title: In vitro comparison in a manikin model: increasing apical enlargement with K3 and K3XF rotary instruments.
abstract: BACKGROUND
  The aim of the study was to compare the K3 and K3XF systems (SybronEndo, Glendora, CA) after 1 and 2 uses by evaluating apical transportation, working length loss, and working time in a manikin model.
  
  
  METHODS
  Mesial canals of 40 extracted first mandibular molars were instrumented. Radiographs taken after instrumentation with #25, #30, #35, and #40 files were superimposed on the preoperative image in both mesiodistal and buccolingual angulations. AutoCAD (Autodesk Inc, San Rafael, CA) was used to measure working length loss and apical transportation at 0, 0.5, and 1 mm from the working length (WL). The working time was measured. Group comparison was analyzed using post hoc Tukey honestly significant difference tests (P < .05).
  
  
  RESULTS
  No significant differences were found in apical transportation, working length loss between K3 and K3XF systems, or between the number of uses. Significant differences were found when canal enlargement was performed to a #35-40 (P < .05). K3 instrumentation performed significantly faster (29.6 ± 15.4) than with the K3XF system (40.2 ± 17.7) (P < .05). No differences were observed in working time when comparing the number of uses.
  
  
  CONCLUSIONS
  K3 and R-phase K3XF rotary systems shaped curved root canals safely with minimal apical transportation, even up to a 40/04 file.
authors.affiliation: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: Juan Gonzalo
authors.initials: JG
authors.lastname: Olivieri
authors.affiliation: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Stöber
authors.affiliation: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: Marc
authors.initials: M
authors.lastname: García Font
authors.affiliation: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: González
authors.affiliation: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Bragado
authors.affiliation: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Barcelona, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Roig
authors.affiliation: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Barcelona, Spain. Electronic address: fduranst@hotmail.com.
authors.forename: Fernando
authors.initials: F
authors.lastname: Duran-Sindreu
mesh_terms: D003754:Dental High-Speed Equipment; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D018130:Diamond / Q000737:chemistry; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008348:Manikins; D008422:Materials Testing; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D009811:Odontometry / Q000295:instrumentation; D011859:Radiography; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D013997:Time Factors; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D019415:Torque
chemical_list: D018130:Diamond
keywords: Apical transportation; K3; K3XF; R-phase; increased apical enlargement; manikin; root canal preparation