[Model of abutment screw fixation for single tooth implantation]

An experimental model was constructed to test the abutment screw fixation for two Hungarian implant systems. First, abutments were tightened to 22.4 Ncm and after 4.25 hour loosening torques varied between 13.8-20.9 Ncm. Secondly, premolar-form crowns were casted and cemented on abutment-implant assemblies and cyclic load between 20-60 N was applied. 3.8-18.3 Ncm of loosening torques were measured. Four abutments of nine test assemblies were completely loosened and the cement fixation of one crown was destroyed. It was concluded that the test procedure and the model of crown-abutment-implant assemblies had given a reproducible technique to record changes in torques during a dynamic load.