Poly(methyl methacrylate) Grafted Silica Nanoparitcles via ATRP for Bis-GMA/TEGDMA Dental Restorative Composite Resins

Abstract

To improve the dispersibility of silica nanoparticles in dimethacrylate-based dental restorative composite resins, an efficient way was proposed to surface modify silica nanoparticles with polymer grafts. Firstly, silica nanoparticles reacted with 3-aminopropyl-triethoxysilane and 2-bromoisobutyryl bromide to obtain silica with the derived atom transfer radical polymerization (ATRP) initiators, which subsequently initiated the polymerization of methyl methacrylate to fabricate poly(methyl methacrylate) grafted silica nanohybrids. These nanohybrids could be well dispersed into bisphenol A glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) resin and had good interfacial bonding to the resin matrix. With the addition of modified silica nanopaticles, the flexural strength of the photo-cured composite resin was significantly increased in comparison with that of the unmodified group.