1994 年 38 巻 6 号 p. 1252-1264
Recently, conical telescopic denture has been applied in many clinical treatments. However, it has many problems that need to be solved concerning retentive force of conical doublecrown.The purpose of this study was to clarify the correlation between retentive force and variousfactors affecting conical double-crown. The various factors that were considered to relate to thisproblem were fabricating material, taper angle, height of cone and load.
The results were as follows:
1. Retentive force was the most stable in the Plastic sheet method.
2. Retentive force decreased as the taper angle was iocremm^d, and this effect became greateras the height of cone and load were increased.
3. Retentive force showed an increasing tendency as the height of cone was increased, and theincreasing rate became greater as the height of cone and load were increased.
4. As to the axis mnoa, retentive force slightly increased as the axis area was iocreammd, butunder 250 mm2, the increasing rate was little, and over 250 mm2, the increasing rate became greater.The rate became greater as the load was increased.
5. The retentive force increased in proportion to the load, and this effect became greater as thetaper angle was decreased and the height of the cone was increased.
6. In case of taper angle 2° and 4° the retentive force depends on the load rather than the heightof the cone. In 6°, 8° and 10°, the retentive force depends on the height of the cone rather than the load.