This paper describes a 3D scanning system based on an active vision method using structured light in order to obtain the CAD model of a dental arch. Presently, dental prosthesization requires long times in between detecting the shape of the dental arch, plaster model generation, scanning of it, prosthesis preparation, and implant. The situation is even worse when use of dental implants is required, while early loading of the implants is considered a positive solution. For this reason many devices are actually presented for the intra oral determination of the shape of dental prostheses and inserts. These devices however are able to detect limited portions of the dental arch, since they must be hand held by the doctor. This work presents a new device able to detect with high precision the entire dental arch.