The effect of cigarette smoking on gingival bleeding.
BACKGROUND
The purpose of this study was to investigate the dose-dependent effect of cigarette smoking upon gingival bleeding on probing (BOP) in a large representative sample of the United States population (National Health and Nutrition Examination Survey III).


METHODS
Weighted multiple logistic regression was used to model bleeding on probing of 141,967 mesio-buccal sites in 12,385 individuals with complete case records on all covariates. Adjustments were made for age, gender, race/ethnicity, number of missing teeth, tooth type/jaw, root caries, full crown coverage, socioeconomic status (poverty/income ratio), and survey characteristics. The model stratified by presence of calculus (CALC) and increased probing depth (PD > or = 4 mm). Generalized estimating equations were used to account for dependence of sites within subjects.


RESULTS
Smoking had a strong suppressive effect on gingival bleeding. The effect was strongest in heavier smokers (> 10 cigarettes/day) and smallest in former smokers. In healthy sites (no CALC, PD < or = 3 mm), the odds ratio (OR) of bleeding for sites in heavier smokers compared to never-smokers was 0.56 (95% CI: 0.45-0.70). Sites with CALC and/or PD > or = 4 mm were more likely to bleed in never-smokers (OR: 5.7; 95% CI: 4.3-7.6). This relationship was less evident among heavier smokers (OR: 1.3; 95% CI: 0.8-1.9). The effect of smoking did not differ between maxillary and mandibular molars, premolars, or incisors.


CONCLUSIONS
Smoking exerts a strong, chronic, and dose-dependent suppressive effect on gingival bleeding on probing.
Dietrich
Thomas
T
Department of Periodontology, Charité, Humboldt University, Berlin, Germany. tommi@tomsoft.com
Bernimoulin
Jean-Pierre
JP
Glynn
Robert J
RJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D003728:Dental Calculus / Q000453:epidemiology; D005260:Female; D005881:Gingiva / Q000098:blood supply; D005882:Gingival Diseases / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010512:Periodontal Index; D012494:Sampling Studies; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D014481:United States / Q000453:epidemiology