Department of Orthodontics, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.
PLoS One. 2012;7(8):e43312. doi: 10.1371/journal.pone.0043312. Epub 2012 Aug 22.
Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared.
A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intra-oral scanners: the CEREC (Sirona), the iTero (Cadent) and the Lava COS (3M). In software the digital files were imported and the distance between the centres of the cylinders and the angulation between the cylinders was assessed. These values were compared to the measurements made on a high accuracy 3D scan of the master model.
The distance errors were the smallest and most consistent for the Lava COS. The distance errors for the Cerec were the largest and least consistent. All the angulation errors were small.
The Lava COS in combination with a high accuracy scanning protocol resulted in the smallest and most consistent errors of all three scanners tested when considering mean distance errors in full arch impressions both in absolute values and in consistency for both measured distances. For the mean angulation errors, the Lava COS had the smallest errors between cylinders 1-2 and the largest errors between cylinders 1-3, although the absolute difference with the smallest mean value (iTero) was very small (0,0529°). An expected increase in distance and/or angular errors over the length of the arch due to an accumulation of registration errors of the patched 3D surfaces could be observed in this study design, but the effects were statistically not significant.
For making impressions of implant cases for digital workflows, the most accurate scanner with the scanning protocol that will ensure the most accurate digital impression should be used. In our study model that was the Lava COS with the high accuracy scanning protocol.
在不久的将来,口腔内扫描仪将在数字牙科中发挥核心作用。本研究比较了三种口腔内扫描仪的准确性。
用石制模型制作一个带有三个高精度制造的 PEEK 圆柱体的母模,并使用三种口腔内扫描仪进行扫描:CEREC(西诺德)、iTero(卡登特)和 Lava COS(3M)。在软件中,导入数字文件,并评估圆柱体中心之间的距离和圆柱体之间的角度。将这些值与高精度母模 3D 扫描的测量值进行比较。
Lava COS 的距离误差最小且最一致。Cerec 的距离误差最大且最不一致。所有角度误差都很小。
Lava COS 与高精度扫描方案相结合,在考虑全弓印模的平均距离误差时,所有三个测试扫描仪中,无论是绝对值还是两个测量距离的一致性,均产生最小且最一致的误差。对于平均角度误差,Lava COS 在圆柱体 1-2 之间的误差最小,在圆柱体 1-3 之间的误差最大,尽管与最小平均值(iTero)的绝对差异非常小(0.0529°)。在本研究设计中,可以观察到由于拼接 3D 表面的注册误差的累积而导致的沿弓长的距离和/或角度误差的预期增加,但这些影响在统计学上并不显著。
对于进行数字化工作流程的种植体病例印模,应使用具有可确保最准确数字印模的最准确扫描仪和扫描方案。在我们的研究模型中,这是具有高精度扫描方案的 Lava COS。