title: Torsional Performance of ProTaper Gold Rotary Instruments during Shaping of Small Root Canals after 2 Different Glide Path Preparations.
abstract: BACKGROUND
  The purpose of this study was to assess the ex vivo torsional performance of a novel rotary system in small root canals after 2 different glide path preparations.
  
  
  METHODS
  Each independent canal of 8 mesial roots of mandibular molars was randomly assigned to achieve a reproducible glide path with a new set of either PathFile #1 (Dentsply Maillefer, Ballaigues, Switzerland) and #2 or ProGlider (Dentsply Maillefer) after negotiation with a 10 K-file. After glide path preparation, root canals in both groups were shaped with the same sequence of ProTaper Gold (Dentsply Tulsa Dental Specialties, Tulsa, OK) following the directions for use recommended by the manufacturer. A total of 16 new sets of each instrument of the ProTaper Gold (PTG) system were used. The tests were run in a standardized fashion in a torque-testing platform. Peak torque (Ncm) and force (N) were registered during the shaping procedure and compared with Student t tests after normal distribution of data was confirmed.
  
  
  RESULTS
  No significant differences were found for any of the instruments in peak torque or force after the 2 different glide path preparations (P > .05). Data presented in this study also serve as a basis for the recommended torque for the use of PTG instruments.
  
  
  CONCLUSIONS
  Under the conditions of this study, differences in the torsional performance of PTG rotary instruments after 2 different glide path preparations could not be shown. The different geometry of glide path rotary systems seemed to have no effect on peak torque and force induced by PTG rotary instruments when shaping small root canals in extracted teeth.
authors.affiliation: Department of Endodontics, University of the Pacific, Arthur A Dugoni School of Dentistry, San Francisco, California; Department of Conservative Dentistry, School of Dentistry, Complutense University, Madrid, Spain. Electronic address: aariaspa@ucm.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Arias
authors.affiliation: Centro Universitário Tiradentes, Maceio, Alagoas, Brazil.
authors.forename: Rafaela Andrade
authors.initials: RA
authors.lastname: de Vasconcelos
authors.affiliation: Department of Endodontics, University of the Pacific, Arthur A Dugoni School of Dentistry, San Francisco, California.
authors.forename: Alexis
authors.initials: A
authors.lastname: Hernández
authors.affiliation: Department of Endodontics, University of the Pacific, Arthur A Dugoni School of Dentistry, San Francisco, California.
authors.forename: Ove A
authors.initials: OA
authors.lastname: Peters
mesh_terms: D004868:Equipment Failure; D006801:Humans; D008422:Materials Testing; D008963:Molar / Q000601:surgery; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D054159:Torsion, Mechanical
keywords: Glide path; PathFile; ProGlider; ProTaper Gold; torque