Stress analysis of a light-cured composite resin due to polymerization shrinkage

This study examined the shrinkage stress of a light-cured composite resin on cavity wall experimentally and analytically. The shrinkage force was measured using artificial cylindrical cavities fabricated in two stainless steel plates and a load-cell attached to the steel plate. An analytical model was introduced to evaluate the stress distribution in the cavities and to compare the shrinkage force experimentally determined, and following results were obtained: (1) The shrinkage force was dependent on both the cavity depth and irradiation time of the resin. (2) The analytical model can predict all the important features of the shrinkage force. (3) The stress on the cavity wall was dependent on the irradiation time.