Multimethod assessment of design, mechanical and metallurgical characteristics of ProTaper Ultimate, TruNatomy Glider, ProGlider, Hyflex EDM and WaveOne Gold Glider glide path instruments

Nickel-titanium (NiTi) glide path instruments have been developed to enhance performance, but their mechanical and metallurgical properties vary significantly among different systems. This study compared the design, mechanical, and metallurgical properties of six nickel-titanium (NiTi) glide path instruments using a multimethod approach. A total of 420 ProGlider (PG) (16/.02-.06), WaveOne Gold Glider (WOGG) (15/.02-.06) and glide path files from the ProTaper Ultimate (PTU Slider) (16/.02-.06), TruNatomy (TNG) (17/.02), and Hyflex EDM (HF EDM) 10.05 and 15.03 systems were analyzed. Design features were assessed using a dental operating microscope and scanning electron microscopy (SEM). Mechanical properties, including static and dynamic cyclic fatigue, torsional resistance, bending resistance, and buckling resistance, were tested following standardized protocols. Metallurgical properties were evaluated through differential scanning calorimetry (DSC), SEM, energy dispersive spectrometry (EDS), and Vickers microhardness testing. Statistical analyses were performed using the Shapiro-Wilk test to assess normality, followed by appropriate parametric or non-parametric tests, including ANOVA with post-hoc Tukey and Kruskal-Wallis H tests with Bonferroni correction (α = 0.05). Design analysis revealed no major defects or deformations. WOGG and PG exhibited the highest cyclic fatigue resistance, while HF EDM 15.03 had the greatest torsional resistance. PTU Slider demonstrated the highest bending and buckling resistance. Metallurgical analysis indicated differences in phase transformation behavior, with TN Glider showing a two-stage phase transformation. Significant differences were observed among the tested instruments in terms of design, mechanical properties, and metallurgical characteristics. The multimethod approach provided a comprehensive understanding of these instruments, highlighting their suitability for clinical use based on specific mechanical and metallurgical properties. This multimethod analysis highlights significant differences in cyclic fatigue, torsional resistance, and flexibility among glide path instruments. WOGG and PG may be preferred for curved canals due to their superior fatigue resistance, HF EDM 15.03 for calcified canals requiring higher torsional strength, and PTU Slider for cases needing increased resistance to bending and buckling.