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

Abstract

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. 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. 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. 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.