Abstract:

 Objective This work lays the foundation for establishing a digital model database with normal occlusion. A digital dental cast is acquired through grating projection, and model features are measured through reverse engineering. Methods The grating projection system controlled by a computer was projected onto the surface of a normal dental model. Threedimensional contour data were obtained through multi-angle shooting. A three-dimensional model was constructed, and the model features were analyzed by using reverse engineering. The digital model was compared with the plaster model to determine the accuracy of the measurement system. Results The structure of three-dimensional reconstruction model was clear. The digital models of two measurements exhibited no significant difference (P>0.05). When digital and plaster models were measured, we found that the crown length and arch width were not statistically different (P>0.05), whereas the difference between the crown width and arch length was statistically significant (P<0.05). Conclusion The reconstruction of a digital model by using the grating projection technique and reverse engineering can be used for dental model measurement in clinic al and scientific research and can provide a scientific method for establishing a digital model database with normal occlusion.

Key words: grating projection, reverse engineering, dental model, three-dimensional reconstruction, three-dimensional measurement