MTA versus Biodentine in Root Perforation Repair: Influence of Obturation Strategy on Fracture Risk in Maxillary First Premolars - A FEA and Weibull Analysis.

INTRODUCTION: The aim of this study was to compare the biomechanical effects of mineral trioxide aggregate (MTA) and Biodentine for repairing root perforations in conjunction with 2 obturation strategies (complete versus partial gutta-percha obturation) on the fracture resistance of maxillary first premolars. The incidence of these treatment modalities on the probability of fracture risk was evaluated quantitatively.

METHODS: Seven three-dimensional finite element models were constructed from cone-beam computed tomography data. The tooth models that were used consisted of a sound tooth model (SD), a root canal-filled model, an unrepaired perforation model, and four treatment models consisting of MTA/Biodentine combined with complete (All GP) or partial gutta-percha obturation being Part GP. The stress distribution under a 300 newton (N) occlusal load was then analyzed, and the fracture probability (Pf) was assessed using a Weibull analysis over a load range of 0-600 N.

RESULTS: Under a 300 N load, the unrepaired perforation model showed a significantly higher Pf (10.15%), which was 10.6 times greater than SD's. All treatment models restored dentin stress to near-SD levels (9.71-10.01 MPa). When combined with the All GP strategy, both MTA and Biodentine achieved Pf values comparable to root canal-filled model (2.84% at 300 N). In contrast, the Part GP strategy resulted in higher stress values in the coronal enamel and midroot dentin, and higher Pf values (3.24%-3.99% at 300 N).

CONCLUSION: Both MTA and Biodentine are effective at restoring the biomechanical performance of perforated teeth. The obturation strategy significantly influences the long-term fracture risk. The All GP strategy combined with either repair material optimizes fracture resistance and minimizes failure risk. As a result, it is recommended as the preferred clinical technique.