Curing depth of prosthetic composite materials polymerized with their proprietary photo-curing units

This study examined curing depth of eight prosthetic composite materials polymerized by means of six photo-curing units for the purpose of evaluating the curing performance of material-curing unit combinations. Each composite material was exposed with a photo-curing unit recommended by the manufacturer. The light sources of the units were halogen/fluorescent, xenon, metal halide, fluorescent, and halogen lamps, and exposure periods were 20, 30, 60, and 90 s. Curing depth of the materials was determined according to the method described by the International Organization for Standardization (ISO 4049). The results were analysed by factorial analysis of variance (ANOVA) and multiple comparison intervals. Two-factor ANOVA revealed that the depth of cure was influenced both by the material-unit combination and by the exposure period (P = 0.0001). Among the eight combinations, a hybrid composite material (Prywood color) polymerized with a metal halide curing unit (Hyper LII) exhibited the greatest depth of cure after 90-s exposure. For all combinations, longer exposure increased the depth of cure.