Finite Element Analysis of Teeth Restored with Ceramic Crowns

摘要

Owing to improved material properties of ceramics, jacket crowns have become popular as esthetic restorations. However, in order to function for a long term, it is necessary to ensure that they possess high mechanical strength and that microleakage should be avoided as much as possible. Therefore, in choosing a material for the definitive restorations, it should be one where stress will not concentrate at the cervical area. Finite element analyses have been used for many investigations, because they can reproduce structures of various shapes of teeth with many elements defined with specific Young's modulus and Poisson's ratio values. In this manner, the distribution and magnitude of stress at any point can be precisely analyzed. The objective of the studies was to evaluate, by finite element analysis, the influence of different parameters on the stress distribution in teeth prepared for full ceramic crowns and in the restorations. The geometry of the teeth were obtained by 3D scanning using a manufactured device. The nonparametric modeling software was used to obtain the shape of the teeth structures. Different tooth preparations were designed and complete ceramic crowns were designed for all preparation types. Models were exported in Ansys finite element analysis software for structural simulations. Maximal equivalent stresses were recorded in the tooth structures and in the restoration for all preparation types. Numerical simulations provide a biomechanical explanation for stress distribution in prepared teeth and overlying crowns. Acknowledgements: This work was supported by CNCSIS-UEFISCSU, project number PN II-RU TE_217/2010.