title: Longitudinal association between plaque and gingival bleeding in smokers and non-smokers.
abstract: OBJECTIVE
  Whereas accumulation of dentogingival plaque inevitably leads to inflammatory reactions in the adjacent gingival tissue, there is limited information with regard to factors influencing naturally occurring fluctuation between gingival health and disease. The major aims of the present study were to investigate site-specific associations between plaque and gingivitis as well as transition dynamics of naturally occurring gingivitis in smoking and non-smoking young adults.
  
  
  METHODS
  65 systemically healthy young adults, 19 to 30 years old, participated. 33 volunteers smoked at least 20 cigarettes per day, whereas 32 subjects were non-smokers. Clinical periodontal conditions were assessed four times within a time period of 6 months. An ecological approach in data analysis as well as site-specific analyses considering the correlated structure of data were performed.
  
  
  RESULTS
  At the outset and after 6 months, smokers had significantly more supragingival plaque than non-smokers. At the final examination, bleeding upon probing as well as calculus were more prevalent in smokers. A site-by-site analysis revealed that smokers tended to have a weaker association between supragingival plaque and bleeding on probing than non-smokers (median Mantel-Haenszel's common odds ratio 1.91 vs. 2.89, p=0.07). Multiple logistic regression analyses adjusted for periodontal probing depth, plaque and calculus identified smoking status to significantly increase the risk for the first transition of non-bleeding to bleeding upon probing by 86% (p<0.01). In contrast, recovery of bleeding sites was positively influenced by female gender, but not smoking.
  
  
  CONCLUSIONS
  In multivariate analyses adjusted for probing depth, plaque and calculus, smokers appeared to be at higher risk for the transition from non-bleeding to bleeding on probing. Weaker associations between plaque and naturally occurring gingivitis in smokers may have important consequences for preventive strategies for gingivitis.
authors.affiliation: School of Dental Medicine, University of Heidelberg, Germany. perio@t-online.de
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Müller
authors.forename: Sabine
authors.initials: S
authors.lastname: Stadermann
authors.forename: Achim
authors.initials: A
authors.lastname: Heinecke
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003728:Dental Calculus / Q000209:etiology; D003742:Dental Devices, Home Care; D003773:Dental Plaque / Q000209:etiology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005884:Gingival Hemorrhage / Q000209:etiology*; D005889:Gingival Recession / Q000209:etiology; D005891:Gingivitis / Q000209:etiology*; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D017622:Periodontal Attachment Loss / Q000209:etiology; D010514:Periodontal Pocket / Q000209:etiology; D015203:Reproducibility of Results; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects*; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D014099:Toothbrushing