三种灭菌法对高速裂钻腐蚀和切削率的影响

Effects of three sterilization procedures on the cutting efficiency and the corrosion of dental fissure burs

目的:观察湿热灭菌法、干热灭菌法、化学浸泡灭菌法处理高速裂钻后其表面腐蚀情况,以及对高速裂钻切削率的影响。方法:100根新高速裂钻随机分成10组分别用3种灭菌方法处理5、10、15次,体视显微镜观察处理前后裂钻表面形态的变化,参考Siegel标准自制设备测试裂钻的垂直和侧向切削率,统计分析灭菌处理对切削率的影响。结果:3种灭菌方法中,湿热灭菌法引起的裂钻表面腐蚀最严重;干热法最轻;湿热灭菌法引起的裂钻切削率下降幅度最明显,化学浸泡法、干热法次之。灭菌次数与腐蚀程度、切削率的降低幅度成正比,处理15次后,裂钻的垂直和侧向切削率均有明显下降。结论:湿热灭菌法引起的裂钻腐蚀改变最明显、切削率降低幅度最大,化学浸泡法、干热法较轻,建议牙用高速裂钻类小器械采用玻璃珠灭菌器进行灭菌。

AIM： To analyze the effects of three sterilization methods, steam autoclave, bead sterilizer and chemical immersion on the corrosion and the cutting efficiency of dental fissure burs after repeated sterilization cycles. METHODS： 100 dental fissure burs were randomly divided into one control and nine experimental groups of 10 burs in each. The burs of experimental groups were treated by three sterilization methods with 5,10,15 cycles respectively. Be- fore and after sterilization cycles, the outline forms and outer appearances of those burs were observed in detail by stereo- microscope and two types of cutting studies. Perpendicular and lateral cutting were tested on a machinable glass ceramic block using an established testing regimen which has been introduced by Siegel. Each bur made perpendicular cutting of 15 seconds and lateral cutting of 13 millimeters. The determined cutting efficiency as the time to transect or drill the block was determined and the data was analyzed by a one - way analysis of variance. RESULTS ： Compare with the control group, the most surface corrosion and decrease of cutting efficiency were seen in the steam autoclave groups with 15 cycles, followed by chemical immersion and bead sterilizer groups, and the degree of decrease of cutting efficiency was significantly changed after 15 cycles of sterilization for all sterilization procedures （ P 〈 0.05 ）, with the perpendicular cutting efficiency changed more severe. CONCLUSION： The steam autoclave could cause more surface corrosion and decreases of cutting efficiency than another two sterilized methods. The cutting efficiency of dental burs is close correlated to the degree of corrosion. In regarding to the corrosion appearance and the changes of cutting efficiency, the bead steri- lizer method might be the best one to sterilize the dental fissure burs and these small appliances of dental clinic.