Optical and thermal properties in experimental Bis-GMA-based resins influenced by filler characteristics

Abstract

The optical and thermal properties were examined in experimental 2,2-Bis-[4-(3-methacryloxy-2-hydroxypropoxy)phenel]propane (Bis-GMA)-based composite resin systems, each of which contained silica, silica-alumina and alumina filler particles. The filler particles were surface-treated by 1% γ-methacryloxypropyl trimethoxy silane and directly dispersed into the visible-light-cured Bis-GMA-based resin matrix. The average particle size was from 0.012 to 70 µm (silica filler), 2.4 to 8.4 µm (silica-alumina) and 0.02 µm (alumina). The analyses indicated that the filler-containing resin had a larger value of light transmittance when the difference in refractive index between comonomer and filler was smaller. In selected properties such as light transmittance, refractive index and depth of cure, the transmittance and the refractive index difference were important in the increased depth of cure in the Bis-GMA-based resins.