title: Shaping ability and safety of five different rotary nickel-titanium instruments compared with stainless steel hand instrumentation in simulated curved root canals.
abstract: OBJECTIVE
  To compare the shaping ability and safety of engine-driven FlexMaster, GT Rotary, ProFile, ProTaper, and RaCe rotary instrumentation and Hedström hand instrumentation in simulated root canals.
  
  
  METHODS
  One hundred fifty simulated colored root canals with a curvature of 20 degrees and a radius of 10 mm were randomly distributed among 6 groups of 25 specimens each. After preparation to apical size 30 the area of remaining color on the canal wall indicating unprepared areas was measured in mm2 using image analyzer software.
  
  
  RESULTS
  Specimens treated with RaCe left least areas of remaining color compared to all other groups (P < .001), followed by ProTaper. Preparation with ProFile left behind the highest amount of unprepared areas. The ProFile group revealed significantly more remaining color than ProTaper, GT Rotary, and FlexMaster (P < .05). Four FlexMaster files separated.
  
  
  CONCLUSIONS
  RaCe rotary files were safe and more effective compared to the other instruments.
authors.affiliation: Department of Operative Dentistry and Periodontology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany. joerg.schirrmeister@uniklinik-freiburg.de
authors.forename: Jörg F
authors.initials: JF
authors.lastname: Schirrmeister
authors.forename: Christian
authors.initials: C
authors.lastname: Strohl
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Altenburger
authors.forename: Karl-Thomas
authors.initials: KT
authors.lastname: Wrbas
authors.forename: Elmar
authors.initials: E
authors.lastname: Hellwig
mesh_terms: D003722:Dental Alloys; D003762:Dental Instruments; D003799:Dental Stress Analysis; D004868:Equipment Failure; D004869:Equipment Safety; D003765:Models, Dental; D009532:Nickel; D012117:Resins, Synthetic; D018915:Root Canal Preparation / Q000295:instrumentation*; D013193:Stainless Steel; D018709:Statistics, Nonparametric; D014025:Titanium
chemical_list: D003722:Dental Alloys; D012117:Resins, Synthetic; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium