title: Wound healing of apical tissues after root canal therapy: a long-term clinical, radiographic, and histopathologic observation study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the pulp healing process and the dentin-cementum complex in 51 endodontically treated human teeth after long observation periods and to correlate histologic observations with conventional periapical radiographic findings.
  
  
  METHODS
  Specimens were obtained from the extraction of 77 treated teeth, which were deemed to be unrestorable, with no evidence of periapical bone lesion at the follow-up. After stringent evaluation of the radiographs, 51 cases that 3 independent evaluators assessed as having normal periapical conditions were selected. The specimens were histologically evaluated using serial sections.
  
  
  RESULTS
  In the majority of the cases, complete healing was observed, with no signs of acute or chronic inflammatory processes in the remaining apical tissue or periodontal tissue fragments. Some cases showed moderate inflammation in the root canal tissue. Narrowing of the apical root canal by cementum was a common finding in most cases, but total closure was not observed. Debris intermixed with necrotic tissue and sealer particles was a common finding in the pulp stump. Bacteria were present in the coronal portion of the root in almost all cases, but in only 1 case could bacteria be demonstrated in the coronal and apical portions of the root.
  
  
  CONCLUSIONS
  Apical tissue of properly treated teeth with no signs of periapical changes is only rarely significantly inflamed. When the tissue is inflamed, microbial causes can always be demonstrated. Despite the presence of microorganisms coronally in nearly all cases, apical tissue is seldom affected.
authors.affiliation: dricucci@libero.it
authors.forename: Domenico
authors.initials: D
authors.lastname: Ricucci
authors.forename: Louis M
authors.initials: LM
authors.lastname: Lin
authors.forename: Larz S W
authors.initials: LS
authors.lastname: Spångberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003739:Dental Cementum / Q000000981:diagnostic imaging / Q000473:pathology; D003782:Dental Pulp / Q000000981:diagnostic imaging / Q000473:pathology; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D003788:Dental Pulp Diseases / Q000628:therapy; D003790:Dental Pulp Necrosis / Q000000981:diagnostic imaging / Q000473:pathology; D003804:Dentin / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging / Q000473:pathology; D010486:Periapical Tissue / Q000000981:diagnostic imaging / Q000473:pathology*; D010513:Periodontal Ligament / Q000000981:diagnostic imaging / Q000473:pathology; D011671:Pulpitis / Q000000981:diagnostic imaging / Q000473:pathology; D016300:Radiography, Bitewing; D012387:Root Canal Filling Materials / Q000737:chemistry; D012390:Root Canal Therapy; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000473:pathology; D014945:Wound Healing / Q000502:physiology; D055815:Young Adult
chemical_list: D012387:Root Canal Filling Materials