Subgingival microbiota more prevalent in smokers than in former smokers or those who have never smoked

A RT I C L E A N A LY S I S & E VA LUAT I O N Subgingival microbiota more prevalent in smokers than in former smokers or those who have never smoked Original Article:

Haffajee AD, Socransky SS. Relationship of cigarette smoking to the subgingival microbiota. J Clin Periodontol 2001;28:377-88.

• Level of Evidence: • Purpose:

3b

• Source of Funding: • Type of Study/Design:

National Institute of Dental and Craniofacial Research

To compare the prevalence and proportions of subgingival bacteria between smokers and nonsmokers

Cross-sectional exploratory study

SUMMARY SUBJECTS The subjects were 272 adults examined at the Department of Periodontology, Forsyth Institute Periodontal Clinic, Boston, Mass. They were 20 to 86 years old and included 31 periodontally healthy subjects, 35 well-maintained elderly, and 206 with periodontitis. All subjects had at least 20 teeth. Exclusion criteria included pregnancy, periodontal therapy or antibiotics in the past 3 months, and any systemic condition that might have affected the progression or treatment of periodontitis. Localized juvenile periodontitis, rapidly progressive periodontitis,

and acute necrotizing ulcerative gingivitis were not included in the study.

EXPOSURE Patients were compared on the basis of smoking status. Smoking history was obtained using a questionnaire, and patients were divided into 3 groups: (1) never smoked (n = 124), (2) past smokers (n = 98), and (3) current smokers (n = 50). MAIN OUTCOME MEASURE The main outcome measure was the prevalence and count of subgingival 29 periodontal

bacteria among patients with periodontitis. No control subjects (individuals without periodontitis) were included in the study.

MAIN RESULTS E nodatum, F nucleatum ss vincentti, P intermedia, P micros, P nigrescens, B forsythus, P gingivalis, and T denticola were significantly more prevalent in current smokers than in the other groups. The greater extent of colonization in smokers appeared to be due to greater colonization at a pocket depth of less than 4 mm (Fig 5).

J Evid Base Dent Pract 2002;2:52-53 © 2002 Mosby, Inc. All rights reserved doi:10.1067/med.2002.122658

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C OMMENT ARY Fig 5. Bar chart of mean prevalence (% of sites colonized, ± SEM) of individual species in subgingival plaque samples taken from subjects with different smoking histories. The bars represent the mean prevalence and the whiskers indicate the standard error of the mean. Prevalence for each species was computed for each subject and then averaged across subjects in the 3 smoking groups. Ordering of species and testing of significance of differences were performed as described in Figure 1 (not included here). (Reprinted from Haffajee AD, Socransky SS. J Clin Periodontal2001;28:37788. By permission.)

CONCLUSIONS In this study, the prevalence of some subgingival bacterial species differed in subjects with different smoking histories.

ANALYSIS These results suggested that smokers with periodontitis have different compositions of specific clusters of subgingival microflora. The authors adjusted the analyses for pocket depth and attachment level. As subgingival microflora can easily change its

• Content Reviewer:

Journal of Evidence-Based Dental Practice Volume 2, Number 1

pattern with an increase of pocket depth, this adjustment was a significant strength of this study. The difference in prevalence between smokers and nonsmokers was mainly due to the greater difference at sites with a pocket depth of less than 4 mm. These specific pathogenic bacteria might be related to future damage of periodontal tissues, but the implication of these clusters of bacteria for tissue destruction is currently unclear. In particular, due to absence of control subjects without periodontitis, the etiological role of these organisms is unclear.

Toru Naito, DDS, PhD, Kyushu Dental College, Kitakyushu, Japan

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