title: Tobacco smoking and subgingival dental calculus.
abstract: OBJECTIVE
  A radiographic investigation into the relationship between tobacco smoking and subgingival dental calculus was conducted in an adult population, including 48 current smokers, 57 former smokers, and 125 non-smokers.
  
  
  METHODS
  Assessment of subgingival calculus was based on a full set of radiographs. Mesial and distal root surfaces were assessed as to presence or absence of radiopaque deposits apical to the cemento-enamel junction. The severity of subgingival calculus deposition, labeled subgingival calculus load, was estimated from both the total number and the proportion of proximal sites affected.
  
  
  RESULTS
  The overall prevalence of individuals exhibiting at least one subgingival calculus positive site was 43%, ranging from 15% in age stratum 20-34 years to 72% in age stratum 50-69 years. The prevalence among current smokers, former smokers, and non-smokers was 71%, 53%, and 28%, respectively. The differences between smoking groups were statistically significant (p<0.001). The mean subgingival calculus load of current smokers, former smokers, and non-smokers was 3.4, 1.2, and 0.6 affected sites per person, respectively, or expressed as mean proportions, 6.2%, 2.4%, and 1.1%, respectively. The association between smoking and subgingival calculus load was statistically significant (p<0.001). The subgingival calculus load increased with increasing smoking exposure, suggesting a dose-response relationship.
  
  
  CONCLUSIONS
  The present observations in dentally aware adults indicate a strong and independent impact of tobacco smoking on subgingival calculus deposition.
authors.affiliation: Institute of Odontology, Karolinska Institutet, Stockholm, Sweden. Jan.bergstrom@ofa.ki.se
authors.forename: Jan
authors.initials: J
authors.lastname: Bergström
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003728:Dental Calculus / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology