Microbiological monitoring and results of treatment of extraradicular endodontic infection

Abstract This report describes a case where aggressive treatment of a tooth with Asymptomatic apical periodontitis was at first unsuccessful. The reason for the failure of the treatment was an established infection extraradicularly in the periapical lesion that only partly could be influenced by local and systemic antimicrobial treatment. The effectiveness of this treatment was monitored by microbiological sampling from the root canal, a fistulous tract, and, in the end, directly from the periapical lesion. The results of the monitoring were meaningful. They showed that the bacterial flora could be influenced, but not eliminated, and were strongly suggestive of an established infection outside the root. Scanning electron microscopy confirmed the presence of a bacterial plaque on the surface of the root tip removed during the final surgical-endodontic treatment of the tooth. Following apicoectomy and removal of the periapical lesion, repair was uneventful with the formation of new bone in the surgical cavity after 6 months.