A dental attachment system has an abutment member configured for attachment to a tooth root, implant, or adjacent tooth, the abutment member having a head and an annular seat adjacent the head. An elastomeric ring is configured for releasable engagement in the seat on the abutment member, and is retained...http://www.google.es/patents/US7704076?utm_source=gb-gplus-sharePatente US7704076 - Dental attachment assembly and method
