Effect of preheating on the mechanical properties of resin composites.

Objectives: The purpose of this study was to compare the flexural strength and modulus of two commercial resin composites, at room temperature and 40, 45 and 50 degrees C prior to light polymerization with standard and step-cure protocols.

Methods: One nanohybrid (Grandio, VOCO, Cuxhaven, Germany), and microhybrid composite resin (Filtek Z250, 3M ESPE, St. Paul, MN, USA) were used.