临床废弃机用M-two镍钛锉的损伤分析  

Defects in discarded M-two rotary instruments after routine clinical use

作　　者：张平虎 屈铁军 倪龙兴 

机构地区：[1]军事口腔医学国家重点实验室,陕西省口腔医学重点实验室,第四军医大学口腔医院牙体牙髓病科,陕西西安710032

出　　处：《牙体牙髓牙周病学杂志》2016年第3期175-179,共5页Chinese Journal of Conservative Dentistry

基　　金：国家自然科学基金青年项目(31200738);陕西省国际合作课题(2014KW22-01)

摘　　要：目的:探讨M-two镍钛锉在根管治疗中的损伤、断裂机制。方法:从临床收集近6个月内906支废弃的机用M-two镍钛锉,体视显微镜观察损伤情况,并且对断锉进行微距数码摄影,同时运用ImagePro Plus软件对断点位置进行测量。采用SPSS 17.0软件包对数据进行统计学分析。结果:906支M-two镍钛锉中,有196支锉刃发生塑性形变(21.6%);221支锉发生断裂(24.4%)。#10.04锉器械分离率最高(39.3%),#15.05次之(33.6%)。#30.05锉的断裂位点最高(3.65±0.80)mm。折断的类型主要包括:弯曲疲劳折断(65.2%)和扭转折断(34.8%)。结论:#10.04和#15.05锉塑性形变占有较高比例,因此建议一次性使用;其余锉建议临床降低使用次数,并且定期更换。AIM： To evaluate the deformation and fracture rate of discarded M-two rotary nickel- titanium instruments after routine clinical use,and to explore the failure mechanism during root canal preparation. METHODS： 906 M-two rotary Ni Ti instruments were collected after clinical use from Endodontics clinic over a peiod of 6 m.The files were observed under stero-microscope to determine the types of the defects. The fractured files were photographed digitally and the pictures were analyzed by software Image- Pro Plus to measure the distance from the break point to the tip. The data were statistically analyzed using SPSS 17. 0 software. RESULTS： Plastic deformation was observed in 196 files（ 21. 6%）. Instrument separation occurred in 221 files（ 24. 4%）,and the most frequently fractured file was #10. 04（ 39. 3%） followed by #15. 05（ 33. 6%）. The #30. 05 file group had the highest fracture level,and the mean distance from the breakpoint to the file tip was 3. 65 ± 0. 80 mm. The types of fracture were flexural fatigue（ 65. 2%） and torsional fatigue（ 34. 8%）. CONCLUSION： #10. 04 and #15. 05 files have higher rate of deformation during clinical use. These files should be considered as single- use instruments,not be used for the maximum usage times recommended by the manufacturer and discard the instruments on a regular basis.

关 键 词：器械分离 M-two镍钛锉 疲劳失效 

分 类 号：R780.8[医药卫生—口腔医学]