Mechanical properties of direct and post-cured composites.

Surface mechanical properties (diametral tensile strength, Knoop hardness, and Rockwell Superficial indentation and recovery) and bulk mechanical properties (compressive strength and modulus of elasticity in compression) of seven composites were measured in vitro under two curing conditions (light-curing only and light-curing plus manufacturer's recommended post-curing). Post-curing improved the Knoop hardeness by 7 to 46% and diametral tensile strength by 15 to 39% of some of the composites. None of the composites had improved compressive strength and only two had an improved modulus of elasticity.