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Systematic review of water fluoridation

BMJ 2000; 321 doi: (Published 07 October 2000) Cite this as: BMJ 2000;321:855
  1. Marian S McDonagh (msm7{at}, research fellowa,
  2. Penny F Whiting, research fellowa,
  3. Paul M Wilson, research fellowa,
  4. Alex J Sutton, lecturer in medical statisticsc,
  5. Ivor Chestnutt, senior lecturerb,
  6. Jan Cooper, research fellowb,
  7. Kate Misso, information officera,
  8. Matthew Bradley, research fellowa,
  9. Elizabeth Treasure, professorb,
  10. Jos Kleijnen, professora
  1. a NHS Centre for Reviews and Dissemination, University of York, York YO10 5DD
  2. b Dental Public Health Unit, Dental School, University of Wales College of Medicine, Cardiff CF14 4XY,
  3. c Department of Epidemiology and Public Health, University of Leicester, Leicester LE1 6TP
  1. Correspondence to: M McDonagh
  • Accepted 12 September 2000


Objective: To review the safety and efficacy of fluoridation of drinking water.

Design: Search of 25 electronic databases and world wide web. Relevant journals hand searched; further information requested from authors. Inclusion criteria were a predefined hierarchy of evidence and objectives. Study validity was assessed with checklists. Two reviewers independently screened sources, extracted data, and assessed validity.

Main outcome measures: Decayed, missing, and filled primary/permanent teeth. Proportion of children without caries. Measure of effect was the difference in change in prevalence of caries from baseline to final examination in fluoridated compared with control areas. For potential adverse effects, all outcomes reported were used.

Results: 214 studies were included. The quality of studies was low to moderate. Water fluoridation was associated with an increased proportion of children without caries and a reduction in the number of teeth affected by caries. The range (median) of mean differences in the proportion of children without caries was −5.0% to 64% (14.6%). The range (median) of mean change in decayed, missing, and filled primary/permanent teeth was 0.5 to 4.4 (2.25) teeth. A dose-dependent increase in dental fluorosis was found. At a fluoride level of 1 ppm an estimated 12.5% (95% confidence interval 7.0% to 21.5%) of exposed people would have fluorosis that they would find aesthetically concerning.

Conclusions: The evidence of a beneficial reduction in caries should be considered together with the increased prevalence of dental fluorosis. There was no clear evidence of other potential adverse effects.


  • Funding This review was commissioned and funded by the Department of Health. The views expressed in this review are those of the authors and not necessarily those of the Department of Health.

  • Competing interests None declared.

  • Embedded Image Additional material comprising criteria for inclusion, members of the advisory panel, references (w1 etc) for included studies, and meta-regression table can be found on the BMJ's website

  • Accepted 12 September 2000
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