Effect of preheating on polymerization shrinkage strain of BIS-GMA free and containing resin composite restorative materials (in vitro study)

Abstract Background This study investigated the effect of preheating bulk-fill BIS-GMA free and containing resin composite on post-gel shrinkage strain. In a split Teflon mold, sixty specimens were prepared with dimensions 7 mm length × 4 width height . Thirty each tested restorative materials prepared, ten for selected temperature used in (room 23 °C, 50 °C 65 °C). The was monitored strain 3 min after light irradiation using gauges. For pairwise comparisons, Duncan’s multiple range test to analyze data two-way ANOVA. p ≤ 0.05 significance level chosen. Results Viscalor thermoviscous Bis-GMA had lowest polymerization values three different temperatures. There statistically significant difference between groups according material at Both showed highest when preheated °C. Conclusions While technology is introduced deliver viscosity flowable so reducing strain, it actually adverse it. Preheating either or no decreasing Polymerization contains without far superior that composite.