Biomechanical Impact Of Labiolingual Diameter On Endodontically Treated Anterior Teeth

To evaluate the effect of the labiolingual diameter and construction of an endodontically treated (ET) anterior tooth with crown restoration on stress distribution and biomechanical safety in various occlusal relationships using finite element (FE) analysis. Three-dimensional FE models of maxillary central incisors with all-ceramic crowns were created. Three labiolingual diameters (D1: 6.85 mm, D2: 6.35 mm, D3: 5.85 mm) and two tooth structures (S0: vital pulp tooth; S1: ET tooth) were varied, resulting in six models. Three occlusal relationships were simulated. In normal occlusion, a 100 N static load was applied at a 45° angle near the incisal edge on the palatal surface. For deep overbite, the load was applied at 45° to the middle of the palatal surface, and for deep overbite with increased overjet, at 60°. Von Mises stress distribution and maximum stress of the models were analyzed. In all models, stress concentrated in the labial cervical 1/3 of the root (15.22 - 47.48MPa). Occlusal relationships and labiolingual diameter affected maximum stress in residual tooth tissue, with the former having a greater impact. Smaller labiolingual diameters increased maximum stress. In the same occlusal and diameter conditions, S0 and S1 models had little difference in stress. Occlusal relationships have a more significant impact on the biomechanics of ET anterior teeth with crown restoration than labiolingual diameter.