title: Long-term effect of smoking on vertical periodontal bone loss.
abstract: OBJECTIVE
  The objective of the present study was to investigate the influence of smoking on vertical periodontal bone loss over 10 years.
  
  
  METHODS
  The study base consisted of a population that was examined on two occasions with a 10-year interval, including 91 individuals, 24 smokers, 24 former smokers, and 43 non-smokers. The assessment of vertical bone loss was based on full sets of intra-oral radiographs from both time points. The severity of vertical bone loss was expressed as the proportion of proximal sites with vertical defects per person.
  
  
  RESULTS
  The 10-year increase in the proportion of vertical defects was statistically significant in all groups (p<0.001) and, in addition, significantly associated with smoking (p<0.05). In particular, the difference between smokers and non-smokers was significant (p<0.01) whereas former smokers did not differ from non-smokers. Moreover, the 10-year vertical bone loss was significantly greater in heavy exposure smokers than in light exposure smokers suggesting an exposure-response effect (p<0.01). Compared with non-smokers the unadjusted 10-year relative risk was 2.3-fold increased in light exposure smokers and 5.3-fold increased in heavy exposure smokers (p<0.05).
  
  
  CONCLUSIONS
  The present observations indicate a significant long-term influence of smoking on vertical periodontal bone loss, yielding additional evidence that smoking is a risk factor for periodontal bone loss.
authors.affiliation: Institute of Odontology, Karolinska Institutet, SE-141 04 Stockholm, Sweden. Balgoon@hotmail.com
authors.forename: Mostafa
authors.initials: M
authors.lastname: Baljoon
authors.forename: Suzan
authors.initials: S
authors.lastname: Natto
authors.forename: Jan
authors.initials: J
authors.lastname: Bergström
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology*; D000704:Analysis of Variance; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008875:Middle Aged; D010512:Periodontal Index; D011446:Prospective Studies; D011859:Radiography; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects*