Diagnosis and treatment of a large periapical implant lesion associated with adjacent natural tooth: a case report.

A possible cause for dental implant failure is the periapical implant lesion (PIL). In this case report we describe an apical periodontitis on a tooth adjacent to a dental implant that may have communicated with the apical region of the dental implant, and causing retrograde peri-implantitis. To our knowledge this is the first report demonstrating the concomitant successful treatment of the periapical implant pathology and the adjacent natural tooth without the removal of the implant. The presence of large bony defect at the apical region of the natural tooth and the implant, resulting in a sinus tract and a deep periodontal pocket, was also confirmed with computerized tomography. The treatment procedure included root canal treatment followed by the debridement of the apical bone lesion, and guided bone regeneration. An uneventful healing with acceptable esthetic was observed.