使用过的镍钛旋转器械加工硬化的维氏硬度研究
Vickers hardness investigation of work-hardening in used NiTi rotary instruments.
作者信息
Alapati Satish B, Brantley William A, Nusstein John M, Daehn Glenn S, Svec Timothy A, Powers John M, Johnston William M, Guo Wenhua
机构信息
Section of Oral Biology, College of Dentistry, The Ohio State University, Columbus, Ohio 43218-2357, USA.
出版信息
J Endod. 2006 Dec;32(12):1191-3. doi: 10.1016/j.joen.2006.07.007. Epub 2006 Oct 13.
A contributing mechanism for clinical failure of NiTi rotary instruments might be excessive work hardening. Vickers hardness was measured with 300 gm load near the flutes in three regions (D2-D4, D6-D10, and D14 towards the shank) for nine representative clinically used ProFile GT instruments that had been axially sectioned (10 measurements in each region). Consistent values could not be obtained at D1. Minimum hardness occurred at D2 to D4, with means from 313 to 324 (SD from 7 to 16). Maximum hardness with means ranging widely from 330 to 481 was found beyond D14. Mean hardness at D2 to D4 was 320 for an as-received ProFile instrument. Because a mean Vickers hardness of 326 has been reported for a shape-memory NiTi orthodontic wire product, it can be concluded that the NiTi instruments did not experience substantial work hardening at D2 to D4 during clinical use, in agreement with previous differential scanning calorimetric analyses.
镍钛旋转器械临床失效的一个促成机制可能是过度加工硬化。对于九种具有代表性的临床使用的ProFile GT器械（已进行轴向切片），在靠近凹槽的三个区域（D2 - D4、D6 - D10以及朝向柄部的D14）用300克载荷测量维氏硬度（每个区域进行10次测量）。在D1处无法获得一致的值。最低硬度出现在D2至D4，平均值为313至324（标准差为7至16）。在D14之后发现最大硬度，平均值范围从330至481。对于新收到的ProFile器械，D2至D4处的平均硬度为320。由于已报道一种形状记忆镍钛正畸丝产品的维氏平均硬度为326，因此可以得出结论，镍钛器械在临床使用期间在D2至D4处未经历显著的加工硬化，这与先前的差示扫描量热分析结果一致。
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