A study on the ultrasonic-tomography of a vital tooth

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When a dentist prepares a vital tooth, it is very important to know the distance between the prepared surface and the pulp chamber wall, and now we have developed ultrasonic diagnostic equipment which can indicate the nearness of two boundaies by measuring the thickness of the remaining dentin.To measure the thickness more exactly and to confirm the thinnest point of the remaining dentin, the ultrasonic-tomography by B-scanning is very useful. So, I investigatid the method of indicating the ultrasonic-tomography of a vital tooth.Experimentally, a defect in the shape of a dome or a defect in the shape of a sylinder was prepared in a side of the thin human dentin plate. By the ultrasonic probe, the defect was scaned on the other side of the specimen. And, the figure of the defect was indicated on a CRT.As a result, when the figure of the defect was indicated by the energy of ultrasonic reflective wave, the dome shaped defect is clear, but the sylinder shaped defect is not clear.By this equipment, the grey scaling representation is the most suitable method to present the area of the defect.But, a development of the scanning method and a distinction of the grey scaling representation are remaining problems.