Detection and quantification of periodontal pathogens in smokers and never-smokers with chronic periodontitis by real-time polymerase chain reaction

J Periodontol. 2014 Oct;85(10):1450-7. doi: 10.1902/jop.2014.140048. Epub 2014 May 2.


Background: The purpose of the present investigation is to compare the presence and number of periodontal pathogens in the subgingival microbiota of smokers versus never-smokers with chronic periodontitis and matched probing depths (PDs) using real-time polymerase chain reaction (RT-PCR).

Methods: Forty current smokers and 40 never-smokers, matched for age, sex, and mean PD of sampling site, were included in this investigation. A full-mouth periodontal examination was performed, and a pooled subgingival plaque sample was collected from the deepest site in each quadrant of each participant. To confirm smoking status, expired carbon monoxide (CO) concentrations were measured with a CO monitor. The presence and quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were determined using RT-PCR.

Results: Smokers had greater overall mean PD (P = 0.001) and attachment loss (P = 0.006) and fewer bleeding on probing sites (P = 0.001). An association was observed between smoking status and the presence of A. actinomycetemcomitans (P <0.001). The counts of A. actinomycetemcomitans (P <0.001), P. gingivalis (P = 0.042), and T. forsythia (P <0.001) were significantly higher in smokers.

Conclusions: Smokers showed significantly greater amounts of P. gingivalis, A. actinomycetemcomitans, and T. forsythia than never-smokers. There was a significant association between smoking and the presence of A. actinomycetemcomitans.

Keywords: Aggregatibacter actinomycetemcomitans; bacteria; chronic periodontitis; microbiology; polymerase chain reaction; smoking.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aggregatibacter actinomycetemcomitans / isolation & purification
  • Bacteria / classification*
  • Bacterial Load
  • Bacteroides / isolation & purification
  • Carbon Monoxide / analysis
  • Case-Control Studies
  • Chronic Periodontitis / microbiology*
  • Cross-Sectional Studies
  • Dental Plaque / microbiology
  • Female
  • Gingiva / microbiology
  • Gingival Hemorrhage / microbiology
  • Humans
  • Male
  • Middle Aged
  • Periodontal Attachment Loss / microbiology
  • Periodontal Pocket / microbiology
  • Porphyromonas gingivalis / isolation & purification
  • Real-Time Polymerase Chain Reaction / methods
  • Smoking*
  • Treponema denticola / isolation & purification


  • Carbon Monoxide