Justus-Liebig-University, Dental Clinic, Department of Prosthodontics, Giessen, Germany.
Int J Oral Maxillofac Implants. 2013 Jul-Aug;28(4):989-95. doi: 10.11607/jomi.2938.
This in vitro study aimed to identify the effects of the implant system, impression technique, and impression material on the transfer accuracy of implant impressions. The null hypothesis tested was that, in vitro and within the parameters of the experiment, the spatial relationship of a working cast to the placement of implants is not related to (1) the implant system, (2) the impression technique, or (3) the impression material.
A steel maxilla was used as a reference model. Six implants of two different implant systems (Standard Plus, Straumann; Semados, Bego) were fixed in the reference model. The target variables were: three-dimensional (3D) shift in all directions, implant axis direction, and rotation. The target variables were assessed using a 3D coordinate measuring machine, and the respective deviations of the plaster models from the nominal values of the reference model were calculated. Two different impression techniques (reposition/pickup) and four impression materials (Aquasil Ultra, Flexitime, Impregum Penta, P2 Magnum 360) were investigated. In all, 80 implant impressions for each implant system were taken. Statistical analysis was performed using multivariate analysis of variance.
The implant system significantly influenced the transfer accuracy for most spatial dimensions, including the overall 3D shift and implant axis direction. There was no significant difference between the two implant systems with regard to rotation. Multivariate analysis of variance showed a significant effect on transfer accuracy only for the implant system.
Within the limits of the present study, it can be concluded that the transfer accuracy of the intraoral implant position on the working cast is far more dependent on the implant system than on the selection of a specific impression technique or material.
本体外研究旨在确定种植体系统、印模技术和印模材料对种植体印模转移精度的影响。本实验检验的零假设为，在体外和实验参数范围内，工作模型中种植体的位置与种植体的空间关系与（1）种植体系统、（2）印模技术或（3）印模材料无关。
使用钢上颌作为参考模型。将两种不同种植体系统（Straumann Standard Plus；Bego Semados）的六颗种植体固定在参考模型中。目标变量为各个方向的三维（3D）移位、种植体轴方向和旋转。使用三坐标测量机评估目标变量，并计算石膏模型相对于参考模型的标称值的各自偏差。研究了两种不同的印模技术（复位/拾取）和四种印模材料（Aquasil Ultra、Flexitime、Impregum Penta、P2 Magnum 360）。每个种植体系统共进行 80 次种植体印模。使用多元方差分析进行统计分析。
种植体系统对大多数空间维度的转移精度有显著影响，包括整体 3D 移位和种植体轴方向。两种种植体系统在旋转方面没有显著差异。多元方差分析仅显示对转移精度有显著影响的是种植体系统。
在本研究的限制范围内，可以得出结论，工作模型中口腔内种植体位置的转移精度更多地取决于种植体系统，而不是特定印模技术或材料的选择。
