Cyclic fatigue resistance: comparison of AF F-One and One Curve rotary instruments with Hyflex EDM OneFile in root canal therapy

  • Yasamin Ghahramani Shiraz university of Medical sciences
  • Mahdi Sedigh-Shams
  • Mohammad Atbaei
  • Sahar Asar
Keywords: Endodontics, fatigue fracture, NiTi instrument


Background and Objectives: Cyclic fatigue is a major reason for file fractures as a complicated challenge in root canal therapy. The advantages of single-file rotary systems include time saving, cost-effectivenes and low risks of instrument fractures. This study selected an optimal file in terms of cost and clinical function by comparing cyclic fatigue among three files.

Materials and Methods:  This in-vitro study employed artificial steel canal. Fifteen files of One-Curve, One-File and F-One were rotated according to their manufacturer's recommendation for speed and torque until they fractured. The number of cycles until fracture and the length of the fractured part were measured. The data obtaind were analyzed using the Kruskal-Wallis and Dunn's tests with a statistically-significant threshold of P<0.05.

Results: The mean fracture time of One-File was 456±14 seconds. The mean number of rotations was 3043±937 for One-File, 1333±234 for One-Curve and 462±116 for F-One, suggesting statistically-signficant diffrences (P<0.001). The mean length of the fractured part was 8.32±0.64 mm in One-File, 5.17±0.917 mm in One-Curve and 6.58±1.16 mm in F-One, suggesting statistically-signficant diffrences (P<0.001).

Conclusion: Resistance to cyclic fatigue in inside curved canals was the highest in One-File, followed by One-Curve and F-One, which cannot be used as an appropriate alternative to the other two types of file in single-file systems.


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How to Cite
Ghahramani Y, Sedigh-Shams M, Atbaei M, Asar S. Cyclic fatigue resistance: comparison of AF F-One and One Curve rotary instruments with Hyflex EDM OneFile in root canal therapy. AANBT [Internet]. 20Mar.2022 [cited 29Nov.2021];3(1):14-7. Available from: