Evaluation of Stress Distribution in Splinted Crowns on a Hemisected Tooth: A Finite Element Analysis

The objective of this study was to compare the stress distribution on splinted crowns made of two different materials placed on hemisected teeth using finite element analysis (FEA).

This study employed FEA to assess the stress distribution on the remaining dentin after placing two types of splinted crowns made of different materials on hemisected mandibular first molar models. Two hemisected mandibular first molar models were used for the study. The root canals of both models were filled with gutta-percha by FEA simulation. The splinted crown was the coronal restoration placed on the hemisected mandibular first molar and its adjacent tooth, the mandibular second molar. In the first model, a lithium disilicate splinted crown was placed, and in the second model, a zirconia splinted crown was placed. Using a three-dimensional finite element model, both crown models were subjected to loading and tested. Static loads of 450 N and 600 N were sequentially simulated on both models in vertical and oblique directions to the occlusal plane, and their maximum von Mises stresses were obtained using FEA.

Under a 450 N load, the maximum stress for the lithium disilicate splinted crown was 60.889 MPa on the adjacent tooth and 49.858 MPa on the hemisected tooth restored with the lithium disilicate splinted crown, whereas the maximum stress for the zirconia splinted crown was 61.421 MPa on the adjacent tooth and 49.034 MPa on the hemisected tooth restored with the zirconia splinted crown. Under a 600 N load, the maximum stress for the lithium disilicate splinted crown was 81.185 MPa on the adjacent tooth and 66.478 MPa on the hemisected tooth restored with the lithium disilicate splinted crown, whereas the maximum stress for the zirconia splinted crown was 81.824 MPa on the adjacent tooth and 65.547 MPa on the hemisected tooth restored with the zirconia splinted crown.

This study concludes that zirconia splinted crowns transferred numerically less stress to the hemisected tooth than lithium disilicate crowns; however, the difference was not statistically significant. The use of splinted crowns in hemisected teeth significantly improves stress distribution and reduces the load on the remaining tooth structure.