Observations of three dimensional images for cracks of doweled teeth. Comparison of images from specimen sections and dental tomograms from small three dimensional X-ray CT

Intraoral views of teeth with dowel and post hole taken by small three-dimensional X-ray CT (3 DX) were compared with three-dimensional images from specimen sections of the same extracted teeth. This comparison shows the usefulness of 3 DX for examination of cracked teeth in the oral cavity. After taking dental tomographic images using 3 DX for fractured teeth in the oral cavity, the fractured teeth were extracted and three-dimensional images for them and their cracks were obtained from a set of photographed sections. Then both sets of three-dimensional images for the fractured teeth were compared in terms of the form and region of the cracks. The tooth cracks were observed at the root face region in the intraoral view. Also, in the extracted teeth, fracture lines were recognized from the three-dimensional images. Moreover, a discontinuous image was obtained in teeth from the dental tomographic image using 3 DX. This discontinuous image in teeth was observed in the same region and direction as the cracks of the three dimensional image from specimen sections of the extracted teeth. The discontinuous images of teeth in the dental tomographic images from 3 DX were observed in the same region and direction as the cracks of teeth in the three-dimensional images from specimen sections of the extracted teeth. It was confirmed that dental tomographic images from 3 DX are useful for finding cracks in living teeth. However, dental tomographic images from small three-dimensional X-ray CT are not perfectly reliable because the discontinuous image is not found in some teeth where the cracks are recognized by images from specimen sections after extraction. (author)