The effect of quitting smoking on chronic periodontitis.

OBJECTIVES To evaluate longitudinally the effect of smoking cessation on clinical and radiographic outcomes following non-surgical treatment in smokers with chronic periodontitis. MATERIAL AND METHODS Forty-nine smokers with chronic periodontitis who wished to quit smoking were recruited. Full-mouth probing depths, bleeding and plaque data were recorded at baseline, 3, 6 and 12 months. Clinical attachment levels were recorded at target sites and subtraction radiography was used to assess bone density changes. Patients received non-surgical periodontal therapy during the first 3 months and supportive periodontal care over the remainder of the study. Smoking cessation counselling was provided according to individual need. RESULTS After 12 months, of patients with complete data, 10 had continuously quit smoking (20% of the original population), 10 continued smoking and six were oscillators (those patients who quit and then relapsed). There were no differences between the groups following treatment with respect to mean clinical or radiographic parameters. Analysis of probing depth reductions between baseline and month 12, however, and comparing quitters with the other two groups combined, demonstrated a significant difference in favour of quitters (p<0.05). Furthermore, quitters were significantly more likely to demonstrate probing depth reductions > or =2 and > or =3 mm than non-quitters and oscillators (p<0.05). CONCLUSION Quitting smoking has an additional beneficial effect in reducing probing depths following non-surgical treatment over a 12-month period.