title: Exuberant Biofilm infection in a lateral canal as the cause of short-term endodontic treatment failure: report of a case.
abstract: BACKGROUND
  This article describes a case in which signs and symptoms persisted in spite of the endodontic treatment following high standards to characterize a short-term failure.
  
  
  METHODS
  After several appointments of root canal treatment in an attempt to resolve persistent symptoms, including 106 days of calcium hydroxide intracanal medication, periradicular surgery was performed, and the root apex and the lesion were subjected to histologic and histobacteriologic analyses.
  
  
  RESULTS
  The lesion was diagnosed as a cyst, and the main root canal was free of bacteria and debris.
  
  
  CONCLUSIONS
  The cause of the short-term failure was an exuberant bacterial biofilm colonizing a lateral canal in the apical root segment. This case report highlights one of the major problems of modern endodontic therapy; bacteria located in areas distant from the main root canal can remain unaffected by treatment procedures and maintain disease. The challenge for researchers and clinicians that arises from this problem is to develop strategies, instruments, or substances that can reach those areas and achieve sufficient reduction in the infectious bioburden to permit predictable periradicular healing.
authors.affiliation: Private practice, Cetraro, Italy. dricucci@libero.it
authors.forename: Domenico
authors.initials: D
authors.lastname: Ricucci
authors.forename: Simona
authors.initials: S
authors.lastname: Loghin
authors.forename: José F
authors.initials: JF
authors.lastname: Siqueira
mesh_terms: D000328:Adult; D001047:Apicoectomy / Q000379:methods; D018441:Biofilms; D002126:Calcium Hydroxide / Q000627:therapeutic use; D003751:Dental Fistula / Q000175:diagnosis / Q000628:therapy; D003786:Dental Pulp Cavity / Q000382:microbiology*; D006801:Humans; D007180:Incisor / Q000382:microbiology; D008297:Male; D008439:Maxillary Diseases / Q000175:diagnosis / Q000628:therapy; D010485:Periapical Periodontitis / Q000175:diagnosis / Q000628:therapy; D011842:Radicular Cyst / Q000175:diagnosis / Q000628:therapy; D019233:Retreatment; D012184:Retrograde Obturation / Q000379:methods; D012388:Root Canal Irrigants / Q000627:therapeutic use; D012390:Root Canal Therapy / Q000379:methods*; D019227:Tooth Apex / Q000382:microbiology; D017211:Treatment Failure
chemical_list: D012388:Root Canal Irrigants; D002126:Calcium Hydroxide