Intercuspal dimensional changes in teeth restored with three surface composite resin restorations

Abstract

We studied how polymerization shrinkage and water sorption of composite resins produced dimensional changes in teeth. We determined the polymerization shrinkage and water sorption of four composite resins with different inorganic filler content. We also examined intercuspal dimensional changes in the teeth for various types of mesioocclusaldistal (MOD) cavity preparations. We found that dimensional changes increased together with increases in the cavity depth and/or width. The extent of the dimensional changes were dependent on polymerization shrinkage and water sorption of the composite resins. Water sorption expansion of the experimental composite resins could not compensate for polymerization shrinkage. Improvements in filling methods and cavity design are recommended to diminish residual stress in both the tooth and resin.