Cyclic fatigue resistance of waveone gold, protaper next and 2shape nickel titanium rotary instruments using a reliable method for measuring temperature

The purpose of this study was to evaluate the cyclic fatigue resistances of the WaveOne Gold (WOG), ProTaper Next (PTN), 2Shape (TS) instruments.Totally 45 new WOG (25/.07), PTN (25/.06), TS (25/.06) files were tested inside the artificial canal of a custom-made stainless steel block with an inner diameter of 1.5 mm, a 60° angle, and a 5-mm radius of curvature. A 16-mm-long file segment (from the tip) was introduced and was immersed in 37°C water. The number of cycles to fracture (NCF), time to failure (TTF), fractured fragment length (FL) was recorded and the fractured surface was examined using microscope.WOG > PTN > TS according to TTF results (P = 0.00). PTN > TS according to NCF results (P = 0.00). The FL values showed no significant difference (P = 0.335).Reciprocating motion can be used more safely than continuous rotation due to the higher cyclic fatigue resistance.