Marginal adaptation of a low-shrinkage silorane-based composite: 1-year randomized clinical trial

The aim of the present study was to examine the marginal adaptation of a new low-shrinkage silorane-based composite material (Filtek™ Silorane, 3M-Espe) by comparing it with a methacrylate-based composite material (CeramX™, Dentsply DeTrey). In particular, we wanted to test the hypothesis that reduced polymerization shrinkage would improve the marginal adaptation. Seventy-two patients participated in the study. A total of 158 restorations were placed in 80 premolars and 78 molars. Only Class II restorations were included, and each patient could contribute with more than one tooth. The restorations were scored at baseline and after one year. While statistical comparison of marginal adaptation at follow-up indicated better performance of CeramX™ both occlusally and approximally (p = 0.01 and p < 0.01), the low kappa value (32%) reflects the difficulty to assess marginal adaptation clinically. The reduction in polymerization shrinkage demonstrated in the laboratory was not clinically significant in the present study.