Dahl Bjørn E, Dahl Jon E, Rønold Hans J
Department of Prosthetic Dentistry, Institute of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Institute of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Eur J Oral Sci. 2018 Dec;126(6):512-517. doi: 10.1111/eos.12576. Epub 2018 Oct 8.
The present study used a new, digitized version of the impression replica technique, namely the dual-scan technique, to evaluate the adaptation of single-crown fixed dental prostheses (FDPs). Scans of the bare master model and of the master model with a silicone layer representing the cement layer were superimposed and analyzed using designated software. Single crowns produced using the lost-wax metal casting technique were included. The cement space of the band width, 0.5-1.0 mm from the preparation margin (marginal fit), was smallest for crowns made from laser-sintered cobalt-chromium. The internal fit in both mesial-distal and buccal-palatal directions was statistically significantly better for crowns made using the conventional lost-wax metal casting technique than for crowns produced using computer-aided design/computer-aided manufacturing (CAD/CAM). Fixed dental prostheses produced by milled cobalt-chromium had the loosest internal fit. The results agree with those of our previous study of the same test specimens, in which the triple-scan method was used, and imply that the dual-scan method is well suited for adaptation studies.
本研究采用一种新的数字化印模复制技术，即双扫描技术，来评估单冠固定义齿（FDPs）的适合性。使用指定软件对裸主模型以及带有代表粘结层的硅树脂层的主模型进行扫描并叠加分析。纳入了采用失蜡金属铸造技术制作的单冠。对于激光烧结钴铬合金制作的冠，距预备边缘0.5 - 1.0 mm带宽的粘结间隙（边缘适合性）最小。在近远中方向和颊舌方向上，采用传统失蜡金属铸造技术制作的冠的内部适合性在统计学上显著优于采用计算机辅助设计/计算机辅助制造（CAD/CAM）制作的冠。铣削钴铬合金制作的固定义齿内部适合性最松。这些结果与我们之前使用三扫描方法对相同测试样本进行研究的结果一致，这意味着双扫描方法非常适合进行适合性研究。
