Analysis










Ch
apte
r 12
Analys is
Jordi
Manauta
Walter
Devoto
Interview
with
Luiz
Narciso
Baratieri

''
Ncothing
a
new
truth
mcorce
than
an
cold
errcor.

/
./
418
Prof Luiz Narciso Baratieri was born in the small town of Capinzal,
Santa Catarina,
in
southern Brazil.
He
graduated with a degree in
dentistry
from the Federal University
of Santa
Catarina, Brazil,
in
1976.
He
has a certification in
periodontics and
completed his master's and doctoral degrees
at
the Bauru School of Dentistry in
Sao
Paulo, Brazil.
He
obtained a
postdoctoral degree
from
the University of Sheffield, England, in
2000.
Prof Baratieri has published more than 15 textbooks and more
than
100
scientific papers in several languages.
He
is
a well-known
lecturer
on
the subject of operative
dentistry
and has presented
more than
1,000
lectures worldwide.
In
addition,
he
is
editor-
in-chief of the Journal
Clfnica-lnternational
Journal of Brazilian
Dentistry.
Prof Baratieri
is
professor and chair of Operative Dentistry and
coordinator of the Graduate Program in Operative Dentistry at the
Federal University of Catarina, Florian6polis, Brazil.
He
maintains
a private practice in
Florian6polis.

Q:
In
a deep analysis of composite resin materials, what
is
the most important thing to
assess?
A:
In
my opinion, besides the outline, contour, and surface
texture, which
should
be
considered important aspects
for achieving esthetic
excellence with composite resins
in
anterior teeth, there
are
other insertion techniques and
material-related aspects. Actually, there are a couple of
aspects of composite resins
that
I consider relevant:
1.
The
degree of translucency or opacity, which will allow or
block visualization
of
the tooth structure and adjacent layers
of composite resin.
2.
The
opalescence. Opalescence can
be
defined in a simple
manner
as
the object's ability to reflect light with short (blue)
wavelengths
and to transmit light with large (red, orange)
wavelengths.
Opalescent materials present the ability
to
change
Hue,
Chroma, and Value without changing their
translucency.
As
a consequence, transparent
or
translucent
materials can appear
totally opaque,
even
in
tiny thicknesses
such
as
0.1 to 0.5 mm, depending
on
the manner in which
light hits their surface, and can present a number of colors.
Considering that
in
the stratification technique composite
resins are
layered differently when stains are used, opalescent
materials
yield
m·ore
vivid (brighter) colors,
even
when they
are
clear (colorless). Accordingly, such materials should
offer counteropalescence, a phenomenon that is observed
in
natural teeth, especially
at
the mamelon tips
in
anterior
teeth.
The
shades produced by these composites present
variable intensity depending
on
moisture and lighting
conditions, unlike restorations that incorporate stains. This
gives the restorations a dynamic behavior, very
similar to the
surrounding sound tooth structure.
Thus,
in
spite of my belief that the outline, contour, and
surface texture
should
be
considered fundamental aspects,
I would like to stress that the opalescence
is
the most
important property that composites
should present to
simulate the amazing polychromatic effects of natural teeth.
411

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Chapter 12 Analys is Jordi Manauta • Walter Devoto Interview with Luiz Narciso Baratieri '' Ncothing a new truth mcorce than an cold errcor. / ./ 418 Prof Luiz Narciso Baratieri was born in the small town of Capinzal, Santa Catarina, in southern Brazil. He graduated with a degree in dentistry from the Federal University of Santa Catarina, Brazil, in 1976. He has a certification in periodontics and completed his master's and doctoral degrees at the Bauru School of Dentistry in Sao Paulo, Brazil. He obtained a postdoctoral degree from the University of Sheffield, England, in 2000. Prof Baratieri has published more than 15 textbooks and more than 100 scientific papers in several languages. He is a well-known lecturer on the subject of operative dentistry and has presented more than 1,000 lectures worldwide. In addition, he is editor-in-chief of the Journal Clfnica-lnternational Journal of Brazilian Dentistry. Prof Baratieri is professor and chair of Operative Dentistry and coordinator of the Graduate Program in Operative Dentistry at the Federal University of Catarina, Florian6polis, Brazil. He maintains a private practice in Florian6polis. Q: In a deep analysis of composite resin materials, what is the most important thing to assess? A: In my opinion, besides the outline, contour, and surface texture, which should be considered important aspects for achieving esthetic excellence with composite resins in anterior teeth, there are other insertion techniques and material-related aspects. Actually, there are a couple of aspects of composite resins that I consider relevant: 1. The degree of translucency or opacity, which will allow or block visualization of the tooth structure and adjacent layers of composite resin. 2. The opalescence. Opalescence can be defined in a simple manner as the object's ability to reflect light with short (blue) wavelengths and to transmit light with large (red, orange) wavelengths. Opalescent materials present the ability to change Hue, Chroma, and Value without changing their translucency. As a consequence, transparent or translucent materials can appear totally opaque, even in tiny thicknesses such as 0.1 to 0.5 mm, depending on the manner in which light hits their surface, and can present a number of colors. Considering that in the stratification technique composite resins are layered differently when stains are used, opalescent materials yield m·ore vivid (brighter) colors, even when they are clear (colorless). Accordingly, such materials should offer counteropalescence, a phenomenon that is observed in natural teeth, especially at the mamelon tips in anterior teeth. The shades produced by these composites present variable intensity depending on moisture and lighting conditions, unlike restorations that incorporate stains. This gives the restorations a dynamic behavior, very similar to the surrounding sound tooth structure. Thus, in spite of my belief that the outline, contour, and surface texture should be considered fundamental aspects, I would like to stress that the opalescence is the most important property that composites should present to simulate the amazing polychromatic effects of natural teeth. 411 ,/ 412 Manufacturers of composite resins usually design kits made up of a number of syringes that contain dentin and enamel materials. The dentin materials are divided into color groups (A, B, C, and D) and different Chroma according to their color saturation. The different tones of chromaticity are then indicated by numbers, the highest number corresponding to the darkest dentin color. There are two trends on the market at present. First, some manufacturers simplify their systems and eliminate all dentin Hues except A. On the basis of reports in the literature and the authors' clinical experience, this would appear to be a wise decision. Second, several systems recommend linking enamel and dentin materials of the same type (eg, A2 dentin composite with A2 enamel composite). This choice seems to be based mainly on the desire to simplify our manipulation and comprehension of the system rather than on scientific research. In reality, as has already been highlighted, enamel modifies the color of the dentinal base, and its influence is directly linked to the natural enamel thickness; the thicker the enamel is, the whiter and more opaque the tooth is. Presumably, the aforementioned products are characterized by a chromatic contrast between dentin and enamel , which has less color saturation in order to appear more translucent, as if enamel were diluted by dentin rather than the other way around. Some manufacturers include in their systems a product called body. According to the instructions, a layer of rather opaque missing dental tissue should be built up with a corresponding layer of body material and later covered by a layer of enamel. This body shade seems to be a material of intermediate translucency and is sometimes known as universal (a single product used to realize a complete one-shade restoration). Yet other manufacturers propose systems that contain only general dentin and enamel materials. Usually, dentin composites in these systems are very intense, and the enamel composite modifies the base color with white or amber nuances. These manufacturers suggest identifying the required enamel according to the age of the patient and the thickness of the residual enamel, which physiologically loses Value or whiteness over time, allowing the dentinal base color to show through. In addition, almost every manufacturer offers "special effects" enamels for reproduction of highly translucent layers, such as the orange or blue opalescence of the incisal third of natural teeth. The American market and its demands can be a principal example of this phenomenon. The American , market fecuses its attention on materials that favor smile uniformity and brilliance, usually obtained by the use of white and chromatically "simple" materials such as low-saturation dentins (sometimes less than Al) and enamels that are suitable for postbleaching restorations. Certain conclusions may be drawn from this general analysis: Manufacturers have a tendency to offer systems that are, at least theoretically, increasingly simplified to speed up and optimize the final result. "Globalization" in dentistry leads manufacturers to develop products that can be accepted by different markets with diverse needs and operational philosophies. The European market, on the other hand, tends to be more conservative and endeavors to find materials that will integrate a restoration with the patient's natural smile. Clinicians working in Europe are attentive to detail and to the nuances of color and effects that are obtainable with modern composites. 413 . / 41"1 Objective Assessment of Materials There is, therefore, much opportunity for confusion. Experience shows that the instructions that come with products are often of little use. What is more, clinicians often fall into the trap of dividing materials into those considered "simple" and those designed for the "esthetically obsessed," as if there might be patients or dentists interested in esthetically displeasing restorations. Moreover, clinicians request materials with chameleon-like properties, as if a syringe could possibly contain such a miracle product. However, there are ways to overcome these difficulties: To be perfectly clear, the miracle product does not exist. If used badly, even the most esthetically favorable material can give terrible results, just as the worst material, in the right hands, can give satisfactory results. Consequently, continual practice with the material of choice, construction of various samples, and application of different stratification techniques is the path to success. The first thing to suggest is construction of a personalized shade guide. Too often, color guides presented by a manufacturer are unrealistic. Moreover, they are often made of a different material such as plastic or paper, or sometimes are missing completely . An interesting exercise is to try to decide whether a tube contains a dentin or an enamel shade of composite resin without looking at the label. Some syringes turn out to be of little use, and others offer the possibility of successfu I integration into different restorations. Naturally, this experiment does not reveal everything, but it is a good beginning for a critical and analytical evaluation. .-· / Objectively, it is clear that when we compare composite samples that are the "same" color and even thickness .but different brands, the Chroma and translucency are completely different. This accounts for the need to create an individual color scale, especially if we use different composite systems. Just one shade of translucent or semiopaque composite material will change color dramatically depending on its thickness. A fundamental exercise to understand the role of thickness is to prepare enamel disks of 1.0 mm, 0.7 mm, 0.5 mm, and 0.3 mm and overlap them with a dentin disk to appreciate the change. There are many instruments on the market that can be used to create disks with a precise thickness (eg, Ceramic Sampler, Smile Line). Such disks can give us a clear idea of a material's properties, such as opacity, translucency, and pigment saturation . 415 ,/ The next step is to focus on the physical and optical properties of the composites we use, to create a gen-eral scale for correct guidance. Composite resin features Enamel Dentin Opalescence Intensity Fluorescence 2 5 1 4 Hybrid 4 5 4 4 Opalescence 4 1 5 1 Nanofilled 3 3 3 1 Dark stains 4 4 1 1 Light sta ins 4 4 1 1 Deep Me melon dentin masses 5 5 5 5 1 1 0 0 Microfilled 1 0 1 1 1 1 0 0 ................................................................................................................................. Flowable 1 4 1 1 4 4 3 . 0 . The table shows some mechanical, structural, and optical properties, in relation to the restoration area and necessity (on a scale of 0 to 5). Some properties are absolutely necessary (5, 4), while others are appealing (3, 2) or useless (1), and some may be damaging (0). The first step to follow is to take the A2 shade tab from the Vita shade guide (Vident) and select the closest shades to the different tooth thirds . Cervical third: The shades that usually this third are chromatic colors with a high opacity. For the first attempt to "discover" the system color we intend to analyze, we need to understand what we are dealing with; to this end, we should make a deep study of the available shades, colors, and opacities. From that variety of options, we must choose the right shades to stratify correctly. Middle third: Usually this third is the result of over-lapping dentin and enam-el shades; some systems have body shades. lncisal third: The shades are less chromatic and translucent. Once we obtain the approximate shades for each third, we must try sample stratifications on the tab. Performing this exercise before we start using a material in patients can save a lot of time and material in the future and is an excellent exercise for one of the most challenging restorations, diastema closure. '416 f / Once we have completed this simple trial, we can predict more precisely the thicknesses needed when that particular material is used. The strategy we propose is to use the Cera.mic Sampler, in this case for composite resins, to prepare uniform disks of the approximate thicknesses of every shade. We will build the following disks: • Dentins: 2.0 mm. • Bodies: 0.3 mm, 0.5 mm, and 1.0 mm. • Enamels: 0.1 mm, 0.2 mm, 0.3 mm, and 0.5 mm. Depending on the system, and the.number of colors, we will obtain an average of 30 to 40 disks. Once we have organized every sample, we will start overlapping disks starting with a dentin, then a body (if present), and finally the incisal enamel. Ii is very important to place glycerin between every disk, or we may obtain a color that is too light. We start overlapping the lightest colors and switching the deepest layers, until we achieve a color similar to the Vita shade guide (A2) in the middle of the sample (blue circle). Many trials are needed, but this is easier than stratifying; disks are immediately replaceable and switched with very little time and effort, and no material is wasted . After we have overlapped the disks, we will write down the thicknesses of the best matches for each tab in the Vita shade guide, and therefore create a recipe to obtain a determined color with a particular composite system. At the moment, this technique provides the most advanced and faithful shade guide. Through this exercise, we are prepared for stratification or to make personalized tooth-shaped samples. 417 Based on the recent literature, but above all on clinical experience and passion for the field , we have attempted to set up a system for evaluating the composite materials present on the market. While concentrating on the anatomical form of the natural teeth and with the previously analyzed disks, it is possible to make some suggestions on the layer thicknesses. It is in fact dentin that makes up the most important layer from a volumetric and chromatic point of view, and represents the crucial layer for the final restoration for integration with the rest of the teeth. At this point, it is possible to model the dentinal body three dimensionally, as has been shown before, limiting masses of dentin to two at most and exploiting the thickness variation of the tooth. A rigid silicone impression was taken from an intact natural incisor to allow the reproduction of a copy in composite. Fabrication of the base dentinal mass was followed by application of the second dentin to simulate different mamelon anatomies. (left to right) Base mass and young, adult, and old teeth. This copy was used to divide the tooth into three layers: dentinal body, dentin (to create features of internal anatomy such as mamelons and opalescence), and the facial superficial enamel. Composite teeth immediately after removal from the flask. The excess enamel composite (0.1 mm) is easily removed mechanically. The finished and polished samples are ready to be used and analyzed. '\19 Al Vita: 2.0-mm A2 dentin, 0.3-mm Al body, and 0.3-mm high-Value enamel. A2 Vita: 2.0-mm A2 dentin, 0.5-mm A2 body, and 0.3-mm medium-Val-ue enamel. A3 Vita: 2.0-mm A3 dentin, 0.3-mm A3.5 body, and 0.2-mm low-Value enamel. ' After manufacturing hundreds of samples, we came to the following conclusions: • Every composite resin system on the market can be reduced to a limited number of syringes that are use-ful in all natural teeth. Any exceptions can be man -aged by using special effect masses and super col· ors, which are suitable for emphasizing particular translucencies and individual features. • To optimize work with the chosen composite, it is imperative to construct a personalized shade guide with even and known thickness to identify the correct mass. 420 •Clinicians and specialized dental technicians possess an extraordinary amount of knowledge and expertise concerning the problems linked to reproducing the natural tooth color and the suitable materials for this purpose. • By listening to the suggestions of dental profession· als and analyzing materials with the color measuring instruments that are available today (spectrophotom· eter), manufacturers could further simplify their sys· terns, which would be extremely advantageous for the everyday practice of dentistry. Indeed, it was found that the materials with the best performance were produced with this collaborative spirit. ,• Tooth color is derived from the dentin, but the role of the enamel is of fundamental importance, as can be seen from these specially constructed composite samples. It is the thickness of the enamel that determines the different dental ages . Mastering enamel thickness is the keystone to excellence in esthetics and conservative dentistry. Today, composite materials allow clinicians to realize restorations that are highly esthetic yet minimally invasive, affordable for patients, and long lasting. In addition, the associated risk level over time is low and manageable. Reintervention is relatively easy and cheap, and fractures or defects that may appear over time can be repaired without remaking the whole restoration, which provides tooth-conservative and financial advantages for patients. Doubts that some clinicians may have about these techniques are usually associated with the amount of chairtime required as well as the difficulty in achieving good esfhetic results every day. As a consequence, more invasive techniques such as ceramic restorations are favored. We believe that operation times are inevitably linked to certain obligatory steps (preparation, adhesion phase, buildup with limited quantities of composite to reduce contraction, and correct curing times for each material layer). By carefully adjusting the thickness of the enamel on the incisors, it is possible to reproduce the natural opalescence without the addition of transparent composite and to change the "age" of the tooth as well. Nevertheless, with the instruments and guides that have been analyzed in the present chapter, stratification techniques can be key to the long-term success of restorations from both the clinical and esthetic points of view. This enables us to avoid short-term disappointments that require refacing and waste time. It is crucial to understand that a successful restoration begins with the correct choice of material. However, there is no miracle material on the market, and the final result is fundamentally linked to our manual skills and, moreover, our ability to choose the correct techniques that simplify everyday work in this profession. Success should not be measured solely by exceptional results in certain cases but rather by a good everyday standard for time management and limiting long-term risk. 421 A3 Teeth reproduction with different compos ites Adonis Am ari s Artiste Empress Enamel Estelite Esthet-X Filtek XT 422 Gradia Herculite Majesty Miris Opal I is Rename I Sinergy Venus 423 424 Conclusions 1. It is mandatory to understand the color of any composite resin perfectly prior to use, even if this only involves opening and comparing the syringes. 2. Shade guides included in most composite systems are not suitable for color matching, especially if they are not manufactured with the same composite. 3. Layering of composite resin disks has proven to be one of the most effective and least expensive methods for creating a personalized shade guide. 4. The relationship of enamel-dentin thicknesses is the key to successful layering. 5. All modern materials have excellent properties, but they always have at least one property that is markedly detrimental to another.

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