Mattheos Nikos, Li Xiaona, Zampelis Antonios, Ma Li, Janda Martin
Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
Dalian Stomatological Hospital, Dalian, China.
Clin Oral Implants Res. 2016 Nov;27(11):e134-e143. doi: 10.1111/clr.12578. Epub 2015 Mar 9.
The aim of this pilot study was to investigate the morphological micro-features of three commercially available implant-abutment joints, using compatible and original prosthetic components. Furthermore, possible correlations between the micromorphology and potential functional complications were investigated with the use of finite element analysis.
Three abutments (one original and two compatibles) were torqued on original Straumann RN implants, as according to each of the manufacturer's instructions. The implant-abutment units were sliced in the microtome and photographed under different magnifications (10×-500×) through a scanning electron microscope. Finite element analysis models were reconstructed for each of the implant-abutment units using the precise measurements from the SEM. Differences in stress, strain and deformation for the three different abutments were then calculated using ANSYS Workbench v13.
Major dimensional differences were identified between all studied contact areas of the three units. The tight contact in the implant shoulder was similar in all three units, but engagement of the internal connection and, in particular, the anti-rotation elements was seriously compromised in the compatible abutments. One compatible abutment demonstrated compromised engagement of the abutment screw as well. Equivalent stress and strain in the FEA were much higher for the compatible abutments. An evaluation of the sequence of preload application revealed differences in the pattern of deformation between the original and compatible abutments, which can have serious clinical implications.
Compatible abutments can present critical morphological differences from the original ones. The differences in the cross-sectional geometry result in large differences in the overall contact areas, both in terms of quality and quantity which could have serious implications for the long-term stability of the prosthesis.
本初步研究的目的是使用兼容和原装修复组件，研究三种市售种植体-基台连接的形态微观特征。此外，通过有限元分析研究微观形态与潜在功能并发症之间的可能相关性。
按照每个制造商的说明，将三个基台（一个原装和两个兼容）拧到原装的士卓曼RN种植体上。将种植体-基台单元在切片机中切片，并通过扫描电子显微镜在不同放大倍数（10×-500×）下拍照。使用扫描电子显微镜的精确测量值为每个种植体-基台单元重建有限元分析模型。然后使用ANSYS Workbench v13计算三种不同基台的应力、应变和变形差异。
在三个单元的所有研究接触区域之间发现了主要尺寸差异。所有三个单元中种植体肩部的紧密接触相似，但兼容基台的内部连接，特别是防旋转元件的啮合严重受损。一个兼容基台的基台螺钉啮合也受损。兼容基台在有限元分析中的等效应力和应变要高得多。对预加载顺序的评估揭示了原装和兼容基台之间变形模式的差异，这可能具有严重的临床意义。
兼容基台可能与原装基台存在关键的形态差异。横截面几何形状的差异导致整体接触面积在质量和数量方面存在很大差异，这可能对假体的长期稳定性产生严重影响。
