[Study on CAM system for dental model].

The purpose of this study was to introduce our newly-developed CAM system for dental model and to examine the shape reproducibility and measurement reliability of the CAM modelling. The system is composed of a measuring unit, which obtains three-dimensional shape information from the dental model using laser scanning, and an engineering workstation, which creates a three-dimensional graph of the dental model. Output module program which can directly process and output the three-dimensional shape data to the wide use modeling systems was developed as the software of this CAM system. Four different CAM models, that, WAX model, STL model, FDM model, and SL model, were made based on the graph of the dental model taken from a mandibular prognathic patient. The measurement reliability of each CAM model were evaluated using a contact three-dimensional measurement unit. All CAM models except a WAX model demonstrated good shape reproducibility without a blind area, suggesting no problem of the three-dimensional shape data and the output module program. Measurement reliability of each CAM model was 0.12 +/- 0.08 mm in graph, 0.25 +/- 0.05 mm in WAX, 0.28 +/- 0.16 mm in SL, 0.31 +/- 0.15 mm in FDM, and 0.39 +/- 0.18 mm in STL. These results suggested clinical feasibility of this system in accordance with electronic storage of medical information.