3D finite element analysis of stress distribution in dental tissues and materials as a result of oblique and horizontal forces after regenerative endodontic treatment Part II: Comparison of Material Thickness

Abstract

Abstract Aim This study aimed to evaluate the stress distribution caused by secondary trauma forces after regenerative endodontic treatment (RET) using different thicknesses of coronary barrier material, with three-dimensional finite element analysis(FEA). Method A control model was created using the tomography image of the immature maxillary central tooth with computer software. Study models were created with the modulus of elasticity and Poisson’s ratio of the materials used in RET.Enamel, dentin, cementum, periodontal ligament, cortical, and cancellous bone were modeled. Coronary barrier materials were applied in 3mm and 5mm thicknesses(Model 1:control model, model 2:3mm/Calcium Enriched Mixture(CEM), model 3:3mm/Mineral Trioxide Aggregate(MTA), model 4:3mm/Biodentin, model 5:5mm/CEM, model 6:5mm/MTA, model 7:5mm/Biodentin). Forthe trauma force simulation, 300N force in the horizontal direction was applied to the buccal surface of the tooth in the first scenario. For the second scenario, maximum bite force simulation, a force of 240N in the oblique direction was applied to the palatal surface of the tooth. FEA was performed with Algor Fempro. The resulting stresses were recorded as Von Mises, maximum and minimum principal stresses. Results Lower stress values were obtained in 5mm models compared to 3mmmodels. However, the difference between them was insignificant. Lower stress values were obtained in all RET models compared to the control model. The lowest stress values in dental tissues and bone tissue were obtained inthe CEM models. Conclusion This is the first study in which the stress caused by different thicknesses of CEM on dental tissues was evaluated with FEA. RET strengthens immature teeth biomechanically CEM andBiodentin are more successful materials in stress distribution than MTA. Considering the cost of treatment, 3 mm material thickness is ideal for RET since there is no significant difference between the stress values resulting from the use of 5mm and 3mm coronary barrier material.