【摘要】 目的:观察Hero642镍钛根管锉临床损伤的形态特点,探索形变与折断之间的内在联系。方法:用肉眼、立体显微镜和扫描电子显微镜观察临床使用致变形、折断的Hero642镍钛器械71支。结果:Hero642镍钛根管锉损伤的形态特点为:断裂、螺纹旋紧、松解,一些螺纹工作刃的细微缺损或裂纹仅在35倍以上立体显微镜下才可发现。扫描电镜下,断口形貌呈现典型的“韧窝花样”。结论:Hero642镍钛根管锉的断裂主要发生在工作刃尖端4mm以内区段,属于韧性断裂,断裂前的形变应以35倍以上放大镜仔细检查,以减少临床器械折断的发生。更多还原

【Abstract】 Objective:To analyze the morphological characteristics of damaged Hero642 Ni-Ti dental files, and explain the relationship between deformation and fracture.Methods:71 discarded files were observed under naked eyes and stereomicroscope. 5 of which were observed under S360 scanning electronic microscope (SEM), and typical photos were taken for analysis.Results:The damage of Hero642 Ni-Ti dental files was characterized by fracture, tightened or loosened spiral and some kind of deformation detected at more than 35 times magnification. Under SEM, the dimple pattern was represented in the fracture surface of the files. Conclusion:Most Hero642 Ni-Ti files fractured within 4 mm from the tip which belongs to the pattern of ductile fracture.更多还原