title: Persistent presence of Bacteroides forsythus as a risk factor for attachment loss in a population with low prevalence and severity of adult periodontitis.
abstract: BACKGROUND
  Previous longitudinal studies investigating the role of microorganisms in periodontitis have focused on subjects with a high prevalence and severity of disease. The complex profile of microbial species in severe cases of periodontitis might not allow us to differentiate which bacterial species initiate disease or which species simply proliferate after disease progression. This prospective longitudinal study followed a group of 205 subjects who showed a low prevalence and severity of adult periodontitis, and thus allowed us to monitor early microbiological changes in the development of periodontitis.
  
  
  METHODS
  Subgingival plaque was collected from proximal surfaces of a posterior sextant at 6-month intervals for 2 years. During the monitoring period, 44 subjects had either attachment loss or attachment gain. Using multiplex polymerase chain reaction (PCR), all plaque samples from those 44 subjects were analyzed for the presence of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Porphyromonas gingivalis.
  
  
  RESULTS
  Both subjects with attachment loss and those with attachment gain had a high prevalence of these 3 periodontal pathogens. The mere presence of any of the 3 species at a site could not predict future attachment loss at that specific site. However, subjects with a persistent presence of B. forsythus at any site across all visits had 5.3 times higher odds of having at least one site in their mouth losing attachment compared to subjects with occasional or no presence of B. forsythus.
  
  
  CONCLUSIONS
  The persistence of B. forsythus identified subjects at higher risk, but not which specific sites in those subjects would lose attachment.
authors.affiliation: Department of Oral Science, School of Dentistry, University of Minnesota, Minneapolis, USA. stran@dir.nidcr.nih.gov
authors.forename: S D
authors.initials: SD
authors.lastname: Tran
authors.forename: J D
authors.initials: JD
authors.lastname: Rudney
authors.forename: B S
authors.initials: BS
authors.lastname: Sparks
authors.forename: J S
authors.initials: JS
authors.lastname: Hodges
mesh_terms: D000189:Actinobacillus Infections / Q000145:classification; D000328:Adult; D000368:Aged; D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification; D000704:Analysis of Variance; D016866:Bacteroidaceae Infections / Q000145:classification; D001439:Bacteroides / Q000145:classification*; D001442:Bacteroides Infections / Q000145:classification*; D016009:Chi-Square Distribution; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D005544:Forecasting; D006801:Humans; D016013:Likelihood Functions; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D017622:Periodontal Attachment Loss / Q000382:microbiology*; D010518:Periodontitis / Q000145:classification / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000145:classification; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors