Rotational Pathを組み込んだClasping System

In this study, 12 removable partial dentures with rotational path clasping system were applied in the clinical field. The authors examined the retention of the dentures, mesiodistal distance of edentulous space, and undercut of rigid retentive component and inclination of mesial surface of posterior abutment tooth. Thefollowing results were obtained:1. Retention of 12 dentures was varied from187 g to 1, 380g.2. Retention decreased in the order when mesio-distal distance of edentulous space was changed 10.9 mm to 27.7 mm, and the coefficient of correlation between retention and mesiodistal distance was-0.56.3. Retentionshowed a tendency to increase in order when inclination of mesial surface was changed 0° to 51°, and the coefficient of correlation between retention and inclination of mesial surface was +0.47. The coefficient of correlation between retention and undercut of rigid retentive component was +0.13.4. Long mesio-distal distance as well as small inclination of mesial surface are present inthree patients who answered that their dentures were sometimes displaced during mastication.These results showed that the retention of rotational path clasping system was influenced not only by conventional clasp, mesio-distal distanceof edentulous space and undercut of rigid retentive component but also by inclination of mesial surface of posterior abutment tooth.