3D shape recognization technique is rapidly advancing from last decade in the fields of manufacturing, computer science, entertainment and medical technology. Due to the restriction of size and area of cavity, it's challenging to develop such non-contact optical technologies for scanning. 3D digitization technology plays a vital role in the field of dentistry benefiting dentists and patients by eliminating long time procedures for making the prosthesis/abutments and results into ultimate comfort. In this paper, we have recounted a design of a prototype for a three-dimensional intra-oral scanner using the principle of fringe projection and active triangulation method. LED as a light source passed through the liquid crystal on silicon (LCoS) which radiates the light into three colors and strikes onto the collimating lens assembly and then passed through the optical deflectors. Once the light strikes the object through scanning window it is guided back through the flat reflectors and the fringe pattern on the object is stored into the gray encoding plate. With the help of camera all these images are stored. After the acquisition of images, firstly it will calculate the phase distribution using four-step phase shifting algorithm and unwrap the wrap phase which helps us in getting accurate images. Later, we get display of scanned oral cavity onto the computer screen. Phase-height mapping algorithm has been realized for the reconstruction of the 3D real time reconstruction of the scanned oral cavity which helps us in fast scanning with accurate data. A novel approach of LED as a light source and LCoS display for scattering light fragments into three different colors helps us to scan more effectively for registration of dental surfaces from the patient's mouth more accurately. Apart from that, its sleek design helps to scan with less pain to the patient's having low mouth opening. Experiment was performed on the prototype of denture and using this proposed method we have achieved the accuracy of 25 μm and it took around 180 sec for the full arc scan of the lower oral cavity. The result of scanned data was checked using the CAD/CAM software for dentistry and compared with the prototype data of denture. Further this image can be used for making prosthesis/abutment directly into production using 3D printing machine or the milling machine. Thus, an abutment or prosthesis obtained with this method is of high quality and eliminates conventional long procedures which helps in reducing pain of patient's and helps dentists to attain more patients in less time.
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