Clasping system with rotational path of insertion Part 3. Clinical application.

This study investigated the retentive forces of rotational path clasping systems. Twelve rotational path removable partial dentures were applied in the clinical field and the retentive forces of the dentures were measured. The following results were obtained; 1. Retentive forces of the 12 dentures were varied from 187g to 1,380g. 2. As distances between abutment teeth increased from 10.9 mm to 27.7 mm, the retentive forces decreased accordingly (r = -0.56; p < 0.05). 3. As the inclination of the proximal surfaces was increased from 0 degrees to 50 degrees, the retentive forces showed a tendency to increase (r = +0.47). 4. Longer distances between abutment teeth as well as smaller inclination of proximal surface were present in three patients who answered that their dentures showed movement while eating. From these results, it became clear that the distance between abutment teeth and the inclination of the proximal surfaces greatly influenced the retention of the rotational path clasping system in the clinical field.