Study of high-strength, low-shrinkage dental resin composites with bifunctional polysilsesquioxane

Objectives The aim of this study was to develop a new composite resin to solve the problem of volume shrinkage of conventional dental restorative composite resins during the curing process in order to improve their mechanical properties and reduce the risk of restoration failure. Methods We synthesized the mercapto-alkenyl click chemical reaction product (MN-POSS) of acrylate-based POSS (MAP-POSS) with N-Acetylcysteine (NAC) using a bifunctional polysilsesquioxane modification technique and improved its dispersion in the resin matrix by physicochemical methods. In addition, methacrylate-based epoxy POSS (ME-POSS) was further synthesized and used to modify acrylate dental resins to form a free radical-cation hybrid light-curing system. Results The results showed that the composites modified with MN-POSS significantly improved mechanical strength, while the application of ME-POSS effectively reduced polymerization shrinkage, improved the water absorption and dissolution properties of the materials, and enhanced mechanical properties and hardness. This study provides new ideas and material solutions to improve the performance of dental restorative materials. Significance Both of these improved solutions demonstrate the potential of bifunctional POSS as a modified filler, providing new ideas and methods for the design of future dental restorative materials.