title: Extracellular neutrophil traps in periodontitis.
abstract: OBJECTIVE
  Chronic periodontitis, the chronic inflammatory disease of the periodontium, is caused by bacteria and is characterized by an influx of neutrophils into the gingival crevice. Recently, a 'new' extracellular neutrophil defense mechanism - neutrophil extracellular traps - has been described. However, their role in periodontitis has not yet been investigated.
  
  
  METHODS
  Clinical examinations, transmission and scanning electron microscopy, as well as cytology and confocal laser-scanning microscopy, were employed to analyze gingiva biopsies and crevicular exudate from patients with chronic periodontitis.
  
  
  RESULTS
  An abundance of neutrophil extracellular traps and some phagocytic neutrophils was found on the gingival pocket surface and in the purulent crevicular exudate. Finding neutrophil extracellular traps in the spontaneously effused purulent crevicular exudate clearly indicated that they are flushed from the pocket by the crevicular exudate. In cases of dispersal of subgingival plaque bacteria, their trapping by neutrophil extracellular traps in purulent crevicular exudate and on the gingival surface was demonstrated.
  
  
  CONCLUSIONS
  Trapping the crevicular bacteria prevents their adhesion to and invasion of the gingiva. The combination of neutrophil extracellular traps and crevicular exudate outflow appears to be a 'novel' defense mechanism for the clearance of crevicular bacteria in chronic periodontitis.
authors.affiliation: Department of Operative Dentistry & Periodontology, Saarland University, Homburg, Germany. lvitkov@yahoo.com
authors.forename: L
authors.initials: L
authors.lastname: Vitkov
authors.forename: M
authors.initials: M
authors.lastname: Klappacher
authors.forename: M
authors.initials: M
authors.lastname: Hannig
authors.forename: W D
authors.initials: WD
authors.lastname: Krautgartner
mesh_terms: D000328:Adult; D001422:Bacterial Adhesion / Q000502:physiology; D018441:Biofilms; D001706:Biopsy; D022081:Cell Surface Extensions / Q000502:physiology*; D055113:Chronic Periodontitis / Q000382:microbiology* / Q000473:pathology; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000382:microbiology; D003851:Deoxyribonucleases / Q000032:analysis; D005881:Gingiva / Q000382:microbiology / Q000473:pathology; D005883:Gingival Crevicular Fluid / Q000382:microbiology / Q000502:physiology; D006801:Humans; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D018375:Neutrophil Activation / Q000502:physiology; D009504:Neutrophils / Q000502:physiology*; D010514:Periodontal Pocket / Q000382:microbiology / Q000473:pathology; D010587:Phagocytosis / Q000502:physiology; D013492:Suppuration
chemical_list: D003851:Deoxyribonucleases