Shrinkage Analysis of a Light-Cured Composite Resin in Cavities by X-ray CT Images

抄録

The polymerization shrinkage of light-cured composite resin, a dental restoration material, was studied using X-ray CT images and digital image correlation. An artificial cylindrical cavity in a bovine tooth was filled with the resin using a bonding agent. Two CT images were recorded, one before and one after irradiation of the area by visible light. The shrinkage behavior was evaluated by matching the bottom of the cavity floor in both images. The results showed that a large deformation was caused on the top free surface of the cavity, suggesting that this surface deformation can reduce the contraction stress around the interface between the resin and tooth structure. The inhomogeneous shrinkage behavior was also deduced from the internal displacement and strain fields of the resin