Wang J, Yu H J, Sun J D, Qiu L X
Fourth Clinical Division, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China.
Beijing D&E Medical Limited Company, Dental Digital & Esthetics Laboratory, Beijing 100176, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2022 Feb 18;54(1):187-192. doi: 10.19723/j.issn.1671-167X.2022.01.030.
To compare the operation complexity and accuracy of traditional splint impression technique and impression technique with prefabricated rigid connecting bar system for full-arch implants-supported fixed protheses .
Standard mandibular edentulous model with six implant analogs was prepared. The implants were placed at the bone level and multiunit abutments screwed into the implants. Two impression techniques were performed: the traditional splint impression technique was used in the control group, and the rigid connecting bar system was used in the test group. In the control group, impression copings were screwed into the multiunit abutments and connected with autopolymerizing acrylic resin. Open tray impression was fabricated with custom tray and polyether. In the test group, cylinders were screwed into the multiunit abutments. Prefabricated rigid bars with suitable length were selected and connected to the cylinders with small amount of autopolymerizing acrylic resin, and open tray impression was obtained. Impression procedures were repeated 6 times in each group. The working time of the two impression methods were recorded and compared. Analogs were screws into the impressions and gypsum casts were poured. The gypsum casts and the standard model were transferred to stereolithography (STL) files with model scanner. Comparative analysis of the STL files of the gypsum casts and the standard model was carried out and the root mean square (RMS) error value of the gypsum casts of the control and test groups compared with the standard model was recorded. The trueness of the two impression techniques was compared.
The work time in the test group was significantly lower than that in the control group and the difference was statistically significant [(984.5±63.3) s . (1 478.3±156.2) s, < 0.05]. Compared with the standard model, the RMS error value of the implant abutments in the test group was (16.9±5.5) μm. The RMS value in the control group was (20.2±8.0) μm. The difference between the two groups was not significant (>0.05).
The prefabricated rigid connecting bar can save the chair-side work time in implants immediate loading of edentulous jaw and simplify the impression process. The impression accuracy is not significantly different from the traditional impression technology. The impression technique with prefabricated rigid connecting bar system is worthy of clinical application.
比较传统夹板印模技术与采用预制刚性连接杆系统的印模技术用于全牙弓种植体支持的固定修复体时的操作复杂性和准确性。
制备带有六个种植体代型的标准下颌无牙颌模型。种植体植入骨水平，将多单位基台拧入种植体。进行两种印模技术：对照组采用传统夹板印模技术，试验组采用刚性连接杆系统。对照组中，将印模帽拧入多单位基台并用自凝丙烯酸树脂连接。用定制托盘和聚醚制作开口托盘印模。试验组中，将圆柱体拧入多单位基台。选择合适长度的预制刚性杆并用少量自凝丙烯酸树脂连接到圆柱体上，获得开口托盘印模。每组印模程序重复6次。记录并比较两种印模方法的工作时间。将代型拧入印模并灌注石膏模型。用模型扫描仪将石膏模型和标准模型转换为立体光刻（STL）文件。对石膏模型和标准模型的STL文件进行对比分析，记录对照组和试验组石膏模型与标准模型相比的均方根（RMS）误差值。比较两种印模技术的准确性。
试验组的工作时间显著低于对照组，差异有统计学意义[（984.5±63.3）秒 对 （1478.3±156.2）秒；P<0.05]。与标准模型相比，试验组种植体基台的RMS误差值为（16.9±5.5）μm。对照组的RMS值为（20.2±8.0）μm。两组间差异无统计学意义（P>0.05）。
预制刚性连接杆可节省无牙颌种植即刻负重时的椅旁工作时间并简化印模过程。印模准确性与传统印模技术相比无显著差异。采用预制刚性连接杆系统的印模技术值得临床应用。
