title: Comparison of Canal Transportation and Centering Ability of K-files, ProGlider File, and G-Files: A Micro-Computed Tomography Study of Curved Root Canals.
abstract: BACKGROUND
  The 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.
  
  
  METHODS
  Thirty 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.
  
  
  RESULTS
  KF 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).
  
  
  CONCLUSIONS
  NiTi files cause less transportation than KF. At D1, KF was less centered than both NiTi files. PG remained more centered at Dmc and D7.
authors.affiliation: Department of Odontology, School of Dentistry, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa. Electronic address: farzanapaleker@gmail.com.
authors.forename: Farzana
authors.initials: F
authors.lastname: Paleker
authors.affiliation: Department of Odontology, School of Dentistry, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
authors.forename: Peet J
authors.initials: PJ
authors.lastname: van der Vyver
mesh_terms: D003762:Dental Instruments; D004867:Equipment Design; D006801:Humans; D066298:In Vitro Techniques; D008963:Molar / Q000000981:diagnostic imaging* / Q000601:surgery*; D009532:Nickel; D011897:Random Allocation; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium; D055114:X-Ray Microtomography
chemical_list: C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Centering ability; G-Files; K-files; ProGlider; glide path enlargement; micro-computed tomography; transportation