Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Goethestrasse 70, 80336 Munich, Germany.
Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Goethestrasse 70, 80336 Munich, Germany.
Dent Mater. 2014 Apr;30(4):400-7. doi: 10.1016/j.dental.2014.01.006. Epub 2014 Feb 9.
To analyse the marginal fit of 4-unit fixed dental prostheses (FDPs) and the accuracy of three-dimensional cast-datasets using both approaches to Computer Aided Design (CAD)/Computer Aided Manufacturing (CAM): direct and indirect digitalization.
A titanium model of a 4-unit FDP was digitized by an intraoral scanning device (iTero, Align Technology, Carlstadt, US; DD, n=12). Additionally 12 conventional impressions were taken and referring master casts were digitized by a laboratory scanner (CS2, Straumann, Basel, Switzerland; ID, n=12). Frameworks were fabricated (CARES CADCAM GmbH, Straumann, Markkleeberg, Germany) from base metal alloy (coron, Straumann; DD-C: n=12; ID-C: n=12) and zirconia (zerion, Straumann; DD-Z: n=12; ID-Z: n=12) from the same datasets. The marginal fit of the resulting frameworks and the accuracy of the underlying datasets from DD and ID were evaluated. Data were analyzed by unpaired two sample Student's t-test with Levene-test (p<0.05).
Frameworks from group DD-C showed significantly better marginal fit than ID-C (DD-C: 56.90±27.37 μm, ID-C: 90.64±90.81 μm). For zirconia frameworks no differences between both digitalization methods (DD-Z: 127.23±66.87 μm, ID-Z: 141.08±193.17 μm) could be observed. Base metal alloy frameworks exhibited significantly better marginal fit than zirconia frameworks (DD: p<0.001; ID: p=0.022). Regarding the accuracy group DD showed significantly higher "trueness" than ID.
Direct and indirect digitalization lead to clinically acceptable marginal fit of 4-unit FDPs from base metal alloy and zirconia. Higher accuracy of datasets from DD leads to better marginal fit of frameworks from base metal alloy but not for ones from zirconia.
分析 4 单位固定义齿（FDP）的边缘适合性和使用两种 CAD/CAM 方法（直接和间接数字化）的三维铸型数据集的准确性。
使用口腔内扫描设备（iTero，Align Technology，美国卡尔斯塔特；DD，n=12）对 4 单位 FDP 的钛模型进行数字化。此外，还进行了 12 次常规印模，并通过实验室扫描仪（CS2，Straumann，瑞士巴塞尔；ID，n=12）对参照主模型进行数字化。从相同的数据集制作基底金属合金（coron，Straumann；DD-C：n=12；ID-C：n=12）和氧化锆（zerion，Straumann；DD-Z：n=12；ID-Z：n=12）的框架。评估由此产生的框架的边缘适合性和 DD 和 ID 中基础数据集的准确性。使用不带配对的两样本学生 t 检验和 Levene 检验（p<0.05）分析数据。
DD-C 组的框架显示出比 ID-C 更好的边缘适合性（DD-C：56.90±27.37μm，ID-C：90.64±90.81μm）。对于氧化锆框架，两种数字化方法之间没有差异（DD-Z：127.23±66.87μm，ID-Z：141.08±193.17μm）。基底金属合金框架显示出比氧化锆框架更好的边缘适合性（DD：p<0.001；ID：p=0.022）。关于准确性，DD 组显示出比 ID 组更高的“真实性”。
直接和间接数字化可实现临床可接受的基底金属合金和氧化锆 4 单位 FDP 的边缘适合性。DD 组数据集的准确性更高，导致基底金属合金框架的边缘适合性更好，但氧化锆框架的边缘适合性则不然。
