牙颌模型三维扫描仪精度定量评价

Quantitative evaluation for the accuracy of dental model three-dimensional scanner

目的:建立一种牙颌模型三维扫描仪精度的定量评价方法,应用该方法对3Shape D700商品化扫描仪进行精度这一核心指标的定量评价。方法:在三维逆向软件中设计一个整体外形类似于牙弓的标准几何样块,用高精度数控加工技术加工,利用此样块评价分析牙颌模型扫描仪关键技术指标,包括单次扫描精度、空间一致性、重复扫描精度共3项指标。结果:3Shape D700商品化扫描仪的单次扫描精度结果为(15.00±10.84)μm,和厂家说明书给出的精度结果 20μm差异无统计学意义(P=0.053);此外,空间一致性(垂直方向和水平方向,P=0.524)和重复扫描精度(垂直方向P=0.633,水平方向P=0.221)的检测结果差异亦无统计学意义。结论:使用该方法评价牙科扫描仪精度,可以避免手工选点法存在的观察者误差,是有效可行的。

Objective：To establish a method to evaluate dental model three-dimensional scanner quan- titatively, and to evaluate the accuracy which is a core indicator of 3Shape DT00 scanner. Methods： A standard geometric model similar to the dental arch was designed by three-dimensional reverse software and processed by high precision CNC （computer numerical control） processing technology. Core indica- tors of dental model three-dimensional scanner including single scanning accuracy, space consistency and rescan accuracy were evaluated. Results： The result of single scanning accuracy of 3Shape DT00 scanner was （15.00±10.8d） μm, and there was no statistics difference between the accuracy given by manufac- turer＇ s instructions which is 20 μm （ P = 0. 053 ）, and same as the results of space consistency （ compare the accuracy in vertical direction and horizontal direction, P = 0.524） and rescan accuracy （ compare the rescan accuracy in vertical direction, P =0. 633, and in horizontal direction P =0.221 ）. Conclusion： It is feasible to evaluate accuracy of dental model three-dimensional scanner by this method, which can avoid observer error caused bv selecting points manuallv.