In Vitro Comparison of Cyclic Fatigue Resistance of ProTaper Next, HyFlex CM, OneShape, and ProTaper Universal Instruments in a Canal with a Double Curvature.
BACKGROUND
The aim of this study was to compare the resistance to cyclic fatigue of ProTaper Next X2 (PTN X2; size 25, 0.06 taper), Hyflex CM (HCM; size 25, 0.06 taper), OneShape (OS; size 25, 0.06 taper), and ProTaper Universal F2 (PTU F2; size 25, 0.08 taper) nickel-titanium files in an artificial root canal with a double (S-shaped) curvature.


METHODS
A total of 160 new PTN X2, OS, HCM, and PTU F2 files were tested in an artificial stainless steel canal with a double curvature. Forty files from each system were rotated until fracture to calculate the number of cycles to failure. The length of each fractured fragment was recorded. Data were analyzed by using one-way analysis of variance and Tukey post hoc tests.


RESULTS
The resistance to cyclic fatigue of the PTN X2 and HCM instruments was significantly greater than the OS and PTU F2 instruments in the apical curvature (P < .05). There was no statistical difference in the cyclic fatigue resistance of the PTN X2 and HCM instruments in the apical curvature (P > .05). In addition, there was no statistical difference between the OS and PTU F2 instruments in the apical curvature (P > .05). PTN X2, OS, HCM, and PTU F2 instruments showed similar cyclic fatigue resistance values in the coronal curvature (P > .05).


CONCLUSIONS
This study showed that PTN X2 and HCM instruments exhibit greater resistance to cyclic fatigue than OS and PTU F2 instruments in the apical curvature of an artificial canal with a double curvature.
Department of Endodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey. Electronic address: topcuogluhs@hotmail.com.
Hüseyin Sinan
HS
Topçuoğlu
Department of Pedodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
Gamze
G
Topçuoğlu
Department of Endodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
Ahmet
A
Akti
Department of Endodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
Salih
S
Düzgün
D003722:Dental Alloys / Q000737:chemistry*; D003786:Dental Pulp Cavity; D004867:Equipment Design; D004868:Equipment Failure; D019544:Equipment Failure Analysis; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
Cyclic fatigue; Hyflex CM; NiTi files; ProTaper Next; S-shaped canal