title: Shaping ability of different nickel-titanium systems in simulated S-shaped canals with and without glide path.
abstract: BACKGROUND
  The objective of this study was to compare the shaping ability of different rotary and reciprocating nickel-titanium file systems with and without previous glide path preparation in simulated S-shaped canals.
  
  
  METHODS
  One hundred twenty S-shaped canals in resin blocks were prepared to an apical size 25 by using Reciproc, WaveOne, HyflexCM, F360, and OneShape systems either with or without previous glide path preparation (Pathfile) (12 canals/group). Material removal was measured at 20 measuring points, beginning 1 mm from the end point of preparation. Incidence of canal aberrations (zip/elbow, ledge formation), preparation time, and instrument failures were also recorded. Statistical analyses were performed by using analysis of variance and Tukey and χ(2) tests.
  
  
  RESULTS
  For all systems, glide path preparation exerted no significant effect on preparation times (P > .05). Glide path preparation had no influence on the incidence of canal aberrations and instrument fractures (P > .05), with no significant differences between the 5 systems (P > .05). Glide path preparation had no influence on the centering ability of all systems (P > .05). On average, canals prepared with F360, OneShape, and HyflexCM remained better centered compared with those enlarged with WaveOne and Reciproc.
  
  
  CONCLUSIONS
  Under the conditions of this study, glide path preparation had no significant impact on canal straightening. Less tapered instruments maintained the original canal curvature better than instruments having greater tapers.
authors: Central Interdisciplinary Ambulance in the School of Dentistry, University of Münster, Münster, Germany.
authors: Sebastian
authors: S
authors: Bürklein
authors: Central Interdisciplinary Ambulance in the School of Dentistry, University of Münster, Münster, Germany.
authors: Thomas
authors: T
authors: Poschmann
authors: Central Interdisciplinary Ambulance in the School of Dentistry, University of Münster, Münster, Germany. Electronic address: eschaef@uni-muenster.de.
authors: Edgar
authors: E
authors: Schäfer
mesh_terms: D003722:Dental Alloys / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry*; D011897:Random Allocation; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D019415:Torque
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Canal transportation; glide path; nickel-titanium; reciprocating; rotary; single-file systems; taper