Influence of filler on the difference between the transmitted and reflected colors of experimental resin composites

Objectives This study sought to determine the influence of filler size and amount on the difference between the transmitted and reflected colors and the translucency of experimental resin composites. Methods The color of experimental resin composites (38 mm in diameter and 1 mm in thickness) was measured in the transmittance and reflectance modes. Opalescence parameter (OP) was calculated as the difference in blue–yellow and red–green coordinates between the transmitted and reflected colors. Translucency parameter (TP) was calculated as the color difference between the reflected colors over a white and a black background. Results The range of OP was between 1.0 and 5.7, which was varied by the size and amount of filler. TP decreased as the amount of filler increased when the filler size was the same. Significance Controls on the proper filler size and amount should be studied further to modify the opalescence and translucency of resin composites, considering also the effect of filler on mechanical properties.