Cigarette smoking: a major risk factor for periodontitis.

Cigarette smoking is a risk factor for many diseases, and recent evidence indicates that it adversely affects periodontal health. A number of epidemiologic studies have shown strong associations between smoking and the prevalence and severity of periodontitis, as well as interproximal bone loss. Although the pathogenesis of periodontitis in smokers is poorly understood, there are data suggesting that smoking causes defects in neutrophil function, impaired serum antibody responses to periodontal pathogens, and potentially diminished gingival fibroblast function. The prevalence and severity of periodontitis in former smokers is decreased compared to current smokers, providing evidence that smoking cessation is beneficial. Smoking markedly influences response to treatment, and a subset of smokers predominates among refractory periodontitis patients who are resistant to conventional treatment. A patient's smoking history is a useful clinical predictor of future disease activity. Current estimates suggest that smoking is associated with a large proportion of periodontitis cases and constitutes a major public dental health problem.