title: Effect of non-surgical periodontal treatment on clinical parameters and the numbers of Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans at adult periodontitis sites.
abstract: OBJECTIVE
  The purpose of this study was to relate the numbers of Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans cells to clinical parameters at diseased and healthy periodontal sites before and after non-surgical periodontal therapy using a sensitive quantitative PCR method (Q-PCR).
  
  
  METHODS
  The sensitivity of the Q-PCR was less than 10 cells for all three species. Subgingival plaque samples were collected from 541 sites in 50 adult periodontitis subjects pre-treatment, post-treatment and at a follow-up visit (3-6 months post-treatment). Pocket probing depth, attachment loss and bleeding on probing were recorded at each visit and both healthy and diseased sites in each subject were sampled.
  
  
  RESULTS
  Quantification revealed that P. gingivalis counts were associated with pocket depth (p=0.006) and attachment loss (p=0.010); however, neither P. intermedia nor A. actinomycetemcomitans was associated with the clinical signs examined. Post-treatment, there was a significant decrease in the numbers of all three species in both the diseased and healthy sites (86-99%) but none were eradicated. Positive associations were found between any two of the three species studied both pre- and post-therapy. By the follow-up visit, there was a significant improvement in the probing depth of deep sites (p=0.001) but in no other clinical parameters.
  
  
  CONCLUSIONS
  This study demonstrates the usefulness of Q-PCR for enumerating putative pathogens in clinical periodontal specimens and that the numbers of the three organisms in all sites decrease with non-surgical periodontal therapy.
authors.affiliation: Department of Oral Pathology, School of Clinical Dentistry, University of Sheffield, UK.
authors.forename: S
authors.initials: S
authors.lastname: Doungudomdacha
authors.forename: A
authors.initials: A
authors.lastname: Rawlinson
authors.forename: T F
authors.initials: TF
authors.lastname: Walsh
authors.forename: C W
authors.initials: CW
authors.lastname: Douglas
mesh_terms: D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans / Q000254:growth & development*; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000382:microbiology / Q000517:prevention & control; D012534:Dental Scaling; D005500:Follow-Up Studies; D005884:Gingival Hemorrhage / Q000382:microbiology / Q000628:therapy; D006801:Humans; D016014:Linear Models; D015588:Observer Variation; D009910:Oral Hygiene; D017622:Periodontal Attachment Loss / Q000382:microbiology / Q000628:therapy; D010514:Periodontal Pocket / Q000382:microbiology / Q000628:therapy; D010518:Periodontitis / Q000382:microbiology / Q000628:therapy*; D010519:Periodontium / Q000382:microbiology; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000254:growth & development*; D018713:Prevotella intermedia / Q000254:growth & development*; D015203:Reproducibility of Results; D016745:Root Planing; D012680:Sensitivity and Specificity; D012907:Smoking; D013223:Statistics as Topic; D018709:Statistics, Nonparametric