ABSTRACT
Temperature rise occurs during photoactivation of dental composites due to the exothermic polymerization reaction and different curing units. The aim of this study was evaluation of temperature rise in two kinds of composites with different curing units. In this experimental study, five samples of each composite resin [Filtek Z250, Filtek P90] were placed in two-millimeter deep Teflon molds which were 4mm in diameter. Curing was done from top surface with LED, high power LED and argon laser and temperature was recorded by a thermometer placed under the samples. After reaching room temperature, samples were cured and the temperature was recorded again. The time of maximum temperature was also recorded. The data were analyzed by two-way ANOVA and Tukey HSD. Composites and curing units had statistically significant influence on the temperature rise [p<0.001] Silorane-based composites showed significantly higher temperature rise than methacrylate-based ones. A significantly lower rise in temperature occurred when illumination was performed by argon laser. There was no significant difference in temperature rise between the two types of LEDs. The type of composite had no effect on the time of maximum temperature and in all samples the maximum temperature was recorded at the beginning of irradiation. Silorane-based composites showed higher temperature rise than methacrylatebased ones. Argon laser revealed less heat than LEDs. The maximum temperature rise was recorded at the beginning of irradiation