[Prosthetic application of a new measuring instrument of the dynamic periodontal function].

To investigate the principle of Periotest measurement, we compared PT-value and the duration of contact between the rod of the Periotest-Instrument and the tooth measured directly in an oral cavity. Then we applied this apparatus to the subjects with normal periodontium and the patients of prosthetic treatment. The conclusions are as follows: 1. We confirmed that PT-value was calculated from the duration of contact between the rod of the Periotest and the tooth and it showed mainly the dumping effect of the periodontium. 2. There was a close relationship between PT-value and the clinical degree of tooth mobility, especially in the degree of 0 and 1 of tooth mobility. 3. Periotest was very useful not only for the periodontal treatment but also prosthetic application.