Alcohol use and periodontal pocket development: findings from a 4-yr longitudinal study Sankaranarayanan R, Saxlin T, Yl € ostalo P, Khan S, Knuuttila M, Suominen AL. Alcohol use and periodontal pocket development: findings from a 4-yr longitudinal study. Eur J Oral Sci 2019; 37: 1–9. © 2019 Eur J Oral Sci This study investigated whether alcohol use influences periodontal pocket develop- ment during a 4-yr follow-up period. The study included those participants who took part in both the Health 2000 Survey and the Follow-up Study on Finnish Adults’ Oral Health. The participants at baseline were aged ≥30 yr, periodontally healthy, and did not have diabetes or rheumatoid arthritis. The development of periodontal pockets at follow-up was measured as the number of teeth with peri- odontal pockets and the presence of periodontal pockets. Alcohol use at baseline was measured as g/wk, frequency, and use over the risk limit. Incidence rate ratios with 95% CI were estimated using negative binomial regression models and Poisson regression models with a robust variance estimator. No consistent association was found between any of the alcohol variables and periodontal pocket development in the total population or among non-smokers. Among smokers, a positive association was found with the frequency of alcohol use. In general, risk estimates were slightly higher for women than for men. In summary, light-to-moderate alcohol use appears not to be consistently associated with the development of periodontal pockets. The adverse effects on the periodontium seem, to some extent, to be dependent on gen- der and smoking. Rajeswari Sankaranarayanan 1 , Tuomas Saxlin 1,2,3 , Pekka Yl € ostalo 3,4 , Sohaib Khan 5 , Matti Knuuttila 4 , Anna L. Suominen 1,2,6 1 Institute of Dentistry, University of Eastern Finland, Kuopio; 2 Department of Oral and Maxillofacial Diseases, Kuopio University Hospital, Kuopio; 3 Research Unit of Oral Health Sciences, Medical Research Centre Oulu (MRC Oulu), University of Oulu, Oulu; 4 Department of Oral and Maxillofacial Surgery, Oulu University Hospital, Oulu; 5 Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio; 6 Unit of Public Health Evaluation and Projection, National Institute for Health and Welfare (THL), Helsinki, Finland Rajeswari Sankaranarayanan, Institute of Dentistry, University of Eastern Finland, Kuopio Campus, Canthia, Yliopistonranta 1 C, B-door, Kuopio 70211, Finland E-mail: rajeswari.sankaranarayanan@uef.fi Key words: alcohol intake; follow-up study; frequency of alcohol use; incidence; periodontal condition Accepted for publication January 2019 Several epidemiological studies have examined the association between alcohol consumption and peri- odontal disease; however, the findings remain unclear because harmful, null, and protective effects were all observed (1, 2). Several biologically plausible mecha- nisms could explain the potentially harmful effects of alcohol on periodontal health. Studies have shown that alcohol intake in high amounts could affect the host immune response, increase the levels of inflam- matory cytokines, impair neutrophil and macrophage functions, increase bacterial growth, and increase sus- ceptibility to infections (3, 4). On the other hand, the well-documented bactericidal effect of alcohol could partly account for the null or protective effects observed. The current evidence is based mainly on numerous cross-sectional (5–8) and a few longitudinal (9–12) stud- ies. The longitudinal studies examined the role of alco- hol use both in the development and the progression of periodontal disease. Of those studies, only two focussed on the development of periodontal disease: PITIPHAT et al. (10) reported that alcohol use is associated with a higher incidence of self-reported periodontitis, while OKAMOTO et al. (11) reported that alcohol use is not associated with the development of periodontitis. The co-occurrence of alcohol use with smoking has been suggested in several reports (13). Studies have also reported that heavy drinkers are much more likely to smoke, and vice versa (14, 15), which poses challenges to studying the independent effect of alco- hol use because of the confounding effect of smoking (16). Besides smoking, it is important to take into account the confounding role of poor oral hygiene and inadequate dental care as previous studies have suggested that among heavy alcohol users, it is poor oral hygiene and inadequate dental care – rather than the alcohol use itself – that adversely affect periodon- tal health (17, 18). It is still unclear why the association between alcohol use and periodontal disease development appears to be different between genders (12, 19–21). It could be spec- ulated that these discrepancies relate to either beha- vioural or biological differences between men and women, such as disparities in drinking behaviour (22, 23) or metabolism of alcohol (24, 25). Considering the knowledge gap, it is important to investigate the long-term effects of alcohol use on the periodontium. To address this question, in this paper we aimed to investigate whether alcohol use (amount, frequency, and use over the risk limit) predicts the Eur J Oral Sci 2019; 1–9 DOI: 10.1111/eos.12610 Printed in Singapore. All rights reserved © 2019 Eur J Oral Sci European Journal of Oral Sciences