Histobacteriology Of Teeth With Failed Root Canal Treatment – A Pilot Study

Abstract

While several in vitro studies have focused on the antibacterial activity of root canal disinfection protocols and sealing ability of root filling materials, the exact clinical relevance remains unknown. In this pilot study, we aimed at identifying the possible causes of treatment failure in teeth that had been endodontically treated and diagnosed as treatment failures due to persistent pain. Teeth (n=12) diagnosed as failed root canal treatment were extracted when patients were unwilling for revision endodontics and analyzed histologically after staining using Taylor modified Brown and Brenn staining. Nine specimens demonstrated intraradicular bacteria and bacteria within the dentinal tubules while the voids between the root filling material and root canal wall (which was present in all specimens), as well as voids within the root filling material showed minimal or no bacteria. The results of the study also indicated the need for identifying extraradicular biofilms as potential causes of root canal treatment failure. Remnant bacteria within the root canal system appears to be the primary cause for treatment failure and methods should be developed to completely disrupt biofilms within the root canal system.