title: Similarities in the subgingival microbiota assessed by a curet sampling method at sites with chronic periodontitis.
abstract: BACKGROUND
  The goal of this study was to determine whether site-specific differences in the subgingival microbiota could be detected by the checkerboard method in subjects with periodontitis.
  
  
  METHODS
  Subjects with at least six periodontal pockets with a probing depth (PD) between 5 and 7 mm were enrolled in the study. Subgingival plaque samples were collected with sterile curets by a single-stroke procedure at six selected periodontal sites from 161 subjects (966 subgingival sites). Subgingival bacterial samples were assayed with the checkerboard DNA-DNA hybridization method identifying 37 species.
  
  
  RESULTS
  Probing depths of 5, 6, and 7 mm were found at 50% (n = 483), 34% (n = 328), and 16% (n = 155) of sites, respectively. Statistical analysis failed to demonstrate differences in the sum of bacterial counts by tooth type (P = 0.18) or specific location of the sample (P = 0.78). With the exceptions of Campylobacter gracilis (P <0.001) and Actinomyces naeslundii (P <0.001), analysis by general linear model multivariate regression failed to identify subject or sample location factors as explanatory to microbiologic results. A trend of difference in bacterial load by tooth type was found for Prevotella nigrescens (P <0.01). At a cutoff level of > or = 1.0 x 10(5), Porphyromonas gingivalis and Tannerella forsythia (previously T. forsythensis) were present at 48.0% to 56.3% and 46.0% to 51.2% of sampled sites, respectively.
  
  
  CONCLUSIONS
  Given the similarities in the clinical evidence of periodontitis, the presence and levels of 37 species commonly studied in periodontitis are similar, with no differences between molar, premolar, and incisor/cuspid subgingival sites. This may facilitate microbiologic sampling strategies in subjects during periodontal therapy.
authors.affiliation: Department of Periodontology, Division of Oral Microbiology, School of Dental Medicine, University of Bern, Bern, Switzerland. rutger.persson@zmk.unibe.ch
authors.forename: G Rutger
authors.initials: GR
authors.lastname: Persson
authors.forename: Marianne
authors.initials: M
authors.lastname: Weibel
authors.forename: Regula
authors.initials: R
authors.lastname: Hirschi
authors.forename: Joannis
authors.initials: J
authors.lastname: Katsoulis
mesh_terms: D000190:Actinomyces / Q000302:isolation & purification; D000328:Adult; D000368:Aged; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification; D001439:Bacteroides / Q000302:isolation & purification; D001641:Bicuspid / Q000382:microbiology; D002167:Campylobacter / Q000302:isolation & purification; D055113:Chronic Periodontitis / Q000382:microbiology* / Q000628:therapy; D015169:Colony Count, Microbial; D003481:Cuspid / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005881:Gingiva / Q000382:microbiology*; D006801:Humans; D007180:Incisor / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D008963:Molar / Q000382:microbiology; D009693:Nucleic Acid Hybridization / Q000379:methods; D010514:Periodontal Pocket / Q000382:microbiology* / Q000628:therapy; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D045242:Prevotella nigrescens / Q000302:isolation & purification; D013357:Subgingival Curettage / Q000295:instrumentation
chemical_list: D004269:DNA, Bacterial