Biomechanical Behavior and Life Span of Maxillary Molar According to the Access Preparation and Pericervical Dentin Preservation: Finite Element Analysis.

INTRODUCTION

This study investigated the significance of pericervical dentin after coronal canal flaring on the biomechanical behavior and life span of a maxillary molar using finite element analysis (FEA).

METHODS

In addition to the intact tooth (IT) model, 4 experimental FE models were designed: conservative access cavity model (CON), and 3 models with different radicular preparations for the coronal 4 mL considering 3 instruments: ProTaper SX model (SX), OneFlare model (OF), and Gates-Glidden model (GG). Cyclic loading of 50 N was applied on the occlusal surface and number of cycles until failure (NCF) was compared with the IT model. Mathematical analysis was done to evaluate the stress distribution patterns and calculated maximum von Mises (VM) and maximum principal stresses.

RESULTS

Access cavity preparation (CON) decreased NCF significantly when compared with the IT model (93.99%). The coronal preparation of the root canal did not have a significant effect even when the preparation was taken to the extreme (GG: 92.02%). VM analysis confirmed apical dispersion of stresses, with maximum value registered on the occlusal surface in the GG model (7.88 MPa), and minimum on the IT model (7.01 MPa). The furcation area showed higher maximum principal stresses, yet stress values remained minimal and distributed over larger surfaces with the progressive enlargement among models.

CONCLUSIONS

Within the limitations of this study, coronal canal flaring affects tooth integrity minimally, and when loading conditions lie within normal functional ranges, tooth structure has the capacity to disperse increasing stresses over a wider surface area.