title: An in vitro comparison of apically extruded debris and instrumentation times with ProTaper Universal, ProTaper Next, Twisted File Adaptive, and HyFlex instruments.
abstract: BACKGROUND
  The purpose of this study was to compare the in vitro amount of apically extruded debris with new endodontic rotary nickel-titanium instruments.
  
  
  METHODS
  Sixty mandibular premolars were instrumented up to size 25 using ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next (Dentsply Maillefer), Twisted File Adaptive (SybronEndo, Orange, CA), and HyFlex (Coltene-Whaledent, Allstetten, Switzerland) rotary systems. The apically extruded debris was collected and dried in preweighed Eppendorf tubes. The amount of extruded debris was assessed with an electronic balance. The total time required to complete root canal shaping with the different instruments was also recorded. The significance level was set at P = .05.
  
  
  RESULTS
  The instrumentation time with the ProTaper Universal rotary system was significantly longer than with all the other instruments (P < .05). The Twisted File Adaptive and ProTaper Next systems extruded significantly less debris than the ProTaper Universal and HyFlex systems (P < .05).
  
  
  CONCLUSIONS
  The ProTaper Next and Twisted File Adaptive instrumentation systems were associated with less debris extrusion compared with the ProTaper Universal and HyFlex systems.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, İzmir Katip Çelebi University, İzmir, Turkey. Electronic address: capardt@hotmail.com.
authors.forename: Ismail Davut
authors.initials: ID
authors.lastname: Capar
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Atatürk University, Erzurum, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Arslan
authors.affiliation: Department of Pedodontics, Faculty of Dentistry, İzmir Katip Çelebi University, İzmir, Turkey.
authors.forename: Merve
authors.initials: M
authors.lastname: Akcay
authors.affiliation: Department of Endodontics, Faculty of Dentistry, İzmir Katip Çelebi University, İzmir, Turkey.
authors.forename: Huseyin
authors.initials: H
authors.lastname: Ertas
mesh_terms: D000328:Adult; D001641:Bicuspid / Q000473:pathology; D003722:Dental Alloys / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000473:pathology*; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D008875:Middle Aged; D009532:Nickel / Q000737:chemistry; D010486:Periapical Tissue / Q000473:pathology*; D012388:Root Canal Irrigants / Q000008:administration & dosage; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D016369:Smear Layer / Q000473:pathology*; D007507:Therapeutic Irrigation / Q000295:instrumentation; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D019227:Tooth Apex / Q000473:pathology*; D019415:Torque
chemical_list: D003722:Dental Alloys; D012388:Root Canal Irrigants; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Controlled memory nickel-titanium; HyFlex; ProTaper Next; ProTaper Universal; Twisted File Adaptive; debris extrusion