The effect of canal curvature on cyclic fatigue resistance of rotary instruments using different irrigation materials (in vitro study)

Abstract

Background: The mechanical qualities of Ni-Ti is crucial because they give the files their flexibility and enable us to prepare curved and double-curved canals with more ease. It happens frequently for instruments to separate during canal preparation, and cyclic fatigue (metal fatigue) is a frequent cause. This study aimed to assess how irrigation affected the two rotary endodontic instruments’ cyclic fatigue resistance. Methods: The Edge File and Fanta File rotary endodontic instrument groups were chosen. Each group (n = 42) was split into 3 subgroups (n = 14 each), one receiving NaOH, one Glycine, and one EDTA treatment. The number of cycles to failure (NCF) was determined after each subgroup underwent testing for cyclic fatigue resistance. Results: The result appeared different significant between the two group and sub-group with the different materials that used with it with the length of fractures and time that recorded in each group. Conclusion: NaOCl, glycine, and EDTA as chemical materials appeared to have considerably varied cycle fatigue resistance for various lengths of fractures and durations, according to the comparison between the two evaluated instruments.