电火花蚀刻镍钛根管锉HyFlex EDM的表面形态和抗疲劳折断性能  

Surface microstructure and cyclic fatigue resistance of electro discharged machining nickel-titanium endodontic instrument

作　　者：王芳芳 杨殷杰 侯晓玫[1] WANG Fang-fang;YANG Yin-jie;HOU Xiao-mei(Second Clinical Division,Peking University School and Hospital of Stomatology ＆ National Clinical Research Center for Oral Diseases ＆ National Engineering Laboratory for Digital and Material Technology of Stomatology ＆ Beijing Key La-boratory-of Digital Stomatology,Beijing 100101,China;Department of Stomatology,Xuanwu Hospital,Capital Medical University,Beijing 100053,China;Department of Stomatology,Beijing Xicheng District Xinjiekou Comnmnity Health Service Center,Beijing 100035,China)

机构地区：[1]北京大学口腔医学院.口腔医院第二门诊部国家口腔疾病临床医学研究中心口腔数字化医疗技术和材料国家工程实验室口腔数字医学北京市重点实验室,北京100101 [2]首都医科大学宣武医院口腔科,北京100053 [3]北京市西城区新街口社区卫生服务中心口腔科,北京100035

出　　处：《北京大学学报（医学版）》2018年第5期876-881,共6页Journal of Peking University:Health Sciences

基　　金：国家自然科学基金(81200826)~~

摘　　要：目的:比较镍钛根管锉HyFlex EDM、HyFlex CM和HyFlex NT的表面形态和抗疲劳折断性能。方法:选取新的25mm长、25#/尖端4mm为0.08锥度的变锥度HyFlex EDM12支;25mm长、25#/0.06锥度的HyFlex CM和HyFlex NT各12支。每组随机选取2支,在扫描电子显微镜(scanning electron microscope,SEM)下观察表面形态,剩余10支使用60°弯曲角度、3.5mm弯曲半径的模拟金属根管检测抗疲劳折断性能。记录疲劳折断时间、计算疲劳折断圈数(number of cyclic fatigue,NCF);测量折断段长度(fragment length),并在SEM下观察断口。以上数据使用one-wayANOVA进行统计分析,显著性水平0.05。结果:SEM显示Hyflex EDM表面呈熔蚀状,可见均匀孔洞样结构;HyFlex CM和HyFlex NT表面较光滑,均可见明显的车磨条纹和缺陷。HyFlex EDM的疲劳折断圈数为838±223,HyFlex CM为582±99,HyFlex NT为81±20,两两比较差异有统计学意义(P<0.05);HyFlex EDM的断段长度显著长于HyFlex CM和HyFlex NT(P<0.05),所有断口均呈现典型的疲劳折断特征。结论:电火花蚀刻工艺使HyFlex EDM呈现熔蚀伴孔洞样表面形态,未见明显车磨缺陷,抗疲劳折断性能显著提高。Objective： To compare the surface microstructures and cyclic fatigue resistance of HyFlex EDM with HyFlex CM and HyFlex NT. Methods： Twelve 25 mm-long 25#/~ HyFlex EDM and twelve25 mm-long 25#/0. 06 taper HyFlex CM or HyFlex NT were selected. The surface microstructure of the 2 instruments which were randomly selected from each group was observed by using scanning electron microscope （SEM）. The remaining 10 instruments from each group were submitted to the cyclic fatigue test by using a simulated stainless steel root canal with 60° angle of curvature and curvature radius of 3. 5 mm. The time till fracture was recorded,the number of cyclic fatigue （NCF） was calculated,the length of fracture fragment was evaluated,and the topographic features were analyzed by using SEM. The data were analyzed by using one-way analysis via SPSS 23. 0 software. The statistical significance level was set at 0. 05. Results： SEM observation of the surface and microstructural characterization revealed peculiar melting appearance and evenly distributed micropores on the surface of HyFlex EDM while observations of the surface of both HyFlex CM and HyFlex NT demonstrated machining grooves and irregularities. The NCF of HyFlex EDM was 838 ± 223,which was significantly higher than not only that of HyFlex CM （582 ± 99）,but also that of HyFlex NT （81 ± 20） （P 〈0. 05）,and the difference between the latter two groups was significant,as well （P〈 0. 05）. The length of fractured fragments of HyFlex EDM was （7. 27 ± 0. 28） mm,which was significantly longer than the HyFlex CM and HyFlex NT,with values of （6. 72 ± 0. 26） mm and （6. 62 ± 0. 37） mm,respectively （P 〈0. 05）. Topographic features demonstrated typical cyclic fatigue for all the three groups while the region of crack origins was more for HyFlex EDM and HyFlex CM than that of HyFlex NT. As far as the dimple area was concerned,that of HyFlex EDM was deeper and larger than that of HyFlex CM and HyFlex NT. Conclusion： Within the limitat

关 键 词：牙科器械 镍 钛 电火花蚀刻 疲劳折断 

分 类 号：R783.2[医药卫生—口腔医学]