title: The efficacy of two rotary NiTi instruments and H-files  to remove gutta-percha from root canals.
abstract: OBJECTIVE
  The aim of this study was to evaluate the efficacy of R-Endo® and K3® rotary nickel-titanium instruments compared with manual instrumentation with H-files, with use of a solvent, for removal of gutta-percha during retreatment.
  
  
  METHODS
  Forty five freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH 26® sealer. The teeth were randomly divided into three groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: Group 1 (H-files), Group 2 (R-Endo®), and Group 3 (K3®). The specimens were rendered transparent for the evaluation of the area of remaining gutta-percha/sealer in buccolingual and mesiodistal directions. Statistical analysis as performed by using one-way ANOVA and Kruskal-Wallis tests (p=0.05).
  
  
  RESULTS
  All retreatment techniques used in this study left some filling material inside the root canal. Images in buccolingual and mesiodistal directions showed no significant differences between the groups (p>0.05).
  
  
  CONCLUSIONS
  Under the experimental conditions, the remaining filling material after retreatment was similar for each group.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey.
authors.forename: Kerem-Engin
authors.initials: KE
authors.lastname: Akpınar
authors.forename: Demet
authors.initials: D
authors.lastname: Altunbaş
authors.forename: Alper
authors.initials: A
authors.lastname: Kuştarcı
mesh_terms: D003786:Dental Pulp Cavity; D006171:Gutta-Percha; D006801:Humans; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium
chemical_list: C040654:titanium nickelide; D009532:Nickel; D006171:Gutta-Percha; D014025:Titanium