新型镍钛器械循环疲劳抗性的研究

Resistance to Cyclic Fatigue Failure of New Nickel-titanium Rotary Instruments

目的:运用金属模拟弯曲根管观察四种镍钛器械循环疲劳抗性能力的差异,为临床治疗提供参考资料。方法:将30/.06Hyflex CM、TF、K3XF和K3各30支,放入弯曲度为60°,曲率半径为3mm的金属弯曲根管内,体外模拟器械抗疲劳折断的过程,计算折断时器械旋转的圈数,并用扫描电镜观察器械断面的特征。结果:Hyflex CM、TF、K3XF的循环疲劳折断旋转圈数显著高于K3。结论:经过热处理的新型镍钛器械Hyflex CM、TF、K3XF较传统镍钛器械K3在抗循环疲劳能力方面有明显优势。

Objective：To evaluate the cyclic fatigue resistance of rotary endodontic instruments made of traditional or new nickel-titanium（NiTi）alloys.Methods：30/.06 Hyflex CM,TF,K3 XF and K3 were tested in a simulated canal with 60°of curvature and 3-mm radius.The number of rotations until fracture was recorded for each instrument.All fracture surfaces were examined under the SEM.Results：Hyflex CM,TF and K3 XF showed a significantly higher resistance to cyclic fatigue than K3.Scanning electron microscopy examination revealed a typical pattern of cyclic fatigue fracture for Hyflex CM,TF,K3 XF and K3 that was characterized by fatigue striations and microcrack.Conclusion：Hyflex CM,TF,and K3 XF instruments composed of new thermal treated alloy appeared more resistant to cyclic fatigue failure than K3 in a simulated canal model.