Polymerization shrinkage and contraction stress of dental resin composites

High shrinkage and/or high contraction stress may lead to failure of the bond between the resin composites and the tooth structure. This study shows that the unpolymerized resin content determines the amount of shrinkage, contraction stress and tensile modules. Therefore, using pre-polymerized clusters will improve shrinkage/contraction stress properties, as was shown in Heliomolar, while high polymerization rates, and low flow factors have a deteriorative effect on the shrinkage/contraction stress properties.