ON THE INFLUENCE OF SUPERSTRUCTURE CONNECTION ON IMPLANT PRELOAD - A METHODOLOGICAL AND CLINICAL-STUDY

In a combined in vitro and in who study strain gauges were used to reg ister the deformation in two terminal implant abutment cylinders, when connecting three different prosthetic appliances. The prosthetic cons tructions were placed on the abutments and fastened both in vitro and in vivo by using different torque sequences. Furthermore, in the in vi tro situation the three medial abutments were replaced by abutments wh ich were 100 mu m shorter. The results show that even if the prostheti c constructions were judged to have a good clinical fit, relatively la rge External Preloads were registered both in vitro and in vivo. No si gnificant differences in axial force or in bending moment were found b etween the torque sequences in vivo. There were, however, significant differences in axial force as well as in bending moment in the in vitr o experiment. When the shorter medial abutments were used in vitro, a change in the axial force of approximately 200 N was registered. The r esults confirm that the methodological approach used in this study is valid when evaluating preloads.