Shen Ya, Haapasalo Markus, Cheung Gary Shun-Pan, Peng Bin
Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada.
J Endod. 2009 Jan;35(1):129-32. doi: 10.1016/j.joen.2008.10.014.
The purpose of this study was to examine three different types of nickel-titanium (NiTi) systems (ProTaper [Dentsply Maillefer, Ballaigues, Switzerland], ProTaper for Hand Use [Dentsply Maillefer], and K3 [SybronEndo, Orange, CA]) that were discarded by 3 endodontic clinics. The instruments were evaluated for defects and factors leading to instrument deformation or fracture. A total of 1682 instruments were collected over 16 months and were examined. The location of the defect, if any, was recorded. The overall prevalence of unwinding defects was 3% and fracture 5%; the rates differed significantly between clinics. For one brand (ProTaper) used at two different clinics, a defect rate (fracture and distortion combined) of 7% (clinic A) vs. 13% (clinic B) for Shaping files (P < 0.05), and about 4% vs. 10% for Finishing files (P < 0.05) was observed. Fragments of broken Shaping file were significantly longer in clinic A than for clinic B (P < 0.05). The lowest defect rate was found for K3 instruments: unwinding 1%, and fracture 3%. It was concluded that the defect rates of NiTi instruments were influenced by such factors as the operator, preparation technique and instrument design.
本研究的目的是检查3家牙髓病诊所丢弃的3种不同类型的镍钛（NiTi）系统（ProTaper [登士柏迈福，瑞士巴拉格]、手动使用的ProTaper [登士柏迈福]和K3 [SybronEndo，加利福尼亚州奥兰治]）。对这些器械进行评估，以确定导致器械变形或折断的缺陷及因素。在16个月的时间里共收集了1682件器械并进行检查。记录了如有缺陷的位置。松开缺陷的总体发生率为3%，折断为5%；各诊所之间的发生率差异显著。对于在两家不同诊所使用的一个品牌（ProTaper），成形锉的缺陷率（折断和变形合并）在诊所A为7%，在诊所B为13%（P < 0.05），修整锉的缺陷率约为4%对10%（P < 0.05）。诊所A中折断的成形锉碎片明显比诊所B中的长（P < 0.05）。K3器械的缺陷率最低：松开为1%，折断为3%。得出的结论是，NiTi器械的缺陷率受操作人员、预备技术和器械设计等因素的影响。
