Accurate grasp of dimensional accuracy and deformation of stone cast, which is considered difficult by conventional methods, was attempted by means of a three-dimensional measuring system. In the present study, a standard model in the system having a standardized settlement out of stone cast was used. The effects of the type of mold (straight, tapered and undercut) and the various impression materials (alginate, polysulfide and silicone) were investigated.
With respect to the straight and tapered types with all impression materials, no deformations were observed, but with respect to the undercut type, deformations attributable to different impression materials were observed on the side faces of the stone cast. This measuring method appears to be appropriate for measuring dimensional accuracy and deformation of stone cast.