Experimental-numerical investigation on the biomimetic recovery of natural tooth structural response after porcelain veneer restoration

This study analyzes the effect of porcelain veneer restoration on the structural response of a maxillary incisor. Tooth deformation is evaluated, prior to and after restoration, by the synergic use of Phase-Shifting Electronic Speckle Pattern Interferometry (PS-ESPI) and 3D finite element (FE) analyses. The intact maxillary incisor and the porcelain veneer restored tooth are subject to flexural load. Displacement fields are measured with Phase-Shifting Electronic Speckle Pattern Interferometry. Experimental tests are simulated with 3D FE analyses tuning materials parameters via an optimisation-based inverse procedure. ESPI measurements indicate that the restoration design under study produced deformations very similar to those of the intact tooth under load. FE results show sharp changes in displacement and stress 1 mm above the cementenamel junction on the facial side of the restored tooth. Severe stress concentration (about 50% increase with respect to natural tooth) appears at the interface between veneer restoration and intact enamel and dentine tissues. This confirms the hypothesis that veneer restorations can amplify the effect of occlusal loading on the loss of dental hard tissue in the tooth cervical region.