Clinical Evaluation of Chairside-Fabricated Partial Crowns Made of Zirconia Reinforced Lithium Silicate Ceramic - 2-Year-Results

Introduction: In a prospective study, the clinical performance of chairside-fabricated partial-crowns made of zirconia-reinforced lithiumsilicate (ZLS)-ceramic was evaluated after 2 years. Materials and methods: 45 patients (28 female/17 male) underwent restoration with 61 chairside-fabricated ZLS partial-crowns on vital premolars and molars. In variation from the manufacturer’s recommendations (minimum material thickness (MMT)=1.0 mm), partial-crowns with reduced material thicknesses were fabricated: group 1, MMT=0.5-0.74 mm (n=31); group 2, MMT=0.75-1.0 mm (n=30). The restorations were luted with either a self-adhesive cement (SAC) or the total-etch technique using a dual-curing composite cement (DC). The MMT and cementation technique (SAC vs. DC) were evaluated as possible covariates of the time-dependent survival (SVR) and success rate (SCR) using univariate log-rank-tests. Results: Forty-four patients with 59 restorations participated in the 2-year follow-up examinations. In group 1 (n=31), there were 2 losses due to ceramic fracture (SVR: 94.0% (95% confidence interval (CI): 0.85-1)). In group 2, no losses were documented (SVR: 100%). In 2 restorations cemented with SAC, recementation was necessary (overall SCR: 93% (CI: 0.87-1)). Conclusion: To avoid early material-related fractures, observing the recommended minimum thickness of 1.0 mm is essential. However, further validation of these results in studies with longer observational periods is required.

Clinical Study Survival Rate High-Strength Glass-Ceramics Partial Crown Success Rate