Influence of silica and zirconia particles as filler loading on the radiopacity of dental resin composites

摘要

The aim of this study is to evaluate the radiopacity of silica (SiO_2) and zirconia (ZrO_2) particles dispersed in a bisphenol-a-glycidyl methacrylate (Bis-GMA) as a base resin and triethylene glycol dimethacrylate (TEGDMA) as a diluent. The fillers were mixed separately with bis-GMA/TEGDMA monomers, in proportions of 40, 50 and 60 wt.%. A resin matrix containing 0 wt.% filler was used as the control composition to evaluate the effect of filler loading on the radiopacity. Samples of the composites with 2.5 mm thickness were compared their radiopacity with the same thickness of the standard aluminum plate. The radiopacity of both resin matrix/SiO_2 and resin matrix/ZrO_2 composites increased gradually as the filler loading increased. The resin matrix/ZrO_2 composites possessed radiopacity higher than the standard aluminum plate. The increase of filler loading showed highly significant differences in the radiopacity as tested by ANOVA (P = 0.000).