METHODS: Forty-five edentulous jaws (35 patients) underwent intraoral complete-arch digital scans with the double digital scanning (DDS) technique and the generated standard tessellation language (STL) files were superimposed and imported into computer-aided design software. After STL merging, each master STL file was used for printing a prosthesis prototype. The primary outcome was the accuracy of fit assessment of the printed prototypes on verified master stone casts. Two experienced clinicians tested the accuracy of fit with radiographs and screw-resistance tests. Secondary outcomes were the effect of the scan body shape and implant number on the accuracy of fit.
RESULTS: Out of the 45 DDS-generated prosthesis prototypes, 39 presented with accurate fit on verified master stone casts, yielding an 86.70% accuracy of fit. Cylindrical scan bodies led to 100% accuracy of fit (25/25), whereas polygonal scan bodies presented with 70% accuracy of fit (14/20). Four implant-supported prostheses yielded 100% accuracy of fit (12/12), compared with 25/29 (86.30%) accuracy of fit for the six-implant-supported ones. Fisher\'s exact test was used to assess the effect of different scan body shapes (p = 0.005) and implant number on accuracy of fit. Chi-squared test was used to assess the association between the number of implants per arch and the accuracy of fit (p = 0.039).
CONCLUSIONS: Thirty-nine out of 45 complete-arch prosthesis prototypes generated with a completely digital workflow presented with clinically acceptable fit. The effect of the scan body design and implant number was statistically significant, favoring cylindrical scan bodies and four-implant-supported prostheses.
方法:45例无牙颌(35例)采用双数字扫描(DDS)技术进行口内完整弓数字扫描,并将生成的标准镶嵌语言(STL)文件叠加并导入计算机辅助设计(CAD)软件。STL合并后,每个主STL文件用于打印假体原型.主要结果是在经过验证的母石铸模上对印刷原型进行拟合评估的准确性。两名经验丰富的临床医生测试了X射线照片和螺钉阻力测试的准确性。次要结果是扫描体形和植入物数量对拟合准确性的影响。
结果:在45个DDS生成的假体原型中,39在经过验证的主石模上精确拟合,产生86.70%的拟合精度。圆柱扫描体导致100%的拟合精度(25/25),而多边形扫描体的拟合精度为70%(14/20)。四个植入物支撑的假体产生了100%的配合精度(12/12),与25/29(86.30%)的6个植入物支持的配合精度相比。Fisher精确检验用于评估不同扫描体形(P=0.005)和植入物数量对拟合精度的影响。卡方检验用于评估每弓的植入物数量与拟合精度之间的关联(P=0.039)。
结论:45个完整的足弓假体原型中有39个是通过完全数字化的工作流程生成的,具有临床上可接受的配合。扫描体设计和植入物数量的影响具有统计学意义,有利于圆柱形扫描体和4-植入物支持的假体。本文受版权保护。保留所有权利。