Correlation between endodontic pulpal/periapical disease and retrograde peri-implantitis: a case series

Retrograde peri-implantitis is a symptomatic complication, characterised by radiographic detection of bone loss at the periapex of the implant. The aim of this study was to investigate the possible endodontic aetiology, evaluating the effectiveness of surgical treatment without endodontic therapy of adjacent teeth. In the 10-year interval, three patients reported symptoms of retrograde peri-implantitis after a mean period of 30.6 days from implant placement. Mean follow-up after surgical procedures was 8.66 years, with an implant survival of 100%. Retrograde peri-implantitis was probably caused by colonisation of the apical surface of the implant by bacteria persisting in the area after endodontic failure/apical periodontitis, reactivated by drilling in the site. In all cases, the adjacent teeth remained vital during the years, showing that a direct cause-and-effect relationship between pulpal/periapical disease of adjacent teeth and retrograde peri-implantitis was never present.