Aim: To compare the cyclic fatigue resistance of Revo-S, Genius, and RC Gold Primary files using static cyclic fatigue test device.

Materials and Methods: Twenty Revo-S (25/.06), 20 Genius (25/.04), and 20 RC Gold (25/.08) instruments were included in this study. The cyclic fatigue tests were performed using a cyclic fatigue testing device, which has an artificial stainless-steel canal with a 60° angle of curvature and a 5-mm radius of curvature. The files were randomly divided into 3 groups (group 1: Revo-S; group 2: Genius; and group 3: RC Gold). All the instruments were rotated until fracture occurred, and the time to fracture was recorded in seconds using a digital chronometer. The number of cycles to failure (NCF) and the length of the fractured segments were calculated. The data were analyzed statistically using Kruskal-Wallis test (P < .05).

Results: There was a significant difference among the groups (P < .05). The Genius showed the greatest mean of NCF (4155.22 ± 139.55), and the Revo-S showed the lowest mean of NCF (1480.60 ± 118.92).

Conclusions: Within the limitations of this in vitro study, the cyclic fatigue resistance of the Genius system was higher than the Revo-S and RC Gold instruments.