacent tooth as a fulcrum (see Fig. 18.60C). is procedure is repeated on the other ABC• Fig. 18.60 Initiating the removal of the inlay before cementation. A, Place 7.5 × 7.5 cm gauze throat screen to prevent swallowing or aspiration of casting should it be accidentally mishandled. B, The tip of a sharp Black spoon (15-8-14) is inserted rst as deep as possible in the occlusal embrasure with the back of the spoon against the adjacent marginal ridge. C, The spoon is pivoted in the direction of the curved arrow by using the adjacent tooth as a fulcrum. The casting has lifted from its seating. After only slight unseating, a similar procedure is applied to the distal aspect. EFGHABCD• Fig. 18.61 Cementing the cast-metal onlay on the preparation initially shown in Fig. 18.39B. A, Isolating the tooth from saliva with cotton rolls. B, Applying cement with No. 2 beaver-tail burnisher to preparation side of onlay. C, Seating the onlay by using a ball burnisher and hand pressure. D, Placing a rubber polishing disk over the onlay and cementing the cast-metal onlay on the preparation initially shown in Fig. 18.39B. E, The patient is instructed to apply masticatory pressure while slightly moving the jaw from side to side. F, When the disk is lifted from the casting, much of the occlusal aspect is free of cement. With a sweeping, rolling motion of the forenger, any accessible facial surface margin is cleaned of excess cement to permit visual inspection for verication of proper seating of the onlay. Similarly, any accessible lingual margin is cleaned of excess cement. Full seating also should be veried tactilely with the explorer tine. G, Excess set cement is removed by using the explorer and air-water spray. Dental tape with a small knot is used to dislodge small pieces of interproximal cement. H, Onlay after cementation. e154 CHAPTER 18 Class II Cast-Metal Restorationsthrough the contact, carried into the interproximal gingival embrasures and sulci, and pulled facially and lingually to help in the removal of cement in this region (see Fig. 18.61G). Tying a small knot in the oss helps dislodge small bits of interproximal cement. Finally, directing a stream of air into the gingival sulcus opens it and reveals any remaining small pieces of cement, which should be removed. When cementing has been properly accom-plished, a cement line should not be visible at the margins (see Fig. 18.61H). A quadrant of inlays after cementation is illustrated in Fig. 18.62.BA• Fig. 18.62 A, Cemented castings on teeth rst shown in Fig. 18.41E. This photo was taken imme-diately after cementation and insertion of the composite insert on the molar. B, Bitewing radiograph of the restored quadrant shown in A. Note the t of inlays at the gingival margins and the contour of the proximal surfaces. Repaire weak link of most cast-metal inlays and onlays is the cement seal. At times, the operator may nd discrepancies at margins that require replacement or repair. If the restoration is intact and retentive and if the defective margin area is small and accessible, small repairs can be attempted with amalgam or composite. If cement loss is found in one area of the restoration, however, other areas are usually suspect. When defects are found, the most common procedure is to remove the defective restoration and replace it.SummaryCast-metal inlays and onlays oer excellent restorations that may be underused in dentistry. e technique requires multiple patient visits and excellent laboratory support, but the resulting restorations have the potential to last for decades. High noble alloys are desirable for patients concerned with allergy or sensitivity to other restorative materials. Cast-metal onlays, in particular, can be designed to strengthen the restored tooth while conserving more tooth structure than does a full crown. Disadvantages such as high cost and esthetics limit their use, but when indicated, cast-metal inlays and onlays provide a restorative option that is less damaging to pulpal and periodontal tissues compared with a full crown.References1. Donovan T, Simonsen RJ, Guertin G, et al: Retrospective clinical evaluation of 1,314 cast gold restorations in service from 1 to 52 years. J Esthet Restor Dent 16(3):194–204, 2004.2. Wataha JC: Biocompatibility of dental casting alloys: a review. J Prosthet Dent 83:223–234, 2000.3. Stanley HR: Eects of dental restorative materials: local and systemic responses reviewed. J Am Dent Assoc 124:76–80, 1993.4. Hood JA: Biomechanics of the intact, prepared and restored tooth: some clinical implications. Int Dent J 41:25–32, 1991.5. Carson J, Rider T, Nash D: A thermographic study of heat distribution during ultra-speed cavity preparation. J Dent Res 58(7):1681–1684, 1979.6. Fisher DW, Caputo AA, Shillingburg H, et al: Photoelastic analysis of inlay and onlay preparations. J Prosthet Dent 33:47–53, 1975.7. Payne E: Reproduction of tooth form. Ney Tech Bull 1:1961.8. Grajower R, Shaharbani S, Kaufman E: Temperature rise in pulp chamber during fabrication of temporary self-curing resin crowns. J Prosthet Dent 41:535–540, 1979.9. Hume WR: A new technique for screening chemical toxicity to the pulp from dental restorative materials and procedures. J Dent Res 64:1322–1325, 1985.10. Moulding MB, Loney RW: e eect of cooling techniques on intrapulpal temperature during direct fabrication of provisional restora-tions. Int J Prosthodont 4:332–336, 1991.11. Crispin BL, Watson JF, Caputo AA: e marginal accuracy of treatment restorations: a comparative analysis. J Prosthet Dent 44:283–290, 1980.12. Malamed SF: Handbook of local anesthesia, ed 5, St. Louis, 2005, Mosby.13. Dawson PE: A classication system for occlusions that relates maximal intercuspation to the position and condition of the temporomandibular joints. J Prosthet Dent 75:60–66, 1996. 511IndexAAbfraction, 105f, 106treatment of, 115Abrasion, 105f, 106treatment of, 115Abutment, removable, cast metal restoration and, e95Access, operative dentistry and, e26Acellular cementum, 10–11Achromatopsia, 200Acid-etchingdentin, 140f, 143–144enamel, 137, 138f–139fresin-bonded splint and, e52Acidic agents, erosion due to, 105–106, 105fACP. see Amorphous calcium-phosphateActinobolin, for dental caries, 84tADA. see American Dental AssociationAdheSE One F, 149Adhesion, 136–169adsorption, 136basic concepts of, 136biocompatibility and, 153–154clinical performance and, 154–155combination, 136dened, 136dentin, 138–159development of, 142–143diusion, 136electrostatic, 136enamel, 137mechanical, 136of resin to dentin, 140tto root canal dentin, 156–157in vitro studies in, relevance of, 154Adhesion bridges, e60Adhesive amalgam restorations, for tooth preparation, 133Adhesive bonding, 443–444Adhesive ceramics, 443Adhesive dentistrybases and cavity liners in, 482–484clinical recommendations for, 483dentin, bonding to, 479–482, 480f, 480tnew developments in, 482enamel, bonding to, 477–479, 477f–478fAdhesivesacetone-based, 150–151categorized, by adhesion strategy, 145tdentin, indications for, 156–159etch-and-rinse, 150–151ethanol-based, 150–151indirect, restorations with, 157–159light-cured, 155amalgam restoration and, 308, 308fmoist versus dry, 150–151placement ofin Class I composite restoration, 226in Class II composite restoration, 235in Class III composite restoration, 245in Class IV composite restoration, 251in Class V composite restoration, 256self-etchone-step, 145t, 149role of water in, 151two-step, 145t, 146–149three-step etch-and-rinse, 143–145, 145tfor tooth preparation, 131two-step etch-and-rinse, 145–146, 145tuniversal, 149–151, 155–156Admixed alloys, 463Adolescents, all-porcelain pontics for, e66Adper Single Bond, 139fAdper Single Bond Plus, 146fAdsorption adhesion, 136Aerosols, cutting as cause of, e21Agglutinin, in saliva, 58Agingcaries risk and, 77ttooth color aected by, 269Alcohol, consumption of, caries risk and, 71, 77tAlexidine, for dental caries, 84tAlginateimpression material, e128, e128fimpression with, 485All-Bond 2, 144–145All-Bond 3, 144–145All-Bond SE, 148–149All-ceramic crowns, evolution of, 501–504, 502fAlloys, dental casting, strength of, e95Alpha-receptor antagonists, xerostomia from, 59tAltered passive eruption, gingivectomy for, 425, 425fAluminum chloride, to widen gingival sulcus, e132Aluminum oxide, hardness value of, e17–e18Alveolar bone, 415Alveolar bone proper, 15Alveolar mucosa, 15Page numbers followed by b indicate boxes; f, gures; t, tables; and e, online only materials.Alveolar process, 15Alveolus, tooth attachment to, 15Amalgam, 306admixed, 307advantages of, 309alloys for, 307bases and cavity liners in, 483bonded, 307–308, 308f, 464burnishing of, 357–359postcarve, 319precarve, 317butt-joint form for, 307carving of, 317in Class I amalgam restoration, 330in Class II amalgam restoration, 365–366in Class V amalgam restoration, 383–384condensation of, 464in Class II amalgam restoration, 365–366in Class III amalgam restoration, 375considerations for, 307–310contouring of, 307, 338, 407–409contraindications to, 309conventional, 316, 316f, 462, 463fdental, hardness value of, e17–e18disadvantages of, 310enamel butt-joint relationship to, 348nishing of, 319–322in Class I amalgam restoration, 330–332, 338in Class II amalgam restoration, 367in Class V amalgam restoration, 384–385in complex amalgam restoration, 407–409foundation, 310f, 404–405fracture, 307general concepts guiding restoration with, 316–322high-copper, 306–307, 462for complex amalgam restoration, 407creep and ow of, 307insertion of, 316–317in Class I amalgam restoration, 330in Class V amalgam restoration, 383–384low-copper, 306mercury-free, 307mercury in, 306mixed, class I amalgam restoration and, 333fmixing of, 316Adhesives (Continued) 512 Indexovercarved, 319pin-retained, 392–404polishing of, 319–322, 321fin Class I amalgam restoration, 330–332in Class II amalgam restoration, 367in Class V amalgam restoration, 384–385precarve burnishing of, 317properties of, 307removal of excess, 318f–319frepair of, 322restoration with. see Amalgam restorationssilver, 461–464advantages of, 461–462composition of, 462–463, 462t–463t, 463fevaluation of, 463–464manipulation of, 464mercury and, 464–469removal of, unwarranted, impact of, 468–469spherical, 307in complex amalgam restoration, 407success rate of, 309triturating of, 316tunnel tooth preparations for, 133types of, 306–307undercarved, 330–332, 334fuses of, 308–309Amalgam blues, 102Amalgam pins, for tooth preparation, 131Amalgam restorations, 306–414, 453, 454fadjoining, 354–355, 356fadvantages of, 309cavosurface margin in, 314, 314fcervical, 385, 386fClass I, 309f, 322–338carving in, 330, 333fclinical procedures for, 323condensation of amalgam in, 338contouring of, 338desensitizer placement in, 330, 332f, 336example of, 322fextensive, 328fnishing of, 330–332, 334f, 338insertion of amalgam in, 330, 338matrix placement in, 330, 337–338preparations for, 323–330, 330f–332frestorative technique for, 330–332tooth preparation for, 323–329, 324f–329f, 332–336tooth preparation outline forms in, 323f, 328fClass I occlusofacial, 332–338, 339fClass I occlusolingual, 332–338, 334f–337fClass II, 308f, 338–368abutment teeth and, 355, 356fadjoining, 354–355, 356fburnishing in, 357–359, 358fcarving in, 352, 365–366clinical procedures for, 338condensation of amalgam in, 365–366desensitizer placement in, 355diagram of, 308fentry for, 340fexample of, 322fnishing of, 367for mandibular rst molar, 353, 353ffor mandibular rst premolar, 348–349, 349f–350f, 352for mandibular second premolar, 352, 352fmatrix placement in, 355for maxillary rst molar, 349–350, 350f, 352, 352ffor maxillary rst premolar, 350–351, 351ffor maxillary second molar, 352–353, 353focclusal outline form of, 338–341, 340f–341focclusal step for, 340foutline form of, 346fpartial denture and, 355polishing of, 367proximal outline form of, 341–345, 342f–344fquadrant dentistry in, 367–368restorative technique in, 355–368for rotated teeth, 353–354slot preparation in, 353tooth preparation for, 338, 345–348, 345f–346ftwo-surface, 362Class III, 368–375carving in, 375, 377fcondensation in, 375, 377fdesensitizer placement in, 375matrix placement in, 375, 376fprocedures of, 369restorative technique for, 375tooth preparation for, 369–375, 369f–375fClass V, 375–385carving in, 383–384, 385fcontouring in, 385fdesensitizer placement in, 383–385nishing in, 384–385, 386finsertion of amalgam in, 383–384, 384fline angles in, 380–383, 382f–383fmatrix placement in, 383, 383f–384fpolishing in, 384–385, 385f–386fprocedures of, 377–378, 378f–379frestorative technique for, 383–385tooth preparation for, 378–383, 379f–382fClass VI, 385–386preparation of, 386fclinical examination of, 102–104clinical technique for, 310–311commitment factors and, 309complex. see Complex amalgam restorationconsiderations for, 307–310contraindications to, 309convenience form for, 315debridement in, 315–316defective restorative material and/or soft dentin, removal of, 315disadvantages of, 310example of, 307ffacial area and, 318, 318fnishing of, 319–322, 322ffoundation of, 310ffracture in, 307general concepts guiding preparation for, 311–312improper occlusal contacts in, 104indications for, 309, 309f–310finspection in, 315–316isolation factors for, 309isolation of operating site of, 311lingual area and, 318, 318flocal anesthesia for, 311long-term, 369fmargins in, 313f–314f, 317fmatrix placement in, 316occlusal areas in, 317–318, 317f–318fevaluation of, 319, 320focclusion factors and, 309operator ability and, 309pin-retained, 392–404polishing of, 319–322, 321f–322fpreoperative considerations in, 311, 311fpreparation designs for, 316, 316fprocedures for, 310–311proximal embrasure areas and, 318–319, 318f–319fpulp protection in, 315, 315frepairing, 322resistance form for, 314secondary, 315retention form for, 314–315, 314fsecondary, 315slot-retained, 391–392, 391f–392ftooth preparationnal, 315–316initial, 312–315, 312foutline form in, 313–314, 313fprinciples for, 312treatment with, 116Ameloblasts, 2–3Amelogenesis, 2Amelogenesis imperfecta, 105American Dental Association (ADA), 461radiographic examination guidelines from, 107, 108t–109tspecication from, for casting gold alloys, e94American Dental Association Caries Classication System (ADA CCS), 97–99, 98fAmorphous calcium-phosphate (ACP), 85Anatomic crown, 122–123Anesthesiafor cast metal restorations, e95local, e26for amalgam restorations, 311for composite restoration, 224Angle, 123amalgam, 307axial line, in Class III amalgam restoration, 370–371axiogingival, in Class III amalgam restoration, 370–371axiopulpal, in Class I amalgam restoration, 334, 335faxiopulpal line, 346, 346fcavosurfacein Class I amalgam restoration, 327–328, 328f, 332, 334fAmalgam (Continued)Amalgam restorations (Continued)Amalgam restorations (Continued) Index 513 in Class II amalgam restoration, 353in Class III amalgam restoration, 369facial, reduction of, 270line, Class V amalgam restoration and, 380–383, 382f–383fAngle classication, 16, 17fAnnealing, e69Anteroposterior interarch relationship, 16–18Antidepressants, xerostomia from, 59tAntihistamines, xerostomia from, 59tAnti-HIV drugs, xerostomia from, 59tAntihypertensive agents, xerostomia from, 59tAntimicrobial agents, 84, 84tAntimigraine agents, xerostomia from, 59tAntipsychotics, xerostomia from, 59tApatite crystallites, 4, 5fAppetite suppressants, xerostomia from, 59tArch formo-center, rubber dam and, e44, e46fsmile aected by, 268Arginine, in saliva, 59Argon-ion lasers, 178–179, 178f–179fArticular disc, 22Articular eminence, slope of, 32Articulating paper, diastema treatment and, 274Articulatorhinge, e139semiadjustable, e127Assessment, patient. see Patient, assessment ofAssimilation, chromatic induction of, 203Assistantinstrument exchange with operator by, e24position of, e26fseated work position for, e24At-home bleaching, 277Atropine, salivation controlled with, e49Attached gingiva, 15, 415, 416fAttrition, treatment of, 115Auditory threshold, e21Augmentationcomposite, diastema treatment with, 272linguoversion treated with, 268Auto-deceleration, 170AutoMatrix, for complex amalgam restoration, 407, 410fAutomix dispensing system, e134Axial wall, 123BBacteriain biolm, caries and, 40clearance of, 58infection from, dentin adhesive systems and, 153oral habitats for, 50tplaque formation and, 44f–46fpulpal reaction to restoration and, 153Balance, hand instrument and, e1Barriers, for light curing, 189, 189fBase, 130glass ionomer, e103f–e104f, e125Base materials, in adhesive dentistry, 482, 482fBase metal alloys, 496–497Batteries, dental curing lights and, 182Beer-Lambert law, 175–176Bennett shift, 25f, 28–30Betel nut juice, teeth stained by, 275–276, 275fBevelof hand instrument, e2–e4preparations of, in cast metal restoration, e104–e108reversed, e113Bevelingcavosurface, 242fin Class III composite restoration, 242fBinocular loupes, 109Biocompatibilityadhesion and, 153–154cast metal restoration and, e95of porcelain bonding alloys, 499Biolmbacterial, analysis of, 75caries and, 40role in, 43–48cariogenic, tooth habitats for, 48–50composition of, 43–44control of, 80diet and, 42fmixed-species, 47fplaquecaries treatment and, 78tlamentous bacteria in, 47fformation of, 44f–47fphotomicrograph of, 44f–46fBiologic width, 107–108, 110f, 416, 417f, 417tviolation of, 422, 427Biomaterials, 453–510in adhesive dentistry, 477–484all-ceramic crowns, 501–504, 502fbiologic properties of, 460–461composite resins, 469–474contemporary ceramic, 505–508, 505f–506fdirect restorative, 461–469glass ionomer restorative materials, 474–477, 474f–475fgold alloys, 494–495, 494fimplant, 500–501, 500f–501findirect restorative, 484–494physical, mechanical, and optical properties of, 454–461porcelain bonding alloys, 495–499Biotypes, gingival, 418, 418f–419fBis-acryl material, veneer and, 300Bisphenol A ethoxylated dimethacrylate, 142, 143tBisphenol A-glycidyl methacrylate, 142, 143tBite collapse, diastema associated with, 272Bite registration paste, e126, e140fBlack, G.V., 461, 461fBlack’s classication system, e2Black’s spoon, 300f–302f, 302Bladebur design and, e15cleoid, example of, e5fdiscoid, example of, e5fexample of, e2fof hand instrument, e1surgical, composite restoration nishing with, 259Bleaching, 277–282at-home, 277uorosis treated with, 279home-applied, 280–282in-oce nonvital, 278in-oce vital, 279–280intrinsic discoloration treated with, 277nightguard vital, 277, 280, 281fnonvital, 278–279power, 279of tetracycline-stained teeth, 281, 281fthermocatalytic eect in, 280vital, 279–282life expectancy of, 277walking, 278–279“Bleaching mishap,” curious case of, 216, 217fBleeding, overcontoured veneer and, 285Blending eect, of color, 203Blocks, 438–443Blue light, 174blocking protection, 193–194, 194fhazard, 191–193, 193fBolton discrepancy, 272Bond strengthenamel, 142, 148microtensile testing of, 154, 154fshear, 154testing, of dental material, 460Bonded amalgam, 464Bondingadhesive, 443–444chemical, 138dentinchallenges in, 138–142matrix metalloproteinases and, 152role of proteins in, 151–152metallic, e69micromechanical, 138microtensile testing of, 154, 154fresin-dentin, options for, 143–150, 144fto sclerotic dentin, 154of veneer to tooth, 297Bonding agent, splinting and, e52–e54Bonding systemagentsetch-and-rinse, 480–481, 481finitial, 480, 480fdentin, 479–482, 480f, 480tenamel, 477–479, 477f–478ftotal-etch, 480–481, 481fBondlite, 143Boxdistal, in maxillary molar, cast metal restoration for, e111fproximalin cast metal onlay, e117ffor cast metal restoration, e99–e101Bridgesall-metal, e66fconservative, e56–e68xedprocedure for, e43frubber dam and, e41–e42Angle (Continued) 514 Indexmandibular anterior porcelain-fused-to-metal, e63fmandibular posterior, e64–e66, e64fbonding steps for, e65, e65flaboratory phase of, e64–e65preparation for, e64try-in stage of, e65Maryland, e60, e60f–e61f, e64–e66, e65f–e66fmaxillary, e65–e66, e65fmaxillary anterior, e60–e62bonding steps for, e61–e62nishing procedure for, e62, e63flaboratory phase of, e61porcelain-fused-to-metal, e62fpreparation for, e61try-in stage of, e61metal, resin-bonded, e60fresin-bonded, e52–e68Rochette, e60, e60f–e63f, e62–66types of, e56veneer, e66Brilliant Crios (Coltene), 446Brinell hardness value, e18tBrittle fracture, e18Bronchodilators, xerostomia from, 59tBruxism, 106Buccal crossbite, 20Budget curing lights, 182, 185fBulk-ll composite resin materials, 473“Bulk-ll composites”, 228Bursblade of, e15, e15fcarbide, e10blade of, e15head size of, e13tcarbide nishing, 256carbide ssure, e13classication system for, e10concentricity of, e14–e15crosscut, e12–13description of, e10–e15design modication of, e12–e13example of, e11futes of, e14head of, design features of, e12fhead size of, e12thistorical development of, e10inverted cone, e10, e11fnames and key dimensions of, e14tneck diameter of, e14pear-shaped, e10–e11round, e10, e11frounded corners for, e13runout of, e14–e15shapes of, e10–e11sizes of, e11–e12spiral angle of, e14steel, head size of, e13tstraight ssure, e11, e11ftapered ssure, e11, e11fCCAD/CAM. see Computer-assisted design, computer-assisted machiningCalcium hydroxide, 89bleaching with, 278Calcium hydroxide liners, 130in cast metal restoration, e101, e103fin Class III composite restoration, 241–242Calcium ions, saliva saturated with, 59–60, 63–64Calcium-sulfate dihydrate, 491, 491fCalcium-sulfate hemihydrate., 491Camphorquinone (CQ), spectral absorption prole of, 174, 174fCamX Spectra Caries Detection Aid, 110Canaliculi, 8Canine guidance, 28Canines, 1, 2fcervical retainer placement on, e41maxillary, Class III tooth preparation and restoration for, e85rubber dam hole size for, e35Carbamide peroxide, 279Carbohydratescaries and, 40, 60intake of, caries risk assessment and, 71Carbopol, bleaching materials and, 280Carborundum disk, e17Carestream system, 434–435Cariesactive, 41fbalance of, 42fin cervical areas, 102Class V composite restoration and, 254, 254fclinical, 49fclinical characteristics of, 40–94clinical examination for, 97–102, 98fdened, 40–60denitive diagnosis of, 222–223demineralization and, 40dentin, 43bbacteria in, 50tdetection technologies for, 110–111diagnostic test for, accuracy of, 112bdiet and, 60enamel, 43bbacteria in, 50tetiology of, 40–94extensive, 55fformation ofclinical sites for, 60–61saliva and, 58–60, 58thigh rate, cast metal restoration and, e95incipient, 282management of, 40–94calcium and phosphate compounds for, 85uoride exposure and, 80–83, 82timmunization for, 83–84medical model for, 42t, 78toral hygiene and, 79–80probiotics for, 85restorations for, 85–87sealants for, 85, 86fsilver diamine uoride for, 83, 83fsurgical model for, 70multiple, 41focclusal surface, 43b, 56f, 66f, 99–101, 100fradiographic examination of, 107in older adults, 117oral hygiene and, 50, 58pit-and-ssure, 43b, 51f–52f, 60progression of, 52f–54fprevention ofchlorhexidine for, 84protocols or strategies for, 75–89, 76bprimary, 43bprogression of, longitudinal section of, 57fproximal surface, 43b, 101–102, 101fradiographic examination of, 107rampant, 41f, 43b, 67f–68fdiet and, 77–79recurrent, 104radiographic examination of, 107remineralization and, 40removal of, clinical considerations for, 87–89residual, 43brisk assessment of, 40–94for children, 75dental clinical analysis for, 75form for, 72f–74frisk categories in, 70risk categories of, interventions and, 75trisk ofexamination ndings associated with, 77thealth history factors associated with, 77troot-surface, 43b, 50, 102bacteria in, 50tmanagement of, 89–90treatment of, 115secondary, 43bsmooth-surface, 43b, 101–102subgingival, gingivectomy for, 424fsugar use and, 49ftooth brushing and, 79f–80ftreatment strategies for, 78twhite spotformation in, 49f, 61, 81fsealants for, 85Caries around restorations and sealants (CARS), 85–87Caries-control restoration, 87, 89, 89tschematic representation of, 88fCaries lesion, 43bactive, 43b, 68fadvanced (deep), 43barrested, 65fcavitated, 43bpreventive protocol for, 76bcharacteristics of, 99tclinical characteristics of, 60–69dentin, 64–69change associated with, 51fcross section of, 67fzones of, 69detection of, 99diagnosis of, 71enamel, 61–64, 62f–63fcavitated, 64change associated with, 51fclinical signicance of, 64tcross section of, 61f–62fnoncavitated, 61–63Bridges (Continued)Caries (Continued) Index 515 inactive, 43b, 71initial, 43bon maxillary lateral incisor, 240fmoderate, 43bat pits and ssures, 60progression of, 61restoration of, 219at root surfaces, 61at smooth enamel surfaces, 60, 60fCaries Management by Risk Assessment (CAMBRA)movement, 97–99risk assessment with, 70CarieScan PRO, 110Carolina bridge, 479, 479fCasein phosphopeptide (CPP), 85Castadjusting of, e142–e145burnishing of, e151fgypsum, e139occluding of, e148–e150, e149f–e150focclusion of, e145, e147fpolishing of, e142–e145removing, e152, e152fseating of, e145–e152, e146f, e148fsplit, e136trying-in, e145workingin cast metal restoration, e136–e139completing, e136–e139, e137fCast-metal alloysdental rehabilitation with, e94strength of, e95Cast-metal restorations, 436–437, 437f, e94–e154abutment teeth in, e110advantages of, e95anesthesia for, e95cementation in, e152–e154, e153f–e154fconsiderations for temporary restorations before, e96, e96fcontraindications to, e95cost of, e95direct temporary restoration and, e130disadvantages of, e95for endodontically treated teeth, e94, e125–e126nal impression in, e130–e134indications for, e94–e95indirect, 483–484indirect temporary restoration and, e128–e130, e128f–e130finitial procedures for, e95–e96large, e94material qualities for, e94modications for esthetics in, e125occlusal step, e97–e99occlusion, evaluation for, e95, e96fonlay, e116–e126polyvinyl siloxane impression and, e134, e134frepair in, e154restorative techniques for, e126–e154temporary restoration for, e127–e128tooth preparations for, e96–e126Casting investments, 493–494, 493f–494fCavit, 278Cavitated caries lesion, 43bCavity, 120Cavity liners, 476–477, 482, 483fCavity sealer, 483Cavity varnish, 483Cavosurface angle, 123Cavosurface margin, 123, 124fCellular cementum, 10–11Cellulose wafer, isolation with, e45Celtra Duo (Dentsply Sirona), 444, 446fCementconventional glass ionomer, 474–475dental, 474–476glass ionomer, in cast metal restorations, e101, e125resinlight-cured, 297self-adhesive, 157fshade of, 297–298veneer application and, 293f–296fresin-modied glass ionomer, 475–476, 475fnonvital bleaching and, 278silicate, 469Cemental tear, periodontal health and, 420, 421fCementoblasts, 10Cementodentinal junction, 11Cementoenamel junction, enamel formation and, 2Cementum, 10–11, 11f, 415, 417fCentral fossa occlusal line, 16Central groove, 16Central pattern generator, 38Centric cusps, 26Centric occlusion, 26Centric relation, 26Centric relation occlusion, 26Ceramic based commercial shade guides, 205–207, 206fCeramicsadhesive, 443high-strength, 443leucite-reinforced glass, 446polycrystalline, 158–159pressed, veneer with, 299, 299fresilient, 443–446resin-matrix, 159veneer with, 283zirconia and, 158Cerasmart (GC America), 446CEREC system, 433–434, 434f, 438f–443fCEREC zirconia, 446–447Cervical caries lesion, Geristore for, 428, 428fCervical enamel projections (CEPs), periodontal health and, 420, 420fCervical resorption, 278, 278fCervident, 143C-factor. see Conguration factorChair, dental, position of, e23Chairside CAD/CAM systems, 433–435, 434f, 435tclinical workow, 437–438, 438f–443frestorativeclinical longevity of, 449–450materials, 438–447, 443t, 444f–447fCharge couple detector (CCD), 184Cheeks, precautions for, cutting and, e20Chemical bonding, of porcelain, 498, 498fChemical cure composite resin, 470, 470fChemotherapy, caries risk and, 77Chewingcondyle point during, 27cycle of, 38at incisor point, 30Childrencaries risk assessment for, 75rubber dam used for, e43, e44fChiselsapplication of, e4–e5bin-angle, e4example of, e3fblade design for, e3fexamples of, e3fstraight, e4example of, e3fWedelstaedt, e4in direct gold restorations, e79, e82f, e86, e87fexample of, e3fChlorhexidinefor dental caries, 84, 84tas dentin bonding agent, 152as protease inhibitor, 152Chromaas color dimension, 201–202as element of color, 268–269Chromatic assimilation, 203Chromatic induction, 203Chromium-cobalt alloys, 497Class I amalgam restorations, 309f, 322–338carving in, 330, 333fclinical procedures for, 323condensation of amalgam in, 338contouring of, 338desensitizer placement in, 330, 332f, 336example of, 322fextensive, 328fnishing of, 330–332, 334f, 338insertion of amalgam in, 330, 338matrix placement in, 330, 337–338preparations for, 323–330, 330f–332frestorative technique for, 330–332tooth preparation for, 323–329, 324f–329f, 332–336tooth preparation outline forms in, 323f, 328fClass II amalgam restorations, 308f, 338–368abutment teeth and, 355, 356fadjoining, 354–355, 356fburnishing in, 357–359, 358fcarving in, 352, 365–366, 366fclinical procedures for, 338condensation of amalgam in, 365–366, 366fdesensitizer placement in, 355diagram of, 308fentry for, 340fexample of, 322fnishing of, 367, 368ffor mandibular rst molar, 353, 353ffor mandibular rst premolar, 348–349, 349f–350f, 352for mandibular second premolar, 352, 352fmatrix placement in, 355Caries lesion (Continued) 516 Indexfor maxillary rst molar, 349–350, 350f, 352, 352ffor maxillary rst premolar, 350–351, 351ffor maxillary second molar, 352–353, 353focclusal outline form of, 338–341, 340f–341focclusal step for, 340fopen proximal contact in, 463, 463foutline form of, 346funusual, 354, 355fpartial denture and, 355polishing of, 367, 368fprecontoured sectional matrix strips, 365, 365fproximal outline form of, 341–345, 342f–344fquadrant dentistry in, 367–368restorative technique in, 355–368rigid-material supported sectional matrix for, 364–365, 364f–365ffor rotated teeth, 353–354, 355fslot preparation in, 353, 354ftooth preparation for, 338, 345–348two-surface, 362universal matrix for, 355–364, 357f–364fClass III amalgam restorations, 368–375carving in, 375, 377fcondensation in, 375, 377fdesensitizer placement in, 375matrix placement in, 375, 376fprocedures of, 369restorative technique for, 375tooth preparation for, 369–375, 369f–375fClass V amalgam restorations, 375–385, 377f–378fcarving in, 383–384, 385fcontouring in, 385fdesensitizer placement in, 383–385nishing in, 384–385, 386finsertion of amalgam in, 383–384, 384fline angles in, 380–383, 382f–383fmatrix placement in, 383, 383f–384fpolishing in, 384–385, 385f–386fprocedures of, 377–378, 378f–379frestorative technique for, 383–385tooth preparation for, 378–383, 379f–382fClass VI amalgam restorations, 385–386preparation of, 386fClearance angle, bur design and, e15Clearl Bond System Fc, 143Clearl New Bond, 143Clearl S3 Bond Plus, 149Clearl SE Bond, 148Clearl Universal Bond, 157–158Clenching, muscle involved in, 22–26Clinical crown, 121–122Clinical examinationof amalgam restorations, 102–104for caries, 97–102, 98fof composite restorations, 104diagnostic study models for, 110esthetic appearance, 96–97of implant-supported restorations, 104of implants, 104of indirect metal restorations, 104preparation for, 97Collagenacid etching of, 150feect of phosphoric acid on, 151type I, in enamel, 138–139Collagenase, in dentin, 152Collar, preparation of, e124Colorelements of, 200, 268–269modiers of, 269, 270fsurround eects and blending of, 203tooth, 203–204, 204fvalue of, 268–269Color corrected lighting, use of, 211–212, 211fColor deciency, 200Color dimensions, 200–202Color Education and Training Programs, 216tColor Matching Curriculum (CMC), 216Color matching instruments, 208–209, 208f–210fColor rendering index (CRI), 211Color triplet (observer situation), 200, 201fColor vision, 200, 201fchecking of, 211Commercial shade guides, 205–207Community water system, uoridated, 80–81Compatibility, of restorative materials, 205Complementary afterimage, of color, 203Complex amalgam restoration, 386–409advantages of, 388age and health in, 388contouring in, 407–409contraindications to, 388desensitizer placement in, 405disadvantages of, 388economics and, 388, 388fnishing in, 407–409foundations of, 404–405, 405findications for, 386–388, 387finsertion in, 407–409matrix placement in, 405–407occlusion and, 388pin-retained, 392–404considerations in, 404factors aecting, 393placement factors and technique in, 393–401, 394f–402f, 397tproblems with, 401–404, 403f–404ftypes of, 392–393, 392f–393f, 393tresistance form for, 387–388, 387frestorative technique for, 405–409retention form for, 387–388role of tooth, 387–388, 387fslot-retained, 391–392, 391f–392ftooth preparation for, 388–391cusp coverage, 388–390, 389fmandibular rst molar, 390–391, 390fmandibular rst premolar, 390fmaxillary rst molar, 390, 390ftooth status and prognosis and, 387Complex motion, mandibular, 24f, 27Compositeadvantages of, 220clinical procedures for, 223–224contraindications to, 219–220diastema closure with, 273fdiastema treatment with, 272direct, clinical technique for, 219–263disadvantages of, 220nishing of, 247fin Class I direct composite restorations, 228–229in Class II composite restoration, 235–237, 236fin Class IV direct composite restorations, 251in Class V direct composite restorations, 256–258hardness value of, e18tindications for, 219–220insertion ofin Class I composite restoration, 226–228, 227f–228fin Class II composite restoration, 235, 235fin Class III composite restoration, 245–246, 246fin Class IV composite restoration, 251in Class V composite restoration, 256light activation ofin Class II composite restoration, 235, 235fin Class III composite restoration, 245–246, 246fin Class IV composite restoration, 251in Class V composite restoration, 256light-curedbleaching and, 278, 279ffor bonding all-porcelain pontics, e68for bonding natural tooth pontics, e57–e58for denture tooth pontic, e58for diastema closure, 272–274for direct veneer, 288fmicroll, 286modulus of elasticity of, 226–228nanoll, 286for open embrasure, 272operating siteisolation of, 224preparation of, 224polishing ofin Class I direct composite restorations, 228–229in Class II composite restoration, 235–237, 236fin Class III composite restoration, 246–248in Class IV composite restoration, 251in Class V direct composite restorations, 256–258polymerization shrinkage stress of, 226problems in, 259–261processed, indirect veneer and, 287resin-based, factors aecting polymerization of, 175–176shade selection of, 224inaccurate, 261tooth preparation for, Class I, 224–226, 224f–225fveneer with, 283–284Composite resin block materials, 443, 446Class II amalgam restorations (Continued)Composite (Continued) Index 517 Composite resin materials, 469–474bulk-ll, 473classication of, 470–472according to ller particle size, 470–472according to polymerization reaction initiation, 470composition of, 469–470, 469flow shrinkage, 472–473restorative, manipulative variables with, 473–474summary and conclusion about, 474Composite resins, 469–474bases and cavity liners in, 483history of, 469tunnel tooth preparations for, 133Composite restoration. see also Compositeadhesive in, 251advantages of, 220Class I directclinical technique for, 219, 223–229, 223fcontouring and polishing in, 229f–230finitial clinical procedures of, 223–224restorative technique of, 226–229tooth preparation for, 224–226, 224f–225fClass II directclinical technique for, 220f, 229–238extensive and foundations of, 237–238, 238finitial clinical procedures of, 229matrix application in, 233–235restorative technique, 233–237tooth preparation of, 226f, 229–233, 231f–233fClass III directclinical technique for, 219, 238–248initial clinical procedures of, 238–239restorative technique of, 243–248tooth preparation of, 239–243, 241f–244f, 255fClass IV direct, 474clinical technique for, 219, 220f, 248–251example of, 259finitial clinical procedures of, 248restorative technique of, 249–251tooth preparation for, 248–249, 249f–251fClass V directclinical technique for, 219, 253–258, 253finitial clinical procedures of, 253restorative, 255–258tooth preparation for, 253–255, 254f, 256f–257fClass VI direct, clinical technique for, 219, 258clinical examination of, 104conservative, clinical technique for preventive resin and, 222–223, 222f–223fcontouring problems in, 261contraindications to, 219–220disadvantages of, 220nishing problems in, 261general considerations for, 219–220glass ionomer, clinical techniques for, 219–263initial clinical procedures for, 223–224missing proximal contact in, 260–261operator factors in, 219repairing, 259shade selection inaccuracy in, 261treatment with, 116voids in, 260white line adjacent to enamel margin in, 259–260Compression bonding, of porcelain, 498Compressive strengthof amalgam, 463, 463tof dental materials, 457–458, 458fComputer-assisted design, computer-assisted machining (CAD/CAM), 433chairside, 433–435, 434f, 435tclinical workow, 437–438, 438f–443frestorative materials, 438–447, 443t, 444f–447fresearch relative to, 448–449restorations, tooth preparation principles for, 435three sequences in, 433Condensation, of amalgam, 464Condensers, e70, e71fin Class V tooth preparation and restoration, e79in gold foil, compaction of, e72hand, e91fline of force, e72fmonangle, e86, e91foblique-faced, e72foset, e86, e90fCondylar guidancehorizontal, 32, 34flateral, 35fCondyle point, 27Cones, in color vision, 200Conguration factor (C-factor), 141, 473–474Conservative composite restoration, clinical technique for preventive resin and, 222–223, 222f–223fConservative esthetic procedures, 264–305artistic elements, 264–269clinical considerations for, 270examples of, 265ffor tooth contours and contacts, 270–274Conservative intraenamel preparation, 288–289Contemporary ceramic materials, 505–508, 505f–506findications for, 508Contouring, cosmetic, 264, 265f, 274fContrast, chromatic induction of, 203Convenience formfor Class III composite restoration, 241ffor Class III tooth preparation and restoration, e84for Class V tooth preparation and restoration, e76for direct gold restorations, e73Conventional amalgam, 462, 463fConventional glass ionomer cements, 474–475Conventional impression, 447Coolants, for instruments, e19–e20Corn cobs, plaque formation and, 44f–46fCoronal pulp, 6Correlated color temperature (CCT), 211Corrosion, 456, 456fCosmetic contouring, 264, 265f, 274fCotton rollcomposite restoration and use of, 224examples of, e46fisolation with, e45placement of, e45, e46f–e47fCounterbevel, e113, e116f, e120fCovesfor Class III composite restoration, 237retention, for tooth preparation, 131CPP. see Casein phosphopeptideCraze lines, 8enamel, 106Creep, as material property, 456Cross-linking, 170Crown, 435–436, 435f–436f, 438f–443fcaries development at, 51ffracture of, example of, 138ffullonlay and, e116tooth preparations for, e116lengthening, 422–424, 423ffor lingual smooth surfaces aected by caries, e114–e115porcelain, 274–275success rates of, 309CS 3500, 434–435Cusps, 16capping of, 128fin cast metal restoration, e113–e114, e114f–e115ffracture of, 106–107, 106ffunctional, 16, 20–22, 21fholding, 20incline of, 20nonfunctional, 16, 22, 23fposterior, 19f, 20reduction of, 238fin cast metal onlays, e116–119, e118fin cast metal restoration, e113, e116ftooth preparation and, 127–128, 128fridges, ssures in, cast metal restoration and, e110–e113shape of, 20Custom lingual matrix, 252fCustom shade guides, 207–208, 207f–208fCuttingabrasive, e19, e19fbladed, e18, e18fdiamond instrument for, e16fear precautions during, e20–e21equipment for, e7–e8evaluation of, e18eye precautions and, e20hand instruments for, e1–e22high-speed, e7–e8inhalation precautions during, e21instrument velocity and, e7low-speed, e7pulpal precautions and, e19–e20recommendations for, e19rotary speed ranges for, e7–e8Composite restoration (Continued) 518 Indexsoft tissue precautions and, e20, e20fwatts of power for, e7Cuttleboneabrasion with, e17–e18hardness value of, e17–e18Cycle of re-restoration, 113Cytotoxic drugs, xerostomia from, 59tDDead tracts, 51fDecongestants, xerostomia from, 59tDegassing, e69–e70DEJ. see Dentinoenamel junctionDemineralizationcaries and, 40remineralization and, balance in, 40, 42fDensite or improved dental stone, 491t, 492Dental anatomy, clinical signicance of, 1–39Dental arch, tooth alignment and, 16, 17fDental caries. see CariesDental curing lightsargon-ion lasers as, 178–179, 178f–179fbatteries and, 182budget, 182, 185fdevelopment of, 176–182electromagnetic risk from, 194emission from, radiometric terminology for, 171tgeneral recommendations for, 196irradiance of, distribution of, 184–186, 187flight emitting diode technology and, 180–182, 180foutput from, monitoring of, 186–187, 187fplasma-arc lights as, 176f, 177–178, 178f, 184fquartz-tungsten-halogen lights as, 176–177, 176f–177fsoft-start exposures and, 180stress development during polymerization and, 179“turbo” light guides in, 179tip design for, 188, 188fDental disease, 111–112Dental ossretainer tied with, e29frubber dam anchored with, e30rubber dam application and, e33–34, e34fsurgeon’s knot and, e45fDental history. see also Medical historyof patient, 96Dental photography, 209–211, 211tDental plaque. see PlaqueDental shade guides, 205Dental stone, 491t, 492, e139Dental tape, rubber dam anchored with, e30Dentinacid etching of, 140f, 143–144adhesion to, 136–169clinical factors in, 154adhesives forindications for, 156–159in vitro studies on, relevance of, 154air-dried, 150–151, 150fbonding to, 479–482, 480f, 480tchallenges in, 138–142chlorhexidine and, 152matrix metalloproteinases and, 152new developments in, 482role of proteins in, 151–152caries lesion in, 43b, 64–69bacteria in, 50tcross section of, 67fzones of, 69caries progression in, longitudinal section of, 57fcarious, 129inner, 69cavitation of, 52fcollagen brils in, 151composition of, 8, 141fcoronal, 9–10cutting of, e1demineralized, 40pH of, 89enamel and, 5, 5f, 8–9etchedcollapse of, 150fmicrograph of, 141frm, 69, 129formation of, 6–7hard, 69hardness of, 8, e18thypersensitivity of, 156infected, 69, 129removal of, e101–e104intrinsic discoloration of, 275leathery, 43b, 69, 89matrix metalloproteinases (MMPs) in, 152moist, 151fnecrotic, 69peritubular, 138–139demineralization of, 144permeability of, 9–10, 9f–10f, 139–141pH of, 40acid aected by, 153primary, 6–7, 7f, 43bproximal box in, for cast metal restoration, e99–e100, e100freactionary, 10remineralization of, 66–69reparative, 10, 11f, 66fresin adhesion to, 140tresin bonding to, 143–150, 144fresin interface with, 146f–148fstresses at, 141–142rewetting of, 150–151rinsing after etching, example of, 144froot canal, adhesion to, 156–157sclerotic, 43b, 66–69, 129bonding to, 154secondary, 8, 9f, 43bsensitivity of, 9, 9fslot in, e124–e125soft, 129surface area of, 7tertiary, 10, 43bof tooth color, 203, 204ftranslucent, 69transparent, 10, 10fDentin bonding agents (DBAs), 479Dentin phosphoprotein (DPP), 152Dentin sclerosis, 8Dentinal crystallites, 8Dentinal uid, 9–10Dentinal hypersensitivity, 115Dentinal tubules, 7, 7f–9f, 139, 141fcutting precautions and, e20dentinal uid in, 9–10Dentinal wall, 123Dentinoenamel junction (DEJ), 5, 5fcaries at, 60enamel demineralization in, 64Dentinogenesis, 6, 7fDentinogenesis imperfecta, 105Dentistrydevelopment of polymerization strategies for, 171–172evidence-based, 95operative. see Operative dentistryrestorative, trends in, 136–137Dentitions, 1Depth cut, for cast metal onlay, e116–e119, e118fDepth of focus, 109Desensitizationdentin adhesives and, 156for tooth preparation, 133–135Deuteranomaly, 200DIAGNOdent device, 110Diametral tensile strength, of dental materials, 457–458Diamond abrasive instrument. see Instruments, diamond abrasiveDiamondshardness value of, e17–e18particle factors of, e17types of, in diamond abrasive instrument, e15Diastemacast metal restoration for, e94closure of, 266, 267f, 273fcosmetic contouring and, 274fconservative alteration for, 270correction of, 272–274full veneer and, 286–287illusion of tooth dimension and, 265–266large, 274midline, 275fmultiple, treatment of, 274, 274fDicor, ceramic restoration by, 502, 502fDie stone, e136, e136fDiesremovable, e136working, in cast metal restoration, e136–e139Diet, dental caries and, 60risk assessment of, 71treatment of, 77–79Dietary counseling, 77–79Dierential acid attack, 478Diusion adhesion, 136Digital dentistry, in operative dentistry, 433–452CAD/CAM systemschairside, 433–435, 434f, 435tresearch relative to, 448–449restorations, tooth preparation principles for, 435Cutting (Continued)Dentin (Continued) Index 519 clinical application of, 433crowns, 435–436, 435f–436fdigital impressions, accuracy of, 447–448inlays and onlays, 436–437, 436f–437fDigital impression systems, 433accuracy of, 447–448Dimensional change, of dental material, 454Diopter single-lens loupes, 109Dipentaerythritol penta-acrylate monophosphate, 143t, 155Direct gold. see also Goldcohesion of, e69–e70compaction of, diagrammatic order of, e72fdegassing of, e69–e70materials and manufacture of, e69micrographs of, e71fprinciples of compaction of, e70–e72restorations of, e69–e93tooth preparation for, e73types of, e69Direct rear position, e24, e25fDisc-condyle complex, 22Discolorationextrinsic, 275–276, 275fetiology, 275–276treatment of, 276, 276fintrinsic, 276–277, 276fetiology of, 276–277treatment of, 277, 277froot canal therapy and, 278Disinfectant sprays, light curing and, 190Disk, abrasive, nishing composites with, 246, 247fDisocclusion, 37Dispersalloy, 461, 462f, 463tDistal wedge, 425, 425fDitch cut, proximal, in cast metal restoration, e99–e100Ditching, 102, 103fDiuretics, xerostomia from, 59tDo no harm, 113Dovetail, for cast metal restorations, e98Drugs, salivation controlled with, e49Dry mouth. see also Xerostomiamedications causing, 59t, 89salivary analysis and, 71–75Dual-cure composite, 155–156, 470, 471fDuctile fracture, e18Dynamic occlusal relationship, 16“Dynamic seating” technique, 475–476Dysmineralization, microabrasion and, 282EE4D Dentist System, 434Ear, precautions for, cutting procedures and, e20–e21Economic status, caries risk assessment and, 71Ectoderm, enamel and, 2Edge angle, bur design and, e15Education status, caries risk assessment and, 71Eight-chamber chewing simulator, 459fElastic modulus, 458, 459fElectrical properties, in dentistry, 456, 456fElectrical shock, 456Electro-Mallet, e70, e72–e73Electromagnetic energy, 172–173Electromagnetic radiation, materials interaction with, 458fElectromagnetic spectrum, 172–173, 172fElectrostatic adhesion, 136Elevator muscles, 22–26E.max, 299Embrasure, 12–14alterations of, 271–272correct anatomic form of, 14, 14fcorrect relationships of, 13–14, 13ffacial, 12fgingival, 12–13, 13fincisal, 270closing of, 272floss of, 271, 271flingual, 12f, 13–14reshaping of, 271treatment of, 272–274Embrasure formgingival, 266incisal, 266Enamel, 2–5acid etching of, 137, 138f–139fadaptation reaction of, 64fadhesion to, 136–169bond strength in, 142bonding to, 138–139, 477–479, 477f–478fcaries lesion in, 43b, 61–64, 62f–63fbacteria in, 50tclinical signicance of, 64tcross section of, 61f–62fcaries progression in, longitudinal section of, 57fcavitation of, 64clinical characteristics of, 63tcomposition of, 141fcutting of, e1demineralization of, 40, 49fdiscolored, veneer and, 286fault in, cast metal restoration for, e99fgnarled, 3, 3fhardness of, 5, 5f, e18thypoplasia ofdirect full veneer and, 286–287example of, 287fintrinsic discoloration of, 275marginal, white line adjacent to, 259–260maturation of, 4mottled, 80–81permeability of, 4, 5fpH of, 40plaque biolm and, 44f–46fposteruptive changes in, 81fprismless, 3proximal box in, cast metal restoration and, e99–e100, e100fsmooth surfaces ofbiolm on, 49–50, 51fcaries initiation on, 60, 60fsolubility of, 4–5structure of, 3thickness of, 2–3of tooth color, 203–204, 204ftooth preparation for, 121, 121fEnamel cuticle, 3–4Enamel hatchets, e3f, e4Enamel hypocalcication, nonhereditary, 101, 104fEnamel lamellae, 4Enamel margins, beveled, for tooth preparation, 131Enamel pearls, periodontal health and, 420Enamel projections, cervical, 420, 420fEnamel rods, 3, 4fplaque biolm and, 44f–46fin tooth preparation, 131–132, 132fEnamel spindles, 6, 7fEnamel tufts, 4, 5fEnamel wall, 123Enameloplasty, 124, 124f, 125bfor cast metal restorations, e97–e98, e110–e112, e112f–e113fEnamelysin, in dentin, 152Enamic (Vita), 446Endodontics, 114Endogenous uids, erosion due to, 105–106, 105fEnergy, electromagnetic, 172–173Equipment. see also Instrumentsair abrasion, e8, e8f–e9flaser, e8eye precautions and, e20powered cutting, e7–e8rotary-powered cutting, e7–e8for tooth preparation, e1–e22Erosion, 105–106, 105ftreatment of, 115Erosive tooth wear, 105–106Eruption, altered passive, gingivectomy for, 425, 425fEstheticscast metal restoration and, e95Class II preparation for, e108Class V composite restoration and, 254clinical examination of, 96–97concerns, treatment of, 116–117modications to, cast metal restoration for, e125Etch-and-rinse adhesives, 150–151Etch-and-rinse technique, 143–144, 144fEthyl acetate, denture tooth pontic and, e58Ethyl-silicate investments, 493–494Ethylenediamine tetra-acetic acid, 143, 143tEutectic mixture, 495Evacuatorshigh-volume, e46–e48position of, e46–e47, e48fretraction with, e48, e49fEvidence-based dentistry, 95, 453, 454fExamination. see Patient, examination ofExcavatorsangle former, e4application of, e4examples of, e3fhoe, e4spoon, e3f, e4ExciTE, 145–146Excursion, mandibular, muscles involved in, 26Exposures, soft-start, 180Extension for prevention, 127External line angle, 123Digital dentistry, in operative dentistry (Continued) 520 IndexExternal wall, 123, 123fEye, precautions for, cutting procedures and, e20Eye protection, for blue light hazard, 191E-Z Gold, e69–e70, e74in Class V tooth preparation and restoration, e79compaction of, e72technique for, e73FFace, of hand instrument, e1Facial crossbite, 20Facial cusp ridges, 20Facial occlusal line, 16Facial surface groove extension, e108–e110False negative, patient diagnosis and, 111False positive, patient diagnosis and, 111Farnsworth-Munsell test, 200Fatigue testing, 458–459, 459fFeldspathic porcelain, indirect veneer and, 287Ferrier separator, e85–e86Filesapplication of, e5example of, e5fFiller, refractive indices of, 176Filler particlesin composite resin, 469, 469f–470fwavelength of light and, interaction between, 175–176, 176fFinishing stripin composite restoration, 248diastema treatment and, 273f, 274Fissures, 2–3, 3fin cusp ridges, cast metal restoration and, e110–e113lingual occlusal, cast metal restoration and, e110–e112Fixed prosthodontics, 115Flarefacial secondary, e105–e106lingual primary, e104–e105, e106flingual secondary, e104–e105, e106fpreparation of, in cast metal restoration, e104–e108secondary, in cast metal restoration, e107Flexural strength, of dental materials, 457, 458fFlossing, caries anddevelopment of, 50, 57fprevention of, 79Flowable base bulk-ll composites, 228, 473Flowable composite resin materials, 472Fluorescence, optical properties and, 203Fluorideenamel and, 4–5exposure tocaries management and, 80–83, 82t, 84tcaries risk and, 77trelease of, from glass ionomer, 476–477rinses with, self-administered, 82stannous, 82teeth stained by, 276topical application of, 82varnishes, 82Fluoride ionanticaries eect of, 81in saliva, 63–64Fluorosis, 80–81bleaching for, 279generalized, veneer for, 291microabrasion for, 282, 283fsevere, example of, 293f–296fteeth discoloration from, 276Forcepsrubber dam, e30frubber dam retainer, e29Fossae, occlusions and, 16Fractureamalgam restorations and, 102, 103f, 307brittle, e18crown lengthening for, 422, 423fductile, e18endodontically treated teeth and, e125–e126gingivectomy for, 424Fracture lines, in amalgam restoration, 102, 103fFracture toughness, dental materials and, 457–458, 458fFrame, for rubber dam, e27, e27f, e32, e32fFree gingiva, 15, 415, 416fFree radicalgeneration of, 173–174polymerization of, methacrylate-based, 170, 171factivation and initiation of, 170propagation of, 170termination of, 170Fuji IX, 476Full-arch impression, cast metal restoration and, e126, e128fFull-body bulk-ll composites, 228, 473Functional shift, 26Furcation, periodontal health and, 417–422, 419f–420fGGalvanism, 456Garnetabrasion with, e17–e18hardness value of, e17–e18Gastroesophageal reux disease (GERD), erosion and, 105–106Gauze sponges, example of, e46fGelatinase, in dentin, 152Geristore, 428, 428fGingiva, 415, 416f–417fembrasure form of, 266sensitive, bleaching as cause of, 281Gingival areas, light-curing of, 191Gingival biotypes, 418, 418f–419fGingival crevice, bacteria in, 50tGingival display, 416–417, 417fexcessive, 418fGingival oorin cast metal restorations, e99–e100extension of, in cast metal restoration, e110Gingival health, Class V composite restoration and, 254Gingival margin trimmer, e3f, e4–e5Gingival sulcus, 15open, in cast metal restoration, e105ftissue retraction and, e132Gingival unit, 15Gingivectomy, 424–425Gingivitis, 418periodontics for, 114–115plaque and, 79Ginglymoarthrodial joint, 22Glass ionomerclinical techniques for, 219–263, 260fconventional, 261fdental cements/luting agents, 474–476conventional, 474–475light-cured, in cast metal restorations, e101materials, types of, 474–477resin-modied. see Resin-modied glass ionomerrestorative, 476–477cavity liners, 476–477materials, 469, 474–477, 474f–475fpolyacid modied composites (compomers), 477reinforced, 476tunnel tooth preparations for, 133Glass-matrix ceramics, 157–158Glasses, blue light ltering, 194Glenoid fossa, 22Gliding contacts, 16Gloss, optical properties and, 203Glucosyltransferase, uoride ion and, 81GLUMA desensitizer, 156Gluma system, 143Glutaraldehyde, desensitization and, 156Glycerophosphoric acid dimethacrylate, 142–143, 143tGoggles, protective, e20Gold. see also Direct goldpowdered, e69principles of compaction in, e70–e72restorations with, e69–e93Gold alloys, 494–495, 494fhardness value of, e17–e18types of, 495, 495tGold casting, 493Gold crowns, success rates of, 309Gold foil, e69book of, e70fbox of, e70fin Class I tooth preparation and restoration, e74in Class V tooth preparation and restoration, e79compacted, e72fcompaction of, e83ftechnique for, e72–e73degassing of, e71fGold foil restoration, 494–495, 494fGold pellets, e69degassing of, e71fGold-plus-platinum-metals content, e94Gold standard, patient diagnosis and, 111Golden proportion, 266–267Groovefor Class III composite restoration, 237extension, 226fin cast metal restoration, e108–e110gingival retention, 249, 251fpalatoradicular, 421Grotthuss-Draper law, 173Group function, 37Gummy smile, 417f Index 521 Gypsum bonded investments, 493components ofbinder, 493modier, 494refractory, 493expansion associated with, 494Gypsum products, 490–493classication of, 491–492, 491t, 492fnature of, 491, 492fselection and manipulation of, 492–493HH2 antagonists, xerostomia from, 59tHamp classication, 419Handheld “dental radiometers”, 187–188, 187fHandheld shade matching lights, 212fHandle, of hand instrument, e1Handpiecesair-driven, e7noise from, e21soft-tissue precautions for, e20variable control of, e8description of, e7electric, e7soft-tissue precautions for, e20electric motor-driven, e7friction-grip contra-angle, shank design for, e9flatch angle, shank design for, e9fshank design for, e9sterilization of, e8straight, shank design for, e9fHardness testing, of dental material, 460, 460fHatchetbibeveled, e3f, e86, e88fenamel, e3f, e4ordinary, e4Head, design of, for handpiece, in rotary cutting instruments, e10Headlamp, in operative dentistry, e24–e25Health, general, caries risk and, 77, 77tHeatblade cutting and, e18soft tissue damage and, 191Heat hardening, for cast gold restoration, 495Heat softening, for cast gold restoration, 495Heat treatment, for cast gold restoration, 495High copper amalgam, 462High expansion stone, 491t, 492High-gold alloys, 496, e94biocompatibility of, e95High noble alloys, 496High-strength ceramics, 443Hinge axis, 27Histology, clinical signicance of, 1–39Hoe, in Class V tooth preparation and restoration, e82fHueas color dimension, 201as element of color, 268–269Hunter-Schreger bands, 3, 4fHybrid composite resin materials, 471–472, 472fHybrid dental prosthesis, 500, 500fHydrochloric acid, microabrasion and, 282Hydrocolloid, impression with, 485Hydrodynamic theory, 9, 115Hydrouoric acid, 157, 158fporcelain etching with, 304veneer and, 289, 289fHydrogen peroxidebleaching with, 277nonvital bleaching with, 278Hydroxyapatite, 3, 14bonding and, 138in enamel, 138–1392-Hydroxyethyl methacrylate, 143, 143tHygroscopic expansion, gypsum bonded investments and, 494Hyperemia, overcontoured veneer and, 285Hypnotics, xerostomia from, 59tHypocalcication, clinical examination of, 104–105, 104fHyposalivation, radiation-induced, 61IiBOND Self-Etch, 149ICDAS. see International Caries Detection and Assessment SystemImaging, esthetic, 277Imbrication lines of Pickerill, 3Immune system, caries risk and, 77Immunization, for caries management, 83–84Implant prosthodontics, 115Implants, clinical examination of, 104Impressionalginate, for cast metal restoration, e128ffor cast metal restoration, e96fpreoperative, e129removing and inspecting, e136ftechniques for, e134Impression material, 484–490, 484falginate, e96classication of, 484–487, 484fmanipulation, principles ofadequate mixing, 489control of bulk, 487–488, 488fdisinfection, 489polyvinyl siloxane, 489, 489fpouring, 488putty-wash impression techniques, 490, 490fto tray, adhesion of, 488, 488fviscosity control, 488properties of, 484accuracy, 484–485dimensional stability, 485–486, 485f, 486teconomic factors, 487elastic recovery, 485ow and exibility, 486hydrophilicity, 486–487patient comfort, 487workability, 486, 486fImpression plaster, 491, 491tIn vitro studies, for adhesion, relevance of, 154Incident irradiance, 172Incisal biting, 26Incisal reduction index, 290–291, 296fIncisor overlap, 18–20, 18fIncisor point, 27Incisor point tracing, 31–32Incisors, 1, 2fall-porcelain pontic for, e66centralcomposite for diastema of, 273fdiastema of, 273fcervical retainer placement on, e41embrasure form of, 266embrasure of, 270closing of, 272floss of, 271, 271ffractured, esthetic treatment of, 270irregular edge of, 271fmandibularClass III tooth preparation and restoration for, e85, e86fdenture tooth pontic for, e58splint-and-bridge combination for, e63–e64splinting of, e52, e53fmaxillarybridge for, e60–e61in Class III tooth preparation and restoration, e81–e84denture tooth pontic for, e58diastema of, 272natural tooth pontic for, e56, e57fsplinting of, e52, e55maxillary central, veneer for, 287frecontouring of, 271freshaping of, 270frubber dam hole size for, e35, e36fstaining of, example of, 276fwidth-to-length ratio of, 267Incremental striae of Retzius, 3Infection, bacterial, dentin adhesive systems and, 153Infection control, in light curing, 189–190, 189fInltrants, 85, 86fInfrared radiation, 173Inhalation, patient protection from, e21Inlays, 436–437, 437fdistolingual, e114–e115for lingual smooth surfaces aected by caries, e114–e115for maxillary molar, e117fsplitting force of, e95tooth preparation and, 128tooth preparation for, e97–e116for esthetics, e108mesioocclusodistal, e108modications in, e108–e116Instruments. see also Equipmentabrasive, e17–e18classication of, e17cutting action of, e19, e19fmaterials used in, e17–e18for Class V tooth preparation and restoration, e79, e80f–e81fcoated abrasive, e17coolants for, e19–e20cuttingformulas for, e2hazards with, e19–e21diamond abrasive, e15–e17classication of, e16diamond particle factors and, e17head shape of, e16–e17 522 Indexsize of, e16–e17terminology for, e15, e16fdiamond cutting, e16f, e16tdiamond nishing, 246for direct gold restorations, e74, e74fdiscoid-cleoid, e5, e5fdouble-ended, e2fexchange of, between operator and assistant, e24ne-grit diamond, for cast metal restoration, e101, e107–e108handapplications of, e4–e5bevels of, e2–e4categories of, e1for Class V tooth preparation and restoration, e82fclassication for, e1–e4for cutting, e1–e22design of, e1, e2fformulas for, e2grasps for, e5–e6guards for, e7names of, e2rests for, e6–e7techniques for, e5–e7terminology for, e1–e4molded abrasive, e17rotary cutting, e9–e18design characteristics of, e9–e10, e9ffor rubber dam, e27–e30with three-number and four-number instrument formulas, examples of, e3ffor tooth preparation, e1–e22Integrating sphere, 184, 185fInteractions, of restorative materials, 205, 205fInterarch tooth relationships, 18–20, 18fIntercuspal contact, 2f, 16Interdental gingiva, 415Interdental papilla, 15Intermetallic compound, 495Internal line angle, 123Internal wall, 123, 123fInternational Caries Detection and Assessment System (ICDAS), 97–99, 98fInternational Standards Organization (ISO), bur numbering system from, e13Interocclusal recordcast metal restoration and, e113–e114, e126–e130maximum intercuspation, e126–e127, e127fnal impression and, e139use of, e139wax, cast metal restoration and, e113–e114Iodine, for dental caries, 84tIon, 173Ionomer, glass. see Glass ionomerIPS e.max, 503, 504fIPS Empress, 299IPS EmpressCAD (Ivoclar) restoration, 444, 445fIridescence, optical properties and, 202Irreversible pulpitis, 10Irrigation device, 80, 90Ishihara test, 200, 202fISO. see International Standards OrganizationIsolationamalgam restorations and, 309in Class V amalgam restoration, 377goals of, e26of operating site, of amalgam restorations, 311rubber dam, e26–e45application of, e31b–e35bremoval of, e39b–e40bIsolite, e26Ivocerin, spectral absorption prole of, 174, 174fJJaw closure, 22–26Jaw opening, 22Journal of the American Medical Association, 468KKanamycin, for dental caries, 84tKeyes-Jordan diagram, 40, 41fKnifeamalgam, e5application of, e5nishing, example of, e5fgold, e5Knoop hardness value, e18tLLabial frenum, diastema and, 272Lactobacillianalysis of, 75biolm and, 48chemical agents for, 84occlusal caries and, 66foral hygiene and, 79–80Lactoferrin, in saliva, 58Lactoperoxidase, in saliva, 58Lambertian reectance, 184Lamina propria, 14Laser equipment, e8eye precautions and, e20Lasersargon-ion, 178–179, 178f–179fdened, 178Lateral motion, mandibular, 24f, 27–28Lava Ultimate (3M), 446, 447fLED. see Light emitting diodeLeft front position, e23Left position, e23Left rear position, e23Leucite-reinforced glass ceramic, 446Leucite-reinforced IPS Empress system, 505, 506tglass ceramic crowns, 503, 503fLight, delivery of, factors aecting, 188Light and observer method, setting of, 213, 213fLight beam uniformity, 184–186, 186fLight cure composite resin, 470, 471fLight curing, 170–199blue light blocking protection in, 193–194, 194fblue light hazard and, 191–193, 193fof dental resins in the mouth, practical considerations of, 188–190depth of, 175electromagnetic risk from, 194evaluation of light output in, 183–188exposure time for, 175general recommendations for, 196hands-on training for, 195–196health-related issues in, 190–194how to, teaching for, 194–196, 194f–195finfection control in, 188f–189f, 189–190intrapulpal temperature and, considerations for, 190–191, 190f–192fpolymerization andmethacrylate-based free radical, 170, 171fof resin-based composite, factors aecting, 175–176strategies for, development of, 171–172radiometric terminology in, 172–173of restorative resins, 173–174soft tissue damage and, 191, 192f–193ftarget ofdistance to, 188–189, 188flight delivery to, factors aecting, 188Light-curing units, eye precautions and, e20Light emitting diode (LED)blue spectral range of, 180, 181fdened, 180dental curing lights and, 180–182, 180frst-generation, 180–181, 181fsecond-generation, 181, 182f–184fthird-generation, 181–182, 183f–184fLine angle, 123, 124fLiners, 130in adhesive dentistry, 482, 483fcalcium hydroxidein cast metal restoration, e101, e103fin Class III composite restoration, 241–242cavity, 476–477, 482, 483fLingual crossbite, 20Lingual surface groove extension, e108–e110Linguoincisal line angle, 123Linguoversionaugmentation for, 268example of, 268fLipsprecautions for, cutting and, e20wiping, after rubber dam removal, e39, e39fLithium disilicate reinforced ceramic, 505–506, 506tLoad-to-failure testing, 458–459, 459fLocal anesthesiafor amalgam restorations, 311for composite restoration, 224Loupes, 108–109Low shrinkage composite resin materials, 472–473Lucirin, spectral absorption prole of, 174, 174fLysine, in saliva, 59Lysozyme, in saliva, 58Instruments (Continued)Light curing (Continued) Index 523 MMacroabrasion, 282–283example of, 284fintrinsic discoloration treated with, 277microabrasion versus, 282–283Macrolled composite resin materials, 470–471, 471f–472fMacro-mini-micro shade matching technique, 214, 215fMagnicationin operative dentistry, e24–e25surgical telescope for, e26f“Making the turn,” in direct gold restoration, e90Mallet, in compaction, of direct gold, e70, e71fMandible, 14movement of, 22–26anterior tooth contacts during, 37articulators and, 32, 33f–36fcapacity of, 25f, 27–32frontal view of, 31fhorizontal view of, 29f, 30limits of, 27–30mechanics of, 22–27sagittal view of, 28f, 30tooth contacts during, 36–37, 36ftypes of, 26–27muscle function of, 22–26temporomandibular joints and, 22, 24fMandibular central fossa occlusal line, 17fMandibular condyle, 22Mandibular motion, mechanics of, 22–27Mandibular subperiosteal implant, 500, 500fMARC-Patient Simulator, 195–196, 195fMarginbeveling of, in cast metal restoration, e117f, e119butt-joint, 436–437, 437fcavosurface, in Class I tooth preparation and restoration, e74–e75counterbeveling of, in cast metal onlay, e114f, e120ft, 448gingivalbeveling of, e105, e105f, e109fin Class III tooth preparation and restoration, e81porcelain veneer and, 289veneer and, 285–286incisal, in Class III tooth preparation and restoration, e81lingual, in Class III tooth preparation and restoration, e85focclusalbeveling of, e107–e108, e107ffor Class V tooth preparation and restoration, e76for direct gold restoration, e74fextension of, e113, e115fproximal, aring and beveling of, e106restorative, 428–429, 429fMarginal gap formation, 102, 103fMarginal ridges, 20in amalgam restoration, 104ssures in, cast metal restoration and, e110–e113Maryland bridge, 478–479, 479f, e60, e60f–e61f, e64–e66, e65f–e66fMasticationcontrol of, neurologic correlates and, 38muscles involved in, 26Materialsof commercial shade guides, 207manipulation, 453qualities of, for cast metal restoration, e94selection, 453Matrixapplication, 243–245, 249–251custom lingual, 252fdenition of, 243–244Mylar strip, 244f–245fsubstitution of retainer with, e42–e43, e44fMatrix metalloproteinases (MMPs), 40, 152dentin, 152Maxilla, 14Maxillary arch, bleaching of, 281Maxillary lingual occlusal line, 16, 17fMaximum closure, 16Maximum habitual intercuspation (MHI), 16Maximum intercuspation (MI), 16, 17fMechanical adhesion, 136Mechanical bonding, of porcelain, 498Medical history. see also Dental historyof patient, 96Medicationscaries risk assessment and, 71, 77tdry mouth and, 59t, 89Mercuryin amalgam, 306silver amalgam and, 464–469anti-, research in, critique of, 466–467, 466fclassical research of, 465continued use of, research supporting, 467–468environmental impact of, 468historical review of, 465safety of, research questioning, 465–466toxicity, 306Mesial cusp ridges, 20Mesioocclusal preparation, 123Mesioocclusodistal preparation, 1234-META, bridges and, e60Metal restorationsindirectclinical examination of, 104treatment with, 116veneers for, 302–303Metamerism, 269illuminant, 211Methacrylate-based, free radical polymerization, 170, 171factivation and initiation of, 170propagation of, 170termination of, 1702-(Methacryloxy) ethyl phenyl hydrogen phosphate, 143t4-Methacryloxyethyl trimellitate anhydride, 143t10-Methacryloyloxy decyl dihydrogen phosphate, 143, 143t, 148MHI. see Maximum habitual intercuspationMI. see Maximum intercuspationMicroabrasion, 282example of, 283fintrinsic discoloration treated with, 277macroabrasion versus, 282–283Microetching, veneer repair and, 303–304Microlled composite resin materials, 471Microora, modication of, caries treatment and, 78tMicroleakage, 152–153amalgam restoration and, 306Microscopes, dental, 109–110Microtensile test, 154, 154fMiller classication, 426–427, 426fMineral trioxide aggregate (MTA), 427Mineralization-demineralization cycle, 64fMirror, retraction with, e48, e49fMMPs. see Matrix metalloproteinasesModel plaster, 491t, 492Modulus of elasticity, e18of composite, 226–228Mohs hardness value, e18tMoist bonding technique, 150Moisture, control of, in operative dentistry, e26Molar point, 27Molars, 1, 2fmandibularfractured cusps in, e121, e121fgroove extension in, e121rubber dam retainer for, e28ttooth preparations for class II cast metal restorations for, e97mandibular second, arrested caries on, 65fmaxillarycast metal restoration for, e110, e111fcusp reduction for, e115inlays for, e117flingual collar on, e124fmodications for esthetics on, e125rubber dam retainer for, e28tsealant applied to, 86frubber dam hole size for, e36rubber dam retainer for, e28ttilted, e126fMonochromacy, 200Monolithic full contour zirconia restoration, 504, 504fMonomers, phosphate, bonding and, 138Mouth props, e48–e49, e50fMS. see Mutans streptococciMucogingival junction, 15Mucogingival surgeryconsiderations in, 427noncarious cervical lesions, 425–427Mucosaalveolar, 15bacteria in, 50tmasticatory, 14–15oral, 14–15, 14freective, 15Munsell color system, 202fMuscarinic receptor antagonists, xerostomia from, 59t 524 IndexMutans streptococci (MS)analysis of, 75biolm and, 48chemical agents for, 84occlusal caries and, 66foral hygiene and, 80Mylar strip matrix, 244f–245fNNanoleakage, 152–153, 153fNapkin, for rubber dam, e29–e30, e30f, e32, e32fNasmyth membrane, 3–4, 275Neckdesign of, for handpiece, in rotary cutting instruments, e10in diamond instruments, e15Nib, of hand instrument, e1Nickel-cadmium (NiCad) batteries, 182Nickel-chromium alloy, 496–497Nightguard, plastic, 280fNightguard vital bleaching, 277, 280, 281fNoncarious cervical lesions (NCCLs), 254, 425–427, 426f, 458Noncentric cusps, 26Nonworking interferences, 32N-phenylglycine glycidyl methacrylate, 143, 143tOOcclusal caries, 43b, 56f, 66fOcclusal contact, 16improper, in amalgam restoration, 104Occlusal planecorrection of, cast metal restoration for, e94restoration of, for tilted molar, e126, e126fOcclusion, 15–38amalgam restorations and, 309evaluation of, 319, 320fcentric, 26clinical signicance of, 1–39complex amalgam restoration and, 388description of, 16–22esthetic restoration and, 270evaluation for, for cast metal restoration, e95, e96fexamination of, 97periodontal health and, 421–422reduction of, for cast metal onlay, e116–e119static, 16Odontoblastic process, 142fOdontoblasts, 6, 6fdentin formation and, 66fsecondary, 10Older adults, root caries in, 89Omnicam, 433–434, 434fOne Coat Bond, 145–146One-Step Plus, 145–146One-step self-etch adhesives, 140t, 145t, 149Onlays, 436–437, 436fcast metalresistance form for, e121–e122retention form for, e121–e122tooth preparation for, e116–e126crown and, e116cusp-capping partial, e113–e114, e114ffor fractured cusps, e121, e121fpartial, e113slot for, e125fOpalescence, optical properties and, 202Opalustre, microabrasion and, 282Open contact, e139Open proximal contacts, periodontal health and, 419–420Operating area, isolation problems in, 229Operating eld, isolation of, e25–e49Operating positions, e23–e24Operative dentistryCAD/CAM systemschairside, 433–435, 434f, 435tresearch relative to, 448–449restorations, tooth preparation principles for, 435digital dentistry in, 433–452clinical application of, 433crowns, 435–436, 435f–436fdigital impressions, accuracy of, 447–448inlays and onlays, 436–437, 436f–437fmagnication in, 108–110photography in, 110preliminary considerations for, e23–e51rubber dam and eciency of, e27Operatorability of, in amalgam restoration, 309composite restoration and, 219instrument exchange with assistant by, e24position of, e23–e24rubber dam for protection of, e27seated work position for, e24Opioids, xerostomia from, 59tOptiBond, 152OptiBond All-in-One, 149OptiBond FL, 152OptiBond SOLO Plus, 145–146Optical geometry, 213Optical properties, 202–203of dental materials, 457, 458fOral cavity, as bacterial habitat, 48f, 50tOral ora, caries and, 40Oral hygienedental caries and, 50, 58treatment of, 79–80poor, teeth stained by, 275Oral irrigation device, 80Oral surgery, 115Orthodontic extrusion, crown lengthening and, 422, 423fOrthodontic treatmentfor large diastema, 274for malposed teeth, 268Orthodontic wire, e55–e56Orthodontics, 115Outline formfor cast metal restorations, e97f, e110–e112for Class V tooth preparation and restoration, e76for direct gold restorations, e73for inlay tooth preparations, e108–e116for porcelain veneer, 289in tooth preparation, 127veneer placement and, 293f–296fOvermilling, 435PPackable (condensable) composite resin materials, 472Paindentin hypersensitivity and, 156dentine caries and, 65Palatoradicular grooves, periodontal health and, 421Palladium-silver alloys, 496Palm-and-thumb grasp, e5–e6, e6fmodied, e6, e6fplaning and, e102frest for, e6–e7Paradigm MZ100 (3M), 446Parasagittal plane, 26Paste, bite registration, e126, e140fPatientadult, risk-based interventions for, 75tage of, rubber dam and, e43assessment of, 95–119concern of, 96dental history of, 96diagnosis of, 95–119examination of, 95–119esthetic appearance, 96–97occlusion, 97teeth and restorations, 97–108examination of, caries risk and, 77tmedical history of, 96medically compromised, 77position of, e23–e24, e24fprognosis for, 112–113protection of, rubber dam for, e27response of, cutting procedures and awareness of, e20young, cast metal restoration for, contraindications to, e95Patient history, caries risk and, 71, 77tPatternsproximal contour and contact in, e139wax, e139–e142, e141fspruing, investing, and casting of, e142Pellicle, 3–4enamel, caries formation and, 48Pen grasp, e6finverted, e5, e6fmodied, e5rest for, e6–e7Percolation, denition of, 453, 455, 455f, 455tPeriimplantitis, 104Perikymataplaque biolm and, 44f–46fscanning electron microscope view of, 46fPeriodontal disease, 417–418diastema associated with, 272in older adults, 117Periodontal ligament (PDL), 415–416, 417ffunctions of, 15Periodontics, 114–115Periodontitis, 417–418periodontics for, 114–115Periodontium, 15, 415–417disease of, 417–418restorative treatment oneect of, 427–429importance of maintenance therapy, 418procedures, 422–427Onlays (Continued) Index 525 Peritubular dentin, 8, 138pHacid aect on dentin and, 153caries and, 40Phasealloy, 463t1-phenyl-1,2-propanedione, spectral absorption prole of, 174, 174fPhosphate bonded investments, 493–494Phosphate ions, saliva saturated with, 59–60, 63–64Phosphoric aciddenaturation of collagen by, 151enamel etched with, 137, 138fetching with, 297–298Phosphoric acid gel, 477–478, 478fPhotoinitiator molecule, 173–174spectral absorption proles of, 174, 174ftype I, 174type II, 174Photons, 172–173interaction of, with electrons of photoinitiator atom, 173–174, 173f–174fin ultraviolet range, 173Physiologic dentin sclerosis, 8Physiology, clinical signicance of, 1–39Pin-retained amalgam restorations, 392–404factors aecting, 393placement factors and techniques in, 393–401number of pins, 394pin design, 399–400, 399fpin insertion, 400–401, 400f–402fpin size, 393–394, 394fpinhole location, 394–396, 395f–397fpinhole preparation, 396–399, 397t, 398f–399fproblems with, 401–404broken drills, and pins, 403failure of, 401–403, 403floose pins, 403penetration in pulp, and perforation of external tooth surface, 403–404, 404ftypes of, 392–393, 392f–393f, 393tPindex drilling machine, e136Pindex system, e136Pit, 2–3Pit and ssurecaries in, 43b, 51f, 60initiation of, 60progression of, 52f–54fcariogenic biolm in, 49, 50fsealants for, 85, 137clinical technique for, 220–222, 221fPlanck-Einstein relation, 173Plaquecaries treatment and, 78tlamentous bacteria in, 47fformation of, 44f–47fon posterior teeth, 51fphotomicrograph of, 44f–46fPlasma-arc lights, 176f, 177–178, 178f, 184fPlaster cast, e128fPMMA. see Polymethyl methacrylatePoint angle, 123, 124fPolishing paste, 256fPolishing wheel, e145Polyacid modied composites (compomers), 477Polycrystalline ceramics, 158–159Polycrystalline restorative materials, 121, 122fPolyether, impression with, 485Polymer resin based, of commercial shade guides, 207Polymeric restorative materials, 121Polymerizationcomposites and, 154–155free radical, methacrylate-based, 170, 171finhibition of, 155light-cured, reactions to, 172rapid, 179of resin-based composite, factors aecting, 175–176strategies for, development of, 171–172stress development during, 179of veneer, 298Polymerization shrinkage stressof composite, 226reduction of, 473–474Polymethyl methacrylate (PMMA), 469, 469fPolysulde, impression with, 485Polyvinyl siloxane impression, 484–485techniques for, e134Polyvinyl siloxane impression material, 489, 489fin cast metal restoration, e96, e134, e134fdispenser for, e134, e135fveneer and, 299–300Polywave curing lights, 182, 184fPonticall-metal, e56, e59–e66, e60f–e61fall-porcelain, e66–e68light-cured composite for, e68technique for, e66–e68, e67fdenture tooth, e56, e58–e59, e59ftechnique for, e58–e59metal, e66metal-and-porcelain, e64–e65, e64f–e65fnatural tooth, e56–e58technique for, e56–e58, e57f–e58fporcelain-fused-to-metal, e56, e59–66, e60f–e61f, e65ftip design of, e57ftypes of, e56Porcelaindiscolored teeth treated with, 274–275etched, veneer with, 289–299feldspathic, indirect veneer and, 287fractured, etching with, 304hardness value of, e17–e18opaque, veneer with, 298success rates of, 309veneer with, 283, 289–299clinical procedures for, 291–299example of, 137ffractured, 453, 454fintraenamel preparation for, 293f–296fPorcelain bonding alloys, 495–499alterations for, 495biocompatibility of, 499classication of, 496, 496f, 496tcomposition of, 496–497economic considerations for, 499, 499tstrength of, 497–499bonding to, 498–499t of castings, 497–498Porcelain-fused-to-metal xed prosthesis, 501, 501fPorcelain-fused-to-metal pontic, e56, e59–66, e60f–e61f, e65fPorcelain jacket crown (PJC), 501Posselt diagram, 25f, 27Posterior bite collapse, diastema associated with, 272Posterior guidance, 32Powdered gold, e69Power bleaching, 279Power sensor, laboratory-grade, 183PowerMax-Pro 150HD, 183, 185fPredentin, 6–7Prema compound, 282, 283fmicroabrasion and, 282Premolars, 1, 2fmandibularinlay for, e108ftooth preparations for class II cast metal restorations for, e97maxillary, cast metal restoration for, modications for esthetics on, e125rubber dam hole size for, e36rubber dam retainer for, e28tPreparation extensions, for tooth preparation, 131Preparation oor, 123Primary cutting edge, hand instruments and, e2–e4Primary enamel cuticle, 3–4Primary resistance form, in tooth preparation, 127–128, 128fPrimary retention form, in tooth preparation, 128, 128fPrime & Bond NT, 145–146, 155Principal bers of ligament, 15Prisma Universal Bond, 143Probiotics, for dental caries, 85Prophy Jet, e8Prophy paste, 282Prophylactic odontotomy, 125bProportionality, dental, 266–268Prosthodontics, 115Protanomaly, 200Protease inhibitors, xerostomia from, 59tProtective glasses, 193Proton pump inhibitors, xerostomia from, 59tProtrusion, 26–27mandibular movement during, 27muscles involved in, 26Proximal caries, 43bProximal contactin cast metal restoration, e139, e141f–e142f, e145–e152improper, in amalgam restoration, 104open, in class II amalgam restoration, 463, 463fProximal contact area, 12, 12f–13fProximal margins, aring and beveling, e106Proximal overhangs, 102, 102fPorcelain bonding alloys (Continued) 526 IndexProximal retention grooves, in Class II amalgam restorations, 346–348, 347f–348fProximal walls, in Class II amalgam restorations, 348, 349fPublic water system, uoride level for, 80–81Pulpanatomy of, 6composition of, 6exposed, in cast metal restoration, e101function of, 6inammation of, 153precautions for, cutting procedures and, e19–e20protection ofin cast metal restoration, e101–e104Class V composite restoration and, 254during tooth preparation, 130Pulp capping, 89Pulp cavity, 6, 6fPulp-dentin complex, 6–10, 66pathologic challenge to, 10Pulp stones, 69Pulpal oor, 123in cast metal restoration, e110Pulpal wall, 123Pulse delay, 180Pumiceabrasion with, e17–e18hardness value of, e17–e18microabrasion and, 282operating site prepared with, 224Punch, for rubber dam, e29, e30fPunch cut, for cast metal restoration, e97, e98fQQuartzabrasion with, e17–e18hardness value of, e17–e18, e18tQuartz-tungsten-halogen (QTH) lights, 174, 176–177, 176f–177f“turbo” light guides in, 179tip design for, 188, 188fRRadiant exitance, 172Radiant powercollected, 184measurement of, 183spectral, 183–184temperature and, 190, 190f–192fRadiation, caries risk and, 77Radicular pulp, 6Radiography, for restoration examination, 107–108, 108t–109tRadiometers, dental, handheld, 187–188, 187fRake angle, bur design and, e15Rake face, bur design and, e15Rampant caries, 41f, 43b, 67f–68fdiet and, 77–79Rayleigh scattering, 175–176Reactive dentin sclerosis, 10Reective shields, example of, e46fRefractive indices, of resin and ller, 176Reinforced glass ionomers, 476RelyX Unicem, 159Remineralizationfor caries, 113caries and, 40demineralization and, balance in, 40, 42fof dentin, 66–69saliva and, 59–60, 84Removable partial dentures (RPD), 438Removable prosthodontics, 115Residual caries, 43bResilient ceramics, 443–446Resin-bonded splints and bridges, e52–e68Resin cementadhesive, 443–444light-cured, 297shade of, 297–298veneer application and, 293f–296fResin-dentin bonding, 143–150, 144fResin-dentin interdiusion zone, 145Resin-dentin interface, 139f, 141–142, 146f–147fmarginal gaps at, 152micrograph of, 148fResin-enamel adhesion, 137Resin-matrix ceramic, 159Resin-modied glass ionomer (RMGI), 130, 476cement, 475–476, 475fnonvital bleaching and, 278in composite restoration, 226materials, 90Resinsadhesion to dentin of, 140tcomposite, 146f, 469–474bases and cavity liners in, 483history of, 469light curing of, 170practical considerations for, 188–190matrix, 469, 469frefractive indices of, 176restorative, light curing of, 173–174Resistance formfor cast metal onlay, e121–e122for cast metal restoration, e110for distofacial defect, e115–e116collar and, e124of direct gold restorations, e73Restoration margins, 107–108Restorationsamalgam. see Amalgam restorationscaries-control, 87, 88f, 89, 89tcast, veneer for, 302, 303fcast metal. see Cast metal restorationscomposite. see Composite restorationdefects of, 85–87for dental caries, 85–87direct gold, e69–e93burnishing in, e75Class I, e73–e75, e74f–e76fClass II, e73Class III, e73, e81–e92, e84f–e92fClass V, e73, e75–e81, e77f–e83fClass VI, e73contraindications to, e73nishing of, e75, e76f, e80–e81, e83findications for, e73for maxillary incisors, e81–e84polishing of, e81replacement, e79fseparation of teeth and, e85–e86tooth preparation for, e73–e92direct temporary, e130, e131fexamination of, 97–108adjunctive aids for, 108–111radiographic, 107–108, 108t–109twith glass-matrix ceramics, 157–158indirect adhesive, 157–159indirect temporary, e128–e130, e128f–e130flarge, cast metal restoration for, e94onlay, e116recontour of, 116repair of, 116replacement of, 116small, cast metal restoration for, e95temporary, cast metal restoration for, e95, e127–e128Restorative dentistrycolor andappearance of teeth and dental materials, 203–205perception in, 200–203color matching in, 200–218tools, dental shade guides, 205–211improving shade matching skills of, 216shade matching in, 200–218trends in, 136–137visual shade matching method of, 211–216Restorative materials, 121color-related properties of, 204–205margins and, 428–429Restorative productsdirect, self-curing, 171–172, 172fthickness of, eect of, 175, 175fRetainerapplication of rubber dam before, e41, e41fcervical, e41application of, e42fjaws of, e41stabilization of, e41in Class V tooth preparation and restoration, e75–e76, e77f, e81dental oss tying for, e29finappropriate, e44metal, pontic with, e59–e66removable, stabilization with, e54rubber dam, e27–e29, e28f–e29fpositioning of, e32, e32fremoval of, e39, e39fselection of, e31, e31ftesting of, e32, e32ftypes of, e28fsubstitution with matrix, e42–e43, e44ftissue trauma from, e44types of, e28twinged, e28–e29wingless, e28–e29Retentionwith class I restorations, 229form for foundations, 238finadequate, gingivectomy for, 424–425Retention formfor cast metal onlay, e121–e122for cast metal restoration, e110for Class III tooth preparation and restoration, e84, e89fRestorations (Continued) Index 527 for Class V tooth preparation and restoration, e76collar and, e124for direct gold restorations, e73dovetail, for cast metal restorations, e98, e99fextension of, e108skirting and, e122slot in, e124Retention groovesin cast metal restoration, e101, e102f, e119–e121in maxillary molar, cast metal restoration for, e110, e111fproximal, in Class II amalgam restorations, 346–348, 347f–348ffor tooth preparation, 131Retraction, operative dentistry and, e26Retraction cord, e48, e49fin cast metal restoration, e101, e103f, e105fcomposite restoration and use of, 253diastema treatment and, 272, 273fimpressions and, 429insertion of, in cast metal restoration, e133fin polyvinyl siloxane impression, e135fveneer application and, 293f–296f, 297veneer procedure and, 292–296Retrusion, mandibular, muscles involved in, 26–27Reversible pulpitis, 10Ribbond, e52, e53fRight front position, e23, e25fRight position, e23, e25fRight rear position, e23–e24, e25fRigid-material supported sectional matrix, for Class II amalgam restorations, 364–365, 364f–365fRinsingafter rubber dam removal, e39–e40, e40fcaries risk and, 82Risk assessmentof dental caries, 40–94for children, 75dental clinical analysis for, 75form for, 72f–74frisk categories in, 70patient examination and, 112Risk factor, dened, 69–70Risk indicators, dened, 69–70Risk markers, dened, 69–70Risk prole, 112Rochette bridge, e60, e60f–e63f, e62–66Rods, in color vision, 200Rootcaries in, 43b, 50bacteria in, 50tmanagement of, 89–90preventive protocol for, 89–90risk factors for, 89surface lesions on, cast metal restoration and, e110, e110fsurfaces ofbiolm on, 50caries development at, 51f, 61Root canal dentin, adhesion to, 156–157Root canal therapycast metal restoration and, e104tooth discoloration and, 278Root-surface caries, 50Root-surface sensitivity, treatment of, 115Rotary instrument axis alignment, in tooth preparation, 125, 126fRotationmandibular, 24f, 26–27minor, correction of, 268, 268fRoyal Mineral Succedaneum, 465Rubber damadvantages of, e26–e27in amalgam restorations, 311anchors for, e30, e30f, e33, e33fapplication of, e35, e35fbefore retainer, e41, e41fand retainer simultaneously, e38–e41, e40f–e41ftesting before, e31, e31fin cast metal restoration, e101for Class I amalgam restoration, 323, 332for Class II amalgam restoration, 338for Class V amalgam restoration, 377–378, 378fdisadvantages of, e27ferrors in application and removal of, e44–e45examination of, e40, e40fframe for, e27, e27f, e32, e32fhole size and position in, e30–e38, e36finstruments for, e27–e30inversion of, during application, e34, e34fisolation with, e26–e45lubricant for, e29–e30lubrication of, e31, e31fmaterials for, e27–e30moisture control and, e26moisture prevention with, e26–e27napkin for, e29–e30, e30f, e32, e32fneck strap for, e33, e33fo-center arch form and, e44, e46foperator protection with, e27passing through posterior contact, e33, e33fpatient age and, e43patient protection with, e27placement of, e38punch for, e29, e30fpunching holes in, e31, e31ferrors in, e44removal of, e39, e39fretainer for, e27–e29, e28fpositioning of, e32, e32fremoval of, e39, e39fselection of, e31, e31ftesting of, e32, e32ftypes of, e28fretainer forceps for, e29rigid supporting material for, e33, e33fstamp for, e38ftemplate for, e38fwedge insertion and, e35, e35fRubber wheel abrasive, e147SSalivaanalysis of, caries risk assessment and, 71–75antibacterial activity of, 58–59as anticaries agent, 58–60, 58tbacterial clearance by, 58buer capacity of, 59calcium ions in, 59–60, 63–64drugs for control of, e49uoride ions in, 63–64function of, 84phosphate ions in, 59–60, 63–64remineralization and, 59–60stimulation of, caries treatment and, 78tSaliva ejectors, e46–e48, e48frubber dam application and, e35, e35fScotchbond, 143Scotchbond 2, 143Scotchbond Universal Adhesive, 157–158Sealantsfor dental caries, 85, 86fpit-and-ssure, 85Sealing cement, nonvital bleaching and, 278Secondary cutting edge, hand instruments and, e2–e4Self-adhesive resin cements, 157, 157fSelf-cure composite, 155–156Self-curing direct restorative products, 171–172, 172fSelf-etch adhesivesone-step, 145t, 149role of water in, 151two-step, 145t, 146–149Self-etching primer, 146, 147f, 481SensitivityClass V composite restoration and, 254postoperative, 261Separating disk, e17Separator, for direct gold restoration, e85–86, e86fSeptacutting of, rubber dam removal and, e39, e39fincorrect cutting of, e45rubber dam application and, e33–34, e34fSetting expansion, gypsum bonded investments and, 494Sevriton Cavity Seal, 142–143Shade matching duration, 214, 216fShade matching skills, improving, 216Shade selection, procedure for, 269Shade tab positioning, 213–214, 213f–215fShanksangles of, e2in diamond instruments, e15example of, e2fof hand instrument, e1in rotary cutting instrument, e9–e10, e9fSharpey bers, 10, 11fShelf life, of impression materials, 487Sialin, in saliva, 59Silane agent, veneer application and, 297Silane coupling agents, 157, 469–470Silicate cement, 469Silicoating, bridges and, e60Retention form (Continued) 528 IndexSilicon carbidehardness value of, e17–e18microabrasion and, 282Silicone, impression with, 485Silorane technology, 473Silver amalgam, 461–464advantages of, 461–462composition of, 462–463, 462t–463t, 463fevaluation of, 463–464manipulation of, 464mercury and, 464–469anti-, research in, critique of, 466–467, 466fclassical research of, 465continued use of, research supporting, 467–468environmental impact of, 468historical review of, 465safety of, research questioning, 465–466removal of, unwarranted, impact of, 468–469Silver diamine uoride, for caries management, 83, 83fSilver-tin-copper alloy, 306Simultaneous color contrast, 203, 203fSkeletal muscle relaxants, xerostomia from, 59tSkirtdisadvantages of, e122extension of, e115–e116, e117f, e121, e122f–e123fpreparation of, e122–e124for tooth preparation, 131Slotdistal, for onlay, e125fpreparation of, e124–e125Slot-retained amalgam restorations, 391–392, 391f–392fSmall Class II direct composite restorations, 230Smear layeracidic primer for, 143cutting procedures and, e20demineralization of, 144, 144fdentin surface and, 143removal of, by acid etching and, 143–144Smear plug, 139, 142fSmileesthetic appearance of, 266harmony and balance of, 268Smoking, caries risk and, 71, 77tSmooth-surface caries, 43bSocial status, caries risk assessment and, 71Sodium perborate, bleaching with, 278“Soft-start” curing mode, 180Soft-start exposures, 180“Soft-start” polymerization, 473Soft tissue, precautions for, cutting procedures and, e20, e20fSolubility, 456–457, 457fSpectral radiant power, measurement of, 183–184Spectrometer, optical, 183–184, 185fSpectrophotometer, 183–184Speed of light, wavelength and, 173Spherical alloys, 463Splint-and-bridge combination, mandibular anterior, e63–e64Splinting material, polyethylene-coated woven fabric for, e52–e54Splintsfor anterior teeth, e52–e54, e53ffor avulsed teeth, e55–e56, e55fxed wire, e54–e55orthodontic treatment and, e54–e55, e55fresin-bonded, e52–e68Split cast, e136Split-tooth syndrome, e122SpoonBin-angle, e3ftriple-angle, e3fSpoon excavatorsapplication of, e4examples of, e3fSquamous epithelium, mucosa and, 14Stability, of restorative materials, 205Stabilization, after orthodontic treatment, e54–e55, e55fStain. see DiscolorationStark-Einstein law, 173Sterilization, of handpiece, e8Stools, operating, e24Streptococcus sanguis, pits and ssures and, 49Striae of Retziusplaque biolm and, 44f–46fStrip, splinting and, e52–e54Study cast, 109–110Subgingival caries, gingivectomy for, 424, 424fSubmucosa, 14Sucrosecaries formation and, 60caries risk assessment and, 71Sugar, intake of, caries risk assessment and, 71Supporting alveolar bone, 15Surgeon’s knot, e43, e45fSurround/viewing conditions method, control of, 212, 212fSymmetry, dental, 266–268Syringe, composite inserted with, 251TTarnish, 456, 456fTear, cemental, 420, 421fTechnique sensitivity, 453Teeth, 1–15abutment, in cast metal restoration, e110alignment of, 268, 268fanteriorembrasure of, 271multiple diastemas among, 274proportionality of, 266–267reshaping of, 270frestoration of, 264–265splinting of, e52–e54, e53fwidth-to-length ratio, 267apparent length of, 265apparent size of, 265, 266fattachment apparatus of, 15avulsed, splinting of, e55–e56, e55fbacteria in, 50tcariogenic biolm habitats on, 48–50classes of, 1, 2fcolor of, 219, 268–269aging and, 269appearance and, 203–205contactsanterior, 37conservative alteration of, 270–274posterior, 37contours of, 11–12, 12f, 264conservative alteration of, 270–274normal, 11discoloredextrinsic, 275–276intrinsic, 276–277porcelain veneer for, 298, 299ftreatments for, 274–277endodontically treated, cast metal restoration for, e94, e125–e126examination of, 97–108adjunctive aids for, 108–111radiographic, 107–108, 108t–109tform of, 1conservative esthetic procedures and, 264–266function of, 1, 11hole position for receiving cervical retainer, e41, e43fmalformed, porcelain veneer for, 298, 298fmalposed, treatment of, 268mandibular, rubber dam hole size for, e36, e37fmaxillary, rubber dam hole size for, e36, e37f–e38fmaxillary anterior, veneer for, 286–287mobile, splinting and recontouring of, e53fmobility of, stabilization of, e52normal, bitewing radiograph of, 56fperiodontally involved, e52–e54physiology of, 11–14position of, 268, 268fposteriorbiolm formation on, 51fcervical retainer placement on, e41endodontically treated, e125–e126rubber dam hole size for, e35–e36proportionality of, 266–268, 267fproximal contact area of, 12, 12f–13freshaping of, 270frestored, interfacial gaps and, 142at risk for fracture, e94sensitive, bleaching as cause of, 281separation of, direct gold restoration and, e85–e86shape ofalteration of, 270–271conservative esthetic procedures and, 264–266illusion of, 265, 266ftreatment for, 271stabilization of, after orthodontic treatment, e54–e55, e55fstained, tetracycline as cause of, 269structures of, 1–11surface ofmodication of, caries treatment and, 78ttexture of, 268symmetry of, 266–268Teeth (Continued) Index 529 tetracycline-stained, 281, 281fveneer for, 284ftranslucency of, 269, 269fwidth-to-length ratio, 267, 267fTelescopes, surgical, e26fTelio CAD (Ivoclar), 447Temperature, intrapulpal, considerations for, 190–191, 190f–192fTemporary threshold shift, e21Temporomandibular joints (TMJs)exibility in, 28–30lateral shift, 32, 35fmandible and, 22, 24fmuscle function of, 22–26Tensile strength, of dental materials, 457–458Terminal hinge (TH)closure, 30movement, 26Test sensitivity, 111Test specicity, 111Tetracyclineintrinsic discoloration caused by, 276, 276fteeth stained by, 269bleaching of, 281, 281fcrown for, 281–282veneer for, 281–282, 284fermal coecient of expansion (COE), 454–455, 455f, 455termal conductivity, through dental material, 455–456, 455termal expansion, gypsum bonded investments and, 494ermocatalytic eect, bleaching and, 280ermopile, 183, 185fread Mate System (TMS), 393, 393tree-step etch-and-rinse, 140t, 143–145reshold limit value (TLV), 466–467roat screen, e47froat shields, e46, e47fTin-mercury phase (gamma-2), amalgam restoration and, 306Tint, translucency and, 269Tissue massage, after rubber dam removal, e39–e40, e40fTissuesretraction of, in cast metal restoration, e132–e134, e132f–e133fsupporting, 1–15Titanium alloys, 497TMJs. see Temporomandibular jointsTobacco, teeth stained by, 275Toemire retainer and band, for complex amalgam restoration, 406, 408fToemire-type matrix band, 234, 234fTomes bers, 6, 6fTonguebacteria in, 50tprecautions for, cutting and, e20Tongue thrusting, diastema associated with, 272Tooth colorclinical examination of, 96–97treatment of, 116Tooth dehydration, 212Tooth fracture, gingivectomy for, 424Tooth grinding, 106Tooth position, periodontal health and, 421Tooth preparation, 120–135adhesive amalgam restorations for, 133for amalgam restorationsClass I, 323–329, 323f–329f, 332–336Class II, 338, 345–348Class III, 369–375, 369f–375fClass V, 378–383, 379f–382fnal, 315–316initial, 312–315, 312foutline form in, 313–314, 313fprinciples for, 312box-onlyfor amalgam restoration, 316, 316ffor Class II amalgam restoration, 351, 351ffor cast metal inlays, e97–e116for cast metal onlays, e116–e126for cast metal restoration, e96–e126distoocclusolingual, e110Class I, 120Class II, 120Class III, 120Class IV, 120Class V, 120cervical retainer used in, e41Class VI, 120classication of, 120complex, 123for complex amalgam restoration, 388–391, 389f–390fslot-retained, 391–392, 391ffor composite restorationClass I, 224–226, 224f–225fClass II, 226f, 229–233, 231f–233fClass III facial approach, 239–243, 240f–244f, 255fClass IV, 248–249, 249f–251fClass V, 253–255, 256f–257fcompound, 123consideration to, 120, 121bconvenience form in, 128–129conventional, for amalgam restoration, 316, 316fdebridement in, 132, 133fdefective restorative material and/or soft dentin in, removal of, 129–130denition of, 120–123desensitization of, 133–135design of, for Class I amalgam restoration, 331ffor direct gold restorations, e73Class I, e73–e75, e74f–e76fClass III, e81–e92, e84f–e92fClass V, e75–e81, e77f–e79fdisinfection of, 133–135distoocclusal, for maxillary rst molar, 350equipment for, e1–e22for esthetics, e108external wall nishing in, 131–132, 132fextracoronal, 122–123, 123fnal stage of, 129–132initial depth in, 127initial stage of, 126f, 127–129inspection of, 132instruments for, e1–e22intracoronal, 121–122, 122fmesioocclusal, for maxillary rst molar, 349, 350fmesioocclusodistal, e108mesioocclusolingual, for maxillary rst molar, 350fobjectives of, 120occlusal, amalgam restoration and, 320focclusal contact identication in, 125, 126foutline form in, 127for pin-retained complex amalgam restoration, 392–404for porcelain veneer, 289–291primary resistance form in, 127–128, 128fprimary retention form in, 128, 128fproximal box, 313fpulp protection during, 130for quadrant dentistry, 367rotary instrument axis alignment in, 125, 126fsecondary retention and resistance forms in, 130–131simple, 123for slot-retained complex amalgam restoration, 391–392, 391fstabilization of, 133–135stages of, 124–132steps of, 124–132, 125bterminology in, 123treatments to enhance restoration, 133–135tunnel, 133Tooth strength, Class V composite restoration and, 254–255, 257f–258fTooth-to-tooth relationship, 20Tooth-to-two-tooth contact, 20Toothbrushelectric, 80powered, 90wear from, 79f–80fToothbrushing, caries and, prevention of, 79Transformation toughening phenomenon, 506, 507fTransillumination, for caries, 101Translation, mandibular, 24f, 26–27Translucencyillusion of, 269optical properties and, 202tooth restoration and, 269, 269fTreatment planning, 95–119approval of, 118control phase of, 114denitive phase of, 114general considerations to, 113maintenance phase of, 114for older patients, 117–118operative, interdisciplinary considerations in, 114–115reevaluation phase of, 114sequencing/phasing of, 113–118urgent phase of, 114Trial-t, of casting, e142–e143Triangular ridges, cusp, 20Triangular wood wedge, 245fTricyclic antidepressants, xerostomia from, 59tTrimmer, gingival margin, e3f, e4–e5Tritanomaly, 200Trituration, 464Teeth (Continued)Tooth preparation (Continued) 530 IndexTrue negative, patient diagnosis and, 111True positives, patient diagnosis and, 111Try-in, veneer, 297Two-step etch-and-rinse adhesives, 140t, 145–146, 145tTwo-step self-etch adhesives, 140t, 145t, 146–149Tytin, 463tUUltracapacitors, 182Ultraviolet light, 174Undermilling, 435Uniformity, light beam, 184–186, 186fUniversal adhesives, 149–150, 155–156interfacial bonding degradation in, 149–150moist dentin and, 151Universal matrixfor Class II amalgam restorations, 355–364, 357f–364ffor complex amalgam restoration, 406, 406f–409fUrethane dimethacrylate, 143tVVaccine, anticaries, 83–84Valiant, 463tValuecolor dimension of, 201as element of color, 268–269Vancomycin, for dental caries, 84tVapor, cutting as cause of, e21Varney foot condenser, e70, e80, e90–e92Varnish, cavity, 483Velocity, cutting and, e7Velvalloy, 463tVeneer bridges, e66Veneers, 283–304bonding of, 297butt-joint design preparation, 291butt-joint incisal design, 286, 290f–291fceramic for, 283example of, 299fpressed, 299composite for, 283–284defective composite, 289–299direct, 286–287direct composite, repairing, 304fdirect full, 286–287example of, 287fdirect partial, 285f, 286discolored teeth treated with, 274–275etched porcelain, 289–299t of, 297full, 283–284, 285fpreparation for, 286window preparation for, 286gingival margin of, 285–286incisal-lapping approach for, 286indirect, 284–285, 287–299intraenamel preparation for, 285, 290f–291fintrinsic discoloration treated with, 277lapping preparation for, 291margins of, 298for maxillary anterior teeth, 286–287for metal restoration, 302–303no-prep, 285, 288–289example of, 288f–289fovercontoured, 285partial, 283, 285fpolymerization of, 298porcelain for, 283clinical procedures for, 291–299for discolored teeth, 299fexample of, 293f–296f, 298fincisal-lapping design, 292fincisal lapping preparation, 296findirectly fabricated, 286intraenamel preparation for, 290f–291frepair of, 304temporization of, 300f–302ftooth preparation for, 289–291provisionalization of, 299–302repairs of, 303–304, 304fshade of, 297temporary, 297try-in of, 297types of, 285fVisibility, rubber dam application and, e35, e35fVisual shade matching method, 211–216ve pre-shade matching steps of, 212–216communicate, 214perform at beginning, 212set light and observer, 213use appropriate technique, 213–214verify, 214–216three pre-shade matching steps of, 211–212Vita Bleachedguide 3D-Master, 205–206, 206fVita Linearguide 3D-Master, 207fVita Mark I blocks, 443Vita Mark II blocks, 443, 444fVoids, 102WWallaxialin cast metal restoration, e99–e100for Class V tooth preparation and restoration, e76–79, e78fdistal, for Class V tooth preparation and restoration, e78f, e79, e80f–e81fdistofacial, in cast metal restoration, e102fdistolingual, in cast metal restoration, e102fgingivalin cast metal restoration, e100–e101for Class V tooth preparation and restoration, e77, e78fmesial, for Class V tooth preparation and restoration, e77–79, e78f, e80f–e81focclusal, for Class V tooth preparation and restoration, e77–79, e80f–e82fvertical, in cast metal onlay, e115–e116Wall lesions, 60Water system, uoridated, 80–81Water tree, adhesion and, 153, 153fWavelengthller particles and, interaction between, 175–176, 176fspeed of light and, 173Wax patterns, in cast metal restoration, e139–e142nishing, e141–e142, e144finitial withdrawal and reseating of, e142, e145fWaxing, forming the occlusal surface and, e139–e141, e143fWedelstaedt chisels, e4in direct gold restorations, e79, e82f, e86, e87fexample of, e3fWedgein amalgam restoration, 311in composite restoration, 229distal, 425, 425fdouble, 360, 361fgingival, in Class II amalgam restoration, 343–344at gingival margin, matrix and, 245triangular wood, 245ftypes of, 244Wedge insertion, rubber dam application and, e35, e35fWet-bonding, ethanol, 151Wettability, 459–460, 460fWhite spot defect, macroabrasion for, 282White spotsdecalcied, 276macroabrasion for, 282Whitening, procedures for, 274–275Wide opening, mandibular, 26Work position, seated, e24Working distance, 109Working side, mandibular pathways, 27XXerostomia. see also Dry mouthdened, 58medications causing, 59tXylitol gum, 85YYoung holder, e27, e27fYoung modulus, 154–155Y-TZP-based biomaterials, 158ZZirconiabonding, 507–508ceramics and, 158restorations, 506, 506t, 507fVeneers (Continued)Wall (Continued) This page intentionally left blank This page intentionally left blank

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