抄録
The relationship between the depth estimation on the radiogram and the actual depth of the carious penetration was studied in the subsurface proximal carious lesions. Extracted human premolars with 54 subsurface lesions were radiographed with Kodak Ultraspeed (DF 57) . The radiolucency caused by the caries was examined and the mesio-distal depth of the recognized radiolucency was measured with the aid of a magnifying lens (magnification, 10: 1) . The teeth were embedded in epoxy resin after the bucco-lingual width of the lesions was measured and macrophotographs of the continuously reduced surface were prepared to measure the actual mesio-distal depth of the lesions. On the radiograms 76% of the enamel caries and 90% of the dentin caries were recognized. The estimation of the depth on the radiogram was found to be less than the actual depth. It is concluded that the radiographic diagnosis of the caries is not reliable when the actual depth of the lesion is less than 0.5 mm and that the closer to the dentino-enamel junction the caries is located the greater is the underestimation.
