Fluoridation – does it workPresentation Transcript
Fluoridation – does it work? RCPSG Triennial Conference 6th November 2008 I.G. Chestnutt Professor and Hon Consultant in Dental Public Health Cardiff University School of Dentistry
Fluoridation - does it work?
Fluoridation – the addition/adjustment of fluoride to/in the public water supply with the intention of preventing dental caries
Does it work?
As a caries preventive agent
As a public health policy
Is it safe?
Current fluoridation status in the U.K.
About 6 million people in the U.K currently drink fluoridated water
3.5M in the West Midlands
1.7M in the North East
No artificial fluoridation schemes in Scotland, Wales or N Ireland
Fluoridation – the early years
Distinct geographic distribution
Linked to water supply
Fluoride was the causative agent
Affected individuals no more likely to have caries
Dose response – fluoride and caries
1ppm optimal dose
Grand Rapids / Muskegon / Aurora study 50% reduction in Grand Rapids vs Muskegon after 6.5yrs
“ Water fluoridation significantly improves health and reduces inequalities” “ The present legislation on fluoridation is not working” “ We have commissioned an expert scientific review of fluoride and health” Fluoridation - the recent years Saving lives – our healthier nation
The York Report
What are the effects of fluoridation of drinking water supplies on the incidence of dental caries?
If water fluoridation is shown to have beneficial effects, what is the effect over and above that offered by the use of alternative interventions and strategies?
Does water fluoridation result in a reduction of caries across social groups and between geographical locations bringing equity?
Does water fluoridation have negative effects?
Are there differences in the effects of natural and artificial water fluoridation?
The increase in proportion of caries free children in fluoridated compared with non-fluoridated communities
Does fluoridation prevent dental cares?
The best available evidence suggests that the difference in the change in caries prevalence from baseline to final examination in fluoridated compared to non-fluoridated areas was 14.6% caries free or 2.25 DMFT
This probably equates to a preventive fraction of about 40% (Worthington and Clarkson 2003)
The limitations of the evidence
The studies (of caries preventive effects of fluoridation) were of moderate quality and of limited quantity
Many excluded because there were cross-sectional in design
Only 26 studies included – mainly before- after studies, 2 prospective cohorts, 1 retrospective cohort
Frequently lack of appropriate analysis to control for potentially confounding factors
Adverse effects of fluoridation – Bone fracture incidence
Is fluoridation safe?
No association could be found between fluoridation and
Overall studies examining other possible negative effects provide insufficient evidence on any particular outcome to permit confident conclusions
Fluoridation and Fluorosis
Most widely studied side effect of fluoridation
At 1ppm it was estimated that the prevalence of fluorosis of “aesthetic concern” would be 12.5%
Although 88 studies were included, they were of low quality
Fluoride Level % population with fluorosis of aesthetic concern 0.1 6.3 0.2 6.9 0.4 8.2 0.7 10.0 1 12.5 1.2 14.5 2 24.7 4 63.4
How York has been interpreted - by the pros
“ many studies have confirmed that water fluoridation reduces tooth decay, and has no serious side effects”
The main discussion on the York review describes its conclusions without sufficiently drawing out of the degree of cautioness that was central to the reports findings.
(Working Party, Nuffield Council on Bioethics, 2007)
How York has been interpreted - by the antis
“ The York Review Fiasco”
“ Sham review that deliberately excluded studies that would show fluoridation in a bad light”
Fluoride causes brain damage and lowered IQ in children
Fluoridation causes unsightly discolouration of teeth
The York Review noted in relation to adverse events …there was not enough good quality evidence to reach conclusions.
Cheng, Chalmers & Sheldon, BMJ, Oct 2007 Lennon, Beal & Rugg-Gunn, CDH, March 2008 … . Those opposing fluoridation often claim that it does not reduce caries and they also overstate the evidence on harm. On the other hand, the Department of Health’s objectivity is questionable – it funded the British Fluoridation Society, and along with many other supporters of fluoridation it used the York review’s findings selectively to give an overoptimistic assessment of the evidence in favour of fluoridation. ….
Does it work as a caries preventive agent?
So, it works but the evidence isn’t up to modern standards
It is safe, but there are issues around the quality of the evidence
There are questions about increased fluorosis
Does it work as a public health policy?
The law and fluoridation
The 1985 Water (Fluoridation) Act
“ When requested by a health authority, the water supplier may , while the application remains in force, increase the fluoride content of the water supplied by them within that area ”
Water Companies privatised
Not in commercial interest
Water Act 2003 Section 58 (Fluoridation of Water supplies)
Clarified indemnity issues
Removed Water Companies veto
Strategic Health Authorities are required to consult with the local population
Involving the public
How do we convey scientific information to the public?
The public perception of risk
Public acceptance of scientific information
… GM food / crops
Who needs to be convinced?
… “ middle class ‘I’m alright Jackers’ and the feckless parents”
John and Cordelia Gummer – beef is safe
Communicating the case
“ water fluoridation is still regularly interrupted by a relatively small group of individuals who use misinformation and rhetoric to induce doubts in the minds of the public and government officials”
The role of the media
Propagation of the idea of an ongoing scientific debate
Selective use of evidence
Bamboozling with science
The internet, the media and fluoridation
In an analysis of 240 recent print, radio and television articles over a one year period in Ireland, 52% were negative and only 14% positive
(Adapted from Armfield 2007) “ water fluoridation” “ water fluoridation dangers” Search Engine For Against For Against Google 7 9 0 20 Yahoo 5 11 0 19 MSN 8 10 1 18 AOL 6 9 0 20 Ask 3 16 0 20
The ethics of fluoridation
Reducing risk of ill health
Protecting the vulnerable
Not coercing people to lead healthy lives
Respecting important personal values
The requirement of consent
We suggest the adoption of local decision making procedures that take into account the context in each area … … ongoing monitoring and further research to strengthen the evidence base.. … policy makers and the public need to have access to clear and accurate information (Nuffield Council on Bioethics, 2007)
Fluoridated water – food or medicinal product?
Not regarded as a medicinal product by the MHRA
Water is not a food until it emerges from the tap
(EU directive on addition of vitamins and minerals)
Drinking water quality regulated by UK drinking water regulators
Fluoride policy decided by Department of Health (Eng), Scottish Executive, Wales Assembly Government, Northern Ireland Health and Social Services Board
Devolution and fluoridation Scottish Dental Action Plan Inter sectorial / multi agency approach Emphasis on diet School toothbrushing as method of fluoride delivery
Devolution and fluoridation “ Designed to smile” – £1.44M programme Based around school toothbrushing April 2008 “ Given that it may take some time to introduce a water fluoridation scheme in Northern Ireland, an alternative, evidence based, regional prevention programme for caries in children should be developed and implemented as soon as possible” Oral Health Strategy for Northern Ireland June 2007
Devolution and fluoridation
“… I have seen the benefits for myself. One reason for us putting extra money from the health budget into fluoridation is to encourage it to happen around the country … £14M of extra money is being put in to help with this.
It is a good thing for the teeth of the people of this country.” Rt Hon Gordon Brown PM PMQs 26th March 2008 (Hansard, 2008)
Current public consultation Southampton PCT
Does fluoridation prevent dental caries?
Is it coincidence that in the most recent BASCD survey, six of the ten the PCTs with lowest levels of tooth decay in the U.K. are fluoridated?
Does it work as a public health policy?
The outcome of current consultations are awaited with interest