Causal assessment of smoking and tooth loss: a systematic review of observational studies.

BACKGROUND: Tooth loss impairs oral function. The aim of the present review was to evaluate the causal association between smoking and tooth loss on the basis of high-quality studies. METHODS: Relevant literature was searched and screened, and the methodological quality was assessed. Information on the strength of the association between smoking and tooth loss, the dose-response relationship and natural experimental data was collected and evaluated with respect to consistency and study design. RESULTS: Our literature search yielded 496 citations, and 6 cross-sectional and 2 cohort high-quality studies examining 58,755 subjects in four countries. All studies reported significant associations, although the strength of the association was usually moderate. Four studies reported dose-response relationships between exposure to smoking and the risk of developing tooth loss. A decrease in the risk of tooth loss for former smokers was evident in six studies. Interpretation of evidence for each element was consistent, despite some shortcomings regarding study type and population. CONCLUSIONS: Based on the consistent evidence found with the existing biological plausibility, a causal association between smoking and tooth loss is highly likely. Further studies using a cohort design and different populations are necessary to confirm this association.

Impact of a tobacco curriculum on smoking behaviour and attitudes toward smoking in dental students in Japan: a three-year follow-up study.

AIM: Dental professionals have the potential to influence global smoking rates. This study evaluated the impact of a tobacco curriculum on smoking behaviour and attitudes toward smoking in dental students. METHODS: Immediately before and three years after the implementation of a tobacco curriculum with a no-smoking policy, a questionnaire was administered to students to obtain information about their smoking behaviour and attitudes toward smoking. RESULTS: The number of students who responded to the questionnaire was 580 in 2003 and 554 in 2006. The smoking rate decreased significantly from 35% in 2003 to 26% in 2006; however, analysis of data for each school year suggested that this was due to the prevention of smoking initiation rather than quitting smoking. Attitudes toward patient smoking and public policy were more positive in non-smokers than in current smokers. Improvement in attitudes toward patient smoking was smaller in current smokers than in non-smokers. Little improvement occurred in attitudes toward public policy in both non- and current smokers. CONCLUSIONS: Implementation of a tobacco curriculum was effective in preventing smoking initiation and improving attitudes toward patient smoking in students. Further measures are necessary to improve attitudes toward public policy and to discourage smoking among students.