Clasps for partial dentures and profiles for producing them

摘要

The conventional clasp constructions in which a retention arm is supported against a partial collar on the opposite side, are unsuitable for combined tooth restoration. Whereas telescopic crowns are removed in an axial direction, clasps connected to the frame in the molar region must be taken off more rotatingly, and this leads to damage to the periodontal tissue. In the clasps according to the invention this disadvantage is avoided in that, firstly, the masticatory force is axially transmitted by a closed ring over the equator to the tooth and, secondly, the retention elements gripping under the equator are arranged so as to lie symmetrically opposite each other relative to the tooth centre line in such a way that rotating and tilting moments are avoided. The profiles of the clasps are prefabricated in wax in various shapes and dimensions.