Clinical Evaluation of Glass-ceramic Insert Restorations

Objectives: The aim of the study was to evaluate the clinical performance of preformed beta-quartz glass-ceramic insert restorations. Methods: 53 patients with 143 posterior teeth, who needed replacement of a restoration or caries therapy, were selected for the study. Preformed beta-quartz glass-ceramic inserts (Lee-Pharmaceutical) were luted, using a dual-curing composite (Charisma). 119 of 143 glass-ceramic insert restorations were evaluated up to four years after placement. Modified USPHS criteria were used. Survival probability was evaluated with Kaplan-Meier analyses (95% level of confidence) regarding the ceramic cracking or chipping. Results: 89 restorations were graded Alpha, 8 restorations were rated Bravo and 22 restorations were graded Charlie for the surface inspection (Tab.). Charlie and Delta ratings increased with wearing time of the glass-ceramic insert restorations. The estimated survival rate was 68% after four years. Conclusions: Ceramic chipping and cracking were the main factors, which limited longevity of glass-ceramic insert restorations.