Comparison of Canal Transportation and Centering Ability of K-files, ProGlider File, and G-Files: A Micro-Computed Tomography Study of Curved Root Canals

• Micro-CT comparisons of centering ability and apical canal transportation of 3 glide path enlargement techniques in curved root canals of extracted mandibular molars.
• K-files were least centered and caused more transportation.
• ProGlider displayed superior centering ability.
• ProGlider and G-Files caused significantly less transportation than K-files.

IntroductionThe purpose of this study was to compare centering ability and apical canal transportation of K-files (KF), ProGlider (PG), and G-Files (GF) after glide path enlargement in curved canals by using micro–computed tomography.MethodsThirty canals each were randomly assigned to KF, GF, and PG. Teeth were scanned before and after glide path enlargement to compare centering ability at 3 levels: 1 mm (D1) and 7 mm (D7) from the apical foramen and at the point of maximum root curvature (Dmc). Transportation was assessed in 8 directions at D1.ResultsKF were significantly less centered than both nickel-titanium (NiTi) groups at D1. At Dmc, PG exhibited a significantly more centered enlargement than both GF and KF, which were significantly similar. At D7, PG was significantly more centered than KF, but there were no significant differences between GF and KF or between PG and GF (P < .016). KF exhibited significantly more canal transportation at D1 than the NiTi groups (P < .05).ConclusionsNiTi files cause less transportation than KF. At D1, KF was less centered than both NiTi files. PG remained more centered at Dmc and D7.