Retrospective Clinical Study of Resin Composite and Ceramic Indirect Posterior Restorations up to 11 Years

OBJECTIVE: The purpose of this study was to examine and compare the clinical be-havior of indirect onlays/overlays made of lithium disilicate and composite resin and to investigate risk factors associated with restorations failures. METHODS: 112 indirect partial coverage posterior restorations placed in 51 adult pa-tients between January 2014 and December 2020 were included for examination. The restorations were evaluated using selected FDI criteria (color match, surface gloss, an-atomic form, fracture of restorative material, tooth cracks and fractures, marginal discoloration, marginal integrity and recurrence of initial pathology). The survival of the restorations was analyzed using Kaplan-Meier method. Risk factors (type of resto-ration, type of tooth, tooth vitality, smoking) were investigated using Cox regression analysis. Risk estimation was conducted for each evaluated criterion (p<0.05). RESULTS: For composite restorations, the estimated survival rate was 94.2% after 5 years, dropped to 74.3% in 7.9 years and continued dropping to less than 60% after 8.2 years. On the contrary, for ceramic restorations the estimated survival rate was 90.9% after 5 years, dropped to 85.2% after 5.5 years and remained at 85.2% for the rest of the observation period. Ceramic onlays performed significantly better than ceramic over-lays. Cox regression analysis failed to show linkage of the survival of the indirect par-tial restorations with restoration material, tooth type, restoration type and the pres-ence of previous endodontic treatment. On the other hand, Cox regression analysis re-vealed a statistically significant difference for smoking (p<0.05).