Cyclic Fatigue Resistance of One Curve, 2Shape, ProFile Vortex, Vortex Blue, and RaCe Nickel-Titanium Rotary Instruments in Single and Double Curvature Canals

• Published in: Journal of endodontics Vol. 44; no. 11; pp. 1725 - 1730
• Main Authors: Elnaghy, Amr M., Elsaka, Shaymaa E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2018
• Subjects: 2Shape; Body temperature; cyclic fatigue; Dental Instruments; Dentistry; double curvature; Equipment Design; Equipment Failure; heat treatment; Hot Temperature; Materials Testing; Motion; Nickel; One Curve; Root Canal Preparation - instrumentation; Titanium; cyclic fatigue; One Curve; heat treatment; 2Shape; double curvature; Body temperature
• ISSN: 0099-2399; 1878-3554
• DOI: 10.1016/j.joen.2018.07.023

The aim of this study was to evaluate and compare the resistance to cyclic fatigue of the new One Curve (OC) instrument in double (S-shaped) and single curvature canals compared with other nickel-titanium rotary instruments. Size 25/.06 of OC, 2Shape (TS), Vortex Blue (VB), ProFile Vortex (PV), and RaCe (RC) instruments were tested inside artificial canals with a single curvature (60° curvature, 5 mm radius) and double curvature (coronal curve, 60° curvature, 5 mm radius; and apical curve, 70° curvature and 2 mm radius) while immersed in saline at 37°C ± 1°C. The number of cycles to failure (NCF) was calculated, and the fracture surface was examined by using a scanning electron microscope. The data of NCF and fragment length were analyzed by using one-way analysis of variance and Tukey post hoc tests. The t test was performed between the data of fragment length in different curvatures. The level of significance was set at P < .05. The VB instrument had a significantly higher NCF compared with the other instruments in double (S-shaped) and single curvature canals (P < .05). There was no significant difference between OC and TS in the NCF in single, apical, and coronal double curvature canals (P > .05). The lowest NCF values were recorded for RC instrument in all curvatures (P < .05). The fatigue resistance of VB was greater than that of other instruments. OC and TS instruments displayed superior cyclic fatigue resistance than PV and RC instruments. •Cyclic fatigue resistance of One Curve was assessed in double and single curvature canals.•The fatigue resistance of Vortex Blue was greater than other instruments.•One Curve and 2 Shape instruments showed higher cyclic fatigue resistance.