Fracture toughness comparison of five indirect resin composites under the effect of thermal cycling

Abstract

ABSTRACTThis study investigated the microhardness and fracture toughness values of five dental indirect resin composites under the effect of thermal cycling by single-edge notched beam method. Highest microhardness and fracture toughness were reached in AP-X and Filtek P60 groups (microhybrid resin composite) (P < 0.05). After thermal cycling, significant changes of fracture toughness were found for the tested composites except AP-X. Microdifferences between scanning electron microscope images with and without thermal cycling were observed. It is concluded that irregular-shaped fillers and higher filler content contribute to higher mechanical properties, microhardness, and fracture toughness and result in superior fracture toughness under the effect of thermal cycling.