Stress behavior of cemented fiber-reinforced composite and titanium posts in the upper central incisor according to the post length: Two-dimensional finite element analysis

Background/purposeThis study examined the stress distribution in endodontically treated maxillary central incisors restored with various lengths of either titanium or fiber-reinforced composite (FRC) post-and-core systems, using two-dimensional finite element analysis models.Materials and methodsEight models of the maxillary central incisor were formed, surrounded by cortical bone, cancellous bone, and the periodontal ligament. Two different post-and-core systems, titanium and FRC posts (D.T Light Post), were modeled. In each restorative system, four models were designed by changing the post lengths cemented to the root at 10 mm, 9 mm, 8 mm, and 7 mm. A 100-N load was applied at a 45° angle to the long axis of each model. The stress distribution levels were calculated according to the Von Mises criteria.ResultsThe titanium post showed stress concentrations toward the post when loaded, and its stress concentration shifted toward the direction of the crown with a decreasing post length. In contrast, there was no stress concentration in the FRC post when loaded and no shift of the stress concentration toward the crown with a change in the post length.ConclusionResults suggest that the possibility of fracture of the FRC post is relatively low, compared to the titanium post, even for a short post. The same criteria for installation of a metal post should not be applied to an FRC post.