The basic idea of the Intelligent Dental Care System project is the integration of restoration shape design, articulation simulation, database facilities, and user interface in an easy-to-use system. Since computer-aided dental systems are a relatively new idea, it is unreasonable to expect deep knowledge of computer techniques from the dentist. Therefore we have proposed the virtual reality user interface, referring to tools and techniques used in traditional dentistry which in our system are emulated mainly by software means.
Robust design of occlusal surface of restorations requires simulation of jaw articulation, which involves heavy geometric calculations. We have proposed an efficient cumulative distance maps technique, which takes advantage of graphics hardware for collision detection and calculation of the load on teeth. Our techniques realtime response makes possible interaction of the dentist during design of the occlusal surface of restorations. Our approach might be generalized for the design of human rigid parts which are under stress in motion, e.g., the design of joints.
At present we are using lower jaw motion data acquired by individual measurements. Because the measurement device is expensive, we are working on simulation of ``sliding'' of the lower jaw over the surface of the upper jaw, taking into account constraints imposed by the temporomandibular joint. This is another way of setting valid positions of the lower jaw which can be used for design of the occlusal surface of restorations.
Every step of the occlusal surface design is followed by interference checking for a set of representative lower jaw positions. This requires many sets of distance maps to collect final results into cumulative distance maps. The number of shots can be substantially reduced if, instead of opponent teeth, the so called functionally generated path (FGP) is used. In traditional dentistry, FGP is taken by cupus wax record, but we can calculate this surface, which is the movement envelope of the opponent teeth, using motion data and the shape of teeth.