Evaluation of stress distribution in maxillary central incisor restored with different post materials: A three-dimensional finite element analysis based on micro-CT data

Abstract

Aim: Post-core restorations have been developed to restore and re-functionalize endodontically treated teeth. Today, post-core materials used to show stress distribution similar to a solid tooth are still being researched. This study aimed to compare the von Mises stress (σvm) distributions created by the Zirconium post (ZP), Titanium post (TP), and Glass Fiber post (GFP) materials in the permanent maxillary central incisor using finite element stress analysis (FEA). Methodology: A permanent maxillary central incisor tooth scanned using microcomputed tomography (µCT) was reconstructed, and a three-dimensional model was created. To these models, ZP, TP, and GFP were applied. Composite resin was modeled as the core structure and ceramic crown as the superstructure. Using FEA, 100 N static force was applied in three directions with vertical (F1-0°), oblique (F2-45°), and horizontal (F3-90°) angles to the models whose restoration was completed. As a result of the applied forces, the stresses on the dentine model (Dm), post model (Pm), and the cement model in between the dentine and the post (Cm) were compared. Results: The maximum von Mises stress (σvm max) distribution under F1 for Dm was: ZP = 6,07888 MPa, TP = 6,35719 MPa and GFP = 6,81946 MPa. The σvm max distribution under the force F2 for Dm was: ZP = 26,6542 MPa, TP = 27,3694 MPa, and GFP = 28,4495 MPa. The σvm max distribution under the force F3 for Dm was: ZP = 34,7371 MPa, TP = 34,9828 MPa, and GFP = 35,287 MPa. The σvm max distribution under the force F1 for Pm was: ZP = 17,0361 MPa, TP = 13,1567 MPa, and GFP = 7,85452 MPa. The σvm max distribution under the force F2 for Pm was: ZP = 73,7999 MPa, TP = 52,0089 MPa, and GFP = 25,9903 MPa. The σvm max distribution under the force F3 for Pm was: ZP = 78,8934 MPa, TP = 55,0424 MPa, and GFP = 27,1787 MPa. The σvm max distribution under the force F1 for Cm was: ZP = 7,95074 MPa, TP = 6,66092 MPa, and GFP = 4,60832 MPa. The σvm max distribution under the force F2 for Cm was: ZP = 16,8296 MPa, TP = 16,8514 MPa, and GFP = 16,526 MPa. The σvm max distribution under the force F3 for Cm was: ZP = 17, 5577 MPa, TP = 16,891 MPa, and GFP = 16,5209 MPa. Conclusion: In all three forces, the highest σvm max was at ZP, and the least was at GFP. ZP and TP accumulated forces internally rather than transmitting them to the tooth tissue. GFP distributed the forces more homogeneously to the dentine.