Metal-oxide nanoparticles for the reinforcement of dental restorative resins.

Metal oxide nanoparticles were synthesized from tantalum ethoxide and zirconium isopropoxide and subsequently surface grafted with vinyl silane and silyl methacrylate coupling agents. The nanoparticles were then dispersed into a commercial dental resin, and the composite was photocured into rigid three-point bend and fracture toughness specimens. The optically transparent/translucent cured composites demonstrated strength, toughness, and elastic modulus inferior to the unfilled material. Therefore, modifications in surface functionalization are being made to improve coupling and reduce interparticle associations.