Identification of interfacial stress pattern on dentin post surface

Abstract

OBJECTIVE: The purpose of this study was to develop an interfacial stress distribution model for the post -dentin interface due to 50, 100 and 250 Newton occlusal biting forces by utilizing a finite element model. The hypothesis of the present study is that, on the basis of these interfacial stress models for post-dentine, it is possible to compute interfacial stresses at any given point on the post dentin surface and capture the characteristic behavior of post under the specific loading conditions under consideration. MATERIAL AND METHOD: The two-dimensional FEM was created by a self-developed image processing system, manually digitizing the key points on dental cross-section boundaries obtained from an actual maxillary canine tooth image. Crown, post core and coronal-radicular restoration were modeled by creating key points and transferring them to a two-dimensional coordinate XY system in the FE environment. The generated post in the model was 1.4 mm in diameter and 15 mm in length. A finite element (FE) analysis was performed to investigate the interfacial shear stress distribution on the dentine-post interface frequently used for the restoration of endodontically treated teeth. RESULTS AND CONCLUSION: From the results and within the limitations of the present study it can be concluded that the interfacial stress along the post is nonlinear and is roughly sinusoidal and the peak interfacial stress between the post and the dentin is expected to occur on top of the post. Sinusoidal models were developed to generalize the interfacial stress nonlinearity along the post length. These models can be used for calculation of the interfacial shear stress for 50, 100, and 250 Newton forces applied compressively at 45 degrees angle with respect to the implant axis. This study showed that the interfacial stress along the post was nonlinear and appeared roughly sinusoidal. Regression models were developed to generalize the interfacial stress nonlinearity along the post length.