Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2000 Oct 7;321(7265):855-9.
doi: 10.1136/bmj.321.7265.855.

Systematic review of water fluoridation

M S McDonagh  1 , P F Whiting, P M Wilson, A J Sutton, I Chestnutt, J Cooper, K Misso, M Bradley, E Treasure, J Kleijnen
Affiliations

Systematic review of water fluoridation

M S McDonagh et al. BMJ. .

Abstract

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.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Change in proportion (%) of children without caries in fluoridated compared with non-fluoridated areas (mean difference and 95% confidence interval)
Figure 2
Figure 2
Change in decayed, missing, and filled teeth for primary/permanent teeth (mean difference and 95% confidence interval)
Figure 3
Figure 3
Proportion of population with dental fluorosis by water fluoride concentration with 95% confidence interval for proportion. Fluoride concentration is plotted on log scale because of linear association between this and log (odds) of fluorosis. Each circle represents a study area in which the proportion of people with fluorosis is estimated—the larger the circle, the higher the precision of the estimate
Figure 4
Figure 4
Proportion of population with fluorosis of aesthetic concern by water fluoride concentration (plotted on untransformed scale because of linear association between this and log (odds) of “aesthetic fluorosis”). Each circle represents a study area in which the proportion of people with fluorosis is estimated—the larger the circle, the higher the precision of the estimate
Figure 5
Figure 5
Incidence of bone fracture (estimate of effect and 95% confidence interval). See the BMJ 's website for further details
See this image and copyright information in PMC

Comment in

  • Fluoridation, fractures, and teeth.
    Hausen HW. Hausen HW. BMJ. 2000 Oct 7;321(7265):844-5. doi: 10.1136/bmj.321.7265.844. BMJ. 2000. PMID: 11021844 Free PMC article. No abstract available.

References

    1. Secretary of State for Health. Saving lives: our healthier nation. London: Stationery Office; 1999.
    1. NHS CRD. A systematic review of public water fluoridation. York: NHS Centre for Reviews and Dissemination. University of York; 2000. . (Report 18.)
    1. NHS CRD. Undertaking systematic reviews of research on effectiveness. York: NHS Centre for Reviews and Dissemination, University of York; 1996. . (Report 4.)
    1. Thompson SG, Sharp SJ. Explaining heterogeneity in meta-analysis: a comparison of methods. Stat Med. 1999;18:2693–2708. - PubMed
    1. Dersimonian R, Laird N. Meta-analysis in clinical trials. Cont Clin Trials. 1986;7:177–188. - PubMed

Publication types