Influence of occlusal contacts on stress distribution in two-rooted teeth restored with aesthetic endodontic posts

Aim To investigate the stress distribution of a new composite post and to compare the changes in the stresses in normal occlusion and in malocclusion. Methodology The 3D finite element method (FEM) was used to perform the stress analysis of the two rooted first maxillary premolar restored with glass fibre posts. Composite resin was used as the core material and a full porcelain crown covered the preparation. Four noded tetrahedral elements were applied in the description of the tooth morphology, resulting in 1 684 512 elements and 246 510 nodes with 739 530 degrees of freedom. A total force of 200 N was applied. Results In the case with normal occlusion, stress distribution was mainly compression in its nature (from -4.7 to -230 MPa), except in the fissure where stress was tensile (+2.9MPa). In the case with malocclusion, tensile stress was generated on the cervical areas of both the sound tooth (+74MPa) and restored tooth (+6.5MPa). At the root furcation, tensile stress appeared only on the restored tooth (+4.7MPa). Conclusions In the case of malocclusion, the post and core modified the stress distribution at the root furcation, therefore increasing the possibility of root fracture.