A new pathologic entity called implant periapical lesion has been recently described. This lesion could be produced by contamination of the implant surface, overheating of bone, overloading of the implant, presence of a pre-existing bone pathology, presence of residual root fragments and foreign bodies in bone, implant placement in an infected maxillary sinus, implant placement in a poor bone quality site, or lack of biocompatibility. A 49-year-old female patient underwent the placement of a screw-shaped titanium dental implant in the premolar region of the right mandible. Six months after implant insertion, the patient presented with a persistent pain resistant to analgesics. No fistula was present at a clinical intraoral examination. A periapical x-ray showed the presence of a radiolucency at the apical portion of the implant; this image was confirmed by a CT Scan. The implant was removed. After implant removal, the pain disappeared completely. The specimen was processed to obtain thin ground sections. The histologic examination showed the presence of necrotic bone in the external and apical portion of the antirotational hole of the implant. The etiology of the implant failure in this instance could be related, probably, to an implant contamination of the apical portion of the implant.