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

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.