A webinar hosted by the Health Evidence team, funded by the Canadian Institutes of Health Research (KTB-112487), interpreting the evidence in the topic area of community water fluoridation.

1. This webinar has been made possible with support from the
Canadian Institutes of Health Research
Welcome!
Fluoridation:
What’s the evidence?
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2. What’s the evidence?
 This webinar will focus on a number of sources of
information, including a systematic review featured
on Health Evidence:
 http://www.health-evidence.ca/articles/show/15981

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4. This webinar has been made possible with support from the
Canadian Institutes of Health Research
Welcome!
Fluoridation:
What’s the evidence?

5. The Health Evidence Team
Kara DeCorby Heather Husson Jennifer Yost
Administrative Director Project Manager Guest Presenter
Maureen Dobbins
Scientific Director
Tel: 905 525-9140 ext 22481
E-mail: dobbinsm@mcmaster.ca
Lori Greco Robyn Traynor Lyndsey McRae
Knowledge Broker Research Coordinator Research Assistant

6. What is www.health-evidence.ca?
Evidence
inform
Decision Making

7. Why use www.health-evidence.ca?
1. Saves you time
2. Relevant & current evidence
3. Transparent process
4. Supports for EIDM available
5. Easy to use

8. Knowledge Translation
Supplement Project
CIHR-funded KTB-112487

9. Discussion question:
 What is the evidence on the
effectiveness of water fluoridation
for caries prevention?

10. Questions?

11. Searching for relevant
evidence: The pyramid
 Insert pic of 6S pyramid here
DiCenso, Bayley, & Haynes, 2009

12. What is the “Best
Available” Evidence?

13. Relevance Criteria:
 Addresses impact of water fluoridation in the context
of developed countries
 Produced within the last 15 years
 English-language

14. Search Strategy:
 Searched review-level evidence in public health related
to fluoridation on health-evidence.ca
 Reviewed reference lists of relevant reviews

15. Evidence Reviewed:
 PHAC: Drinking Water Fluoridation in Canada: Review and
Synthesis of Published Literature, 2011
 Quebec PH: Water Fluoridation: An Analysis of the Health
Benefits and Risks, 2007
 Australian Government, NHMRC: A Systematic Review
of the Efficacy and Safety of Fluoridation, 2007
 NHS Centre for Reviews and Dissemination: A
Systematic Review of Water Fluoridation, 2000

16. Is it a Systematic Review?
 Is there a methods section?
 Does the methods section outline a search strategy?
 Are there inclusion criteria given?
 Did the reviewers assess relevance systematically?
 Did the reviewers conduct a quality assessment?

17. Literature Reviews:
 Quebec PH: Water Fluoridation: An Analysis of the Health
Benefits and Risks, 2007
 No methodology reported
 PHAC: Drinking Water Fluoridation in Canada: Review and
Synthesis of Published Literature, 2011
 Report some inclusion/exclusion criteria
 Report some searching methodology
 No quality assessment

18. Systematic Reviews:
 Australian Government, NHMRC: A Systematic Review
of the Efficacy and Safety of Fluoridation, 2007
 Major Strength: Includes systematic reviews and
primary studies
 Major Limitation: Quality assessment (lack of
information about # of reviewers and criteria)
 Minor Limitation: Search strategy (English-only,
limited number of databases)

19. Systematic Reviews:
 NHS Centre for Reviews and Dissemination: A
Systematic Review of Water Fluoridation, 2000
 Health Evidence Quality Rating: 9
 Major Strength: Meta-analyses, when appropriate
 Minor Limitation: Quality assessment (criteria
for case-control studies devised by reviewers)

20. Water Fluoridation is Effective
 Significantly increases the percentage of caries-free
children by 15.4%
 Range from as little of a 10.8% increase to as much
as 20.1% increase [95% Confidence Interval (CI)]
 Six children need to receive fluoridated water for
one additional child to be caries-free
 Range from five children to as many as nine children
[Number Needed To Treat (NNT)]

21. Water Fluoridation is Effective
 Significantly decreases the number of decayed,
missing, filled teeth (dmft/DMFT score) by 2.3
teeth
 Range from a decrease of1.8 teeth to as many as 2.8
teeth [95% Confidence Interval (CI)]
 Based on moderate quality, moderate risk of bias evidence
 Across children of all ages

22. Water Fluoridation is Safe
 Significant increase in the prevalence of fluorosis
 Flouride levels of 1.0ppm and 1.2ppm versus 0.4ppm
 Prevalence of fluorosis causing “aesthetic concern”
 No significant difference between fluoride levels of
0.7ppm, 1.0ppm, and 1.2pmm versus 0.4ppm

23. Water Fluoridation is Safe
 No significant increase in the prevalence of bone
fractures
 Unable to be determined for the prevalence of cancer
(all causes, osteosarcoma, bone, thyroid)
 Based on lowest quality evidence with high risk of bias
 Across children of all ages

24. Overall Considerations
Drinking water fluoridation
Clinically important increase in the prevalence of caries-free
children of all ages
Small number of children need access in order for one child
to be caries-free
No statistically significant increase in fluorosis of aesthetic
concerns with increasing fluoride levels or bone fractures
Evidence suggesting there is a relationship between water
fluoridation and other health outcomes is low quality evidence
Note: Consistent across “Evidence Reviewed”

25. General Implications
Public health should support the fluoridation of
drinking water
Among all children of all ages
At levels that are unlikely to cause to fluorosis and fluorosis
of “aesthetic concern”

26. Practice & Policy Implications
 Support policies for the fluoridation of drinking water
at safe levels of fluoridation
 Be aware of community fluoridation status
 Be aware of the average daily intake of water by the
and the intake of fluoride from other sources
 Communicate evidence on the effectiveness and harms
associated with drinking water fluoridation to
communities considering
 initiating drinking water fluoridation
 continuing drinking water fluoridation

27. Questions?

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