Gracey刮治器磨锐损耗的形态学观察

Morphological observation and study on working blades loss of Gracey curettes after sharpening

目的观察磨锐后Gracey刮治器外形变化,为提高Gracey刮治器磨锐效果提供参考。方法选取报废的Gracey刮治器137把共274个工作端,与全新Gracey刮治器4把共8个工作端进行比较。从工作面、顶端、工作刃口角度及背部四个方面观察刮治器喙部形态的变化,并测量喙部工作端的长度、宽度,测试棒测试是否锋利。结果 19个工作端折断,剩余255个工作端从工作面看废弃时仍双侧刃口平行的有178个(69.80%),工作刃口角度保持不变的121个(47.42%),顶端呈圆弧形的仅有38个(14.90%),背部保持平滑的仅7个(2.75%),报废的Gracey刮治器的平均剩余宽度和平均剩余长度均减少,77个工作端保持锋利。结论报废Gracey刮治器大部分产生变形,可能影响刮治效果,提示临床工作时需要认真学习打磨技术和更仔细地打磨。

ObjectiveTo observe the changes in contour of working blades in Gracey curette after various speed controlled sharpening methods,and to provide the basis for improving the sharpening style of the instrument.Methods274 working ends from 137 discarded Gracey curettes were selected and compared to 4 brand new curettes which were taken as the controls.Comparative observations of the changes in appearances after sharpening were performed for the toes,cutting edge angle,face and back of each instruments.The length and breadth of the cutting edge were measured and compared.Plastic stick was used to test sharpness.Results19 working edges were broken.If observed from the faces of the rest 255 working edges,the double edged blade angle was found to be parallel in 178 instruments(69.80%);the cutting edge remained unchanged in 121(47.42%)cases.Similarly,only in 38(14.90%)working ends rounded contour of the toes were maintained whereas only in 7(2.75%)instruments the back of the cutting edges was still smooth.The average length and breadth of the working edges of these discarded curettes were also found to be decreased in measurement.77 working edges were reported sharp in the test.ConclusionSharpening of Gracey curettes produces deformation in shape and size that affects the effectiveness of the instruments during performance.More attention should be given to the proper sharpening technique.