title: The apical border plaque in chronic adult periodontitis. An ultrastructural study. I. Morphology, structure, and cell content.
abstract: THIS STUDY CONCERNS THE APICAL BORDER (AB) plaque in relation to chronic adult periodontitis (AP). Fifty-six teeth from 24 patients with AP were examined by transmission electron microscopy (TEM). The AB was not discrete with islands of bacteria in the so-called plaque-free zone (PFZ). Coronal to the AB, the established plaque commonly consisted of three to four layers of Gram-positive and Gram-negative cocci, rods, filaments, and spirochetes and a superficial layer, mainly of spirochetes, but including filaments, "test tube brush," and "corn-cob" formations. The most apical apparently intact organisms in the PFZ were in bacterial islands or in isolation and were predominantly Gram-negative cocci and rods, with occasional other morphotypes. The most apical microorganisms were invariably ghost cells. A cuticle of varying thickness and structure was present at the plaque/tooth interface. It was concluded that there was a limited range of intact bacterial morphotypes in the apical border plaque in chronic periodontitis.
authors.affiliation: Department of Periodontology, University of London, UK.
authors.forename: T P
authors.initials: TP
authors.lastname: Vrahopoulos
authors.forename: P M
authors.initials: PM
authors.lastname: Barber
authors.forename: H N
authors.initials: HN
authors.lastname: Newman
mesh_terms: D000328:Adult; D001419:Bacteria / Q000648:ultrastructure*; D002908:Chronic Disease; D003739:Dental Cementum / Q000648:ultrastructure; D003773:Dental Plaque / Q000382:microbiology* / Q000648:ultrastructure*; D005260:Female; D006090:Gram-Negative Bacteria / Q000648:ultrastructure; D006094:Gram-Positive Bacteria / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009504:Neutrophils / Q000648:ultrastructure; D010514:Periodontal Pocket / Q000382:microbiology / Q000473:pathology; D010518:Periodontitis / Q000382:microbiology / Q000473:pathology*; D013144:Spirochaetales / Q000648:ultrastructure