title: A survey of experience-based preference of Nickel-Titanium rotary files and incidence of fracture among general dentists.
abstract: OBJECTIVE
  The purpose was to investigate the preference and usage technique of NiTi rotary instruments and to retrieve data on the frequency of re-use and the estimated incidence of file separation in the clinical practice among general dentists.
  
  
  METHODS
  A survey was disseminated via e-mail and on-site to 673 general dentists. The correlation between the operator's experience or preferred technique and frequency of re-use or incidence of file fracture was assessed.
  
  
  RESULTS
  A total of 348 dentists (51.7%) responded. The most frequently used NiTi instruments was ProFile (39.8%) followed by ProTaper. The most preferred preparation technique was crown-down (44.6%). 54.3% of the respondents re-used NiTi files more than 10 times. There was a significant correlation between experience with NiTi files and the number of reuses (p = 0.0025). 54.6% of the respondents estimated experiencing file separation less than 5 times per year. The frequency of separation was significantly correlated with the instrumentation technique (p = 0.0003).
  
  
  CONCLUSIONS
  A large number of general dentists in Korea prefer to re-use NiTi rotary files. As their experience with NiTi files increased, the number of re-uses increased, while the frequency of breakage decreased. Operators who adopt the hybrid technique showed less tendency of separation even with the increased number of re-use.
authors: Department of Conservative Dentistry, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Korea.
authors: Woocheol
authors: W
authors: Lee
authors: Minju
authors: M
authors: Song
authors: Euiseong
authors: E
authors: Kim
authors: Hyojin
authors: H
authors: Lee
authors: Hyeon-Cheol
authors: HC
authors: Kim
keywords: Crown-down technique; Fracture incidence; Hybrid technique; Nickel-titanium rotary file; Preference