Ｒｏｔａｔｉｏｎａｌ Ｐａｔｈを組み込んだＣｌａｓｐｉｎｇ Ｓｙｓｔｅｍ 第２報 欠損部の近遠心径と義歯の維持

Abstract

The rotational path of insertion differs substantially from the conventional path or straight path of insertion. In the use of rotational path, one segment of the partial denture seated first, then the remainder of the denture is rotated into position. One segment of this system is the rigid retentive component with a long rest and the other is the conventional clasp.This study examined the influence of edentulous mesio-distal distance, point of displacing force, undercut of rigid retentive component and inclination of abutment tooth on retention of this system. The following results were obtained:1. Retention of the denture was the lowest when displacing force was applied at the conventional clasp part in the condition of edentulous mesio-distal distance of 10, 20 and 30 mm, respectively.2. Retention was decreased in the order when edentulous mesio-distal distance was changed 10, 20 and 30 mm, respectively.3. Retention showed a tendency to decrease in order when proximal undercut of rigid retentive component was changed 2.0, 1.5, 1.0 and 0.5 mm, respectively. The values of the decreasing ratio were almost the same whatever the edentulous mesio-distal distance were.4. Retention of the denture was improved, when a tilted tooth was used as an abutment tooth of the rigid retentive component side.