The delineation of normal anatomical structures and the detection of minute changes in proximal caries in extracted teeth and in bone treated with a chemical decalcification process were investigated using the intraoral digital imaging system, Digora. Cathode ray tube (CRT)-output images obtained with the Digora system, film-output images prepared through computed radiography, and conventional periapical film (conventional film) images of the various experimental materials were evaluated visually. The accuracy of detection of the enamel-dentin junction of normal teeth was greater with Digora CRT- and film-output images than with conventional film images. However, no marked differences were observed in the diagnostic power in the examination of other materials. The detection of proximal caries was similar for all three image types, regardless of the caries depth. In the decalcified bone specimens, the increases in the area under the receiver operating characteristic curve (Az value) corresponded to the degree of decalcification, and no differences were observed in the detection of bone changes among the CRT-output, film-output, and conventionals film images. These results suggest that the diagnostic value of Digora system, output primarily as CRT images, is comparable to that of film-output images and conventional film images, and that it is potentially applicable to clinical diagnosis.