Abfraction lesion in central incisor tooth: displacement and stress evaluation by laser speckle and finite element analysis

Abstract

The aim of this study was to evaluate the displacement and stress distribution in the cervical region of a mandibular central incisor tooth (MCIT) within wedge-shaped lesion simulating abfraction lesion by means of Laser Speckle (LS) and 3D Finite Element Analysis (FEA) and then compared. One experimental setup was assembled with a MCIT attached in resin and submitted to the LS. An increasing static load from 12.1 to 42.1N was applied in incisal buccal slope at 15º in relation to the tooth's long axis. A 3D numerical model with linear tetrahedral elements and homogeneous, linear and isotropic behavior was built with the same boundary conditions of the experimental setup. The LS present higher displacement in the wedge-shaped lesion than the FEA, but both had an excellent agreement in the displacement direction. The LS show a nonlinear behavior from 32.1N. The FEA has presented higher tensile stresses at the root dentin. In the FEA cementoenamel junction area, tensile stress isn't exceeding the enamel's tensile strength, under simulated conditions. It was concluded that LS is a faster tool and acceptable when studying the quantitative displacement of the biomechanical behavior in MCIT, and FEA is appropriate for the quantitative stress analysis, and both bring important results of the stress and displacement that are fundamental in planning preventive and restorative approach in non-carious cervical lesions.