Effect of different sizes of Nano-TiO2 on wear resistances and surface hardness of resinbased dental composites

Abstract

Objective: The principal aim of this study was to evaluate the wear resistance and surface hardness of dental nanocomposites. Three difference sizes (5 nm, 21 nm and 80 nm) of nanoTiO2 particles were treated with the 3-methacryloyloxy-propyl-trimethoxysilane (MPTMS). The nano-TiO2 was then place in urethane dimethacrylate (UDMA) matrix. Methods: Nano-TiO2 was sonically dispersed in an ethanol solution containing MPTMS. The treated particles were washed in pure ethanol and then dried. Wear resistance and surface hardness of eighteen groups of experimental dental nanocomposites were evaluated. Each group had a particle size category and was treated with three different concentrations of the silane, (MPTMS), which are 2.5, 10 and 30 wt %. For comparison, a commercially available dental resin, SR Adoro® (Ivoclar Vivadent, Cape Town, South Africa), used as the control, was reinforced with untreated and treated nano-TiO2. Results: Statistical analysis showed that the effect of the concentrations of MPTMS on wear resistance and surface hardness of specimens was significant (p<0.001), which is less than 0.05. The improvement of adding treated 80 nm TiO2 was better than that of adding treated 5 nm or 21 nm TiO2. Conclusions: It is concluded that the most available commercial product for dental restorations could be improved by the addition of nano-TiO2 with relatively large particles size