| Popis: |
mass of the castings, oscillations passing through the fixed partial denture, and the light lifting force exerted by the spring under the center of the pontic. It was somewhat surprising that the impacts directed toward the lingual at a 45-degree angle did not result in failure significantly sooner than the vertical impacts. This may be because inclining the line of force toward the lingual plane did not increase the primary leverage arm in a mesiodistal direction. In addition, the vertical component of a 45-degree angle force is only about seven-tenths that of a 90-degree vertical force, and it is the vertical component that produces the most effective tensile force at the distant retainer. It should be noted that impacts angled toward the mesial and distal planes were not tested, nor were angled impacts that fell between the centers of rotation of the two abutment teeth. |
