Abstract
The following results were obtained from studying the removability of 53 removable partial dentures.
1. All of their retentive forces were less than 2, 000 gf.
2. In 5 out of 31 dentures whose retentive forces were graded D2 and less, the wearers could remove the dentures easily without help of their fingers. Out of 22 dentures graded D4 and more, 3 conic dentures were difficult in removal.
3. The wearers were dissatisfied with 3 dentures graded D2 and less, and with 2 conic dentures graded D4.
4. In 12 dentures graded D1, 9 dentures were evaluated to be too loose by the operators. In 12 dentures graded D4 and more, 2 conic dentures were evaluated to be too tight by both the wearers and the operators.
5. All conic dentures complained had 4-degree-tapered conic studs as the retainer.
6. It is considered that in terms of subjective evaluations, an adequate retentive force for the dentures might be in the range from 800 gf to 2, 000 gf.
