LOCALIZED CHRONIC SUPPURATIVE BONE INFECTION AS A SEQUEL OF PERI-IMPLANTITIS IN A HYDROXYAPATITE-COATED DENTAL IMPLANT

Plaque-induced lesions can produce peri-implant bone loss with ultimat e implant loss. Although the peri-implant tissues seem to be more resi stant than the periodontal ones to plaque and calculus, they can produ ce a more extensive spread of the infection to the deeper tissues arou nd implants. The case of a 45-year-old female patient is presented in which, over a three year period, there was a progressive loss of peri- implant bone and the formation of a periapical radiolucency with an ex ternal fistula. The implant was removed and examined with the cutting- grinding system. Microscopy examination showed that most of the hydrox yapatite (HA) was still adherent to the metal. There was a detachment in the area of the HA-titanium interface. The implant surface was almo st completely covered by bacteria. Bacteria were also present in the b one medullary spaces surrounding the implant. The infection of the per iodontal tissues had progressed into the alveolar bone, thus producing a localized bone infection. The cause of the implant failure is proba bly related to a defective connection of the abutment or to overloadin g of the implant due to the presence of interlocks in the prosthetic r estoration.