Basic ResearchCyclic Fatigue Resistance of OneShape, HyFlex EDM, WaveOne Gold, and Reciproc Blue Nickel-titanium Instruments
Section snippets
Materials and Methods
Thirty RPC Blue R25 (25/.08), 30 HEDM (25/.∼), 30 WOG Primary (25/.07), and 30 OS (25/.06) files were included in the present study. Before the cyclic fatigue test, the files were examined using a stereomicroscope (Leica Imaging Systems Ltd, Cambridge, England) in terms of deformation; all of the files were involved because there was no deformation. For the static cyclic fatigue resistance test, a stainless steel artificial canal with a 5-mm radius of curvature, a 60° angle of curvature, and a
Results
The means and standard deviations of the NCF values and the lengths of fractured segments are shown in Table 1. The HEDM file (3456.33 ± 633.37) had the statistically highest fatigue resistance, and the OS file (1221.63 ± 812.4) had the least fatigue resistance (P < .05). The mean NCF of the RPC Blue file (2875.89 ± 105.35) was statistically higher than the WOG file (1737.00 ± 376.32) (P < .05).
The mean lengths of the fractured segments were recorded in order to evaluate the correct positioning
Discussion
One of the most important complications during root canal preparation when using NiTi rotary files is that the files fracture during the procedure (13). It was reported that the files, which fractured during clinical use, mainly fracture because of cyclic fatigue 14, 15. For this reason, many studies were performed on the cyclic fatigue resistance of NiTi rotary files 16, 17. Manufacturers aim to improve the cyclic fatigue resistance of NiTi rotary files by altering the metallurgy, design, and
Conclusion
Within the limitations of the present in vitro study, HEDM instruments resisted static cyclic fatigue significantly more than OS, RPC Blue, and WOG instruments. The novel NiTi rotary instrument Reciproc Blue showed better cyclic fatigue resistance than WOG and OS instruments.
Acknowledgments
The authors deny any conflicts of interest related to this study.
References (35)
Current challenges and concepts in the preparation of root canal systems: a review
J Endod
(2004)- et al.
A retrospective clinical study of incidence of root canal instrument separation in an endodontics graduate program: a PennEndo database study
J Endod
(2006) - et al.
SEM observations of nickel-titanium rotary endodontic instruments that fractured during clinical use
J Endod
(2005) - et al.
Torsional and cyclic fatigue resistance of a new nickel-titanium instrument manufactured by electrical discharge machining
J Endod
(2016) - et al.
Defects in rotary nickel-titanium files after clinical use
J Endod
(2000) - et al.
Success of ultrasonic technique in removing fractured rotary nickel-titanium endodontic instruments from root canals and its effect on the required force for root fracture
J Endod
(2013) - et al.
Deformation and fracture of Mtwo rotary nickel-titanium instruments after clinical use
J Endod
(2009) - et al.
In vitro comparison of cyclic fatigue resistance of ProTaper Next, HyFlex CM, OneShape, and ProTaper Universal instruments in a canal with a double curvature
J Endod
(2016) Cyclic fatigue resistance of Reciproc, WaveOne, and WaveOne Gold nickel-titanium instruments
J Endod
(2016)- et al.
Current challenges and concepts of the thermomechanical treatment of nickel-titanium instruments
J Endod
(2013)