Curing Units and Dentin Thicknesses

of two restorative composite resins (Filtek P90 silorane-based composite and Heliomolar methacrylate-based composite) with either a quartz-tungsten-halogen (QTH) or lightemitting diodes (LED) light-curing unit (LCU) and using dentin thicknesses (0.5 and 1.0 mm). Standardized cavities (2x2x2 mm) were prepared in 80 bovine incisors, which were randomly assigned to 8 groups according to the photoactivation method and dentin thickness. Filtek P90 and Heliomolar (both in shade A3) were used with their respective adhesive systems (P90 self-etch primer / P90 adhesive bond and Excite adhesive). All experiments were carried out in a controlled environment (37oC). The temperature variations (oC) were recorded using a digital thermometer attached to a K-type thermocouple. The results were analyzed statistically by ANOVA and Tukey’s test (α=0.05). For composite/ dentin thickness interaction, temperature increase was significantly higher in 0.5 mm dentin thickness (40.07oC) compared with 1.0 mm dentin thickness (39.61oC) for Filtek P90. For composite/LCU interaction, the temperature increase was significantly higher for Filtek P90 (39.21oC QTH and 40.47oC LED) compared with Heliomolar (38.40oC QTH and 39.30oC LED). The silorane-based composite promoted higher temperature increase in the pulp chamber than the methacrylate-based composite. Compar i son o f S i l o r ane and Methacrylate-Based Composites on t h e Po l yme r i z a t i on Hea t Generated with Different LightCuring Units and Dentin Thicknesses