QDT 2020 221
Esthetics with Micro Restorations
followed a minimally invasive shoul-
derless preparation, smoothing only the sharp enamel
angles caused by the fracture using soft abrasive disks
(Super-Snap ﬂexible disks, Shofu) and silicone points, thus
creating a facial and proximal light chamfer directly follow-
ing the fracture line (Figs 7a and 7b).
Impressions were taken using polyvinyl siloxane (Virtual,
Ivoclar Vivadent). No retraction cord was required since the
limits of the restoration did not involve the cervical area.
An alveolar model (Fig 8) was made from the ﬁnal impres-
to fabricate the fragments in feldspathic porcelain
(IPS e.max Ceram, Ivoclar Vivadent) on refractory die ma-
terial (G-Cera Orbit Vest refractory die material for crowns/
veneers, DG Europe).
Porcelain layering on a refractory cast provides an ex-
cellent natural outcome, due to the possibility to control
the stratiﬁcation through all the layers using the patient’s
remaining natural teeth as the reference. However, this
technique does not allow major corrections after the re-
moval of the refractory material. Special care needs to be
taken to control volume contraction and positioning of the
Figs 7a and 7b Enamel recontouring following the fracture lines.
Fig 8 Alveolar model for fabricating the fragments in feldspathic porcelain on refractory die material.
Porcelain Layering Step-by-Step
• The refractory dies are dehydrated, and the connecting
ﬁring with Opal Effect 1 is carried out at 800ºC (Fig 9a).
• A ﬁrst bake with opaque porcelains (Deep Dentin A2
and Mamelon Light in a 50% ratio) precedes the tradi-
tional layering. The purpose of this preliminary bake is to
build up the vertical missing dentin of the fractured teeth
with an opaque layer that blocks the light and adds chro-
ma, avoiding the risk of excessive light absorption at the
level of the missing natural dentin, which could lead to a
low-value result. Better volume control of this layer is
achieved by ﬁring it separately (Fig 9b), which is carried
out at 770ºC. The opaque dentin cores after ﬁring are
shown in Fig 9c.
• Modiﬁed Dentin A1 with Mamelon Light in a 50% ratio is
used to fully build the teeth (Fig 9d).
• The basic shape is then reduced in the incisal area (cut-
back) to generate the space for the incoming powders
• The vertical interproximal increment with Opal Effect 1 is
shown in Fig 9f.
• Opal Effect 1 is applied as a thin layer over the concavity
of the cutback, slightly oversized vertically (Fig 9g) to
mimic the dentin-enamel junction (DEJ); this is the trans-
parent zone of aprismatic enamel, over the outer layer in
which facilitates light circulation through
the tooth’s layers.
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QDT 2020 221Esthetics with Micro RestorationsRestorative ProceduresEnamel recontouring8 followed a minimally invasive shoul-derless preparation, smoothing only the sharp enamel angles caused by the fracture using soft abrasive disks (Super-Snap ﬂexible disks, Shofu) and silicone points, thus creating a facial and proximal light chamfer directly follow-ing the fracture line (Figs 7a and 7b). Impressions were taken using polyvinyl siloxane (Virtual, Ivoclar Vivadent). No retraction cord was required since the limits of the restoration did not involve the cervical area. Laboratory ProceduresAn alveolar model (Fig 8) was made from the ﬁnal impres-sion9 to fabricate the fragments in feldspathic porcelain (IPS e.max Ceram, Ivoclar Vivadent) on refractory die ma-terial (G-Cera Orbit Vest refractory die material for crowns/veneers, DG Europe).Porcelain layering on a refractory cast provides an ex-cellent natural outcome, due to the possibility to control the stratiﬁcation through all the layers using the patient’s remaining natural teeth as the reference. However, this technique does not allow major corrections after the re-moval of the refractory material. Special care needs to be taken to control volume contraction and positioning of the different layers.87a 7bFigs 7a and 7b Enamel recontouring following the fracture lines.Fig 8 Alveolar model for fabricating the fragments in feldspathic porcelain on refractory die material. BOLOGNA/LAPLANAQDT 20202229a 9b9c 9d9e 9fPorcelain Layering Step-by-Step • The refractory dies are dehydrated, and the connecting ﬁring with Opal Effect 1 is carried out at 800ºC (Fig 9a). • A ﬁrst bake with opaque porcelains (Deep Dentin A2 and Mamelon Light in a 50% ratio) precedes the tradi-tional layering. The purpose of this preliminary bake is to build up the vertical missing dentin of the fractured teeth with an opaque layer that blocks the light and adds chro-ma, avoiding the risk of excessive light absorption at the level of the missing natural dentin, which could lead to a low-value result. Better volume control of this layer is achieved by ﬁring it separately (Fig 9b), which is carried out at 770ºC. The opaque dentin cores after ﬁring are shown in Fig 9c.• Modiﬁed Dentin A1 with Mamelon Light in a 50% ratio is used to fully build the teeth (Fig 9d). • The basic shape is then reduced in the incisal area (cut-back) to generate the space for the incoming powders (Fig 9e). • The vertical interproximal increment with Opal Effect 1 is shown in Fig 9f.• Opal Effect 1 is applied as a thin layer over the concavity of the cutback, slightly oversized vertically (Fig 9g) to mimic the dentin-enamel junction (DEJ); this is the trans-parent zone of aprismatic enamel, over the outer layer in natural teeth,10 which facilitates light circulation through the tooth’s layers.11 Esthetics with Micro Restorations QDT 2020223• Mamelon Light is placed to create subtle effects, similar to those seen in the opposite lateral and also in the re-maining incisal portion of the contralateral central (Fig 9h). • A preliminary enamel covering is applied using the se-lected incisal shade I2, extending it to the union of the middle and cervical thirds (Fig 9i).• Vertical layering at the incisal third with Opal Effect 1 and 2 provides different opal translucent effects in this area, generating absorption and reﬂection contrast. The ﬁnal shape must be oversized to compensate for the ﬁr-ing shrinkage (Fig 9j). • The complete stratiﬁcation was carried out at one bake at 770ºC. Contraction took place as expected. Surface grinding was performed, following the shape character-istics of the remaining structures. Surface macro and micro morphology was adapted with ﬁne diamond burs to the adjacent tooth structure for a successful integra-tion of the ceramic fragments. The restorations were glazed at 725ºC, with very little paste (Fig 9k). 9g 9h9i 9j9k QDT 2020224BOLOGNA/LAPLANAFinal mechanical polishing was carried out with a long-hair felt brush, and porcelain was moisturized with glaze liquid, replacing the diamond paste (Fig 10), with the res-torations still attached to the refractory dies.The refractory material was sandblasted with 50-micron glass beads. The fragments (Fig 11) were adapted to the stone dies and solid model as well. 1011Fig 10 Longhair felt brush used for ﬁnal mechanical polishing.Fig 11 Porcelain fragments ready for try-in and then bonding. QDT 2020 225Esthetics with Micro RestorationsTry-in, Bonding, and Finishing ProceduresThe try-in was done and did not reveal any need for correc-tions. Adhesive luting procedures were then performed. The internal surface of the feldspathic fragments were acid etched with hydroﬂuoric acid for 90 seconds. After copi-ous rinsing, the restorations were placed in an ultrasonic bath with alcohol and distilled water for 5 minutes. After drying, the intaglio surface was silanized.The enamel was acid etched, and dentin adhesive was used in the areas of dentin exposure. The internal surface of the restorations and the teeth involved were coated with adhesive resin and bonded using Variolink Esthetic LC neutral shade (Ivoclar Vivadent). After the ﬁnal bonding (Figs 12a and 12b), functional adjustments were made, with particular emphasis on main-taining the interrelation of centric occlusion, anterior guid-ance, and mandibular excursions using the patient’s natural remaining dentition as reference. These adjustments were performed with ﬁne diamond burs and polished with sili-cone points. A subsequent appointment was planned to polish the vestibular interface. For this purpose, silicone tips are rec-ommended, starting with the coarse-grained (green and blue) to reﬁne the interface, and ending with the ﬁne-grained (yellow) for a high-shine polishing (Fig 13). It is 12a 12b13Figs 12a and 12b Function is checked and adjustments made after the ﬁnal bonding.Fig 13 Coarse- to ﬁne-grained silicone polishing tips (NTI, Kahla GmbH) are used to reﬁne the interface and ﬁnally polish to a high-shine ﬁnish. BOLOGNA/LAPLANAQDT 2020226important to polish the interface in the correct direction, from the ceramic restoration toward the tooth, smoothing the union until it becomes almost imperceptible. Polishing in the wrong direction may result in a negative effect by emphasizing the interface. Careful photographic evalua-tion during the polishing process is highly recommended (Figs 14a and 14b).Comparative ﬁnal intraoral photographs taken with twin ﬂash (Twin Lite MT-24EX, Canon) and cross-polarized light (polar_eyes, Emulation) show the integration of the ceramic fragments with the dental structures (Figs 15a and 15b). Final extraoral (Fig 16) and facial views (Fig 17) show the esthetic result. REFERENCES1. Scopin de Andrade O, Rodrigues M, Hirata R, Alves Ferreira L. Adhesive oral rehabilitation: Maximizing treatment options with minimally invasive indirect restorations. Quintessence Dent Technol 2014;37:71–93.2. Magne P, Belser U. Bonded Porcelain Restorations in Anterior Denti-tion. A Biomimetic Approach. Ultraconservative Treatment Options. Chicago: Quintessence, 2002:99–127.3. Magne P, Perroud R, Hodges JS, Besler UC. Clinical performance of novel-design porcelain veneers for the recovery of coronal volume and length. Int J Periodontics Restorative Dent 2000;20:441–457.4. Chu SJ, Devigus A, Mieleszko A. Fundamentals of Color: Conven-tional Shade Matching and Communication in Esthetic Dentistry. Chi-cago: Quintessence, 2004:51–76.5. Hein S, Bazos P, Tapia Guadix J, Zago Naves L. Beyond visible: Exploring shade interpretation. Quintessence Dent Technol 2014;37: 199–211.Figs 14a and 14b Photographs aid in evaluating the polishing process.Figs 15a and 15b Final intraoral photographs taken with twin ﬂash and cross-polarized light.14a 14b15a 15b Esthetics with Micro Restorations QDT 20202276. Kina S, Bruguera A. Invisible. Luz y Color. Brazil: Editora Artes Médi-cas Ltda, 2008:79–124.7. Ubassy G. Trucs et Astuces. In: Asselmann P (ed). Tricks and Hints in Colour Selection. Brescia, Italy: Teamwork Media srl, 2008:21–57.8. Clavijo V, Sartori N, Park JH, Duarte S. Novel guidelines for bonded ceramic veneers: Part 1. Is tooth preparation truly necessary? Quin-tessence Dent Technol 2016;39:7–25.9. Magne M, Bazos P, Magne P. The alveolar model. Quintessence Dent Technol 2009;32:39–46.10. Bazos P, Magne P. Bio-Emulation: Biomimetically emulating nature utilizing a histo-anatomic approach: Structural analysis. Eur J Esthet-ic Dent 2011;6:8–19.11. Ubassy G. Shape and Color: The Key to Successful Ceramic Restora-tions. Chicago: Quintessence,1993:73–89.16a 16b17a 17bFigs 16 and 17 Final views of the esthetic result. Inside Out 1Dental Training Center, Barcelona, Spain.2Private Practice, Clinica Gonzalez Solano, Madrid, Spain.3Private Practice, Clinica Stoma, Barcelona, Spain.4Private Practice, Clinica Campuzano, Bilbao, Spain.Correspondence to: August Bruguera, c/Sardenya 229, 6° 5°, 08013 Barcelona, Spain. Email: [email protected] Technique for Faster and More Predictable LayeringTechnology has emerged in our profession in an ir-reversible and positive way. The digitalization of our laboratories has brought greater productivity while democratizing ceramic restoration—meaning that the av-erage laboratory, thanks to this technology, has managed to scale its product and more easily maintain greater regu-larity in quality.Facing this reality, the dental technician often asks: Does ceramic layering have a future? Will it resist the monolithic restoration? The answer is not simple, but we are still far from having a monolithic material that provides the same esthetic quality as a good layering.This article demonstrates a simple protocol that will give technicians the ability to beneﬁt from digitalization (in-crease production and maintain consistent quality) in ce-ramic layering as well.August Bruguera, TPD1Oscar González, DDS2Oriol Llena, DDS3Jon Gurrea, DDS4229 QDT 2020 BRUGUERA ET ALQDT 2020230INCISAL EDGE POSITION The diagnostic wax-up provides a great deal of information about a restoration:• Emergence proﬁle• Volume• Shape• Length• Amplitude• Incisal edge positionA good layering with that information should guarantee success. However, while many authors have developed protocols to guide the ceramist in copying the diagnostic wax-up, unfortunately the results obtained are usually some-what approximate.Without a doubt, the incisal edge position is the most important information provided by the wax-up. The location of the incisal edge will be decisive for the success of layer-ing. Consider the before-and-after images of the two clini-cal cases shown in Figs 1 and 2. If asked what we like best about the deﬁnitive restorations (Figs 1b and 2b), each of us will focus on something different—some on the layer-ing, others on the mamelons. In the end, we will have a set of details that together provide a well-balanced, successful result.Consider next a natural tooth, which is basically formed of two structures—the internal dentin and the enamel. A sagittal cut illustrates these two layers and the intimate relationship between them (Fig 3). In any such example it is apparent that the proportion of enamel and dentin is not symmetric, and that the dentinal structure loses volume as it is projected to the incisal edge, the enamel being the main protagonist. For this reason, it is important to locate the position of the incisal edge in space when layering, since all the internal layers must be projected toward that point. The success of any layering, whether simple or com-plex, is based on the balance between internal and exter-nal masses (Fig 4).Technicians frequently use palatal silicone keys to maintain the incisal position throughout the layering pro-cess. With these keys, the position of the dentin is 100% guaranteed (Fig 5). Once the dentins are added, we must continue applying masses beyond the incisal edge to com-pensate for the vertical contraction of the ceramic. To do so requires removing the silicone key, so the remainder of the layering will be done without any reference (Fig 6). This Figs 1a and 1b Before and after photographs of clinical case (Dr Oriol Llena) demonstrate dentin layering with little prominence of enamel.Figs 2a to 2c Before and after photographs of clinical case (Dr Jon Gurrea) demonstrate layering with prominence of enamel.2a 2b 2c1a 1b Inside Out: A Technique for Faster and More Predictable Layering QDT 2020231is not a problem if a restoration requires only two crowns, since the remaining teeth provide many references to con-trol the correct position of the internal masses. But the ref-erences are lost in a larger rehabilitation, such as six anterior units, and it is easy to lingualize or vestibularize these masses. If all the layering is done with the silicone key as a guide, there will be a good color result but the crown in this case will be approximately 1.5 mm short of the desired length (Fig 7).34Fig 3 The amounts of dentin and enamel are not symmetric in the natural tooth.Fig 4 Layered internal masses must project toward the incisal edge to achieve balance between internal and external masses.Fig 5 With a silicone key it is easy to place the internal masses.Fig 6 Extending a restoration to compensate for the vertical contrac-tion of the ceramic must be done without the silicone reference.Fig 7 If the silicone key can remain in place when layering, the result will be a good balance of color and quicker restoration.5 67 BRUGUERA ET ALQDT 2020232THE INSIDE OUT CONCEPTThe Inside Out concept uses silicone keys that compensate for the vertical contraction of the ceramic and can remain in place to guide the layering process. For this, the amount of contraction of the ceramic being used must be known or can be approximated by measuring a crown before and after baking. In the case illustrated, using IPS e.max (Ivo-clar Vivadent), the contraction will be approximately 1.5 mm.Starting from a diagnostic wax-up (Fig 8), the vertical contraction is compensated for by lengthening the incisal contour 1.5 mm with wax (Fig 9) and then making a sili-cone key that will register this new incisal position (Fig 10).The next step is to cut the silicone key. There are three cutting options at the incisal edge, as shown in Fig 11: (A) the vestibular aspect; (B) the center of the incisal edge, where the dentin is projected; and (C) the palatal aspect. Think of a simple layering of two masses using two, in-stead of one, silicone keys—one cut in the vestibular as-pect (A, which we will call enamel key) and another cut in the center of the incisal edge (B, which we will call dentin key). First the dentin key (B) is ﬁlled with the internal masses, then it is changed to the enamel key (A) and ﬁlled with the incisal (Fig 12). For a complex layering, the procedure would be the same except that on the dentin key (B) all the internal masses are placed (as shown in Figs 13 to 15), resulting in an extremely simple and fast exercise. The dentin key is replaced by the enamel key (A), where the space for the external masses is generated (Figs 16a and 16b). The next step is simply to ﬁll the silicone with the incisals chosen.After the bake, the incisal position of the restoration is the same as in the diagnostic wax-up (Figs 17a and 17b). Note the balance between dentin and enamel, thanks to the guided layering. Finishing of the restoration can then be accomplished and the restoration completed in a short-er amount of time.Fig 8 The diagnostic wax-up indicates the future incisal position.Fig 9 Vertical contraction of the ceramics is compensated for by adding wax. In this case, 1.5 mm is added.Fig 10 A silicone key is made for use as a support throughout the layering.Fig 11 Three cutting options for the silicone key incisal edge: (A) vestibular, (B) center, and (C) palatal.Fig 12 Two silicone keys, the enamel (A) and dentin (B), are removed.8 9 1011 12A B CA B