Comparison of Sequence, ProFile, and K3 endodontic rotary files using finite element analysis.

摘要

While nickel-titanium rotary files have significantly augmented the efficacy of endodontic treatments, there remain clinical concerns regarding rotary file fragmentation and failure due to high stresses resulting from complex canal curvature. Clinicians have taken precautionary measures limiting the rotary files to single use. The purpose of this thesis was to build off the work of Berutti et al. to generate finite element meshes for three systems of nickel-titanium rotary files (Sequence, ProFile, and K3) taking into account rotary file attributes such as tip size, file taper, and file length. The finite element models of the nickel-titanium rotary files were generated from high-power computer tomography (CT) scans, thereby incorporating the full geometry of the files. Files were then evaluated using bending stress analyses, and a working model was created for future investigation into stress distributions within these rotary files. A set of nine files were supplied from each of three rotary file systems: Sequence, ProFile, and K3, with the following file attributes: length of 21mm and 25mm, taper of 0.04 and 0.06, and tip sizes of 20, 30, and 40. A finite element analysis (FEA) was performed on each of the rotary file models and stress distributions were evaluated. An experimental setup using an Instron machine was employed to generate the force-deflection curves for these rotary files. The experimental results and ANSYS modeling results found that Sequence rotary files have more flexibility and increased Von Mises stress concentrations compared to both ProFile and K3 rotary files. Although Sequence rotary files are less likely to reshape canal curvature, they exhibit increased Von Mises stresses compared to ProFile and K3 rotary files. Through the use of CT, a FEA model of rotary files was created preserving complex file geometries which can be used for future comparative studies.