Smoking is recognised as a major risk factor for periodontal disease and a large number of studies have shown a strong and consistent association between smoking and periodontal disease. The aim of this study was to re-examine the periodontal effects of smoking and the impact of the other putative risk factors through early to middle adulthood.

Periodontal examinations were carried out in patients from the Dunedin Multidisciplinary Health and Development Study (DMHDS). DMHDS is a longitudinal study of a complete birth cohort born in Dunedin, New Zealand between 1 April 1972 and 31 March 1973. The periodontal examinations were conducted at ages 26, 32 and 38, with only half-mouth examinations possible at age 26, but full-mouth examinations undertaken at 32 and 38. The plaque (debris) score for each participant was recorded on six teeth (four posterior and two anterior)using Greene and Vermillion’s Simplified Oral Hygiene Index (OHI-S). Flossing status was assessed by a self-report question at ages 26, 32 and 38.Tobacco smoking was determined at ages 15, 18, 21, 26, 32 and 38. With Cannabis smoking being determined at 18, 21, 26 and 32 and 38. Socio-Economic Status (SES) was determined. Generalized Linear Mixed Modelling with a quasi-binomial approach was used to examine associations between chronic smoking and periodontal attachment loss.

• 1037 participants initially enrolled in the study,
• 913 were periodontally examined at age 26, and periodontal data were available for 863 (94.5%) individuals at ages 26, 32, and 38 using listwise deletion.
• At age 32 and 38 respectively, 918 and 905 (98.6%), and 913 and 869 (95.1%) participants were examined and included in the analysis.
• Approximately equal numbers of females and males were included.
• The proportion of current tobacco smokers decreased with age, as did cannabis use. Some 3.9% of the participants smoked cannabis daily at age 26, while none did so at age 38.
• At ages 26, 32 and 38, smokers had 3.5%, 12.8% and 23.2% (respectively) greater attachment loss (AL) than non-smokers.
• Regular cannabis use was associated with greater AL after age 32, but not at age 26.
• Males had more AL than females.
• Participants with high plaque scores had consistently greater AL; those who were of persistently low SES (socio-economic status) had higher AL at age 32 and 38, but not at age 26.
• The amount of AL in anteriors was less than in premolars and molars.
• Gingival bleeding was associated with higher AL at ages 26, 32 and 36

The authors concluded

The smoking-periodontitis association is observable with hierarchical modelling, providing strong evidence that chronic smoking is a risk factor for periodontitis.

Links

Zeng J, Williams SM, Fletcher DJ, Cameron CM, Broadbent JM, Shearer DM, Thomson WM. Re-Examining the Association Between Smoking and Periodontitis in the Dunedin Study With an Enhanced Analytical Approach. J Periodontol. 2014 Feb 20. [Epub ahead of print] PubMed PMID: 24555730.

Thomson WM, Shearer DM, Broadbent JM, Foster Page LA, Poulton R. The natural history of periodontal attachment loss during the third and fourth decades of life. J Clin Periodontol. 2013 Jul;40(7):672-80. doi: 10.1111/jcpe.12108. Epub 2013 May 9. PubMed PMID: 23656174.

Thomson WM, Broadbent JM, Welch D, Beck JD, Poulton R. Cigarette smoking and periodontal disease among 32-year-olds: a prospective study of a representative birth cohort. J Clin Periodontol. 2007 Oct;34(10):828-34. PubMed PMID: 17850601; PubMed Central PMCID: PMC2253679.