RESUMO
Aims: The objective of this study was to clinically evaluate the performance of a conventional resin system and one with low polymerization shrinkage. Study Design: A prospective, randomized, blind, split-mouth study. Place and Duration of Study: Dental Clinic, division of Heath Sciencies, State University of West Parana - UNIOESTE/Brazil, between October, 2011 and October, 2012. Methodology: Teeth were restored with one of the two tested materials (n = 10): Conventional composite resin restorations (CCR) and Silorane-based resin composite restorations (SCR). The materials were used according to manufacturer’s instructions. After time intervals of 30 days, 6 months and 1 year, the restorations were assessed using the USPHS criteria. The data obtained were tabulated and evaluated by the Chi-square test for clinical parameters and for the restoration criteria (p< 0.05). Results: No statistically significant differences between the two composite resins were found, with exception of marginal adaptation, in which CCR showed better results than SCR. Conclusion: The silorane-based composite resin showed no advantage over the methacrylate resin.