Evaluation of stress distribution in maxillary central incisor restored with different post materials: A three dimensional finite element analysis based on micro computed tomography data

Restoration of endodontically treated teeth is an important issue for clinicians. Post-core restorations have been developed to restore these teeth. Studies are still conducted to make the best restoration. It is a desirable situation that post-core restorations show a sound tooth-like stress distribution. The aim of this study is to compare the Von Mises stress values to finite element stress analysis of zirconia post, titanium post and glass fiber post materials. A three-dimensional (3D) model was created by reconstructing a permanent upper central incisor scanned with micro computed tomography. These models were subjected to zirconia post, titanium post and glass fiber post. Composite resin was modeled as the core structure and ceramic crown was used as the upper structure. 100 N force was applied in three different angles (vertical, horizontal and diagonal) by using the finite element stress analysis method. The data were compared in terms of the stresses on the post, dentin and dentin-cement-post. The maximum stress accumulation was observed in zirconia post model while the least stress accumulation was seen in the glass fiber post model. Due to their more rigid structures, zirconia and titanium posts have accumulated within their own structures instead of transferring forces to the tooth tissue. In all models, the lowest stress accumulations were observed in vertical forces in terms of the angles, while the highest stress accumulations were observed in horizontal forces. In addition, stress distribution in glass fiber post was observed to be more homogeneous.Many variables play roles in the clinical successes of post core restorations. In the finite element analysis, some of these variables were ignored. However, the finite element analysis enables experiments which cannot be performed in vital tissues by simulating in the computer environment. According to the results obtained from our study, we believe that glass fiber post restorations, which are close to dentin elasticity modulus, will distribute stresses to surrounding tissues and prevent the occurrence of fractures. Keywords: Finite element analysis, post-core, micro-ct, glass fiber post, biomechanic.