CAD/CAM导板在后牙区种植精度的体外研究

目的 后牙区利用计算机辅助设计和制作（computer aided design and computer aided manufacture，CAD/CAM）导板种植时，比较翻瓣与不翻瓣两种术式的精度。方法 选取20名后牙种植患者的锥形束CT（cone beam CT，CBCT）资料和石膏模型，采用3D打印技术制作翻瓣与不翻瓣树脂模型，运用导板在两种模型上模拟牙种植术，分别计算术前术后种植体位置偏差进而比较两种术式的精度。结果 CAD/CAM导板在后牙区辅助种植时，翻瓣与不翻瓣术式种植体顶端偏差分别为（0.95±0.36）mm、（1.33±0.43）mm；底端偏差分别为（1.53±0.56）mm、（1.94±0.30）mm；角度偏差分别为3.45°±1.10°、3.31°±1.55°；深度偏差分别为（0.75±0.47）mm、（1.43±0.41）mm。翻瓣与不翻瓣两种术式在种植体距离偏差上有统计学差异，角度偏差上没有统计学差异。结论 CAD/CAM导板引导的种植翻瓣术式比不翻瓣术式在种植体距离偏差上更准确。

An in vitro study of the precision of CAD/CAM guides in the posterior area

Objective To compare the accuracy of two methods of flap and flaplss ways in the posterior region when using the CAD/CAM template. Methods Cone Beam CT data and plaster models were selected from 20 patients with posterior teeth implantation. The flap and flapless resin models were fabricated by 3D printing technique. The surgical guides were used to simulate dental implant placement on the two kinds of models,respectively. The preoperative and postoperative implant position deviations were calculated and then accuracies of the two surgical procedures were compared. Results The top deviations of the flap and the flapless ways were(0.95 ±0.36)mm,(1.33±0.43)mm,respectively. The bottom deviations were(1.53±0.56)mm,(1.94±0.30)mm,respectively. The angle deviations were 3.45° ±1.10°,3.31° ±1.55°,respectively. The depth deviations were(0.75± 0.47)mm,(1.43± 0.41)mm,respectively.There is a statistically significant difference in the deviation of the implant between flap and flapless methods,while there is no statistical difference in angle deviation. Conclusion CAD/CAM guided implant flap approach is more accurate than the flapless procedure in distance deviation.