Computer-Aided Design ; Dental Prosthesis Design ; methods ; Humans ; Oral Medicine ; methods ; Research Design ; Technology, Dental ; methods

OBJECTIVETo study the stability and the reliability of the first 3D laser cranio-maxillofacial reconstruction system in China.

METHODSThe same 3D laser scan image of a head plaster model was measured twice three weeks before and after. That head cast was also scanned and reconstructed twice three weeks before and after, and then the 3D images were measured. To the same head cast we compared the laser measurement with the direct manual measurement. The statistical analysis of measurements was made using the paired t test.

RESULTSThere was no significant difference between two sets of measurements on the same image (P > 0.05). The difference in the measurements was not significant between two reconstructed images of the same model (P > 0.05). And there was also no significant difference between the measurements by laser and by hand (P > 0.05).

CONCLUSIONSThe recognition of the author to the 3D laser scan image is reliable. The laser scanning system has a good stability and reliability and can be used in clinical study preliminary.

Cephalometry ; methods ; Facial Bones ; anatomy & histology ; Humans ; Imaging, Three-Dimensional ; methods ; Lasers ; Maxilla ; anatomy & histology ; Orthodontics ; methods ; Reproducibility of Results ; Skull ; anatomy & histology

OBJECTIVETo develop a dental CAD/CAM system with the autonomic intellectual property.

METHOD28 standard teeth crowns were scanned using a newly 3-D laser scanner. As a development platform the Matlab 5.3 were used to process the acquired data, also be used to define the characterized areas on the surfaces of the crowns and to change the crowns form. The software of Surfacer 10.5 to develop a new CAD software for fixed prosthetics, and the 3.5 axis numerical controlled machine to manufacture the prosthetics were used.

RESULTIt is the first time, the 3D graphic data bank of Chinese teeth crowns with a standard form was established. A software of the occlusal adjustment and the form modification were developed. It is also the first time, the authors realized the whole process to use the CAD-CAM for the manufacture of a crown.

CONCLUSIONThe successful result shows, that we have already mastered well the base theory, the mathematics method, the technology of a CAD-CAM system. It provides the basics for the future development.

Computer-Aided Design ; Dental Prosthesis Design ; methods ; trends ; Dental Restoration, Permanent ; methods ; Dentistry, Operative ; methods ; Humans ; Research ; trends ; Research Design