Comparative analysis of postoperative mechanical behavior of immature premolars: apexification vs regeneration

To compare the mechanical behavior of lower premolars with incomplete root formation treated by apexification and regeneration and assess revascularization's impact on dentin thickness using finite element analysis. A mandibular bone model was obtained from a computed tomography scan and modeled using the CAD Rhinoceros 7.0 software program. The models were composed of enamel, dentin, pulp, periodontal ligament, cortical bone, medullary bone, gutta-percha, MTA, blood clot, and composite resin. The study groups were: IT (Intact Tooth); AC (Accessed Tooth); R (revascularization); and AX (apexification). After modeling the structures, the geometries were exported to the Ansys 13.0 finite element analysis software program. The models were submitted to loads of 200 N on the distal sulcus of the occlusal surface. The loading was directed at 45° to the occlusal plane. The results were calculated and qualitatively analyzed using displacement maps and maximum principal stress. The apexification models supported lower compressive and tensile stresses when compared to the revascularization models. Revascularization reduced stress concentration in the periradicular tissues, whereas apexification resulted in lower tensile stress in coronal dentin.