Comparative study of torsional and bending stress in NiTi, graphene, and GUM metal endodontic files by finite element analysis

Introduction: This study investigates the behavior of graphene and GUM in terms of cyclic fatigue resistance and torsion through a finite element analysis on a file with an eccentric rectangular cross section and variable taper, and on a file with a centered triangular cross section, constant taper, and constant pitch. Methods: Root canals and endodontic files were created using Catia V5R21 software. For torsional analysis, the tip of the file was fixed at 1 and 3 mm, and a moment of 2.5 N -mm was generated at the handle. For the bending analysis in curved canals (45 degrees and 60 degrees), the handle was kept fixed and a force of 1 N was applied at the tip while the file was kept fixed at 9 mm. Results: GUM metal instruments showed better torsional resistance. On the other hand, NiTi and graphene performed better under the applied loads during flexion at 45 degrees and 60 degrees. Conclusion: GUM metal is emerging as a promising material in the field of endodontic instrument design due to its physical properties.