Low-shrinkage visible-light-curable urethane-modified epoxy acrylate/SiO2 composites as dental restorative materials

In this study, low-shrinkage high-strength dental restorative materials were prepared and their properties were investigated. Epoxy acrylates modified with various stoichiometric amounts of urethane acrylates were used as the resin matrix and 3-(trimethoxysilyl)p ropy] methacrylate (MSMA)-modified monodisperse nano-sized SiO2 particles were synthesized and used as the inorganic reinforcing filler. Polymer composites suitable for using as dental restorative materials were formed by curing the resin matrices containing MSMA-SiO2 with visible-light. The viscosities of the obtained resin matrices, their polymerization shrinkages, hardness, flexural strengths, and flexural moduli of the obtained polymer composites were investigated. Compared with bisphenol-A/glycidyl dimethacrylate (Bis-GMA)-based dental restorative materials, the polymer composites obtained in this study exhibited greatly reduced degrees of shrinkage and better mechanical and physical properties. (C) 2008 Elsevier Ltd. All rights reserved.