title: Use of water 'softening and conditioning systems' significantly increases the risk of periodontitis: smoking considerations.
abstract: BACKGROUND
  The role of water in the etiology of periodontal disease is poorly understood.
  
  
  OBJECTIVE
  The objective of this study was to examine the association amongst water softness, risk for periodontitis, and smoking status.
  
  
  METHODS
  We examined the association between use of water 'softening and conditioning systems' and the risk for periodontal disease in smokers and non-smokers, using adult participants (18+ years), from the third National Health and Nutrition Examination Survey (NHANES III) data. Zero to 33 per cent (0-33%) of sites with periodontal attachment loss > or = 3 mm was considered a healthy periodontium, and > 33% of sites with periodontal attachment loss > or = 3 mm was defined as periodontitis. Soft water users were divided into 'yes' or 'no' using the question, 'Does your home have a "softening or conditioning system?".' Smoking subjects were divided into groups as follows: current smokers (had smoked > or = 100 cigarettes in their lifetime and currently smoked), former smokers (had smoked > or = 100 cigarettes in their lifetime, not currently smoking), or never smokers (had not smoked > or = 100 cigarettes in their lifetime). Data was analyzed by univariate analyses using SPSS. The 5% level of statistical significance was adopted throughout.
  
  
  RESULTS
  Subjects that answered the question 'yes' to soft water use had a significantly higher risk of periodontitis (p < 0.05), adjusting for confounders. When mineral intake from foods was added to the model, the significance of periodontitis risk remained the same for the non-smoking, soft water-using subjects, whereas for the smoking, soft water-using subjects the risk for periodontitis increased significantly (p < 0.05) in most cases.
  
  
  CONCLUSIONS
  Thus, use of water 'softening and conditioning systems' significantly increased the risk for periodontitis, and smoking increased this risk.
authors.affiliation: Department of Periodontics and Preventive Sciences, University of Mississippi School of Dentistry, Jackson, Mississippi 39216-4505, USA. nwood@sod.umsmed.edu
authors.forename: Nelson
authors.initials: N
authors.lastname: Wood
authors.forename: Roger B
authors.initials: RB
authors.lastname: Johnson
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000209:etiology*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014481:United States; D014880:Water Softening / Q000009:adverse effects*