MICROSCOPIC FEATURES IN RETRIEVED HUMAN BRANEMARK IMPLANTS - A REPORTOF 19 CASES

The authors present a histologic analysis of 19 Branemark titanium imp lants retrieved for different causes: four implants were removed for a butment fracture, one for dental nerve dysesthesia, two for bone overh eating, two for peri-implantitis, nine for mobility, one for unknown c auses. In the implants removed for fracture a high bone-implant contac t percentage was present (71.83 +/- 4.96%) with compact, mature bone a t the interface. The picture of the failure due to bone overheating wa s characteristic with the presence of bone sequestra and of a gap betw een implant and bone filled by lymphocytes and plasma cells: many bact eria surrounded the necrotic bone and no newly regenerated bone was pr esent. In peri-implantitis an inflammatory infiltrate was observed in the peri-implant tissues: a dense fibrous connective tissue was presen t around implants failed for mobility. The microscopical picture is ce rtainly extremely important in identifying the causal determinants of an implant failure. (C) 1998 Published by Elsevier Science Ltd. All ri ghts reserved.