电抛光表面处理对 BioRace 镍钛根管锉循环疲劳强度的影响。
Effects of electropolishing surface treatment on the cyclic fatigue resistance of BioRace nickel-titanium rotary instruments.
机构信息
Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
出版信息
J Endod. 2010 Oct;36(10):1653-7. doi: 10.1016/j.joen.2010.06.026. Epub 2010 Aug 12.
INTRODUCTION
This study evaluated the influence of electropolishing surface treatment on the number of cycles to fracture of BioRace rotary nickel-titanium endodontic instruments.
METHODS
BioRace size BR5C instruments with or without electropolishing surface treatment were used in an artificial curved canal under rotational speed of 300 rpm until fracture. Fractured surfaces and the helical shafts of fractured instruments were analyzed by scanning electron microscopy (SEM).
RESULTS
Polished instruments displayed a significantly higher number of cycles to fracture when compared with nonpolished instruments (P < .001). Actually, the number of cycles to fracture of a polished BR5C instrument was 124% higher than that of a nonpolished instrument. SEM analysis showed that the fractured surface of both polished and nonpolished BR5C instruments had ductile morphologic characteristics. Evaluation of the separated fragments after cyclic fatigue testing showed the presence of microcracks near the fracture surface. Polished instruments exhibited fine cracks that assumed an irregular path (zigzag crack pattern), whereas nonpolished instruments showed cracks running along the machining grooves.
CONCLUSIONS
Electropolishing surface treatment of BioRace endodontic instruments significantly increased the cyclic fatigue resistance.
简介
本研究评估了电解抛光表面处理对 BioRace 旋转镍钛根管器械断裂循环次数的影响。
方法
在转速为 300rpm 的人工弯曲根管中使用有或没有电解抛光表面处理的 BioRace BR5C 器械，直至发生断裂。用扫描电子显微镜（SEM）分析断裂表面和断裂器械的螺旋轴。
结果
与未经抛光的器械相比，抛光器械的断裂循环次数明显更高（P<0.001）。实际上，抛光 BR5C 器械的断裂循环次数比未经抛光的器械高 124%。SEM 分析表明，经过疲劳循环测试后分离的碎片，在断裂表面附近存在微裂纹。抛光器械显示出细小的裂纹，呈现不规则的路径（锯齿状裂纹模式），而未经抛光的器械显示出沿加工槽延伸的裂纹。
结论
BioRace 根管器械的电解抛光表面处理显著提高了循环疲劳阻力。
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