It is a fact that software and machines make our labo- ratory processes faster and easier. Nevertheless, the human mind, with its infinite expertise, is still necessary to perform individual restorations with their differing es- thetic requirements. Restoring a single tooth or a fragment of a tooth does not require a great deal of creativity, since either the contralateral tooth (in the case of a single crown) or the remaining tooth (in the case of a fragment) will be the principal reference. However, reproducing any shape and color by porcelain layering requires the ceramist to master the artistic skills—through knowledge, experience, and continual practice—to confidently achieve esthetically demanding results. Bonded porcelain restorations have been proven, in medium- to long-term evaluations, to provide excellent es- thetics, high patient satisfaction, and no adverse effects on the supporting tissues. They are also associated with max- imum enamel preservation due to their ability to be acid etched and bonded to the dental structure. Bonding proce- dures allow us to replace old preparation concepts, based on restoration retention by friction, with a much more con- servative approach, based on insertion pattern and posi- tional stability, maximizing the preservation of the remaining tooth structure. This article describes the technical steps to develop minimally invasive ceramic fragments to restore the smile of a young girl
CASE PRESENTATION
The patient, a 14-year-old young girl who suffers from coughing syncope, presented with fractured incisal edges of the maxillary central incisors and right lateral incisor af- ter suffering a severe coughing episode that resulted in her fainting and falling down. The preoperative situation is shown in facial view (Fig 1), smile (Fig 2), and intraoral view with black contrast (Fig 3).
When the patient visited the restorative team, tests were done to confirm the vitality of the involved teeth. Teeth fragments were not recovered during the accident, so bonding those fragments to the remaining teeth was not an option. Taking into account the young age of the patient, full-coverage restorations were not considered. Due to the need to restore substantial coronal volume and length, the treatment plan was to develop three feldspath- ic ceramic fragments, following the refractory die technique, and to bond them to the remaining teeth, restoring the missing dental tissue.
Communication of Color and Photographic Protocol
Even with all the technological advances, the selection, communication, and reproduction of color can be challeng- ing in some cases and can result in an unpredictable out- come. Effective communication between the clinical team and the dental laboratory is mandatory to achieve a suc- cessful shade match, with photography being an excellent communication tool for this.
For reference photographs, it is important to note that those taken with a ring flash are good for basic shade in- formation, as well as proportion and arrangement. However, they are not good for sharing information to reproduce the color in a precise way. Lateral light photography is considered a better option, since it allows us to see through the layers of the tooth. Nowadays, cross-polarized light photography is highly recommended, since it reduces the glare, allowing visualization of the gradation of the chroma, which enables an easier and more precise dentin shade selection and layering map.5 Comparative preoperative in- traoral images taken with lateral light (Twin Lite MT-24EX, Canon) and with cross-polarized light (polar_eyes, Emulation) are shown in Figs 4a and 4b.
Shade Selection
When tooth selection is carried out in a conventional way, the knowledge and experience of each professional can make a difference. Conventional shade guides have limitations in communicating the color precisely, due to the significant variability of the shades they represent. For more precise information, shade selection with color scales constructed from the pure materials—for example, deep dentin, mamelon, dentin, incisals, and opals—is highly recommended.
Layering Map—Chromatic Sample
Due to the amount of dentin structure lost vertically, while developing the layering map it was key to mix the Opaque Dentin with the Mamelon Light (the most reflective mate- rial of the system) to block the darkness of the oral cavity, thereby avoiding the risk of a low-value restoration (Figs 5a to 5c).
In any type of single anterior restorations, a chromatic sample is made immediately after the color selection to avoid any doubt as to the correct selection of color and future layering. To make this chromatic sample, once the shade is decided upon, a schematic stratification with the selected materials is made on a piece of tissue paper using the main colors and effects. Incisal is placed only in half of the layering to allow us to check, after the porcelain firing, the veracity of the internal stratification at the uncovered portion by the incisal layer and the correct enamel selec- tion and thickness in the other half.7 The firing process is carried out at 50ºC above the regular firing temperature of the porcelain in order to obtain a shiny sample (Fig 6). This process allows us to detect any corrections required dur- ing the layering of the fragments.
Restorative Procedures
Enamel recontouring 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 Procedures
An alveolar model (Fig 8) was made from the final impression 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.
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 (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
• 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).
Final 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.
Try-in, Bonding, and Finishing Procedures
The try-in was done and did not reveal any need for corrections.
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 important 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.
CASE PRESENTATION
The patient, a 14-year-old young girl who suffers from coughing syncope, presented with fractured incisal edges of the maxillary central incisors and right lateral incisor af- ter suffering a severe coughing episode that resulted in her fainting and falling down. The preoperative situation is shown in facial view (Fig 1), smile (Fig 2), and intraoral view with black contrast (Fig 3).
When the patient visited the restorative team, tests were done to confirm the vitality of the involved teeth. Teeth fragments were not recovered during the accident, so bonding those fragments to the remaining teeth was not an option. Taking into account the young age of the patient, full-coverage restorations were not considered. Due to the need to restore substantial coronal volume and length, the treatment plan was to develop three feldspath- ic ceramic fragments, following the refractory die technique, and to bond them to the remaining teeth, restoring the missing dental tissue.
Communication of Color and Photographic Protocol
Even with all the technological advances, the selection, communication, and reproduction of color can be challeng- ing in some cases and can result in an unpredictable out- come. Effective communication between the clinical team and the dental laboratory is mandatory to achieve a suc- cessful shade match, with photography being an excellent communication tool for this.
For reference photographs, it is important to note that those taken with a ring flash are good for basic shade in- formation, as well as proportion and arrangement. However, they are not good for sharing information to reproduce the color in a precise way. Lateral light photography is considered a better option, since it allows us to see through the layers of the tooth. Nowadays, cross-polarized light photography is highly recommended, since it reduces the glare, allowing visualization of the gradation of the chroma, which enables an easier and more precise dentin shade selection and layering map.5 Comparative preoperative in- traoral images taken with lateral light (Twin Lite MT-24EX, Canon) and with cross-polarized light (polar_eyes, Emulation) are shown in Figs 4a and 4b.
Shade Selection
When tooth selection is carried out in a conventional way, the knowledge and experience of each professional can make a difference. Conventional shade guides have limitations in communicating the color precisely, due to the significant variability of the shades they represent. For more precise information, shade selection with color scales constructed from the pure materials—for example, deep dentin, mamelon, dentin, incisals, and opals—is highly recommended.
Layering Map—Chromatic Sample
Due to the amount of dentin structure lost vertically, while developing the layering map it was key to mix the Opaque Dentin with the Mamelon Light (the most reflective mate- rial of the system) to block the darkness of the oral cavity, thereby avoiding the risk of a low-value restoration (Figs 5a to 5c).
In any type of single anterior restorations, a chromatic sample is made immediately after the color selection to avoid any doubt as to the correct selection of color and future layering. To make this chromatic sample, once the shade is decided upon, a schematic stratification with the selected materials is made on a piece of tissue paper using the main colors and effects. Incisal is placed only in half of the layering to allow us to check, after the porcelain firing, the veracity of the internal stratification at the uncovered portion by the incisal layer and the correct enamel selec- tion and thickness in the other half.7 The firing process is carried out at 50ºC above the regular firing temperature of the porcelain in order to obtain a shiny sample (Fig 6). This process allows us to detect any corrections required dur- ing the layering of the fragments.
Restorative Procedures
Enamel recontouring 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 Procedures
An alveolar model (Fig 8) was made from the final impression 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.
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 (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
• 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).
Final 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.
Try-in, Bonding, and Finishing Procedures
The try-in was done and did not reveal any need for corrections.
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 important 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.
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