title: Oxygen sufficiency in the gingiva of smokers and non-smokers with periodontal disease.
abstract: BACKGROUND
  Epidemiological studies have demonstrated deteriorating effects of smoking on periodontal tissue. The aims of this study were to compare oxygen saturation of hemoglobin in the gingiva (GSo2) of smokers and non-smokers and to evaluate the chronic effect of smoking on gingival oxygen sufficiency.
  
  
  METHODS
  GSo2 was determined using tissue reflectance spectrophotometry in 110 papillary gingival sites of 62 smokers and 100 sites of 60 non-smokers.
  
  
  RESULTS
  No significant difference was found in GSo2 between smokers and non-smokers. In the model of ANOVA with covariates, age (P= 0.0048) and probing depth (P= 0.0012) had significant effects on GSo2. No significant effect was found in either smoking status (P= 0.3557) or the modified gingival index (MGI) (P= 0.3824). The interaction effect between smoking status and the MGI was highly significant (P = 0.0003) indicating that the effect of smoking status on the GSo2 should be compared at each level of the MGI score. GSo2 in healthy gingiva was significantly lower in smokers than non-smokers (P = 0.0014), while smokers showed higher GSo2 than non-smokers in moderately inflamed gingiva (P = 0.0356). The GSo2 in inflamed gingiva was significantly decreased compared with healthy gingiva in non-smokers (P = 0.0044), while smokers showed no significant difference between healthy and inflamed gingiva (P= 0.2772 to 0.8665). GSo2 in smokers was consistently and significantly lower than that of healthy gingiva of non-smokers (P = 0.0391 to 0.0004).
  
  
  CONCLUSIONS
  Smokers exhibit possibly lower function of oxygen sufficiency in healthy gingiva and reduced ability to adapt the function in inflamed gingiva than non-smokers. This suggests that smokers have functional impairments in the gingival microcirculation.
authors.affiliation: Department of Preventive Dentistry, Osaka University Faculty of Dentistry, Suita, Japan. haniokat@dent.osaka-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Hanioka
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Ojima
authors.forename: K
authors.initials: K
authors.lastname: Takaya
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumori
authors.forename: S
authors.initials: S
authors.lastname: Shizukuishi
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D002908:Chronic Disease; D003774:Dental Plaque Index; D005881:Gingiva / Q000098:blood supply*; D005888:Gingival Pocket / Q000097:blood; D005891:Gingivitis / Q000097:blood; D006454:Hemoglobins / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D010108:Oxyhemoglobins / Q000032:analysis; D010313:Partial Pressure; D010510:Periodontal Diseases / Q000097:blood*; D010512:Periodontal Index; D012907:Smoking / Q000097:blood*; D013053:Spectrophotometry; D018709:Statistics, Nonparametric
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen