Exuberant biofilm infection in a lateral canal as the cause of short term endodontic treatment failure: report of a case

By Ricucci D, Loghin S, Siqueira J

Date: 01/2013
Journal: JOE


Report a source of persistent infection


CC: spontaneous pain with intermittent swelling in anterior maxilla.

#7 gross M & D decay

Sinus tract opening between the roots of #6 & 7. Swelling in vestibule + pus drainage upon palpation. Negative to cold & EPT. Sensitivity from both vertical & lateral percussion. PARL 13 x 14.5mm. #6 & 8 normal to sensibility tests & radiographically.

Treatment: 5 instrumentation sessions with > 106 days of CaOH using various [NaOCl]s, and manual dynamic irrigation for 60 seconds at each visit. Persistent sinus tract and pain remained. Canal obturated. Apico completed and root tip analyzed histologically.


  • 7 days after surgery, sinus tract healed and symptoms improved.
  • Complete bone fill-in of defect by 12 months.
  • Lesion was a cyst.
  • No bacteria present in the main canal & dentinal tubules at all levels of canal.
  • No bacteria colonization along the cyst wall.
  • Canal well-prepped, round, no irregularities, & free of debris.
  • Large lateral canal with the proximal half free of debris and the distal half clogged with thick biofilm.

Clinical Significance:

Case report of a short-term failure of RCT from a persistent lateral canal infection