Finite Element Analysis of Stress Distribution in Various Sizes Internal Root Resorption Cavities Filled With Different Materials

This study aimed to investigate the stress distribution on dentine, supporting tissues and restorative materials in simulated tooth models with various sized internal resorption cavities obturated with gutta-percha, MTA or Biodentine. A 3D finite element model was developed using Wheeler's dental atlas. The cortical and trabecular bone, lamina dura, and periodontal ligament were modelled. A healthy tooth served as the control, while the other models featured internal resorption cavities of various sizes in the middle third. In the treated models, the resorption cavities were restored with gutta-percha, MTA or Biodentine; the apical and coronal thirds were filled with gutta-percha. Seventeen models were subjected to a 100 N force at a 135° angle. Stress increased with resorption size but decreased after treatment. Gutta-percha models showed the highest stress on dentine and bone, while Biodentine had the lowest. However, Biodentine accumulated the most stress within the material. Larger resorption cavities increased stress, while Biodentine and MTA transmitted less stress to dentine than gutta-percha.