Finite element analysis of stress distribution in inlay, onlay, and overlay crowns fabricated with different materials

Objective: The aim of this study was to evaluate the stress generated by inlay, onlay, and overlay crowns fabricated using different contemporary materials through finite element analysis, thereby contributing to the understanding of the clinical performance of these materials. Material and Method: Within the scope of the study, a three-dimensional mandibular molar tooth model was constructed in accordance with the data provided in Wheeler's Dental Anatomy Atlas. A total of 15 models were generated using different restoration types and materials. To simulate physiological masticatory forces, a total vertical load of 300 N was applied to multiple contact points on the tooth surfaces. As a result of the applied loading conditions, von Mises stress and maximum principal stress values occurring in both the restorations and the tooth structures were analyzed. Results: When the restoration types were evaluated, the highest von Mises stress values were observed in onlay restorations, whereas the lowest values were detected in overlay restorations. Although the highest von Mises stress value (1225,88 MPa) was recorded in the LithaCon 3Y210 material, this material transmitted the lowest von Mises stress value (34,45 MPa) to the tooth structures. The lowest maximum principal stress value within the restorations (220,85 MPa) was observed in the VarseoSmile Crown Plus material, while the highest maximum principal stress value transmitted to the tooth structures (563,36 MPa) was also detected in this material. Conclusion: An increase in the elastic modulus of restorative materials reduced stress levels within the tooth structures, thereby enhancing biomechanical stability. Von Mises stress levels varied significantly depending on the restoration type. In general, onlay restorations exhibited higher von Mises stress accumulation compared to inlay and overlay restorations. The magnitude of von Mises stress values ranked from highest to lowest as follows: onlay> inlay> overlay. Differences in restorative materials affected both the magnitude and distribution of von Mises stress. Keywords: Different Materials, Finite Element Stress Analysis, Inlay, Onlay, Overlay