Direct composite resins: an update.

Esthetic restorative materials require a bonding procedure to achieve durability and reliability. To accomplish this, the bonding system and restorative material must be biocompatible and bond well to both dentin and enamel. The direct restorative must have sufficient strength to resist masticatory forces as well as mechanical properties close to those of natural tooth structure. These materials should be resistant to degradation in the oral cavity and easy to use. This article reviews the published literature on direct composite restorative materials.