Effect of die material hue and value on polymerization of indirect resin inlays

This study investigated the effects of hue and value of mold materials on the polymerization of resin composite inlays fabricated by an indirect process. Three colors of molds were used, and 10 specimens each of three resin composite materials were light polymerized on each of the die materials for each test. The specimens were postirradiation heat polymerized. Compressive strength, flexural strength, Knoop hardness, and bond strength to enamel and dentin were measured. Although differences in properties between specimens polymerized on different die materials were not always significant, the values obtained from the white mold were highest in all tests followed by those obtained on the gray and then the black molds. Correlations (r2) between lightness or value and compressive and flexural strength, hardness, and bond to enamel and dentin values were greater than 0.90. Die color and value appear to be important factors influencing the properties of indirect resin composite inlays even though they are heat polymerized after light activation.