8-year multicenter retrospective study on partial laminate veneers.

Purpose This retrospective study aimed to evaluate the survival and success rates of ceramic partial laminate veneers. Scanning electron microscopy was used to evaluate fractures and marginal defects.Methods In total, 31 patients received 79 partial laminate veneers on the maxillary anterior teeth. After adhesive luting, restorations were evaluated by calibrated clinicians for up to eight years using modified United States Public Health Service (USPHS) criteria. In addition, epoxy resin replicas were fabricated from silicone impressions and analyzed using scanning electron microscopy. Survival analyses were performed using the Kaplan-Meier and log-rank tests (α = 0.05). Success was analyzed in percentages by comparing the baseline and last follow-up.Results The cumulative survival rates were 100% after 1 year; 95.9% (SE 2.8%) after 5 years; and 61.4% (SE 25.3%) after 8 years. No significant differences (P > 0.05) were observed between functional and non-functional restorations. Changes in the USPHS criteria evaluation were only observed for adaptation: 12.5% (SE 4.7%), marginal discoloration: 4.2% (SE 3.0%), color match: 4.2% (SE 3.0%), and fractures: 16.7% (SE 5.3%). Scanning electron microscopy evaluations revealed undetected initial cracks and deficiencies in the restorations.Conclusions Partial laminate veneers displayed good survival rates during the long-term follow-up. The main problems observed were related to the quality of the margins, color mismatch, and restoration integrity. However, in most cases, restoration replacement was not required.