What happens when fluoridation is stopped?

Tooth fluoride protection icon isolated

When fluoride becomes incorporated in teeth, it makes the enamel more resistant to demineralization, preventing the decay process. Illustration: TuftsNow.

Anti-fluoride propagandists continually assert that fluoride is not effective in reducing tooth decay. One piece of “evidence” they rely on for this is a claim that when fluoridation is stopped dental health does not decline, But is this claim true? Does the scientific literature really show tooth decay doesn’t rise when fluoridation is stopped?

Connett misrepresents the science again

Well, here is what Paul Connett – the self-described world expert on fluoridation – claimed in our exchange (see Fluoride debate: Response to Paul’s 6th article. December 9, 2013):

“modern studies have not found tooth decay when fluoridation has been stopped in various communities.”

In chapter 5 of his book The Case Against Fluoride he provided more detail:

“there is no evidence that where fluoridation has been started and stopped in Europe there has been a rise in tooth decay. Indeed, two studies published in 2000, from Finland and the former East Germany, show that tooth decay continued to decline after fluoridation was halted.11,12 There have been similar reports from Cuba13 and Canada’s British Columbia.14

Pretty definite claim isn’t it? “No evidence” of the expected increase in tooth decay after fluoridation is stopped. And he cites scientific reports to “prove” his claim. But what do those four scientific reports actually say? Let’s look at each one in order and, unlike Connett, I will quote from the papers.

11. L. Seppä, S. Kärkkäinen, and H. Hausen,Caries Trends 1992–1998 in Two Low-Fluoride Finnish Towns Formerly with and without Fluoridation.” Caries Research 34, no. 6 (2000): 462–68. I can’t find the full text, or even an abstract, for this paper but the authors commented on this research in Seppa et al (2002). They found their “longitudinal approach did not reveal a lower caries occurrence in the fluoridated than in the low-fluoride reference community.” But commented:

“The main reason for the modest effect of water fluoridation in Finnish circumstances is probably the widespread use of other measures for caries prevention. The children have been exposed to such intense efforts to increase tooth resistance that the effect of water fluoridation does not show up any more. The results must not be extrapolated to countries with less intensive preventive dental care.”

12. W. Künzel, T. Fischer, R. Lorenz, and S. Brühmann,Decline of caries prevalence after the cessation of water fluoridation in the former East Germany Community Dentistry and Oral Epidemiology 28, no. 5 (2000): 382–89. These authors found no increase of caries in two German cities after fluoridation of water was stopped. But again the authors suggest why:

“The causes for the changed caries trend were seen on the one hand in improvements in attitudes towards oral health behaviour and, on the other hand, to the broader availability and application of preventive measures (F-salt, F-toothpastes, fissure sealants etc.).”

13. W. Künzel and T. Fischer,Caries Prevalence after Cessation of Water Fluoridation in La Salud, Cuba.  Caries Research 34, no. 1 (2000): 20–25. Again this study found no increase in caries after stopping fluoridation but the authors suggested why:

“A possible explanation for this unexpected finding and for the good oral health status of the children in La Salud is the effect of the school mouthrinsing programme, which has involved fortnightly mouthrinses with 0.2% NaF solutions (i.e. 15 times/year) since 1990.”

14. G. Maupomé, D. C. Clark, S. M. Levy, and J. Berkowitz,Patterns of dental caries following the cessation of water fluoridation.” Community Dentistry and Oral Epidemiology 29, no. 1 (2001): 37–47. The authors reported “Caries incidence . . .  was not different between the still-fluoridating and fluoridation-ended communities.” However, they considered other factors and limitations in their own study and concluded this issue was complex:

“Our results suggest a complicated pattern of disease following cessation of fluoridation. Multiple sources of fluoride besides water fluoridation have made it more difficult to detect changes in the epidemiological profile of a population with generally low caries experience, and living in an affluent setting with widely accessible dental services. There are, however, subtle differences in caries and caries treatment experience between children living in fluoridated and fluoridation-ended areas.”

So when we actually read these cherry-picked reports we find that, while no increases in tooth decay were found after fluoridation stopped, in all 4 cases this was attributed to the existence of other sources of fluoride and fluoride dental treatments. This is a similar situation to that I reported about one of Colquhoun’s papers in my recent article Fluoridation: what about reports it is ineffective? In that case all children from non-fluoridated areas had been given six-monthly dental fluoride treatments whereas most children from fluoridated areas had not. So the lack of an effect due to fluoridation is hardly surprising.

Read scientific literature critically and intelligently

This underlines the need to always read the scientific literature critically and intelligently, doing our best to avoid confirmation bias and cherry-picking. Perhaps that was Connett’s mistake – he was just selecting reports supporting his bias without being aware of these details. However, in his book he says:

“The ADA claims that in cases where fluoridation has been halted and no increase in tooth decay observed, other steps have been taken to fight tooth decay.”

So these details had been brought to his attention. But it did not stop him misrepresenting the scientific reports he cited. Nor has it stopped him continuing this misrepresentation, even today. All he has done is to attempt a diversion when these details arise:

“Whether or not that is the explanation, European countries have clearly demonstrated that there are other ways of reducing tooth decay without forcing everyone to take a medicine in their drinking water.”

He had the same response in our exchange when I pointed to the role of other fluoride treatments in these studies. Connett attempts to avoid the issue of his misrepresentation of the published science to support his claim that fluoride does not help prevent tooth decay – by acknowledging fluoride can be beneficial but pretending the argument was about the mode of delivery when it wasn’t!

Connett’s reference to ADA is actually to their booklet Fluoridation Facts. It appears the he has read page 15 – What happens if water fluoridation is discontinued. He has taken the 4 citations he uses from that page. But tellingly he ignores completely another 5 citations reporting deterioration of oral health when fluoridation was stopped. He cannot have missed those citations – in this case his cherry-picking amounts to dishonesty.

Studies do show increase in tooth decay when fluoridation stopped

The ADA booklet referred to above answers its question about the consequences of discontinuing fluoridation this way:

“Over time, dental decay can be expected to increase if water fluoridation in a community is discontinued, even if topical products such as fluoride toothpaste and fluoride rinses are widely used.”

In Fluoride debate: Ken Perrott’s closing response to Paul Connett? I discussed one of the ADA cited papers which did show an increase in tooth decay –  Attwood and Blinkhorn (1991),“Dental health in schoolchildren 5 years after water fluoridation ceased in South-west Scotland.”  They measured dmft and DMFT – decayed, missing and filled teeth in primary and permanent teeth respectively.

The figures below illustrate the data from this paper which compared changes in oral health of two Scottish towns  in both 1980 and 1988. One town, Annan, had never had fluoridated water while the other, Stranraer, had it until 1983. This enabled the effects of both cessation of fluoridation and the generally observed improvement in oral health due to other factors to be compared and considered. The graphics show the results for 5 year old and 10 year old children.

Decayed missing and filled deciduous teeth for 5 year olds. Stranraer fluoridated until 1983. Annan not fluoridated.

Decayed missing and filled teeth for 10 year olds. Stranraer fluoridated until 1983. Annan not fluoridated.

The plots indicate aspects of the complexity of these sort of studies. Because 2 different towns were compared it was possible to measure the decline in oral health after discontinuation of fluoridation against a background of the general improvement in oral health, even in a non-fluoridated situation.

The moral here is don’t accept at face value the claims made by anti-fluoridation propagandists – even if they, or their supporters, insist the propagandist is “the world expert on fluoridation.”

Similar articles

18 responses to “What happens when fluoridation is stopped?

  1. Ken

    Thanks for another very useful piece. I’ve been trying to retrieve/find the Danish advise to not extrapolate for a couple of years – you found it for me.

    At the last US National Oral Health Conference Dr. Jay Kumar presented a computer model which simulated the economic impacts of fluoridation discontinuance. The simulation model was first used on Colorado data and published by the CDC comparing the return on investment for 18 separate interventions for early childhood caries.

    Prev Chronic Dis. 2012 Mar;9:E66. A simulation model for designing effective interventions in early childhood caries. Hirsch GB, Edelstein BL, Frosh M, Anselmo T.

    Kumar’s paper validates the model and predicts the increased costs associated with discontinuance. The model can accommodate added interventions to ameliorate the loss of fluoridated water and will show added costs even if decay measurements don’t fall because of the new public health programs.

    I am hopeful that this computer model will become generally available for use by City Councils and Water Bureaus wishing to predict the outcome of a discontinuance decisions.

    Many of us are also working to use US Medicaid billing data to study the harm from discontinuance. That fluoridation prevents about 2/3rds of the operations and avoids up to 50% of the dental bills for poor preschool children has been confirmed in Louisiana, Australia, England, New York, Texas and Oregon. We have no equivalently compelling discontinuance data and a change should be evident within only 3-4 years. The study requires only evaluation of billing data so is very inexpensive.

    We know from the Brunelle and Carlos data that fluoridation’s effect on school children’s adult teeth is unimpressive prior to the teen years.

    See Howard Pollick’s graph of that at: http://tinyurl.com/lxza37n

    We need to be very careful not to undertake discontinuance studies using an insensitive measure of fluoridation’s benefits. Complicated studies which require a decade or more to complete may be interesting scientifically but are useless for practical fluoridation politics. Done over an inadequate time frame will give Connett and his minions another citation.


  2. Pingback: Ken’s Support for Fundamental Anti-Fluoridation Arguments | Research Blog

  3. It appears from afamildura’s response in the pingback above that he has come on board. Fluoride is safe and effective – his only problem is the mode of delivery. He objects to fluoridation of drinking water but is happy to accept fluoridation of salt and milk and fluoride dental treatments!

    Then why go to so much trouble to attempt to discredit fluoride in general? Why not just stick to the problem he has with supplementing F in drinking water. Then we could have a rational discussion instead of having to continually debunk his claims about toxicity and ineffectiveness.

    No – as with Connett this is only a tactical withdrawal on his part. And it is surrounded by anti-fluoride propaganda in general in Connett’s book and alamildura’s blog. They have no other answer when this is debunked.


  4. We dealing with morons.


  5. @Ken – Just saw your comment. Okay, will reply in a new post on our blog soon.


  6. Pingback: Ken: “Fluoride is safe and effective, says AFAM” – AFAM’s response | Research Blog

  7. I see alamildura has corrected the impression he left with a previous criticism of this article that his only objection to CWF was the method of delivery. He created that impression by attempting to divert attention away from the point in my article that Connett, and other anti-fluoridation propagandists, have distorted and misrepresented their citation of the scientific literature to create the impression that fluoride is actually ineffective in combating tooth decay.

    Good,he has backed away from that diversion – so perhaps he can now comment on the content of my article. That anti-fluoridation propagandists are in the habit of misrepresenting and distorting the science they cite.

    What about it? No more diversions? Honesty is an extremely important question in such discussions.


  8. Dr. Thiessen is certainly entitled to her opinion. It is in direct contradiction to the consensus opinion of the worldwide body of respected science and healthcare, but that is her prerogative. Let me share with you the opinion of Dr. John Doull, highly respected toxicologist and Chair of the 2006 NRC Committee of which, as you stated, Dr. Thiessen was a member:

    “I do not believe there is any valid, scientific reason for fearing adverse health conditions from the consumption of water fluoridated at the optimal level”

    —John Doull, MD, PhD, Chair of the National Academy of Sciences, National Research Council 2006 Committee Report on Fluoride in Drinking Water

    This 2006 Committee deemed fluoride at 2.0 ppm to be adequately protective of the health of the public. Water is fluoridated at 0.7 ppm, one third the level deemed safe by the Committee on which Dr. Thiessen sat.

    Additionally, let me point out a petition filed with the EPA by Dr. William Hirzy, long time antifluoridationist, former EPA Scientist, and current paid lobbyist for the antifluoridationist group, FAN. Hirzy sought for the EPA to recommend cessation of hyfrofluorosilic acid as a fluoridation substance. He based this petition on a study he and fellow antifluoridationist Robert Carton had done supposedly demonstrating costly expenses due to cancer caused by HFA. The EPA recently rejected Hirzy’s petition. The reason? Because he had made an elementary math error which overestimated his figures by 70-fold. When the EPA reviewers corrected for this error they found that Hirzy’s figures actually demonstrated just the opposite of what he had claimed. When Hitzy was notified of this, he stated that he was “embarrassed”

    Ok, so, what does this have to do with Thiessen? Well, Thiessen was asked to comment on Hirzy’s study before he presented his petition. Here is the quote of her assessment:

    “I think this is a reasonable study, and that they haven’t inflated anything,” said Kathleen Thiessen, a senior scientist at SENES Oak Ridge Inc., a health and environmental risk assessment company.”


    Either Thiessen is as incompetent as Hirzy, or she didn’t bother to read the study she so readily endorsed. Either way, she has no credibility.


  9. What MAY happen IF “F” ends and I have hope I’m still alive to see this end.

    1. There MAY be LESS joint damage, hence less replacements going on. I ended up with a hip replacement a year after our city dumped this “stuff” in our pretty clean waters that I lived wtih for 48 yrs… This replacement outcome has been hellish…..going into my 4th year post op. Too many negative side effects from this replacement mess.

    2. There MAY be less thyroid dsyfunction going on and inceased health due to a more healthy thyroid. Hopefully less anti depressant drugs being pushed on folks due to depression and other health issues due to a “sick” thyroid.

    3. There MAY be an increase in toothpaste with “F” sales, our joints and organs don’t need this “F” build up in our bodies….you want to use “F”, brush it on your teeth and SPIT IT OUT.

    4. The polluters will have to find other avenues to get rid of their Hazard Waste Materials. And their 2000% profits will drop off. And plenty of the pushers will lose the profitable jobs.

    There is ABSOLUTELY no ABSOLUTES to this 70 yr fraud, I just know my own experiences of living in this Stuff and what I’ve gone thru in my soon 76 yrs…and what I’ve learned about all this and what I believe and I know I’m not alone in this FRAUD.



  10. we look at your post and you had hip problems 12 months after fluoride started, well that is rubbish to try and blame that on fluoride, it is more likely you had a calcium deficiency.
    And all the ‘may be’,s if you have no peer reviewed evidence, dont say anything


  11. bdcguard-19

    Once you remove the chemicals and processing from your food there is no need for fluoride to protect your teeth. This is the truth, it can’t be argued unless you’ve done it, and if you do it, you can’t argue it because it is your reality. FIN


  12. Once you remove the chemicals and processing from your food there is no need for fluoride to protect your teeth.

    You don’t even know what the word chemical means, yet you write this drivel.



  13. bdcguard-19

    boy you really got me there… sorry inorganic chemicals you tool (man it’s so easy to stoop to your level)


  14. when you look at the fluoride issue from another way Firstly It is not in Connetts interest to stop fluoride. There are too many of his family and friends on the gravy train. It is not hard to find balance sheets and income information on the net for FANN.
    Then you look at it another way,The natural health industry stand to cash in big time with fluoride suppiments. So really the fluoride issue is not about health ,its all about who is going to make the most money



    Connett will be a very old man IF they accomplish STOPPING this horrific poison in our waters.. He is not a rich man, but believes in what he does. Get off your crap you F pushers.

    Talking to 2 people in the water area of my market today, and discussing the great alkaline water we buy, “F” water is major ACID…..

    The one woman said, make sure one does not fill their fish tanks with tap water….nor feed their pets “F” water…..

    Nothing but a FRAUD, if “they/you” want children to get “F” buy them toothpaste with F…..but make sure they SPIT it out….

    Gravy train Connett, no way….the gravy has been the polluters for TOO LONG.


  16. boy you really got me there… sorry inorganic chemicals you tool

    The moron doesn’t know what inorganic chemicals are either.


  17. http://www.uncommonwisdomdaily.com/‎CachedSimilar
    Is the Government Poisoning You? by Brad Hoppmann | Friday, August 15, 2014
    at 8:30am. Throughout our lives, we’ve all been cheated, taken advantage of …



Leave a Reply: please be polite to other commenters & no ad hominems.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s