Minimally invasive restorations (veneers)

An 18-year-old healthy and caries-free man presented himself at the clinic seeking treatment for his fractured incisal composite filling at tooth 21. Furthermore, he disliked the unesthetic appearance of his old composite fillings and the grayish discoloration of tooth 21.

As consequence of an accident several years ago, he received a root canal treatment on tooth 21 that showed a modest but visible grayish discoloration and a direct incisal edge composite restoration that had fractured. In agreement with the patient, a step-by-step treatment plan was established. The first step consisted of an internal bleaching procedure of tooth 21. Depending on the result of the internal bleaching, the second step would either be a new direct composite build-up or the total removal of the old composite and a slight preparation of the teeth for minimally invasive additional ceramic veneers (Fig 2-1-1). The step-by-step approach is described as follows.

Diagnostics

The patient’s chief complaint was the failing composite filling of the maxillary incisor 21. Furthermore, he was also bothered by the lack of esthetic integration of both incisal composite fillings.

Initially, all corrections were performed digitally by means of an image editing software, Photoshop Elements (Adobe Systems, San Jose, CA, USA), to visualize the patient’s treatment. Thereafter, the planned changes were transferred into a wax-up based on a conventional master cast in which the position of the two incisors was adjusted.

Internal bleaching

For the internal bleaching procedure of tooth 21, a mixture of 30% hydrogen peroxide and sodium perborate was mixed to a sand-like consistency and applied to the root canal, provisionally covered with composite, and left there in place for a period of 1 week. After this period a color assessment took place and the change was evaluated. If a further bleaching effect is desired, the substrate can stay in place for an additional few days or up to 1 week before reassessing the bleaching effect. At the follow-up visit 2 weeks after the bleaching material was removed, a major improvement in the color was observed (Fig 2-1-2).

Veneer preparation and impression

A silicone index was fabricated based on the wax-up to facilitate the correct preparation of the teeth. The old composite fillings were removed from teeth 11–21 and then prepared in a minimally invasive way, basically a minimal rounding of the incisal edges and a roughening of the surface, to receive the two veneers (Universal Prep Set, Intensiv, Montagnola, Switzerland).

With an epigingival course solely in the enamel, the final impression was taken using two retraction cords. In order to avoid traumatization of the gingiva and to minimize the risk of recessions, a surgical suturing material (size 4-0, Vicryl Ethicon, Johnson & Johnson, New Brunswick, NJ, USA) was used as the first retraction cord. The second retraction cord was the thinnest cord available on the market (000 Ultrapak, UP Dental, Cologne, Germany) (Fig 2-1-3).

Provisional

In order to deliver a provisional that would not require any kind of pretreatment or spot-etching and as the teeth showed no sensitivities, the decision was made to use a relined removable thermoplastic foil (Erkodur 1.5 mm, Erkodent, Pfalzgrafenweiler, Germany). The thermoplastic foil was produced, based on the wax-up in the dental laboratory. After the minimally invasive preparation was applied, the hollow foil was then intraorally relined with a chemically curing acrylic material in shade Vita A1 (NewOutline A1, Anaxdent, Stuttgart, Germany) and placed over the teeth. The resulting removable provisional additionally served as a communication tool, to visualize the prospective treatment result (Fig 2-1-4).

Fabrication of the veneers in the laboratory

The first step for the final restoration was the fabrication of an alveolar cast. Refractory dies were manufactured (anaxVest, Anaxdent) to guarantee the best possible fit of the veneers.

For the fabrication of the veneers, a reverse planning concept was applied. The laboratory work was guided by the information from the wax-up which was transferred with the aid of silicone indexes (Matrix Form 60, Anaxdent). The ceramic masses were then applied (Creation Classic, Willi Geller, Meiningen, Austria) according to the custom shade that was developed by the dental technician in collaboration with the patient. After two dentin firings, the surface texture and the final shape were shaped with diamond burs. The glaze firing was followed by a mechanical polishing procedure. The polished veneers were removed from the refractory dies by airborne-particle abrasion and cleaned in an ultrasonic waterbed (Fig 2-1-5).

Integration of the restorations

A try-in session was carried out where the two veneers were inserted with a try-in paste (Variolink Esthetic, Ivoclar Vivadent, Schaan, Liechtenstein) in order to improve color assessment and optical integration. The patient and the dental practitioner realized that the veneers were slightly too long. The incisal edges of the veneers were marked and thereby optically shorted using a black waterproof marker until both patient and clinician expressed their satisfaction with the esthetic result. As it was only about three-tenths of a millimeter, the veneers could be shortened on site using an abrasive diamond polishing wheel. Subsequently, in a dry environment (rubber dam) the fragile ceramic veneers were cemented. The abutment teeth were etched with 35% phosphoric acid (Ultra-Etch, Ultradent Products, South Jordan, UT, USA) and bonded with a multistep adhesive system (Syntac Classic, Ivoclar Vivadent). The bond was not light-cured in order not to compromise the fit of the ultra-thin veneers. The veneers were etched with hydrofluoric acid (9% concentration for 1 min) (Porcelain Etch, Ultradent Products). A silane-containing primer (Monobond S, Ivoclar Vivadent) and a bonding system (Heliobond, Ivoclar Vivadent) were applied. Then the veneers were cemented with a dual-curing resin cement (Variolink Esthetic Neutral, Ivoclar Vivadent). Excess cement was removed with rotating diamond instruments. The occlusal and functional contacts were analyzed, and no adjustments were necessary.

All participants were very satisfied with the final treatment outcome (Figs 2-1-6 and 2-1-7). (Dental practitioner: Prof Dr D Thoma; Technician: MDT V Fehmer.)

2.1.2 Anterior veneer after trauma (single maxillary central incisor)

This section describes the minimally invasive rehabilitation of a patient after trauma.

Assessment and treatment planning

A 24-year-old, healthy, and mostly caries-free man presented himself at the clinic seeking treatment for his discolored and worn incisal composite filling at tooth 11. Furthermore, he wanted a replacement for the missing lateral incisor 12 (see Part II, Chapter 2 for the resinbonded fixed dental prosthesis [RBFDP] in detail).

As consequence of an accident several years ago he lost his lateral incisor and horizontally fractured his central incisor. As an initial treatment he received a direct incisal edge composite build-up along with a small removable restoration replacing the missing lateral tooth 12. In agreement with the patient, a treatment plan was developed that foresaw a cantilever RBFDP replacing tooth 12 with a palatal backing on tooth 13. Due to the pronounced individual characteristics of the adjacent central incisor that served as a reference tooth, it was decide to remove the old composite filling and replace it with an individualized layered feldspathic ceramic veneer rather than with a new composite build-up (Fig 2-1-8). The step-by-step approach is described as follows.

Diagnostics

Initially, all corrections were performed digitally by means of the image editing software Keynote (Apple, Cupertino, CA, USA) to visualize the patient’s treatment. Thereafter, the planned changes were transferred into a wax-up based on a conventional master cast in which the shape of the incisor was adjusted and the missing lateral incisor was replaced.

Veneer preparation and impression

A silicone index was fabricated based on the wax-up to facilitate the correct preparation of the tooth. The old composite filling was removed from the tooth and then prepared in a minimally invasive way following the areas marked in black (Universal Prep Set, Intensiv, Montagnola, Switzerland), covering the entire buccal surface in order to prevent a visible horizontal transition zone between the tooth and the veneer.

Provisional

In order to deliver a provisional that would not require any kind of pretreatment and deliver an easy access, the decision was made to use a relined removable thermoplastic foil (Erkodur 1.5 mm, Erkodent, Pfalzgrafenweiler, Germany). The thermoplastic foil was produced based on the wax-up in the dental laboratory. The hollow foil was intraorally relined with a chemically curing acrylic material, in shade Vita B3 (NewOutline B3, Anaxdent, Stuttgart, Germany) and placed over the minimally invasive preparation of the tooth and pontic.

Fabrication of the veneer in the laboratory

The first step for the final restoration was the fabrication of an alveolar cast. Refractory dies were manufactured (anaxVest, Anaxdent) to guarantee the best possible fit of the veneers.

For the fabrication of the veneer, a backward planning concept was applied. The laboratory work was guided by the information from the wax-up, which was transferred with the aid of silicone indexes (Matrix Form 60, Anaxdent). The ceramic masses were then applied (Creation Classic, Willi Geller, Meiningen, Austria) according to the custom shade that was developed by the dental technician in collaboration with the patient. After one dentin firing, the surface texture and the final shape was made with diamond burs. The glaze firing was followed by an additional stain firing and a mechanical polishing procedure. The polished veneer was removed from the refractory die by airborne-particle abrasion and cleaned in an ultrasonic waterbed (Fig 2-1-10).

Integration of the restoration

A try-in session was carried out where the veneer was inserted with a try-in paste (Variolink Esthetic Warm, Ivoclar Vivadent, Schaan, Liechtenstein) in order to improve color assessment and optical integration. Subsequently, in a dry environment (rubber dam) the fragile ceramic veneer was cemented. The abutment tooth was etched with 35% phosphoric acid (Ultra-Etch, Ultradent Products, South Jordan, UT, USA) and bonded with a multistep adhesive system (Syntac Classic, Ivoclar Vivadent). The bond was not light-cured in order not to compromise the fit of the ultra-thin veneer. The veneer was etched with hydrofluoric acid (9% concentration for 1 min) (Porcelain Etch, Ultradent Products). A silane-containing primer (Monobond S, Ivoclar Vivadent) and a bonding system (Heliobond, Ivoclar Vivadent) were applied. Then the veneer was cemented with a dual-curing resin cement (Variolink Esthetic Warm, Ivoclar Vivadent). Excess cement was removed with rotating diamond instruments. The occlusal and functional contacts were analyzed, and no adjustments were necessary.

The patient was very satisfied with the final treatment outcome (Figs 2-1-11 and 2-1-12). (Dental practitioner: Prof Dr I Sailer; Technician: MDT V Fehmer.)

2.1.3 Traditional veneers for restoration of amelogenesis imperfecta (six maxillary anterior teeth)

The following section describes the minimally invasive rehabilitation of a patient with amelogenesis imperfecta.

Assessment and treatment planning

A 27-year-old healthy and almost caries-free woman presented at the clinic seeking treatment for her dark spots on the maxillary incisors and unesthetic gingival margin. A history of trauma, tetracycline staining, or fluorosis could be excluded. The clinical examination did not fully reveal the severity of the amelogenesis imperfecta nor the depth of the staining. In agreement with the patient, a step-by-step treatment plan was established. The first step consisted of a home bleaching procedure. If the stains were still present in the deeper layers of the tooth, a microabrasion technique would be applied. This procedure implies the removal of a 0.03 mm thin layer of enamel. Depending on the result of microabrasion, the third step would be undertaken: preparation of the teeth for ceramic veneers or crowns. The latter option would be considered if the enamel could not be etched due to the hypoplasia. Since the patient did not like the appearance of her gingival margin, a crown-lengthening procedure was planned (Fig 2-1-13). The step-by-step approach is described as follows.

Diagnostics

The patient’s chief complaint was the dark and white-opaque staining of the maxillary incisors and canines. However, she was also bothered by the asymmetrical gingival margin and the difference between the incisal edges of tooth 11 and 23. Furthermore, the patient requested a correction of the overlapping of teeth 21 and 11.

Initially, all corrections were performed digitally by means of an image editing software, Photoshop Elements (Adobe Systems, San Jose, CA, USA), to visualize the patient’s treatment. Thereafter, all the planned changes were transferred into a wax-up. The position of the two incisors was adjusted to better fit into the arch. At teeth 11 and 23, the gingiva on the plaster cast was modified in order to simulate future crown lengthening (Fig 2-1-14).

Mock-up

In order to transfer the simulations into the patient’s mouth, the incisal edge of tooth 23 and the cusp of tooth 24 had to be shortened. A resin cap served as a reference for the amount of incisal reduction required (Acryline clear, Anaxdent, Stuttgart, Germany). Following preparation, the enamel was smoothened with fine-grit diamond burs (Universal Prep Set, Intensiv, Montagnola Switzerland).

A silicone index of the wax-up was prepared in order to directly fabricate a mock-up in the patient’s mouth (Memosil 2, Kulzer, Hanau, Germany). This silicone index was filled with a chemically curing composite material, in shade Vita A1 (Protemp, 3M, Rüschlikon, Switzerland) and placed over the teeth. The resulting mock-up served as a communication tool, and the prospective treatment result could now be discussed with the patient. The mock-up also helped to estimate the extent of the crown lengthening that would be necessary (Fig 2-1-15).

Crown lengthening

On tooth 11, the gingival level had to be moved about 1 mm apically and on tooth 23, about 1.5 mm apically. The periodontal examination revealed that both teeth had pseudo pockets. The vertical distance to the bone was around 4 mm. A gingivectomy was carried out without violating the biological width. The mock-up was used to verify the total prospective crown length. To ensure the success of the crown lengthening, the treatment plan now foresees a healing and stabilizing break of 2 months (Fig 2-1-16).

Home bleaching

For the home bleaching procedure of all teeth, bleaching trays were fabricated in the dental laboratory (Erkodur, Pfalzgrafenweiler, Germany). A carbamide peroxide bleaching gel with a concentration of 15% (Opalescense, Ultradent Products, South Jordan, UT, USA) was administered to the patient to be used for 2 hours a day for the following 3 weeks. At the follow-up visit 1–2 weeks after the last bleaching, a major improvement in the color was observed. The patient became more and more aware of dental esthetics, noticed a positive change, and was motivated to seek further improvement.

Microabrasion

The next stage of the treatment plan was the application of the microabrasion technique (Opalustre, Ultradent Products). The most superficial enamel layer was etched and subsequently removed with an abrasive paste and a rubber cup. Again, in the follow-up visit, a clear improvement was noticed, but the stains could not be fully removed. Moreover, the patient wanted to continue in order to correct the position and shape of her anterior teeth (Fig 2-1-17).

Veneer preparation and impression

A silicone index was fabricated based on the wax-up to facilitate the correct preparation of the teeth. The teeth 13–23 were prepared in a minimally invasive way to receive veneers. With an epigingival course solely in the enamel, the final impression was taken using two retraction cords. In order to avoid traumatization of the gingiva and to minimize the risk of recessions, a surgical suturing material (size 4-0, Vicryl Ethicon, Johnson & Johnson, New Brunswick, NJ, USA) was used as the first retraction cord. The second retraction cord was the thinnest cord available on the market (000 Ultrapak, UP Dental, Cologne, Germany). The preparation margins could be sufficiently exposed with this technique (Fig 2-1-18).

Fabrication of the veneers in the laboratory

Before the dental technician initiated the fabrication of the final restoration, all the information gathered during the diagnostic phase was reviewed in order to ensure that the prospective shape, position, and shade of the teeth would fulfill the patient’s and the dental team’s expectations.

The first step for the final restoration was the fabrication of an alveolar cast. This cast offers a big advantage in comparison with conventional saw-cut casts because it preserves all the information on gingival morphology. Refractory dies were manufactured (anaxVest, Anaxdent, Stuttgart, Germany) to guarantee the best possible fit of the veneers.

For the fabrication of the veneers, a reverse planning concept was applied. The laboratory work was guided by the information from the wax-up and mock-up, which was transferred with the aid of silicone indexes (Matrix Form 60, Anaxdent). The ceramic masses were then applied (Creation Classic, Willi Geller, Meiningen, Austria) according to the custom shade that was developed by the dental technician in collaboration with the patient, and re-adjusted after the evaluation of the preparation. After two dentin firings, the surface texture and the final shape was done with diamond burs. Gold powder was used to highlight the microstructure of the surface and make the texture clearly visible. The glaze firing was followed by a mechanical polishing procedure. The polished veneers were removed from the refractory dies by airborne-particle abrasion and cleaned in an ultrasonic waterbed (Fig 2-1-19).

Integration of the restoration

A try-in session was carried out where the veneers were inserted with glycerin gel in order to improve color assessment. Both the patient and the dental practitioner expressed their satisfaction with the esthetic result. Subsequently, in a dry environment (rubber dam) the fragile ceramic veneers were cemented. The abutment teeth were etched with 35% phosphoric acid (Ultra-Etch, Ultradent Products) and bonded with a multistep adhesive system (Syntac Classic, Ivoclar Vivadent, Schaan, Liechtenstein). The bond was not light-cured in order not to compromise the fit of the veneers. The veneers were etched with hydrofluoric acid (9% concentration for 1 min) (Porcelain Etch, Ultradent Products). A primer (Monobond S, Ivoclar Vivadent) and a bonding system (Heliobond, Ivoclar Vivadent) were applied. Then the veneers were cemented with a dual-curing resin cement (Variolink transparent, Ivoclar Vivadent). Excess cement was removed with rotating diamond instruments. The occlusal and functional contacts were analyzed and no adjustments were necessary (Fig 2-1-20).

All participants were very satisfied with the final treatment outcome. At a follow-up visit 18 months postinsertion, all the veneers looked well integrated without any discoloration of the margin or chipping and fractures of the ceramic (Fig 2-1-21). (Dental practitioner: Dr D Büchi; Technician: MDT V Fehmer.)

2.1.4 Traditional and palatal veneers after deep bite and orthodontic pretreatment (six maxillary anterior teeth)

Minimally invasive rehabilitation of a patient with a negative smile, deep bite, and orthodontic pretreatment.

Assessment and treatment planning

A 28-year-old healthy and caries-free woman presented at the clinic seeking treatment for her abraded central and lateral incisors. She also realized that her anterior teeth had become not only shorter but also much thinner over the previous years and she was concerned that they might eventually break. In agreement with the patient, a step-by-step treatment plan was established. Starting with a sequential diagnostic approach in which first the new outline of the four anterior incisors was defined, in a second phase the functional aspects and limitations were elaborated due to her deep bite. In order to be able to achieve a minimally invasive rehabilitation, not only was an orthodontic pretreatment planned in order to gain space on the palatal side, but also the facial ceramic veneers were to be supported by palatal composite veneers. Owing to this detailed initial planning, the treatment could be executed meticulously according to the planned outline, thereby reducing the need for a subtractive preparation to an absolute minimum (Figs 2-1-22).

After the orthodontic pretreatment, four composite palatal veneers were placed. As a final treatment sequence, four ceramic veneers were then inserted, with a new canine guidance for both the maxillary canines.

Diagnostics

The patient’s chief complaint was her negative and abraded smile and additionally she was concerned that her thin teeth might fracture eventually at a later time point if she did not take any measures to protect them now. The patient requested a lengthening of her anterior incisors and additionally their palatal protection.

She presented herself with a deep bite, with an overall low vertical dimension, which most likely initially led to the abrasion of her anterior maxillary teeth. The main goal was to establish a minimally invasive treatment without raising the entire vertical dimension by additionally placing 6 or 8 overlays in the maxilla. However, this would clearly have been an overtreatment to the virgin maxillary posterior teeth and also extend her financial limitations.

All planned and discussed changes were firstly transferred into a conventional wax-up. The position of the four incisors was slightly rotated buccally to allow space for palatal protection by means of palatal composite veneers (Fig 2-1-23).

Mock-up

To transfer the diagnostic into the patient’s mouth and thus give the patient a chance to visualize and agree on the final outline of her four central incisors, a silicone index of the wax-up was prepared in order to fabricate a direct mock-up (Memosil 2, Kulzer, Hanau, Germany). This silicone index was filled with a chemically curing composite material in shade Vita A1 (Protemp, 3M, Rüschlikon, Switzerland) and placed over the teeth.

The resulting mock-up served as a communication tool as the prospective treatment result could now be discussed with the patient in detail and moreover in mutual understanding (Fig 2-1-24).

Orthodontic pretreatment

In order to gain space on the palatal side without raising the vertical dimension, an orthodontic pretreatment was performed by means of two sequences of a 0.8 mm and 1.5 mm thick thermoplastic foil, translating the set-up sequentially into the actual tooth position. As fortunately the patient’s anterior incisors were slightly inverted, this orthodontic pretreatment gained the necessary space for the protection of the exposed dentin by means of establishing four indirect composite palatal veneers (Fig 2-1-25).

Palatal veneer preparation and impression

After the orthodontic pretreatment, sufficient space was gained to add the palatal veneers in a complete additional preparation free approach. The final impression was taken without any need for retraction cords in order to avoid traumatization of the gingiva and to minimize the risk of recessions, as all margins were located epi- and supragingivally.

Fabrication of the palatal veneers in the laboratory

The first step for the final restoration was the fabrication of a master cast, which was then articulated, prepared, and isolated with an extremely thin layer of wax, to directly receive the composite build-up. For the fabrication of the palatal composite veneers, a backward planning concept was applied. The laboratory work was guided by the information from the wax-up which was transferred with the aid of silicone indexes (Matrix Form 60, Anaxdent, Stuttgart, Germany). The composite masses were then applied (Gradia, GC, Tokyo, Japan) according to the custom shade that was developed by the dental technician in collaboration with the patient. After build up, the final shape was created with stones and diamond polishing wheels. The final glaze was established by means of mechanical polishing procedure. The polished palatal veneers were then carefully removed from the dies by means of hot steam, which melted the thin layer of isolating wax between the die and the composite veneer. The palatal veneers were then airborne-particle abraded with 50-µm alumina oxide powder and cleaned in an ultrasonic waterbed (Fig 2-1-26a).

Integration of the restorations

A try-in session was carried out where the veneers were inserted to verify the fit and approximal contact points. Subsequently, in a dry environment (rubber dam) the composite veneers were cemented. The abutment teeth were etched with 35% phosphoric acid (Ultra-Etch, Ultradent Products, South Jordan, UT, USA) and bonded with a multistep adhesive system (Syntac Classic, Ivoclar Vivadent, Schaan, Liechtenstein). The bond was not light-cured in order not to compromise the fit of the thin palatal veneers. To the palatal veneers a primer (Monobond S, Ivoclar Vivadent) and a bonding system (Heliobond, Ivoclar Vivadent) was applied. Then the veneers were cemented with a light-curing composite (Tetric Classic, Ivoclar Vivadent). Excess composite was removed with rotating and oscillating diamond instruments (Universal Prep Set, Intensiv, Montagnola, Switzerland). The occlusal and functional contacts were analyzed and nearly no adjustments were necessary (Fig 2-1-26).

Veneer preparation and impression

After the finalization of the palatal veneers the next treatment step was to prepare the facial veneers. As the initial orthodontic pretreatment on the one hand had gained sufficient space for the palatal veneers, it was also paramount not to move the teeth too far buccally to allow an absolutely minimally invasive treatment. The teeth 12–22 were prepared with no epigingival course to preserve the maximum tooth substrate, so basically the preparation consisted of mainly smoothening the edges. The final impression was taken without any need for retraction cords, in order to avoid traumatization of the gingiva and to minimize the risk of recessions, as all margins were located epi- and supragingivally (Fig 2-1-27).

Fabrication of the veneers in the laboratory

The first step for the final restoration was the fabrication of an alveolar cast. In order to achieve the thinnest possible restorations, refractory dies were manufactured (anaxVest, Anaxdent, Stuttgart, Germany) to then directly veneer them and in the same step guarantee the best possible fit of the veneers. For the fabrication of the veneer, a backward planning concept was applied. The laboratory work was guided by the information from the wax-up, which was transferred with the aid of silicone indexes (Matrix Form 60, Anaxdent). The ceramic masses were then applied (Creation Classic, Willi Geller, Meiningen, Austria) according to the custom shade that was developed by the dental technician in collaboration with the patient. After one dentin firing, the surface texture and the final shape was created with stones and diamond burs. The glaze firing was followed by an additional stain firing and a mechanical polishing procedure. The polished veneers were carefully removed from the refractory dies by airborne-particle abrasion with glass beads and then cleaned in an ultrasonic waterbed (Fig 2-1-28).

Integration of the restorations

A try-in session was carried out where the veneers were inserted with a try-in paste (Variolink Esthetic neutral and warm, Ivoclar Vivadent) in order to improve color assessment and optical integration. Subsequently, in a dry environment (rubber dam) the fragile ceramic veneers including the two new functional veneers for the canine guidance were cemented. The abutment teeth were etched with 35% phosphoric acid (Ultra-Etch, Ultradent Products) and bonded with a multistep adhesive system (Syntac Classic, Ivoclar Vivadent). The bond was not light-cured in order not to compromise the fit of the ultra-thin veneers.

The veneers were etched with hydrofluoric acid (9% concentration for 1 min) (Porcelain Etch, Ultradent Products). A primer (Monobond S, Ivoclar Vivadent) and a bonding system (Heliobond, Ivoclar Vivadent) were applied. Then the veneers were cemented with a dual-curing resin cement (Variolink Esthetic Nutral, Ivoclar Vivadent). Excess cement was removed with rotating and oscillating diamond instruments (Universal Prep Set, Intensiv). The occlusal and functional contacts were analyzed and no adjustments were necessary (Fig 2-1-29). The patient was extremely satisfied with the final treatment outcome and received a new Michigan splint to protect the new restorations during the night (Fig 2-1-30). (Dental practitioner: Prof Dr I Sailer; Technician: MDT V Fehmer; DT B Sapina.)