Radiographic evaluation of marginal bone levels around platform-switched and non-platform-switched implants used in an immediate loading protocol.

PURPOSE The aim of this clinical study was to assess the marginal bone around two different types of implant-abutment junctions-a so-called platform-switched assembly and a conventional external-hexagon connection-after 24 months. MATERIALS AND METHODS Forty-five patients were included in this prospective study. All selected patients required the extraction of one or two hopeless teeth in maxillary and mandibular region monoradicular and second premolar teeth, and were randomly assigned to one of two groups. The first group received 34 implants with an external-hexagon junction with the abutment and the second group received 30 implants with platform-switched abutments. Implants were positioned immediately after tooth extraction and were loaded immediately. RESULTS After 24 months, a cumulative survival rate of 100% was reported for all implants. The platform-switching group showed a mean bone loss of 0.78 +/- 0.49 mm and the external-hexagon group showed a mean bone loss of 0.73 +/- 0.52 mm (no statistically significant difference between groups). CONCLUSION The results of this study indicate that implants placed immediately in fresh extraction sockets and loaded immediately represent a predictable procedure, with no differences in bone level changes between "platform-switched" and conventional external-hexagon implants after 24 months.