Effects of shade and composition on radiopacity of dental composite restorative materials

Abstract

The aim of this study was to evaluate the effects of the shade and composition of five dental composite resins on their radiopacity. Five composite resins in various shades were used in this study. Composite specimens were prepared in triplicate for each material and shade using Teflon ring molds. In addition, 1-mm-thick enamel and dentin specimens were prepared from freshly extracted premolar teeth. Each specimen was placed on a dental film together with an aluminum step-wedge to establish radiopacity equivalents for the composite materials, dentin, and enamel. Dental films were exposed using a dental X-ray machine at 70 kVp and 8 mA, and processed using an automatic processor. The optical densities of the composite specimens, step-wedge, enamel, and dentin were evaluated using a densitometer. The data were analyzed by one-way and two-way ANOVA and a post hoc Tukey HSD test at a significance level of a = 0.05. The shades of the tested composite resins did not affect their radiopacity level (p > 0.05). The composition of fillers of the tested composite resins influenced their ability to absorb X-ray radiation. All shades of the tested composite resins met the ISO requirement for radiopacity of resin-based restorative materials. The tested shades of the composite resins were appropriate for dental restorations regarding their radiopacity level. Although there were significant differences in radiopacity among the tested composites, they may not have clinical significance.