Evaluation of cyclic flexural fatigue of M-wire nickel-titanium rotary instruments.
BACKGROUND
This study was conducted to investigate cyclic flexural fatigue resistance of GT series X rotary files made from the newly developed M-wire nickel-titanium alloy compared with GT and Profile nickel-titanium files made from a conventional nickel-titanium alloy.


METHODS
Fifteen files, size 30/0.04, of each type were used to evaluate the cyclic flexural fatigue resistance. A simple device was specifically constructed to measure the time each file type required to fail under cyclic flexural fatigue testing.


RESULTS
The results of this experiment indicated that the GT series X files had superior cyclic flexural fatigue resistance than the other 2 file types made from a conventional nickel-titanium alloy (P = .004). On the other hand, the difference between the Profile and the GT files was not statistically significant.


CONCLUSIONS
The findings of this study suggest that size 30/0.04 nickel-titanium rotary files made from the newly developed M-wire alloy have better cyclic flexural fatigue resistance than files of similar design and size made from the conventional nickel-titanium alloy.
Al-Hadlaq
Solaiman M S
SM
Division of Endodontics, Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudia Arabia. salhadlaq@ksu.edu.sa
Aljarbou
Fahad A
FA
AlThumairy
Riyadh I
RI
D003754:Dental High-Speed Equipment / Q000592:standards; D003762:Dental Instruments / Q000592:standards*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D008669:Metallurgy; D009532:Nickel; D018583:Pliability; D018915:Root Canal Preparation / Q000295:instrumentation*; D013314:Stress, Mechanical; D014025:Titanium
C040654:titanium nickelide; D009532:Nickel; D014025:Titanium