Finite Element Analysis of Shrinkage Deformation of Light-Cured Composite Resin for Dental Restoration

In this study, the stress distribution in the shrinkage process when a light-cured composite resin is irradiated with light was estimated. We assumed that shrinkage and hardening of the light-cured composite resin resulted from light irradiation and was the same as that caused thermally. On the basis of this assumption, we simulated the deformation during the shrinkage of the composite resin using thermal elastic-plastic finite element modeling (FEM). The simulation was carried out by changing the adhesive strength of the composite resin and the enamel. We then compared the displacement distribution of the composite resin calculated using FEM with the displacement distribution measured using the digital image correlation method. We found that the displacement distribution of the composite resin calculated using FEM agreed well with the experimental results, and we estimated the stress distribution of composite resin under these conditions. We estimated that a high tensile stress was generated in the composite resin near the corner of the cavity.