To compare the cyclic fatigue of resistance of WaveOne (WO; Dentsply Maillefer, Ballaigues, Switzerland) and WaveOne Gold (WOG, Dentsply Maillefer) small, primary, and large instruments in simulated root canals. Each instrument was rotated until fracture occurred.Methods
One hundred twenty nickel-titanium endodontic instruments were tested in two different curved artificial canals with different angles and radii of curvatures. WO and WOG small, primary, and large instruments were evaluated (n = 10 for each curvature). Each instrument was rotated until fracture occurred. The time to failure was recorded, and the length of the fractured tip was measured. An independent Student't test was used to compare the means between the 2 groups. One-way analysis of variance and Tukey' post hoc tests were used for multiple comparisons (P < .05).Results
At all the sizes tested and both curvatures, the cyclic fatigue resistance of the WOG instruments was higher than that of the WO instruments of corresponding sizes (P < .001). The WOG instruments were approximately twice as resistant to failure as the WO instruments were at a 60° angle of curvature, whereas the WOG instruments were 3 times more resistant at a 90° angle of curvature. The length of the fractured part of the instruments was similar among all the groups (P > .05).Conclusions
Within the limitations of this study, WOG instruments were more resistant to cyclic fatigue than WO instruments.