Adhesively restored anterior maxillary dentitions affected by severe erosion: up to 6-year results of a prospective clinical study.

UNLABELLED: In case of severe dental erosion, the maxillary anterior teeth are often particularly affected. Restoring such teeth conventionally (ie, crowns) would frequently involve elective endodontic therapy and major additional loss of tooth structure. A novel, minimally invasive approach to restore eroded teeth has been developed and is currently being tested in the form of a prospective clinical trial, termed The Geneva Erosion Study. To avoid crowns, two separate veneers with different paths of insertion have been used to restore the affected anterior maxillary teeth, regardless of clinical crown length and amount of remaining enamel. This treatment is called The Sandwich Approach. OBJECTIVES: The purpose of this case series study was to analyze the mid-term clinical outcome of maxillary anterior teeth affected by severe dental erosion that were restored following the Sandwich Approach. MATERIALS AND METHODS: Twelve consecutively consulting patients (mean age: 39.4 years) suffering from advanced dental erosion have been enrolled in the study and were subsequently treated. Due to the late interception of the disease, all patients needed a full-mouth rehabilitation, which was performed without any conventional crowns. At the level of the maxillary anterior teeth, a total of 70 palatal indirect composite restorations and 64 facial feldspathic ceramic veneers were delivered. Both types of veneers were adhesively luted with a hybrid composite. Clinical reevaluations were performed 6 months after insertion of the veneers, and then annually, using modified United States Public Health Service (USPHS) criteria. Marginal adaptation, marginal integrity (seal, absence of infiltration), status of pulp vitality, postoperative sensitivity, esthetics, and restoration success/failure, were the principal clinical parameters analyzed. RESULTS: After an up to 6-year observation time (mean observation time 50.3 months for the palatal veneers and 49.6 months for the facial veneers), no complete or major failure of the restorations was encountered. On the basis of the criteria used, most of the veneers rated Alpha for marginal adaptation and marginal seal. Secondary caries or endodontic complications were not detected. Using visual analogue scale analysis, the patient-centered satisfaction revealed a high esthetic and functional acceptance of 94.6%. CONCLUSIONS: Compared to conventional crown preparation, restoring compromised maxillary anterior teeth by means of 2 veneers prevents excessive tooth structure removal and loss of tooth vitality. Questions on the longevity of this new treatment arise, due to the nonfavorable initial status of the teeth to be restored (eg, lack of enamel, sclerotic dentin substrate and short clinical crowns). The clinical performance of the teeth treated following the Sandwich Approach seems promising, since none of the treated teeth lost their vitality, no failure of any of the restorations was detected, and the patients' overall satisfaction was high. Even though further investigation is needed to determine the clinical long-term performance of the described treatment modality, the encouraging mid-term results (biological, esthetic, and mechanical success) clearly question if conventional crowns in the anterior maxillary segments can still continue to be considered the best and only option to treat this particular population of patients.

Full-mouth minimally invasive adhesive rehabilitation to treat severe dental erosion: a case report.

Dental erosion is increasing, and only recently are clinicians starting to acknowledge the problem. A prospective clinical trial investigating which therapeutic approach must be undertaken to treat erosion and when is under way at the University of Geneva (Geneva Erosion Study). All patients affected by dental erosion who present with signs of dentin exposure are immediately treated using only adhesive techniques. In this article, the full-mouth adhesive rehabilitation of one of these patients affected by severe dental erosion (ACE class IV) is illustrated. By the end of the therapy, a very pleasing esthetic outcome had been achieved (esthetic success), all of the patient's teeth maintained their vitality, and the amount of tooth structure sacrificed to complete the adhesive full-mouth rehabilitation was negligible (biological success).

Fatigue resistance and failure mode of CAD/CAM composite resin implant abutments restored with type III composite resin and porcelain veneers.

OBJECTIVES: This study assessed the fatigue resistance and failure mode of type III porcelain and composite resin veneers bonded to custom composite resin implant abutments. MATERIAL AND METHODS: Using the CEREC 3 machine, 28 composite resin implant abutments (Paradigm MZ100) were fabricated along with non-retentive type III veneers, milled either in ceramic Paradigm C (n=14) or in composite resin Paradigm MZ100 (n=14). The intaglio surfaces of the veneers were hydrofluoric acid etched and silanated (Paradigm C) or airborne-particle abraded and silanated (MZ100). The fitting surface of the abutments was airborne-particle abraded, cleaned, silanated and inserted into a bone level implant (10 mm, BLI RC). All veneers were luted with adhesive resin (Optibond FL) and a preheated light curing composite resin (Filtek Z100). Cyclic isometric chewing (5 Hz, 30° angle) was simulated, starting with a load of 40 N, followed by stages of 80, 120, 160, 200, 240 and 280 N (20,000 cycles each). Samples were loaded until fracture or to a maximum of 140,000 cycles. Groups were compared using the life table survival analysis (Log rank test at P=0.05). Previously published data using same-design zirconia abutments were included for comparison. RESULTS: Paradigm C and MZ100 specimens fractured at an average load of 243 and 206 N (survival rate of 21% and 0%), respectively, with a significant difference in survival probability (P=0.02). Fractured specimens presented mixed failure modes and solely adhesive failures were not observed. The survival of composite resin abutments was similar to that of identical zirconia abutments from a previous study (P=0.76). CONCLUSIONS: Non-retentive porcelain veneers bonded to custom composite resin implant abutments presented a higher survival rate when compared with composite resin veneers. Survival of composite resin abutment did not differ from zirconia ones.

Palatal and facial veneers to treat severe dental erosion: a case report following the three-step technique and the sandwich approach.

Minimally invasive principles should be the driving force behind rehabilitating young individuals affected by severe dental erosion. The maxillary anterior teeth of a patient, class ACE IV, has been treated following the most conservatory approach, the Sandwich Approach. These teeth, if restored by conventional dentistry (eg, crowns) would have required elective endodontic therapy and crown lengthening. To preserve the pulp vitality, six palatal resin composite veneers and four facial ceramic veneers were delivered instead with minimal, if any, removal of tooth structure. In this article, the details about the treatment are described.

Fatigue resistance and failure mode of novel-design anterior single-tooth implant restorations: influence of material selection for type III veneers bonded to zirconia abutments.

OBJECTIVES: This study assessed the fatigue resistance and failure mode of type III porcelain and composite resin veneers bonded to custom zirconia implant abutments. MATERIAL AND METHODS: Twenty-four standardized zirconia implant abutments were fabricated. Using the CEREC 3 machine, type III veneers of standardized shape were milled in ceramic Vita Mark II or in composite resin Paradigm MZ100. The intaglio surfaces of the restorations were hydrofluoric acid etched and silanated (Mark II) or airborne-particle abraded and silanated (MZ100). The fitting surface of the abutments was airborne-particle abraded, cleaned, and inserted into a bone level implant (BLI RC SLActive 10 mm). All veneers (n=24) were adhesively luted with a zirconia primer (Z-Prime Plus), adhesive resin (Optibond FL) and a pre-heated light-curing composite resin (Filtek Z100). Cyclic isometric chewing (5 Hz) was simulated, starting with a load of 40 N, followed by stages of 80, 120, 160, 200, 240, and 280 N (20,000 cycles each). Samples were loaded until fracture or to a maximum of 140,000 cycles. Groups were compared using the life table survival analysis (Logrank test at P=.05). RESULTS: Mark II and MZ100 specimens fractured at an average load of 216 N and 229 N (survival rate of 17% and 8%), respectively, with no difference in survival probability (P=.18). Among the fractured samples, 40% of the failures were at the abutment level for Mark II and 27% were at the abutment level for MZ100. No exclusive adhesive failures were observed. CONCLUSIONS: Type III Mark II and Paradigm MZ100 veneers showed similar fatigue resistance when bonded to custom non-retentive zirconia implant abutments. The bond was strong enough to induce abutment fractures. MZ100 presented a higher percentage of "friendly" failures, i.e. maintaining the restoration-abutment adhesive interface and the abutment itself intact.

Classification and treatment of the anterior maxillary dentition affected by dental erosion: the ACE classification.

Erosive tooth wear is a serious problem with very costly consequences. Intercepting patients at the initial stages of the disease is critical to avoid significant irreversible damages to their dentition and to benefit from still favorable conditions when it comes to clinical performance of the restorative measures proposed. In this article, a new classification is proposed to quantify the severity of the dental destruction and to guide clinicians and patients in the therapeutic decision-making process. The classification is based on several parameters relevant for both the selection of treatment and the assessment of the prognosis, such as dentin exposure in the palatal tooth contact areas, alterations at the level of the incisal edges, and ultimately, loss of pulp vitality.

Full-mouth adhesive rehabilitation of a severely eroded dentition: the three-step technique. Part 2.

Traditionally, a full-mouth rehabilitation based on full-crown coverage has been recommended treatment for patients affected by severe dental erosion. Nowadays, thanks to improved adhesive techniques, the indications for crowns have decreased and a more conservative approach may be proposed. Even though adhesive treatments simplify both the clinical and laboratory procedures, restoring such patients still remains a challenge due to the great amount of tooth destruction. To facilitate the clinician's task during the planning and execution of a full-mouth adhesive rehabilitation, an innovative concept has been developed: the three-step technique. Three laboratory steps are alternated with three clinical steps, allowing the clinician and the laboratory technician to constantly interact to achieve the most predictable esthetic and functional outcome. During the first step, an esthetic evaluation is performed to establish the position of the plane of occlusion. In the second step, the patient's posterior quadrants are restored at an increased vertical dimension. Finally, the third step reestablishes the anterior guidance. Using the three-step technique, the clinician can transform a full-mouth rehabilitation into a rehabilitation for individual quadrants. The present article focuses on the second step, explaining all the laboratory and clinical steps necessary to restore the posterior quadrants with a defined occlusal scheme at an increased vertical dimension. A brief summary of the first step is also included.

Full-mouth adhesive rehabilitation of a severely eroded dentition: the three-step technique. Part 3.

Dental erosion is a frequently underestimated pathology that nowadays affects an increasing number of younger individuals. Often the advanced tooth destruction is the result of not only a difficult initial diagnosis (e.g. multifactorial etiology of tooth wear), but also a lack of timely intervention. A clinical trial testing a fully adhesive approach for patients affected by severe dental erosion is underway at the School of Dental Medicine of the University of Geneva. All the patients are systematically and exclusively treated with adhesive techniques, using onlays in the posterior region and a combination of facially bonded porcelain restorations and indirect palatal resin composite restorations in the anterior maxillary region. To achieve maximum preservation of tooth structure and predict the most esthetic and functional outcome, an innovative concept has been developed: the three-step technique. Three laboratory steps are alternated with three clinical steps, allowing the clinician and the dental technician to constantly interact during the planning and execution of a full-mouth adhesive rehabilitation. In this article, the third and last step of the three-step technique has been described in detail.

Full-mouth adhesive rehabilitation of a severely eroded dentition: the three-step technique. Part 1.

Traditionally, a full-mouth rehabilitation based on full-crown coverage has been the recommended treatment for patients affected by severe dental erosion. Nowadays, thanks to improved adhesive techniques, the indications for crowns have decreased and a more conservative approach may be proposed. Even though adhesive treatments simplify both the clinical and laboratory procedures, restoring such patients still remains a challenge due to the great amount of tooth destruction. To facilitate the clinician's task during the planning and execution of a full-mouth adhesive rehabilitation, an innovative concept has been developed: the three-step technique. Three laboratory steps are alternated with three clinical steps, allowing the clinician and the laboratory technician to constantly interact to achieve the most predictable esthetic and functional outcome. During the first step, an esthetic evaluation is performed to establish the position of the plane of occlusion. In the second step, the patient's posterior quadrants are restored at an increased vertical dimension. Finally, the third step reestablishes the anterior guidance. Using the three-step technique, the clinician can transform a full-mouth rehabilitation into a rehabilitation for individual quadrants. This article illustrates only the first step in detail, explaining all the clinical parameters that should be analyzed before initiating treatment.

A 10-year prospective study of ITI dental implants placed in the posterior region. I: Clinical and radiographic results.

OBJECTIVES: To evaluate the long-term fixture success rate, crestal bone loss and peri-implant soft tissue parameters around ITI dental implants placed in the posterior region of partially edentulous patients. MATERIAL AND METHODS: A total of 192 ITI dental implants were consecutively placed in premolars and molars of 83 partially edentulous patients admitted for treatment at Geneva Dental School. All implants were restored by means of ceramic-to-metal fused fixed partial dentures and single crowns. Patients were followed as part of a prospective longitudinal study focusing on implant success. Surgical, radiographic and clinical variables were collected at the 1-year recall after implant placement and at the most recent clinical evaluation. RESULTS: The mean observation time was 6 years (range 5-10 years). Four implants failed, yielding a 10-year cumulative survival rate of 97.9%. The mean annual crestal bone loss was -0.04+/-0.2 mm. Hollow-cylinder implants displayed more crestal bone loss (-0.13+/-0.24 mm) than hollow-screw implants (-0.02+/-0.19 mm; P=0.032). Clinical parameters such as age, gender, implant length and bone quality did not affect crestal bone levels. Increase in recession depth (P=0.025) and attachment level (P=0.011) were significantly associated with crestal bone loss. CONCLUSIONS: ITI dental implants placed in the posterior jaw demonstrate excellent long-term clinical success. Hollow-cylinder implants seem to display a higher risk for crestal bone loss. Recession depth and attachment levels appear to be good clinical indicators of peri-implant bone loss.

A 10-year prospective study of ITI dental implants placed in the posterior region. II: Influence of the crown-to-implant ratio and different prosthetic treatment modalities on crestal bone loss.

OBJECTIVE: To evaluate the influence of the crown-to-implant ratio (C/I) ratio and different implant prosthetic treatment modalities on crestal bone loss around dental implants placed in the posterior region. MATERIAL AND METHODS: A total of 192 ITI dental implants were consecutively placed in premolars and molars of 83 partially edentulous patients. All implants were restored by means of ceramic-to-metal fused fixed partial dentures or a single crown. Patients were followed as part of a prospective longitudinal study focusing on implant success. Surgical, radiographic and clinical variables were collected at the 1-year recall after implant placement and at the most recent clinical evaluation. Radiographic parameters were evaluated on periapical radiographs taken with a standardized long-cone paralleling technique. Implant restorations were divided into three groups according to their respective clinical C/I ratios: (a) 0-0.99, (b) 1-1.99 and (c) >or=2. RESULTS: The mean clinical C/I ratio was 1.77+/-0.56 mm. A total of 51 implants (26.5%) showed a clinical C/I ratio equal to or greater than 2. In this group, three implants failed, giving a cumulative survival rate of 94.1%. Crestal bone loss was -0.34+/-0.27 mm in group a, -0.03+/-0.15 mm in group b and -0.02+/-0.26 mm in group c. Differences among groups were statistically significant (P=0.009). Mode of retention, splinting or presence of cantilever extensions did not have an effect on crestal bone loss around ITI dental implants. CONCLUSIONS: Implant restorations with C/I ratios between 2 and 3 may be successfully used in the posterior areas of the jaw.

Replacing four missing maxillary incisors with regular- or narrow-neck implants: analysis of treatment options.

The restoration of the missing maxillary incisors is a complex and delicate treatment challenge. When implant therapy is used, proper treatment planning is critical, as selecting the proper number, location, and dimension of the implants is a difficult task. Thus, this article discusses the issues that must be addressed during diagnosis and treatment planning to achieve a predictable esthetic outcome when using implants to replace the maxillary incisors. The advantages and disadvantages of several implant-supported treatment options-using a combination of regular- and narrow-neck implants-are presented. Ultimately, the use of narrow-neck implants at the lateral incisor sites is presented as the best option for ensuring excellent esthetic outcomes, and the corresponding indications and contraindications are discussed. Further, all treatment options are ranked based on the predictability of their esthetic outcomes.