Reconstruction of three-dimensional digital teeth

Dental anatomy is one of the most important basic courses in the education of dentistry. The deep understanding of both the external and internal morphologic characteristics is very important to the teaching, research and clinical practice of dentistry.

In the present study, 32 permanent teeth from the skull specimen of a young man were individually embedded in black fluid resin, each in special containers. They were ground by a numerically-controlled grinding machine at intervals of 0.2 mm per layer. A distinct outline of the tooth could be seen on every section. Black and white photographs were taken and scanned into a computer by a film-scanner to obtain sequences of two-dimensional images of the tooth sections. After pattern recognition, all of the images of each tooth were piled up at intervals of 0.2 mm by the technique of computerized reconstruction.

The three-dimensional stereo tooth models were built up from two-dimensional data. On the basis of those models, computer graphic techniques were used to highlight, smooth, and shade the teeth. These digital teeth and dentitions could function as a series of computerized teaching models. Their high resolution and accuracy could meet the basic demands of dentistry.

The present study developed new techniques of model preparation, image input, and 3-D reconstruction. These digital teeth and dentitions provide an important foundation for the application of computer imaging, CAD/CAM, computer-assisted instruction, and virtual reality in dentistry.