Response to misleading opinion article in the Calgary Herald

Response To Dickson/Limeback January 26, 2019 Op-Ed in Calgary Herald

Steven D. Slott, DDS
Communications Officer
American Fluoridation Society
January 27, 2019

First, to be clear…..Dr. Limeback is a long-time fluoridation opponent who frequently collaborates with members of the New York antifluoridationist faction, “FAN”. Bob Dickson is a local resident whose false claims and misinformation on fluoridation are well documented.

In response to their claims:

1. Smoking, asbestos, mercury, etc, are of no relevance to the public health initiative of water fluoridation. Raising those issues is nothing but a groundless, dishonest attempt to associate fluoridation with negatives.

2. There is nothing “failed” about fluoridation. Countless peer-reviewed studies have clearly demonstrated its effectiveness in preventing significant amounts of very dangerous dental infection in entire populations. A number of the most recent such studies may be viewed: https://americanfluoridationsociety.org/category/research/effectiveness/

3. There is no credible organization in the world which opposes water fluoridation. The attempt to trivialize the widespread support for fluoridation within respected science and healthcare is simply a desperate attempt to negate the unresolvable problem opponents have with zero opposition to, versus overwhelming support for, fluoridation within respected science and healthcare.

In actuality, those who publicly recognize the public health benefits of water fluoridation include those such as the past 6 US Surgeons General, the Deans of the Harvard Schools of Medicine, Dentistry and Public Health, Health Canada, the Canadian Dental Association, the US CDC, the US National Academy of Medicine, the American Dental Association, the World Health Organization, the American Academy of Pediatrics, and over 100 more of the most highly respected healthcare and healthcare-related organizations in the world.

4. “Weak or non-existent evidence”? Given the volumes of peer-reviewed scientific evidence fully supporting fluoridation, this claim is truly laughable. See my item #2 above.

5. In regard to the unsubstantiated claim of some “deleterious effects of fluoride”, the reality is that in the 74 year history of fluoridation, there have been no proven adverse effects. Zero.

There is no valid, peer-reviewed scientific evidence of any “deleterious effects” of fluoride at the optimal level at which water is fluoridated…..on anyone, of any age, socio-economic status, or on whatever such “people of colour” to which is referred.

6. The 2016 study by McLaren, et al. has not been credibly debunked by anyone. An erroneous, misleading opinion piece by antifluoridationists does not constitute debunking of anything. While McLaren has been blatantly libeled by antifluoridationists, her study stands as clear evidence of the adverse effect on dental decay incidence from cessation of fluoridation.

The naive assessment that “caries also increased in fluoridated Edmonton”, the control city of the study, overlooks the point of the study that after cessation, the rate of increase in Calgary rose to nearly the same rate of increase as in Edmonton, which had previously been significantly higher than Calgary.

7. Peer-reviewed science has demonstrated a cost savings to communities through fluoridation. A recently updated (April 2018) Community Guide systematic review found that: “Recent evidence continues to indicate that the economic benefit of community water fluoridation exceeds the intervention cost. Further, the benefit–cost ratio increases with the community population size.”

Savings amongst the studies were found to be anywhere between 1.12:1 to 135:1 depending on population size of the communities. This took into account start-up and annual maintenance, supplies, staffing, and other costs.

Economic Evaluation of Community Water Fluoridation. A Community Guide Systematic Review Tao Ran, PhD, et al. (Am J Prev Med 2016;50(6):790–796)

What Slade, et al. actually found was a reduction of 1.3 decayed primary teeth surfaces and a 0.3 surface reduction in permanent teeth. In reality, this is a 2.0 and 1.0 reduction, respectively.

When even one surface of a tooth is decayed, assuming it is treated, this can, and often does, result in not only an initial filling but, as well, periodic replacement with larger fillings, root canals, crowns, or implants, over a lifetime. Given this, far from a lifetime cost per filling of $5,000 being a “huge exaggeration”, this figure is obviously an underestimation of the potential costs.

If the decay goes untreated, costs can, and do, rise astronomically due not only to dental expenses but to costly medical/hospital expenses incurred in the treatment of resultant serious medical conditions directly caused by this untreated bacterial infection.

8. The claim that the 2006 NRC Committee recommended “to markedly lower the 4.0 ppm limit due to all the adverse health effects” is patently false. This committee simply recommended lowering the 4.0 ppm level, without specifying any particular level, “markedly” or otherwise.

Additionally, the only reasons for this recommendation, as cited by unanimous agreement of the committee, were risk of severe dental fluorosis, bone fracture, and skeletal fluorosis.

Nothing else.

A. As this same 2006 committee noted in its report, severe dental fluorosis does not occur in communities with a water fluoride content below 2.0 ppm. Water is fluoridated at one third this level.

B. The risk of increased bone fracture is a “U” shaped curve with risk occurring at too little, or too much fluoride intake. The area of least risk, the bottom of the “U” is right in the range of the optimal 0.7 ppm at which water is fluoridated.

C. Skeletal fluorosis is so rare in the 74.4% fluoridated US as to be nearly non-existent.

If anything, the final recommendations of the 2006 NRC committee support the safety of optimally fluoridated water, not the other way around.

9. There are no valid, peer-reviewed studies which show that optimally fluoridated water produces any “objectionable” fluorosis, or that it, in any manner, “damages teeth”.

A “prediction” by the New York antifluoridationist faction, FAN, based on its interpretation of raw US CDC dental fluorosis data, is of no relevance.

10. Dr. Limeback’s inexplicable obsession with “randomized double-blinded clinical trial” for water fluoridation, is well-known. It is also without merit.

As noted by the 2015 Cochrane Review, randomized controlled trials are not feasible for large population-based public health initiatives, and such data will never be available. Additionally, peer-reviewed science has demonstrated that RCTs do not provide results superior to quality observational studies.

And….in the hierarchy of reliability of scientific studies, at the top, above RCTs and all others, are systematic reviews of the literature. Numerous such reviews through the decades, right up to the present, have clearly documented the effectiveness and safety of water fluoridation.

“The results of well-designed observational studies (with either a cohort or a case– control design) do not systematically overestimate the magnitude of the effects of treatment as compared with those in randomized, controlled trials on the same topic. (N Engl J Med 2000;342:1887-92.)”

Published in final edited form as:
N Engl J Med. 2000 June 22; 342(25): 1887–1892.
Randomized, Controlled Trials, Observational Studies, and the Hierarchy of Research Designs

11. There is no “toxic waste” involved in water fluoridation. The substance most widely utilized to release additional fluoride ions into water during fluoridation is a co-product of the process used to produce phosphoric acid, a substance incorporated into soft drinks and many foods that we all consume. The fluoride ions released into water are identical to those which already exist in that water, with the amount of any detectable contaminants being far below US EPA mandated maximum allowable levels under Standard 60 of NSF International.

A detailed list of the contents of fluoridated water at the tap, including precise amounts of any detected contaminants and the US EPA maximum allowable level for each, may be found in the “Fact Sheet on Fluoridation Substances” on the website of NSF International.

12 The claim about Health Canada and studies constantly parroted by antifluoridationists, and garbled in this article, is that Health Canada has “admitted that it has no studies to prove the fluoridation substance HFA to be safe to use”, not that it has no studies on the safety of fluoride. As HFA does not exist in fluoridated water at the tap, there is no requirement, or need, for safety studies of this substance.

Published by

seha727

Seong Eon Ha (하성언) University of Calgary Correspondence to: haseongeon@gmail.com

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