Laboratory comparison of cyclic fatigue resistance of WaveOne Gold, Reciproc and WaveOne files in canals with a double curvature

Aim To compare the resistance to cyclic fatigue of WaveOne Gold (WOG), Reciproc and WaveOne (WO) nickel-titanium files in an artificial root canal with a double (S-shaped) curvature. Methodology A total of 120 new WOG primary, Reciproc R25 and WO primary files were tested in an artificial, stainless steel canal with an S-shape (diameter, 1.4 mm and length, 18 mm). Forty files from each system were rotated until fracture to calculate the number of cycles to failure (NCF). The length of each fractured fragment was recorded. Data were analysed using one-way analysis of variance and Tukey's post hoc tests. Results The WOG primary (apical curvature: 928.87 +/- 293.69; coronal curvature 1102.32 +/- 397.39 NCF) had higher cyclic fatigue resistance than Reciproc R25 and WO primary in the apical and coronal curvatures (P < 0.05). The Reciproc R25 file (745.63 +/- 253.49 NCF) had significantly greater cyclic fatigue resistance than the WO primary (583.89 +/- 183.38 NCF) in the apical curvature (P < 0.05). There was no significant difference in the cyclic fatigue resistance of the Reciproc R25 and WO files in the coronal curvature (883.63 +/- 282.56 and 916.53 +/- 268.21 NCF, respectively) (P > 0.05). There was no difference in fractured fragment lengths of the WOG primary, Reciproc R25, and WO primary files in either the apical or coronal curvature (P > 0.05). Conclusions WaveOne Gold primary files exhibited greater cyclic fatigue resistance than Reciproc R25 and WO primary in an artificial canal with an S-shape.