The integration of laser measuring, numerical simulation and rapid-prototyping (RP) into investment casting process proposes a new way for making dental prostheses.Natural tooth crowns were precisely digitized by means of laser measuring technique. The digitized geometry was converted to a standard CAD model. This model was then used to simulate the mold filling, the solidification and the porosity formation etc., hence to improve and ensure the casting quality. The sprue system design was numerically optimized.Real crowns were 'printed' directly out on a RP system from the CAD data. The RP crowns were assembled to the optimized sprue system. Following the investment casting process, titanium crowns with excellent functional contour of the occlusal surface were successfully made on a centrifugal casting machine. For each crown, over 20 replicas were made. All of them were examined by radiograph and no porosity was detected.It is indicated that the traditional waxing procedure in dental laboratory is probably replaced by an integrated RP technique. The quality of the prostheses can be optimized numerically.