Implant periapical lesions: clinical, histologic, and histochemical aspects. A case report.

A new entity, the "implant periapical lesion," has recently been described. The etiology of this condition could be attributed to overheating of the bone, overloading of the implant, presence of a pre-existing infection or of residual root particles and foreign bodies in the bone, implant contamination during production or during insertion, or placement of the implant in an infected maxillary sinus. In this report, a titanium plasma-sprayed implant had been inserted into the mandible of a 53-year-old patient; after 5 months a fistula developed and periapical radiography showed a large radiolucent image around the apical portion of the implant. The implant was removed, and histologic examination showed necrotic bone and an inflammatory infiltrate inside the hollow portion of the implant. The etiology of the implant failure in this instance could be related to a fracture and vascular impairment of the bone inside the implant during insertion, to external contamination of the implant, or to the poor bone quality of the implant site.