Comparison and analysis of ProTaper, ProTaper Next, and ProTaper Gold using finite element analysis

Aim: The aim of this study is to compare three endodontic files: ProTaper Universal (PTU), ProTaper Next (PTN), and ProTaper Gold (PTG) under bending forces using finite element analysis. Methods: This study utilizes finite element analysis conducted with ANSYS software. 3D models of the three endodontic files were prepared using ANSYS. A non-linear material model was applied, idealizing the stress-strain curve for Nickel-Titanium alloy (NiTi), the material of these endodontic files. Static and transient analyses were performed to identify three different material phases: austenitic phase, transition phase, and martensitic phase. Results: Finite element analysis reveals that the PTU file exhibited a maximum von Mises stress magnitude of 1249.7 MPa, PTN showed a maximum von Mises stress magnitude of 798.16 MPa, whereas the PTG file showed a minimum von Mises stress magnitude of 465.68 MPa. PTN showed more bending compared to the other file models for the same load magnitude. PTN remained in the austenitic phase until a tip displacement of 7.3657 mm, while PTU reached a maximum displacement of 4.5633 mm in the austenitic phase. Conclusion: The study concludes that the PTU file is the most rigid among the three file models. PTU generates higher stress magnitudes compared to the other files; thus, it is more likely to fracture under lesser bending forces. The study also concludes that PTG exhibits higher displacement with the lowest von-Mises stresses, making it the most flexible file among the three models.