title: Effects of smoking on periodontal tissues.
abstract: OBJECTIVE
  Most studies about the association between tobacco and periodontal disease have shown that tobacco negatively affects periodontal tissues, although some authors have failed to demonstrate such association. Very few studies have tried to find out whether the effect of tobacco on periodontal tissues was similar for women and men. The aims of this investigation were to confirm the possible relationship between tobacco consumption and periodontitis, to study the correlation between intensity of smoking and disease severity, and to investigate any differences between genders related to the effects of tobacco consumption in periodontal health.
  
  
  METHODS
  In this case-control study, 240 dental patients were selected according to previously defined criteria and were divided in two groups according to their periodontal status. Patients with established periodontitis constituted the case group. The remaining patients constituted the control group. Smoking status, probing depth, gingival recession, clinical attachment level, tooth mobility, periodontal bleeding index and plaque index were determined for each participant. Generated data were processed for statistical analysis using multiple comparisons, covariance analysis and logistic regression analysis.
  
  
  RESULTS
  Logistic regression analysis showed that smokers had 2.7 times and former smokers 2.3 times greater probabilities to have established periodontal disease than non-smokers, independent of age, sex and plaque index. Among cases, probing depth, gingival recession and clinical attachment level were greater in smokers than in former smokers or non-smokers, whereas plaque index did not show differences. Bleeding on probing was less evident in smokers than in non-smokers. There was a dose-effect relationship between cigarette consumption and the probability of having advanced periodontal disease. The association between tobacco smoking and periodontal disease was more evident after 10 years of smoking, independent of age, gender and plaque index. Finally, it was observed that tobacco affected periodontal tissues more severely in men than in women.
  
  
  CONCLUSIONS
  Smoking is a risk factor strongly associated with periodontitis. The effects of smoking on periodontal tissues depend on the number of cigarettes smoked daily and the duration of the habit. The effect of tobacco on periodontal tissues seems to be more pronounced in men than in women.
authors.affiliation: Department of Periodontology, School of Dentistry, University of Barcelona, Barcelona, Spain. gcalsina@infomed.es
authors.forename: Gloria
authors.initials: G
authors.lastname: Calsina
authors.forename: José-María
authors.initials: JM
authors.lastname: Ramón
authors.forename: José-Javier
authors.initials: JJ
authors.lastname: Echeverría
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010512:Periodontal Index; D010518:Periodontitis / Q000209:etiology*; D010519:Periodontium / Q000187:drug effects*; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects*; D014026:Nicotiana