Verification of reproducibility of surface profile and small step height in dental scanners

Abstract

The aim of this present study was to investigate the reproducibility of surface profile and step height in the dental scanners.

A step height specimen (Step Master SERIES516-499), which has 300, 100, 50, and 20 μm height of 4 steps, constructed with 5 ceramic gauge-blocks (G1-G5). The specimen was scanned with 2 laboratory (D900 and Ceramill map400) and 2 intra-oral scanners (Trios3 and CS3600), each 10 times. To evaluate the reproducibility of surface profile, the scanned data within the region of interest (ROI) on G1 was used, and the parallelism tolerance of the target surface was investigated. To evaluate the reproducibility of step height difference, the cumulative step values with respect to a reference plane that best fitting to the mesh data on G1 were calculated.

The parallelism tolerances of target surface in the laboratory and intra-oral scanners were approximately 10 and 20 μm, respectively. It of the CS3600 was significantly lower than those of other 3 scanners. In the laboratory scanners, all step height could be measured. On the other hand, it was difficult to detect under the step height of 50 μm with the Torios3, and under 100 μm with the CS3600.

Within the limitations of this study, in the scanning processes and 3D-construction, the error in the laboratory scanners was significantly less than intra-oral scanners. The results of this study could provide an insight into the appropriate clinical requirement for each CAD/CAM system.