Clinical long-term evaluation and failure characteristics of 1,335 all-ceramic restorations

The aim of this clinical retrospective study was to evaluate the clinical quality, estimated survival rate, and failure analysis of different all-ceramic restorations in a long-term analysis of up to 20 years.

Different all-ceramic restorations (crowns [n = 470], veneers [n = 318], onlays [n = 213], and inlays ]n = 334[) were placed in 302 patients (120 men, 182 women) between 1987 and 2009 at Medical University Innsbruck, Innsbruck, Austria. Clinical examination was performed during patients' regularly scheduled maintenance appointments. Esthetic match, porcelain surface, marginal discoloration, and integrity were evaluated following modified California Dental Association/Ryge criteria. Number of restoration failures and reasons for failure were recorded. The study population included 106 (35.1%) individuals diagnosed with bruxism. The success rate was determined using Kaplan-Meier survival analysis.

The mean observation time was 102 ± 60 months. Ninety-five failures were recorded. The main reason for failure was fracture of the ceramic (33.68%). The estimated survival rate was 97.3% after 5 years, 93.5% at 10 years, and 78.5% at 20 years. Nonvital teeth showed a significantly higher risk of failure (P < .0001). There was a 2.3-times greater risk of failure associated with existing parafunction (bruxism, P = .0045). Cementation using Variolink showed significantly fewer failures than Optec Cement (P = .0217) and Dual Cement (P = .0099). No significant differences were found for type of restoration and distribution in the mouth.

All-ceramic restorations offer a predictable and successful restoration with an estimated survival probability of 93.5% over 10 years. Significantly increased failure rates are associated with bruxism, nonvital teeth, and specific cementation agents.