Efficacy of beveling posterior composite resin preparations

A clinical study was conducted to evaluate the controversy over the need to bevel the occlusal cavosurface margins of posterior composite resin preparations. A total of 43 standard amalgam type cavity preparations were generated. On a randomized basis the preparations were either beveled or left unmodified. The width of the bevel in each case approximated 1 micron. Impressions were made of each preparation to verify occlusal dimension. Each preparation was restored with Estilux Posterior (Kulzer, Inc.) using conventional techniques. Polyvinyl siloxane impressions were generated and then cast with die stone. These casts were evaluated for wear at baseline, 6 months, 1, and 2 years. The loss of composite resin in the beveled preparation at 2 years averaged 81.2 microns while the nonbeveled averaged 69.8 microns. On the basis of this study, it was concluded that beveling of the occlusal cavosurface did not enhance the wear resistance of the composite resin restoration nor any of the other clinical characteristics evaluated in the study.