Polymerization Shrinkage

The formulation of composite resins has been modified during the past years with the purpose of improving their physical, mechanical and handling characteristics. With the advancement of dental materials and clinical technique composites have become the most widely used direct restoration material to satisfy patient aesthetics demand for the restoration of dental caries, crown fracture, tooth wear, and congenital defects Among the main factors related to the clinical outcome of composite resin restorations, the quality of the restorative material tooth interfacial seal and absence of micro-leakage are definitely considered. This is largely determined by the degree of polymerization shrinkage of the composite resin and the quality of bonding to tooth structures.