effect of a cavosurface bevel on microleakage in posterior composite restorations

Composite resin restorative materials currently marketed with high filler ratio have still the unfavourable properties of resin component i.e., polymerization shrinkage of 2% to 3% [volume]. If the resulting volume reduction is forestalled by bonding the restorations to enamel or dentine, the contraction stresses up to 300 kg/cm[2] are produced. These factors may be responsible for microleakage and inducing marginal openings by marginal tooth fractures resulting in post operative sensitivity and recurrent caries. It is the responsibility of the dentist to overcome the unfavourable properties of these materials by the use of sophisticated technical procedures, particularly cavity designing and sensitive manipulative procedures