Association between time since quitting smoking and periodontitis in former smokers in the National Health and Nutrition Examination Surveys (NHANES) 2009 to 2012

Background The aims of this study were to analyze the periodontal conditions among non-smokers, former smokers and current smokers in the two National Health and Nutrition Examination Surveys (NHANES) acquired between 2009 to 2012 and determine the association between time since quitting smoking and periodontal status. Methods Smoking status and periodontal examination data from NHANES 2009 to 2010 and 2011 to 2012 were analyzed. Respondents included in the analysis were aged >= 18 years, had undergone a complete NHANES Oral Health - Periodontal Exam with all measurements recorded as required for the periodontal classification algorithm, and had complete data from the NHANES Smoking - Cigarette Use questionnaire. Logistic regression was conducted with time since quitting as the exposure and presence of periodontitis as the outcome, and included adjustment for confounders. Results Smoking status was significantly associated with periodontal status (Chi-square; P < 0.0001). The rate of periodontitis was highest among smokers (35%), compared with former smokers (19%) and never smokers (13%). Among former smokers, after adjusting for confounders, each additional year since quitting smoking was associated with a significant reduction in the odds ratio (OR) for periodontitis by 3.9% (OR for each year 0.961, 95% confidence interval 0.948 to 0.975). Conclusions Among former smokers, a longer time since quitting smoking was associated with a lower likelihood of periodontitis. Consequently, dental practitioners have a public health mandate to help their patients quit smoking. Future research should determine the best strategies for facilitating smoking cessation in dental patients.