Application of a newly developed 3-D deformation measurement system to prosthetic dentistry

A new system for measuring three-dimensional deformation has been developed. The main components of the system are a fixed TV camera and vertically scanning projectors. The advantages of the system are: (1) since there is no mechanical contact between the object and the sensing unit, hardness and form of the object do not have to be considered; (2) the system does not need any precise geometry except for the reproducibility of the vertical scanning stage; (3) the time required for one measurements is extremely short; and (4) the system is not expensive. From the basic experiments for testing accuracy, this system has about +/- 30 microns range deviation against 1000 microns deformation of the object. The system has been applied to investigate the influence of various impression procedures for a removable partial denture on the displacement of the simulated soft mucosal tissue. It is revealed that deformation forms are expressed precisely. Our results suggest that this measurement system is quite useful for research in dentistry and that it could be widely applied.