导板设计和三维打印技术对根管导板精确度的影响

The effects of guide design and three-dimensional printing technology on the accuracy of endodontic guide

目的:在离体牙模型上比较不同导板设计和不同三维(3D)打印技术制作对根管导板的精确度的影响。方法:建立3D上、下颌前磨牙牙体硬组织和根管模型。在模上根管导板设计为直接打印法和间接制作法;3D打印技术为熔融沉积快速成型(FDM)和光固化成型(SLA)。比较实际开髓通道和虚拟开髓通道的起点(开髓孔),终点(牙全长的1/2位置)和角度偏差,评估导板精确度。结果:FDM直接法的偏差值最大[起点(0.86±0.32)mm,终点(1.20±0.37)mm,角度(5.5°±1.8°)]。SLA间接法的偏差值最小[起点(0.15±0.13)mm,终点(0.30±0.22)mm,角度(1.5°±0.7°)]。结论:导板制作间接法较直接法精确度高,打印技术光固化成型的角度偏差较熔融沉积快速成型小。

Objective:To compare the accuracy of endodontic guides prepared by different guide designs and different 3D printing techniques on the in vitro teeth.Methods:The model of 3D hard tissue and canal of maxillary andibular premolars was established.On the model,endodontic guides were designed by direct printing and indirect manufacture,and prepared by fused deposition modeling(FDM)and stereo lithography appearance(SLA)of 3D printing technology,respectively.The starting point(access opening hole),end point(half of the full length of teeth)and angle deviation of actual and virtual accesses were compared for the evaluation of the accuracy of the guides.Results:The deviation values of FDM with direct printing were the largest[starting point(0.86±0.32)mm,ending point(1.20±0.37)mm,angle(5.5°±1.8°)].The deviation values of SLA indirect method were the smallest[starting point(0.15±0.13)mm,ending point(0.30±0.22)mm,angle(1.5°±0.7°)].Conclusion:The indirect printing is more accurate than the direct method,and the angle deviation of SLA is smaller than that of FDM.