title: Cyclic fatigue resistance of OneShape, Reciproc, and WaveOne: An in vitro comparative study.
abstract: OBJECTIVE
  The aim of this in vitro study was to evaluate the cyclic fatigue resistance of three single-use nickel-titanium (NiTi) instruments.
  
  
  METHODS
  Forty files each of OneShape (OS), Reciproc R25 (R25), WaveOne Primary (WO) file, and ProTaper (PT) F2 (as control) were tested in four curved artificial canals with different angles and radii of curvature. The number of cycles to fracture (NCF) was determined and the data were compared for differences by using two-way analysis of variance (P < 0.05).
  
  
  RESULTS
  In general, all single-use instruments were more resistant than traditional rotary instrument used as control. R25 showed the highest cyclic fatigue resistance. One Shape and WO files showed similar cyclic fatigue resistance values, higher than PT F2.
  
  
  CONCLUSIONS
  Within the limitations of this study, it can be concluded that R25 was the most fatigue resistant. OS rotary instruments seem to have good mechanical resistance, similar to NiTi files developed for reciprocating motion.
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Pediatric Sciences-Section of Dentistry, University of Pavia, Pavia, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Dagna
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Pediatric Sciences-Section of Dentistry, University of Pavia, Pavia, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Poggio
authors.affiliation: Department of Occupational Medicine, Ergonomy and Disability, Laboratory of Nanotechnology, Salvatore Maugeri Foundation IRCCS, Pavia, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Beltrami
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Pediatric Sciences-Section of Dentistry, University of Pavia, Pavia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Colombo
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Pediatric Sciences-Section of Dentistry, University of Pavia, Pavia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Chiesa
authors.affiliation: Department of Clinical, Surgical, Diagnostic and Pediatric Sciences-Section of Dentistry, University of Pavia, Pavia, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bianchi
keywords: Cyclic fatigue; NiTi; reciprocating motion; rotary files; single-use instruments