Successful Ceramic Application on Various Substructures
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Murilo Calgaro, cdt Victor Clavijo, dds, ms, phd Rogerio Goulart da Costa, dds, ms Willy Clavijo, cdt
A wide variety of ceramic materials that replicate the visual characteristics of natural teeth are available for cosmetic layering. However, for customized prosthetic restorations that seek to restore the functions of chewing and speech as well as esthetics, clinicians and technicians are forced to confront the limitations and technical difficulties of the materials. There are many factors for the user to consider when choosing the best material. The number of new systems that are available on the market only increases the chance of error, which is usually associated with lack of experience with new materials. The aim of this chapter is to help technicians and dentists select proper materials and application strategies for successful prosthetic restorations, even when different dental substructures of varied opacity and color are restored with the same ceramic materials. To achieve this purpose, this chapter uses a case report as a context for classifying materials according to their opacity, technical limitations, and implementation strategies. The visual properties and working qualities of the materials are compared to determine the strengths of each and indicate possible solutions to their esthetic limitations. Because most difficulties are related to restoring substructures of varying degrees of translucence, several types of material were selected for this analysis: Ceramill Sintron cobalt-chromium sinter metal, Ceramill ZI A1 anatomical, 0.4-mm Ceramill A1 zirconia, and 0.4-mm Ceramill White Zirconia blocks (Amann Girrbach); and 0.8-mm IPS e.max MO 1 (medium-opacity) and 0.5mm IPS e.max HO 1 (high-opacity) lithium disilicate blocks (Ivoclar Vivadent).
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Successful Ceramic Application on Various Substructures Fig 11-1  Initial case presentation. Note the gingival recession and the discoloration of the maxillary right central incisor.
Types of Substructure Metal
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The opacity of the structure can be managed through anatomical characterization of the coping or by the use of an opaque liner. In addition, the substructure can be pigmented with color compatible with any chromatic base.
Dentists are accustomed to making substructures for removable and fixed prostheses from metal. It is remarkable that technology and materials have evolved from manual centrifugal casting of gold alloys to computer-aided design/ computer-assisted manufacture (CAD/CAM) of cobaltchromium presintered blocks. These innovations have improved the quality and precision of prosthetic fabrication, allowing for thin and resistant structures with excellent marginal fit. The most commonly used prosthetic substructures are metal copings, and their fabrication techniques are so predictable because of their abundant use in prosthetic rehabilitation over the last 100 years. Metal copings can be worked very thin (0.3 mm for single crowns), which allows the application of additional ceramic layers to achieve characterization that replicates natural teeth. Opaque layers can be used on substructures of any color; however, to prevent visible gray halos in the cervical gingiva, the area of transition requires a ceramic shoulder, which demands significant technical skill on the part of the ceramicist to ensure that the marginal adaptation is not compromised during firing.
Pressed ceramics
Zirconia
Evaluation
Zirconia simplifies and minimizes the difficulties with opacity that arise with metal copings. Zirconia copings have good opacity that facilitates masking of discolored tooth structure and simultaneously exhibit sufficient translucency to assist in the transmission, absorption, and reflection of light. Use of CAD/CAM to fabricate the coping ensures flexibility and precision. Technicians favor the use of these metal-free copings because it simplifies the application of ceramic.
A 32-year-old man in the final stage of orthodontic treatment sought esthetic treatment. He was concerned about his darkened maxillary right central incisor (Fig 11-1). The medical history as well as clinical and radiographic evaluations revealed that the maxillary right central incisor had undergone root canal treatment and the darkened crown had been restored with composite resin. The patient had good oral hygiene and no signs of gingivitis and/or periodontal disease.
Pressed ceramic systems provide a wide range of technical possibilities and ensure a customized structure for every case. Ceramic substructures can be layered with highquality esthetic ceramic with excellent mechanical and adhesive properties. Superior esthetics result from the different degrees of opacity that can be obtained by using the various ceramic ingots. Because of the translucency and other characteristics that simulate those of natural tooth structure, dentists and technicians prefer these materials. The prostheses that can be fabricated range from a simple coping of 0.5 to 0.8 mm to structures that require buccal and labial veneers to anatomical crowns requiring characterization with stain and glaze. These ceramic systems are extremely versatile for fabricating various prostheses, including onlays, inlays, veneers, crowns, and even up to three-unit fixed prostheses, through conventional waxing or the use of CAD/CAM technology.
Case Report
Case Report
Fig 11-2 Esthetic repositioning of the maxillary anterior gingiva. (Periodontal surgery by Dr Paulo Fernando Mesquita de Carvalho, São Paulo, Brazil.)
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Fig 11-3 Situation after removal of the orthodontic appliance. Note the health of the soft tissues 4 months after surgery.
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Fig 11-4 Endodontic retreatment of the maxillary right central incisor. (a) Preparation of the canal. (b) Placement of a translucent fiber-reinforced composite endodontic post. (c) Placement of opaque composite resin to build up the core on the endodontic post. (d) Photopolymerization for 40 seconds. (e) Cementation of the endodontic post and core. (f ) Definitive endodontic post and core. (Endodontic therapy by Dr Erika Clavijo, São Paulo, Brazil.)
Initial treatment The treatment plan consisted of repositioning of the maxillary anterior gingiva, endodontic retreatment of the right central incisor, and eventual restoration with a ceramic crown. The maxillary anterior gingiva was surgically reposi-
tioned (Fig 11-2), and 4 months later the orthodontic appliance was removed (Fig 11-3). Endodontic retreatment included immediate placement of an endodontic post (Fig 11-4). A provisional acrylic resin crown (New Outline, Anaxdent) was placed to encourage soft tissue maturation (Fig 11-5). 207
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Successful Ceramic Application on Various Substructures
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Fig 11-5 (a) Rounded shoulder preparation for a crown restoration. (b to d) Provisional acrylic resin crown.
Fig 11-6 Custom acrylic resin die to simulate the prepared tooth.
Comparison of material translucency To determine which material would provide the most esthetic restoration for the patient’s maxillary right central incisor, and to demonstrate the effect of the prosthetic substructure on the outcome of ceramic restorations, ceramic crowns were prepared on copings made of six different materials. To visualize the differences in structural translucency, a custom die that incorporated customized colors found in the substrate of the natural tooth was fabricated in acrylic resin (Fig 11-6). One coping in each of the six materials was 208
fabricated using CAD/CAM technology (Ceramill, Amann Girrbach). Copings in each material were photographed on the custom die to demonstrate the influence of substructure color on translucent prostheses and to determine if each material achieved the expected outcome (Fig 11-7). To better replicate the conditions in the mouth, a liquid glaze was used to cement the coping on the customized die to facilitate visualization of any interference from substrate color in the appearance of the prostheses. The copings were placed on the prepared tooth and photographed to enable evaluation of the possible effects of the substrate (Fig 11-8).
Case Report
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h Fig 11-7  (a) Ceramill Sintron metal coping. (b) Ceramill ZI A1 anatomical coping. (c) Ceramill A1 zirconia coping. (d) Ceramill White Zirconia coping. (e) IPS e.max MO 1 (0.8-mm) lithium disilicate coping. (f ) IPS e.max HO 1 (0.5-mm) lithium disilicate coping. (g and h) Comparison of the translucency of the various copings.
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Successful Ceramic Application on Various Substructures
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Fig 11-8  (a and b) Ceramill Sintron metal coping in situ. (c and d) Ceramill ZI A1 anatomical coping in situ. (e and f ) Ceramill A1 zirconia coping in situ.
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Case Report
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Fig 11-8  (cont) (g and h) Ceramill White Zirconia coping in situ. (i and j) IPS e.max MO 1 lithium disilicate coping in situ. (k and l) IPS e.max HO 1 lithium disilicate coping in situ.
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Successful Ceramic Application on Various Substructures
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Ceramill Sintron metal coping Influence of substrate color. The opacity of the metal coping allowed no show-through of staining or discoloration from the prepared tooth (see Fig 11-7a). In this case, use of minimal metal thickness ensured sufficient space for ceramic layering. Technical limitations. Anterior metal-ceramic restorations require the use of a shoulder porcelain, which increases the number of steps during fabrication and necessitates additional attention to the marginal adaptation. Firing shrinkage and poor adaptation can occur in small ceramic
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Ceramill ZI A1 anatomical coping Influence of substrate color. This anatomical coping allows an increased thickness of zirconia, which can block underlying discoloration with great efficacy (see Fig 11-7b). Technical limitations. Because of the predictability of the fabrication procedures, this coping does not present any major technical difficulties. 212
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Fig 11-9  (a and b) Ceramill Sintron metal coping.
shoulders, occasionally requiring modifications to acquire an acceptable cervical seal. Depending on the design of the ceramic shoulder, the duration and the difficulty of the layering process may increase. In some cases, after a try-in is completed, the fired ceramic may need correction or a new glaze. Implementation strategies. The focus should remain on the cervical region to provide a smooth transition and minimize the overall opacity of the metal structure. It is recommended that sufficient thickness of ceramic be applied in this region to promote reflection and absorption of light, which is always changing.
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Fig 11-10  (a and b) Ceramill ZI A1 anatomical coping.
Implementation strategies. The anatomical zirconia coping provides significant blocking of any residual staining, which simplifies the process of layering in two ways: (1) It eliminates the need to mix opaque dentin with the primary dentin, and (2) it minimizes the need for overbuilding to compensate for firing shrinkage. A liner can be applied to customize the cervical margin and add higher chroma.
Case Report
Fig 11-11  (a and b) Ceramill A1 zirconia coping.
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Ceramill A1 zirconia coping Influence of substrate color. The 0.4-mm A1 zirconia coping does not completely block underlying staining (see Fig 11-7c). However, its opacity is ideal for covering moderate staining that does not include black, green, or metallic pigmentation. Technical limitations. The technician is required to use greater care in condensing the ceramic layers for a 0.4-mmthick coping than for an anatomical coping. In addition, the 0.4-mm coping is more influenced by dark staining of the substrate.
Fig 11-12  (a and b) Ceramill White Zirconia coping.
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Ceramill White Zirconia coping Influence of substrate color. The influence of substrate color on the 0.4-mm White Zirconia coping (see Fig 11-7d) is very similar to that on the A1 zirconia coping; the two materials differ only in pigmentation. However, the high luminosity of White Zirconia offers better blocking of the substrate color.
Implementation strategies. For a coping with a uniform thickness of 0.4 mm, an application of intermediate ceramic is required to provide anatomical shape as well as to compensate for and ensure greater predictability of the shrinkage during the first firing. In addition, a basic dentin mixed with a more opaque dentin must be applied to ensure sufficient luminosity and adequate blocking of the stained tooth underneath. This layer does not require additional characterization; the chroma can be customized during the second firing.
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Technical limitations. The high luminosity makes it difficult to obtain the appropriate chroma. Implementation strategies. The application of a customized layer is essential to raise the chroma and lower the brightness of the coping. In addition, firing shrinkage necessitates overbuilding of the layer.
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IPS e.max MO 1 lithium disilicate coping Influence of substrate color. In some cases, the influence of substrate staining can still be seen through a 0.8-mmthick MO 1 lithium disilicate coping (see Fig 11-7e), even when manufacturer instructions are followed.
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IPS e.max HO 1 lithium disilicate coping Influence of substrate color. The opacity of the HO 1 lithium disilicate block (see Fig 11- 7f ) is consistent with that of zirconia. This favors the use of a coping about 0.5 mm thick, which provides more space for application of the ceramic. Technical limitations. When the thicknesses recommended by the manufacturer are followed, the coping is
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Fig 11-13  (a and b) IPS e.max MO 1 lithium disilicate coping.
Technical limitations. Excess translucency combined with a reduced tooth preparation may hinder application of sufficient layers of ceramic to obtain the correct luminosity and chromaticity. Implementation strategies. The average opacity of the coping necessitates an increase in the opacity and luminosity of the dentin shades in all ceramic layers.
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Fig 11-14  (a and b) IPS e.max HO 1 lithium disilicate coping.
highly opaque. This increases the brightness significantly, often making it difficult to reproduce a natural depth in the definitive restoration, especially if space for ceramic layering is limited. Implementation strategies. When the thickness of the coping is reduced to 0.5 mm, there can be a partial blocking of the prepared tooth, which allows more room for layering and facilitates a more natural end result.
Case Report
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Fig 11-15  (a and b) Selection of color and brightness using Vita shade tabs A1, A2, B1, and B2 (Vident). (c and d) Selection of color and brightness using Vita shade tabs A2, B1, A1, and B2. (e and f ) Selection of color and brightness using natural die shade tabs St3, St5, St8, and St9 (Ivoclar Vivadent).
Selection of color With the help of digital photography, a basic color was selected, as were matches for opalescent effects, mamelons, and areas of absorption and reflection of light (Fig 11-15).
When contrast was increased and glare was reduced in the photographs, it was possible to detect the position and quantity of all ceramics that were used (Fig 11-16). A map of the buildup was created (Fig 11-17).
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Successful Ceramic Application on Various Substructures
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Fig 11-16  (a and b) Visualization of the tooth preparation with and without contrast.
A1 Dentin + OD Orange A1 Dentin TI-2 Mamelon Salmon Special Incisal Gray Opalescent Effect 3 Opalescent Effect 4 Fig 11-17  Color map of the restoration buildup. OD, Opaque Dentin.
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Characterization of copings
Ceramill Sintron metal coping
IPS d.SIGN ceramic (Ivoclar Vivadent) was used to fabricate the crown on the metal coping, and IPS e.max Ceram (Ivoclar Vivadent) was used as the layering ceramic for the zirconia and lithium disilicate copings.
To block the metal coping, an opaque A1 dentin was used, followed by application of a shoulder porcelain with higher chroma, obtained by mixing an A2 shoulder porcelain with an orange intensifier in a proportion of 70% to 30%. A thin layer of A2 shoulder porcelain was added to the incisal edge with the intention of building out the form and providing a smooth transition to the incisal third (Fig 11-18).
Case Report Fig 11-18  Characterization of the metal coping.
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Fig 11-19  (a and b) Characterization of the ZI A1 anatomical coping by layering with a combination of ZirLiner ZL1 and Essence E12 Cappuccino in a 5:1 ratio. (c) First firing.
Ceramill ZI A1 anatomical coping Because the anatomical coping has a thickness greater than 0.4 mm, the opacity at the cervical region causes excessive brightness. This was resolved by following manufacturer guidelines to apply a liner to customize the chroma throughout and slightly reduce the brightness in the cer-
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vical region. A thin layer of ZirLiner ZL1 (Ivoclar Vivadent) was mixed in a 5:1 ratio with Essence E12 Cappuccino and layered on the coping (Fig 11-19). The anatomical shape of the coping requires no additional shaping; it is ready for layering after the first firing. The sequence of layering and characterization was the same as that applied to the other zirconia and pressed ceramic copings.
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Fig 11-20 (a and b) Characterization of the A1 zirconia coping by layering with ZirLiner ZL1. (c) First firing.
Fig 11-21 Buildup on the A1 zirconia coping.
A1 Dentin + OD Orange (1:1) A1 Dentin + Mamelon Light (2:1) TI-2 Mamelon Salmon
Fig 11-22 Color map of the A1 zirconia buildup.
Ceramill A1 zirconia coping For the 0.4-mm A1 zirconia coping, only ZirLiner ZL1 was used (Fig 11-20). This coping already had uniform chroma, which allowed characterization and buildup after the shrinkage of the first firing. Buildup after firing required customized contouring that adequately compensated for shrinkage (Fig 11-21). This step initiated the layering of the base colors (Fig 11-22): • Cervical chroma: A1 Dentin and Opaque Dentin Orange were used in a 1:1 ratio.
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• Body: A1 Dentin and Mamelon Light were used in a 2:1 ratio. • Transitional incisal edge: Incisal TI-2 was applied, and the area was coated with a thin layer of Mamelon Salmon to create a smooth transition between the incisal edge of the coping and the translucent incisal area. Mamelon Light is highly opaque and fluorescent with chroma very close to A1 and B1. The mixture of these components with dentin shades minimizes translucency, increases luminosity, and helps to mask any darkened residual tooth structure.
Case Report
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Fig 11-23 (a and b) Characterization of the White Zirconia coping by layering with a mixture of ZirLiner ZL1 and Essence E12 Cappuccino. (c) First firing.
Fig 11-24 Buildup on the White Zirconia coping.
A1 Dentin + OD Orange (1:1) A1 Dentin + Mamelon Light (2:1) TI-2 Mamelon Salmon
Fig 11-25 Color map of the White Zirconia buildup.
Ceramill White Zirconia coping Because of the higher luminosity of the White Zirconia coping, ZirLiner ZL1 was customized with Essence E12 Cappuccino. The mixture was applied first in a 3:2 ratio in a thin layer in the cervical area and then in a 4:1 ratio for the body.
This step decreased brightness and achieved adequate chroma (Fig 11-23). The buildup was completed identically to that done on the A1 zirconia coping (Fig 11-24). This step initiated layering of the base colors (Fig 11-25).
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Successful Ceramic Application on Various Substructures
a Fig 11-26 MO 1 lithium disilicate coping.
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Fig 11-27 (a and b) Ceramic buildup on the MO 1 coping.
A1 Dentin + OD Orange (1:1) A1 Dentin + Mamelon Light (2:1) TI-2 Mamelon Salmon
Fig 11-28 Color map of the MO 1 buildup.
IPS e.max MO 1 lithium disilicate coping When ceramic is layered on the MO 1 lithium disilicate coping, care must be taken with the translucency. The 0.8-mm thickness may not be enough to totally block any underlying darkness (see Fig 11- 7e). In this case, it was necessary to increase opacity; a mixture of ceramics with greater opacity was used during the layering process (Figs 11-26 to 11-28): • Cervical wash firing: A1 Dentin, Mamelon Light, and Opaque Dentin Orange were used in a 2:1:1 ratio to provide more intense shading to the cervical area. The addition of Mamelon Light also provided greater opacity to the cervical area while preventing excessive absorption of light. • Body wash firing: Dentin A1 and Mamelon Light were applied in a 2:1 ratio. Adding Mamelon Light in this region provided greater opacity to increase the brightness and help neutralize any remaining darkness without losing the reference chroma.
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• Incisal wash firing: Incisal TI-2 was coated with a thin layer of Salmon Mamelon to create a smooth transition from the incisal edge of the coping to the translucent incisal area.
IPS e.max HO 1 lithium disilicate coping A material of high opacity, the HO 1 lithium disilicate coping provides a much higher degree of opacity when made 0.8 mm thick. In most cases, this provides total blocking of the darkened tooth preparation but makes it difficult to obtain depth and remove excess brightness in the definitive restoration. To minimize these limitations, a thinner coping of 0.5 mm was fabricated from an HO 1 lithium disilicate block (see Fig 11-7f ). This coping requires a change in the layering strategy because the structure is more opaque. Highly opaque ceramics such as Mamelon Light were used in smaller amounts; the rest of the layering was the same for all areas (Figs 11-29 to 11-31):
Case Report
a Fig 11-29 HO 1 lithium disilicate coping.
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Fig 11-30 (a and b) Ceramic buildup on the HO 1 coping.
A1 Dentin + OD Orange + Mamelon Light (2:0.5:1) A1 Dentin + Mamelon Light (3:1) TI-2 Mamelon Salmon
Fig 11-31 Color map of the HO 1 buildup.
• Cervical wash firing: Dentin A1, Mamelon Light, and Opaque Dentin Orange were applied in a 2:0.5:1 ratio to provide more intense shading to the cervical area. The amount of Mamelon Light was reduced because of the high opacity of the coping. • Body wash firing: Dentin A1 and Mamelon Light were used in a 3:1 ratio. • Incisal wash firing: Incisal TI-2 was coated with a thin layer of Salmon Mamelon to create a smooth transition from the incisal edge of the coping to the translucent incisal area.
Two-layer application technique Two-layer techniques can be simple; everything that is observed in the inner layer of the natural tooth is part of the first layer and is reproduced in a first firing. This layer comprises the dentin, chroma in cervical areas, areas of proximal light absorption, and opalescent incisal edges and mamelons (see Fig 11-17). This layer is developed only with internal materials that favor short and predictable working times.
The enamel is left to the second layer, which allows for better control over the ceramic contraction and the possibility of reviewing all of the details of the first layer. When there is any irregularity, color can be corrected quickly, without having to waste a lot of ceramic material. Enamel is responsible for giving depth to the natural tooth. This characteristic should be sought in the second layer with the application of opalescent and translucent ceramics. This layer builds up a large amount of material, which requires a greater dedication to shaping the prosthesis without excess and simplifying the procedure for characterization and surface texturing.
First layer The basic dentin color for the first layer of ceramic was selected by comparing the natural teeth to a shade guide (see Fig 11-15). Layering was performed in the same way on every coping, but because of the different opacities of the structures, there were some minor variations in the proportions and distributions of shades used for the dentin assemblies (Fig 11-32). 221
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Successful Ceramic Application on Various Substructures
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A1 Dentin + OD Orange
A1 Dentin + OD Orange (1:1)
A1 Dentin
A1 Dentin + Mamelon Light (3:1)
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Mamelon Salmon
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Special Incisal Gray
Special Incisal Gray
Opalescent Effect 3
Opalescent Effect 3
Opalescent Effect 4
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Opalescent Effect 4
A1 Dentin + OD Orange (1:1)
A1 Dentin + OD Orange (1:1)
A1 Dentin + Mamelon Light (2:1)
A1 Dentin + Mamelon Light (2:1)
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Mamelon Salmon
Mamelon Salmon
Special Incisal Gray
Special Incisal Gray
Opalescent Effect 3
Opalescent Effect 3
Opalescent Effect 4
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Opalescent Effect 4
A1 Dentin + Mamelon Light + OD Orange (2:1:1) A1 Dentin + Mamelon Light (2:1)
A1 Dentin + OD Orange (1:1)
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Special Incisal Gray
Special Incisal Gray
Opalescent Effect 3
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Opalescent Effect 4
A1 Dentin + Mamelon Light (3:1)
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Opalescent Effect 4
Fig 11-32  Color maps of the dentin (first) layer showing the variation in proportions and distributions of dentin porcelain shades applied to the different copings. The differences between each material are highlighted in bold. Dentin buildup on the metal coping (a), ZI A1 anatomical coping (b), A1 zirconia coping (c), White Zirconia coping (d), MO 1 lithium disilicate coping (e), and HO 1 lithium disilicate coping (f ).
The same sequence and application technique were used for all copings. There was a need for minor changes in the proportion of dentin porcelain shades because of varying opacity and brightness of the materials. This application of ceramic is demonstrated on the Ceramill ZI A1 anatomical coping (Fig 11-33). To assess the possible color influence of the substrates, the fired copings were placed in the mouth and photo222
graphed in close-up and from a distance. In close-up photographs, the flash masks any differences in the brightness between adjacent teeth and makes them more homogenous. In photographs taken from a distance, there is less interference from the flash, and the result is a more realistic idea of the brightness. However, close-up photographs reveal the layering in much greater detail (Fig 11-34).
Case Report
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Fig 11-33  (a) Application of ceramic on the Ceramill ZI A1 anatomical coping. (b) Use of a silicone guide. Application of A1 Dentin and Mamelon Light (c and d), Incisal TI-2 and A1 Dentin at the translucent incisal area (e), Salmon Mamelon (f ), and Opalescent Effects (g and h). After first firing of the ceramic crown on the Ceramill Sintron metal coping (i), Ceramill ZI A1 anatomical coping (j), Ceramill A1 zirconia coping (k), Ceramill White Zirconia coping (l), IPS e.max MO1 coping (m), and IPS e.max HO1 coping (n).
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Fig 11-34  Clinical photographs of the fired copings in the mouth. These photographs can be used to assess the possible influence of the substructure on the first layer. Close-up images reveal greater detail of the layering, while more distant photographs provide a more realistic idea of the brightness. (a to d) Fired metal coping. (e to h) Fired ZI A1 anatomical coping.
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Case Report
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Fig 11-34  (cont) (i to l) Fired A1 zirconia coping. (m to p) Fired White Zirconia coping.
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Fig 11-34  (cont) (q to t) Fired MO 1 lithium disilicate coping. (u to x) Fired HO 1 lithium disilicate coping.
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Case Report
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OE 1 + OE 2 + A1 Dentin (1:1:1)
OE 4 + Essence White (3:1)
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OE 1 + OE 2 + A1 Dentin (1:1:1)
OE 4 + Essence White (3:1)
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OE 1 + OE 2 + A1 Dentin (1:1:1)
OE 4 + Essence White (3:1)
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OE 1 + OE 2 + A1 Dentin (1:1:1)
OE 4 + Essence White (3:1)
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OE 1 + OE 2 + A1 Dentin (1:1:2)
OE 4 + Essence White (3:1)
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OE 1 + OE 2 + A1 Dentin (1:1:1)
OE 4 + Essence White (3:1)
Fig 11-35  Opalescence maps of the enamel (second) layer, showing the variation in proportions and distributions of the different opalescent enamel porcelains applied to the different copings. (a) Enamel buildup on the metal coping. (b) Enamel buildup on the ZI A1 anatomical coping. (c) Enamel buildup on the A1 zirconia coping. (d) Enamel buildup on the White Zirconia coping. (e) Enamel buildup on the MO 1 lithium disilicate coping. (f ) Enamel buildup on the HO 1 lithium disilicate coping. OE, Opalescent Enamel.
Second layer The second layer, comparable with dental enamel, was created with a mixture of basic opalescent enamel porcelain composed of Opalescent Enamel 1 and Opalescent Enamel 2 in a 1:1 ratio. When the first firings were placed in the mouth and compared to the Vita shade guide, it was determined that some copings required an increase in
opacity, depending on the translucency displayed at this stage (Fig 11-35). To finesse the brightness and opacity, the proportion of opalescence in the enamel porcelain was customized for each situation (Fig 11-36). This adjustment provided higher brightness and enamel opacity without altering the hue and chroma that are characteristic of natural teeth.
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e Fig 11-36  Application of second layer. (a) Appearance after the first firing. (b) Enamel application of Opalescent Enamel 1, Opalescent Enamel 2, and A1 Dentin in a 1:1:1 ratio. (c and d) Characterization of decalcified white spots using Opalescent Enamel 4 and Essence White in a 3:1 ratio. (e) After second firing.
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Case Report
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Fig 11-37  Clinical photographs of the copings in the mouth after the second firing. These photographs can be used to detect deficiencies in color characterization, which can be corrected during customization of the definitive restoration. (a and b) Fired metal coping. (c and d) Fired ZI A1 anatomical coping. (e and f ) Fired A1 zirconia coping. (g and h) Fired White Zirconia coping. (i and j) Fired MO 1 lithium disilicate coping. (k and l) Fired HO 1 lithium disilicate coping.
After the second firing, the enamel buildups were placed in the mouth, and the results of ceramic layering over different coping materials were observed. Photographs revealed
deficiencies in the color characterizations (Fig 11-37). The deficiencies were corrected during customization of the definitive shape, texture, and glaze.
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Fig 11-38  (a and b) Positioning of line angles for optimal light reflection. (c) Customization of the definitive shape and texture.
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Fig 11-39  Crowns on the cast after glaze firing. (a) Crown on the metal coping. (b) Crown on the ZI A1 anatomical coping. (c) Crown on the A1 zirconia coping. (d) Crown on the White Zirconia coping. (e) Crown on the MO 1 lithium disilicate coping. (f ) Crown on the HO 1 lithium disilicate coping.
Definitive characterization Finishing and texturizing were completed (Fig 11-38), leaving surfaces ready for extrinsic characterization with universal stains and glazes. It was possible at this stage to block excess translucency in some areas of the incisal edge with 230
Stain Crackliner (Ivoclar Vivadent) as well as to reproduce small white spots with White Stain (Ivoclar Vivadent). After the final firing, the shine was refined with the help of finishing diamonds and polishing disks. After glaze firing, the crowns were assessed on the cast (Fig 11-39).
Case Report
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l
Fig 11-40  Esthetic try-in of the crowns prior to crown selection and cementation. (a and b) Completed crown on the metal coping. (c and d) Completed crown on the ZI A1 anatomical coping. (e and f ) Completed crown on the A1 zirconia coping. (g and h) Completed crown on the White Zirconia coping. (i and j) Completed crown on the MO 1 lithium disilicate coping. (k and l) Completed crown on the HO 1 lithium disilicate coping.
Try-in, selection, and cementation The crowns were placed in the mouth during an esthetic try-in (Figs 11-40). The final test was performed with a transparent try-in paste to observe the possible influence of the darkened tooth preparation in the definitive crown. The only restoration that showed the negative influence of the tooth preparation was the crown fabricated on the IPS e.max MO 1 lithium disilicate coping. However, when the
crown was tested with an opaque try-in paste, it was clear that the problem could be solved easily with the use of opaque resin cement (Fig 11-41). Finally, the 0.4-mm A1 zirconia crown was chosen and cemented in place with resin cement (Figs 11-42). All of the crowns fit well, but some of the details on the 0.4-mm A1 zirconia crown were slightly better than the rest of the crowns.
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Successful Ceramic Application on Various Substructures
a
b
c
d
Fig 11-41  Assessment of the influence of the darkened tooth preparation on the definitive crown. (a and b) Transparent try-in paste reveals the negative influence of the tooth preparation on the crown with the IPS e.max MO 1 lithium disilicate coping. (c and d) Use of an opaque try-in paste indicates that the problem could be masked easily with an opaque resin cement.
Conclusion In general, all the materials used for substructures and ceramic layering in this clinical study presented excellent results. However, the technical expertise of the clinician and dental technician as well as their level of experience with each material will have a substantial effect on the outcome. 232
In addition, the technical limitations of each material must be understood and addressed. The primary aspect noted in the laboratory was the influence of the degree of light passage through the structures on appearance; opaque dentin and enamel layers, together with customized ceramic layering, are required to balance the brightness of the restoration in order to better simulate the appearance of a natural tooth.
Conclusion
a
b
c Fig 11-42  (a to c) Definitive 0.4-mm A1 zirconia crown, cemented in place.
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