A comparative study of glide path instruments assessing flexibility and torsion by finite element method

This study presents a novel numerical evaluation of the bending and torsion behavior of four nickel-titanium glide path instruments, addressing a critical gap in understanding their mechanical performance under clinical conditions.

The evaluated instruments include the WaveOne Gold Glider with a parallelogram cross-section, the R-Pilot with an S-shaped cross-section, the ProGlider with a square cross-section, and the V Taper 2H with a triangular cross-section. Using advanced computer-aided design (CAD) software, detailed geometric models of each instrument were created, followed by numerical simulations performed in the SolidWorks finite element platform. Material properties of nickel-titanium alloys and boundary conditions were defined based on ISO 3630-1 specifications for bending and torsion tests.

The findings revealed significant variations in stress distribution and flexibility among the instruments. Notably, the R-Pilot demonstrated superior flexibility, being approximately 57% more flexible than the WaveOne Gold with a 28 mm deflection during bending. Conversely, the V Taper 2H exhibited the highest stress levels in bending tests. While torsional stress was comparable among V Taper 2H, ProGlider, and WaveOne Gold at approximately 500 MPa, R-Pilot showed the highest stress values under torsional loads. Additionally, distinct differences in stress distribution were observed between reciprocating and rotational glide paths.

These insights underscore the necessity of evaluating both bending and torsion behaviors to optimize the design and clinical performance of glide path instruments.