O'Hoy P Y Z, Messer H H, Palamara J E A
School of Dental Science, University of Melbourne, Melbourne, Australia.
Int Endod J. 2003 Nov;36(11):724-32. doi: 10.1046/j.1365-2591.2003.00709.x.
To evaluate the effect of repeated cleaning procedures on fracture properties and corrosion of nickel-titanium (NiTi) files.
New NiTi instruments were subjected to 2, 5 and 10 cleaning cycles with the use of either diluted bleach (1% NaOCl) or Milton's solution (1% NaOCl plus 19% NaCl) as disinfectant. Each cleaning cycle consisted of scrubbing, rinsing and immersing in NaOCl for 10 min followed by 5 min of ultrasonication. Files were then tested for torsional failure and flexural fatigue, and observed for evidence of corrosion using scanning electron microscope (SEM). Four brands of NiTi files were immersed in either Milton's solution or diluted bleach overnight and evaluated for corrosion.
Up to 10 cleaning cycles did not significantly reduce the torque at fracture or number of revolutions to flexural fatigue (P > 0.05, two-way anova), although decreasing values were noted with increasing number of cleaning cycles using Milton's solution. No corrosion was detected on the surface of these files. Files immersed in 1% NaOCl overnight displayed a variety of corrosion patterns. The extent of corrosion was variable amongst different brands of files and amongst files in each brand. Overall, Milton's solution was much more corrosive than diluted bleach. Corrosion of file handles was often extreme.
Files can be cleaned up to 10 times without affecting fracture susceptibility or corrosion, but should not be immersed in NaOCl overnight. Milton's solution is much more corrosive than bleach with the same NaOCl concentration.
评估重复清洁程序对镍钛（NiTi）锉的断裂性能和腐蚀的影响。
使用稀释的漂白剂（1%次氯酸钠）或米尔顿溶液（1%次氯酸钠加19%氯化钠）作为消毒剂，对新的NiTi器械进行2次、5次和10次清洁循环。每个清洁循环包括刷洗、冲洗，然后在次氯酸钠中浸泡10分钟，接着超声处理5分钟。然后对锉进行扭转失效和弯曲疲劳测试，并使用扫描电子显微镜（SEM）观察腐蚀迹象。将四个品牌的NiTi锉在米尔顿溶液或稀释的漂白剂中浸泡过夜，并评估其腐蚀性。
尽管使用米尔顿溶液时随着清洁循环次数的增加数值有所下降，但多达10次清洁循环并未显著降低断裂时的扭矩或弯曲疲劳的转数（P>0.05，双向方差分析）。在这些锉的表面未检测到腐蚀。在1%次氯酸钠中浸泡过夜的锉呈现出各种腐蚀模式。不同品牌的锉以及每个品牌内的锉之间腐蚀程度各不相同。总体而言，米尔顿溶液比稀释的漂白剂腐蚀性更强。锉柄的腐蚀往往很严重。
锉可以清洁多达10次而不影响断裂敏感性或腐蚀，但不应在次氯酸钠中浸泡过夜。相同次氯酸钠浓度下，米尔顿溶液比漂白剂腐蚀性更强。
