中文摘要：

目的研究齿科常用的灭菌方法：干热灭菌法、湿热灭菌法、化学浸泡灭菌法对高速裂钻腐蚀的影响。方法将100根全新高速裂钻随机分为10组,每组10根。第1组为对照组,不予以任何处理;另9组为实验组,分别用湿热灭菌法、干热灭菌法、化学浸泡法处理5、10、15次。采用称重法、扫描电镜观察及成分分析、表面显微硬度测量法对高速裂钻的腐蚀情况进行研究。结果湿热法处理5、10、15次组,干热法处理10、15次组以及化学浸泡法处理15次组与对照组相比,其重量增加均有统计学意义（P〈0.05）。电镜图片显示：湿热组形貌改变最为显著,出现明显腐蚀外观并与灭菌次数呈正相关;干热组最轻微。表面成分分析显示高速裂钻中的主要成分钨、铬、铁、钴、镍在灭菌处理前后其相对体积分数有所改变,其中钨以对照组、干热组、化学浸泡组、湿热组顺序依次增多;铁则以此顺序依次降低。与对照组相比,三种灭菌法均降低裂钻表面硬度（P〈0.05）,其中湿热组影响最大;干热组和化学浸泡组次之。随着灭菌次数的增加,湿热组和化学浸泡组裂钻表面硬度差异具有统计学意义（P〈0.05）,干热组硬度差异无统计学意义（P〉0.05）。结论不同灭菌处理对高速裂钻均产生一定的腐蚀,以湿热法最为明显。温度和湿度对高速裂钻的腐蚀有协同作用,干热灭菌对裂钻的腐蚀作用较轻。

英文摘要：

Objective The purpose was to analyze the effects of three sterilization methods（dry heat sterilization, steam sterilization,chemical sterilization） on the corrosion of dental fissure burs.Methods 100 dental fissure burs were distributed to 10 groups.One was control,the burs in the other 9 groups were treated by dry heat sterilization,steam sterilization,chemical sterilization with 5,10,15 cycles respectively.Weight method,scanning electron microscope,micro-hardness measurement were used to analyze the corrosion of dental fissure burs.Results The fissure burs gained their weight with cycles of sterilization.5,10,15 cycles of dry heat sterilization,10,15 cycles of steam sterilization and 15 cycles of chemical sterilization,the weight of fissure burs were significantly increased（P〈0.05）.Scanning electron microscope showed differences on the surfaces of dental fissure burs among the three sterilization groups.After sterilization,spot or partial erosion were seen on the surface of the burs.The steam sterilization groups showed the most evident changes,followed by chemical sterilization groups and dry heat sterilization groups.X-ray energy spectrometer showed the steam sterilization groups had the largest percentage of W,followed by dry heat sterilization groups,chemical sterilization groups and control group.Fe had the opposite trends.Micro-hardness reduced after sterilization.The reduction was most clear in steam sterilization group,followed by chemical sterilization and dry heat sterilization（P〈0.05）.The difference between 5 and 10 times of steam sterilization and 5,10,15 times of chemical sterilization were significant difference（P〈0.05）.There was no significant difference between 5,10,15 times of dry heat sterilization（P〉0.05）. Conclusion The corrosion is most severe in steamsterilization group,followed by chemical sterilization,dry heat sterilization.Dry heat sterilization shows less corrosion.