title: Treatment of a large cystlike inflammatory periapical lesion associated with mature necrotic teeth using regenerative endodontic therapy.
abstract: BACKGROUND
  Regenerative endodontic therapy is currently used to treat immature permanent teeth with necrotic pulp and/or apical periodontitis. However, mature teeth with necrotic pulp and apical periodontitis have also been treated using regenerative endodontic therapy. The treatment resulted in resolution of apical periodontitis, regression of clinical signs and symptoms but no apparent thickening of the canal walls, and/or continued root development. A recent study in an animal model showed that the tissues formed in the canals of mature teeth with apical periodontitis after regenerative endodontic therapy were cementumlike, bonelike, and periodontal ligament-like tissue with numerous blood vessels. These tissues are similar to the tissues observed in immature permanent teeth with apical periodontitis after regenerative endodontic therapy.
  
  
  METHODS
  A 23-year-old woman had a history of traumatic injury to her upper anterior teeth when she was 8 years old. Subsequently, #8 developed pulp necrosis and an acute apical abscess and #7 symptomatic apical periodontitis. The apex of #8 was slightly open, and the apex of #7 was completely formed. Instead of nonsurgical root canal therapy, regenerative endodontic therapy was attempted, including complete chemomechanical debridement on #8 and #7. This was based on the premise that filling of disinfected root canals with the host's biological vital tissue might be better than filling with foreign materials.
  
  
  RESULTS
  After regenerative endodontic therapy of #8 and #7, there was radiographic evidence of periapical osseous healing and regression of clinical signs and symptoms. The pulp cavity of #8 decreased in size, and the apex closed. The pulp cavity of #7 appeared to be obliterated by mineralized tissue. These indicated ingrowth of new vital tissue into the chemomechanically debrided canals.
  
  
  CONCLUSIONS
  Regenerative endodontic therapy of mature teeth with apical periodontitis and apical abscess can result in the regression of clinical signs and/or symptoms and healing of apical periodontitis but no apparent thickening of the canal walls or continued root development. Filling of the disinfected canals with the host's vital tissue may be better than with foreign materials because vital tissue has innate and adaptive immune defense mechanisms.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, University of Benghazi, Benghazi, Libya.
authors.forename: Tarek Mohamed A
authors.initials: TM
authors.lastname: Saoud
authors.affiliation: Department of Endodontics, College of Dentistry, New York University, New York, New York.
authors.forename: Asgeir
authors.initials: A
authors.lastname: Sigurdsson
authors.affiliation: Department of Endodontics, College of Dentistry, New York University, New York, New York.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rosenberg
authors.affiliation: Department of Endodontics, College of Dentistry, New York University, New York, New York. Electronic address: lml7@nyu.edu.
authors.forename: Louis M
authors.initials: LM
authors.lastname: Lin
authors.affiliation: Private Practice, Rome, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Ricucci
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D056624:Apexification / Q000379:methods; D001777:Blood Coagulation / Q000502:physiology; D002939:Ciprofloxacin / Q000627:therapeutic use; D003790:Dental Pulp Necrosis / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008768:Methylmethacrylates / Q000737:chemistry; D008795:Metronidazole / Q000627:therapeutic use; D008911:Minocycline / Q000627:therapeutic use; D010347:Patient Care Planning; D010482:Periapical Abscess / Q000628:therapy*; D010485:Periapical Periodontitis / Q000628:therapy*; D012038:Regeneration / Q000502:physiology; D018915:Root Canal Preparation / Q000379:methods; D012390:Root Canal Therapy / Q000379:methods*; D055815:Young Adult; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D008768:Methylmethacrylates; D015035:Zinc Oxide-Eugenol Cement; D008795:Metronidazole; D002939:Ciprofloxacin; C031667:IRM cement; D008911:Minocycline
keywords: Apical periodontitis; mature teeth; necrotic pulp; regenerative endodontic therapy; root canal therapy; vital tissue