Comparative FEM study about various posts used on endodontically treated teeth

Objectives. The aim of the present study was to analyze comparatively, through the finite element method (FEM), the biomechanical behavior of different types of devices used to increase the resistance of restorations on endodontically treated teeth, upon the experimental application of a force of 350N. Materials and methods. We studied comparatively three types of posts, respectively: fiberglass post, cast post from Cr-Co-Mo alloy and prefabricated titanium post. Three irretrievable extracted teeth for periodontal reasons were endodontically treated and then specifically prepared for cementation of this devices. The teeth were scanned at a radio-diagnostic center, and the obtained DICOM files were processed with MIMICS and 3-matic and then subjected to finite element analysis with ANSYS. Results. From the 48 simulations carried out for the case of all-ceramic crown coverage, the use of titanium post is associated with 25 situations in which maximum or minimum values appear, the use of cast post presents 12 situations in which maximum or minimum values are developed, the use of fiberglass posts is associated with 10 simulations where maximum or minimum values occur, and in one case the deformations are equal. Regarding the use of the zirconium oxide crown, the results are comparable. Conclusions. The presence of zirconium oxide crowns generally produces less valuable stresses and deformations at the level of the components. The stress and strain values are lowest when using fiberglass posts, followed closely by cast post and far behind by titanium post. In all simulated situations, the limit values of stresses and strains are mostly recorded at the tooth root, which is susceptible to fracture in case of parafunctional forces, followed by the three devices themselves and the covering crowns.