title: Nonsurgical root canal therapy of large cyst-like inflammatory periapical lesions and inflammatory apical cysts.
abstract: It is a general belief that large cyst-like periapical lesions and apical true cysts caused by root canal infection are less likely to heal after nonsurgical root canal therapy. Nevertheless, there is no direct evidence to support this assumption. A large cyst-like periapical lesion or an apical true cyst is formed within an area of apical periodontitis and cannot form by itself. Therefore, both large cyst-like periapical lesions and apical true cysts are of inflammatory and not of neoplastic origin. Apical periodontitis lesions, regardless of whether they are granulomas, abscesses, or cysts, fail to heal after nonsurgical root canal therapy for the same reason, intraradicular and/or extraradicular infection. If the microbial etiology of large cyst-like periapical lesions and inflammatory apical true cysts in the root canal is removed by nonsurgical root canal therapy, the lesions might regress by the mechanism of apoptosis in a manner similar to the resolution of inflammatory apical pocket cysts. To achieve satisfactory periapical wound healing, surgical removal of an apical true cyst must include elimination of root canal infection.
authors.affiliation: Department of Endodontics, New York University College of Dentistry, New York, New York 10010, USA. lml7@nyu.edu
authors.forename: Louis M
authors.initials: LM
authors.lastname: Lin
authors.forename: Domenico
authors.initials: D
authors.lastname: Ricucci
authors.forename: Jarshen
authors.initials: J
authors.lastname: Lin
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rosenberg
mesh_terms: D017209:Apoptosis / Q000502:physiology; D003788:Dental Pulp Diseases / Q000150:complications / Q000382:microbiology; D006801:Humans; D010482:Periapical Abscess / Q000382:microbiology / Q000473:pathology / Q000628:therapy; D010484:Periapical Granuloma / Q000382:microbiology / Q000473:pathology / Q000628:therapy; D010485:Periapical Periodontitis / Q000382:microbiology / Q000473:pathology / Q000628:therapy*; D011842:Radicular Cyst / Q000382:microbiology / Q000473:pathology / Q000628:therapy*; D012390:Root Canal Therapy / Q000379:methods*; D014945:Wound Healing / Q000502:physiology