抄録
As part of Study of splinting, for mobile teeth associating with alveolar pyorrhoea, tooth mobility was investigated experimentally. For the convenience of experiment, real tooth was not used but four types of glass piece were employed. The shapes of glass were cylinder, cone, cuboid and trapezoid and the root of these pieces were implanted within plaster model. The surface of root was circumscribed with rubber tube or rubber impression material to imitate the periodontal membrane. In order to represent various grade of bone destruction, many kind of plaster model was prepared. Square wave of 700kc was given to stroke a model tooth and resulting vibration was recorded using an osciloscope kit. Vibration of model tooth was rapidly increased according with the degree of bone destruction, especially it was remarkable when root was corn-shaped. Even in case of minor bone destruction, thickening of periodontal membrane and vertical bone resorption were extreme accerelating factors to increase the mobility of tooth.
