Patient's aesthetic requirements have increased in the past few years. The limited resistance of composites to wear has delayed their universal adoption for restoration of Class I and II cavity preparations in adult teeth. Although the potential use for posterior composite resin appears promising, the point at which such materials may be regarded as ideal, reliable, routine alternatives to silver amalgam has not been reached for materials of previous generation. To resolve some of the problems associated with the posterior composite resin, new materials (photo-cured GIC, multi step bonding agent, improved composite resins as P-50, Heliomolar Radiopaque, Ray Post) and new techniques have been introduced. In this paper the problems and questions raised with the use of posterior composites have been discussed.