Effects of temperature on mechanical and tribological properties of dental restorative composite materials

Abstract The purpose of this study is to evaluate the effects of temperature on the mechanical and tribological properties of three commercial posterior direct filling resin based restorative composite materials, Synergy (Coltene/Whaledent, Altstatten, Switzerland), Surefil (Dentsply/Caulk, New York, USA) and Alert (Pentron Clinical, Wallingford, USA). The aim of this paper was to evaluate how temperature influences; the hardness, flexural modulus and strength, elastic modulus, and wear of the listed commercial restorative materials. Three commercial resin composites were tested at several temperatures. A closed control system was used to ensure constant test conditions that simulated the temperatures found in an oral environment. For each of the tests, the following mechanical and tribological properties were determined, microhardness (Vickers micro-indentation), elastic modulus (determined both by dynamical methods and by bending tests), flexural resistance and work of fracture parameter (bending tests), and wear (reciprocating tests). Following the tests, the evaluation of the mechanical and tribological properties of the resins suggests that their performance in an oral environment can be significantly affected by temperature, especially the wear resistance. Surefil is the resin least sensitive to temperature variation, while Synergy exhibited the best resistance to wear with respect to temperature variation.