Tag Archives: dental decay

Anti-fluoride “expert” finds the real reason oral health has improved – and it’s not fluoride

Anti-fluoride campaigners always promote people like Geoff Pain as “renowned” or “world experts.” They aren’t. Pain has no credible scientific publications on fluoride.

No, in fact, he claims lead is responsible for tooth decay and the improvement in oral health is a result of removing airborne lead contamination. And the “proof” is even in the title of his report – “Global Decline in Tooth Decay correlates with reduced Airborne Lead (Pb) but water Fluoridation prevents further progress

Mind you, the word “correlate” appears only twice in the document – once in the title and once in the abstract. Nowhere else. Scientists usually restrict the use of words like this to results of proper statistical analyses – but he presents no evidence of a correlation anywhere in the document.

OK, we shouldn’t expect any better. This document is just another one of a series of documents, dressed up as scientific publications, supported by cobbled together citations which are often are irrelevant or don’t support the claims made. Produced by Geoff Pain, well-known Australian anti-fluoride activist, whose concept of scientific publication is to upload his unreviewed documents on to Researchgate. I have written about his citation trawling and false “publication” before in my article  An anti-fluoride trick: Impressing the naive with citations

But, perhaps he is on to something. Irrespective of fluoride (he has a hangup about that element) perhaps lead is somehow implicated in oral health problems. So let’s see what the document actually claims.

It has three aims:

1: Rejection of all evidence of the beneficial effects of fluoridation

He describes the evidence for fluoridation as “false” and “absurd.”

Of course, he doesn’t consider for a minute any of the many studies providing evidence of beneficial effects – he just relies on the naive use of selected World Health Organisation (WHO) data which the Fluoride Action Network is well-known for. I have written about this before (see, for example, Fluoridation: Connett’s naive use of WHO data debunked).

This simply argues that the fact that oral health has improved over time in both fluoridated and unfluoridated countries is “proof” that fluoridation has no effect.

Here is the graph he uses:

This figure is meaningless because of the huge influence of inter-country differences on these data, irrespective of fluoridation. That doesn’t require a scientific training to see. These differences introduce so much noise into the data that no conclusion is possible about the influence of fluoridation. Robyn Whyman pointed this out in his report for the National Fluoridation Information Service – Does delayed tooth eruption negate the effect of water fluoridation?:

“Studies that appropriately compare the effectiveness of water fluoridation do not compare poorly controlled inter-country population samples. They generally compare age, sex, and where possible ethnicity matched groups from similar areas. Inter-country comparisons of health status, including oral health status, are notoriously difficult to interpret for cause and effect, because there are so many environmental, social and contextual differences that need to be considered.”

The figure does not differentiate between fluoridated and unfluoridated areas within countries – a comparison that is more valid. When we look at the same WHO data for fluoridated and unfluoridated areas we can see the beneficial effect. For example, in the data from the Republic of Ireland:

2: Evidence for an effect of lead exposure on oral health

I can accept that – but certainly would not go as far as Pain’s claim that “lead exposure reduction as the major factor in tooth decay decline.” In fact, the articles he cites suggest that the association of  lead exposure with tooth decay is probably weak in most cases.

For example, he cites Gemmel et al., (2002) but ignores what that paper actually says:

“In summary, our findings are consistent with those of several other recent studies (e.g., Campbell et al. 2000; Moss et al. 1999) in suggesting a weak association between children’s lead exposure and caries in primary teeth. The association was region specific, however, suggesting that its magnitude depends on the local distributions of other, more important caries risk factors such as fluoride exposure, diet, and other aspects of environment. The most likely direct role for lead exposure in the development of dental caries, therefore, is as a modifier of host susceptibility. We cannot reject the hypothesis, however, that an elevated lead level is a surrogate or proxy index of some other factor that is itself directly cariogenic.”

Similarly, he cites Martin et al., (2007) but ignores what that paper actually concluded:

“We conclude that this study provides only weak evidence, if any, for an association of low-level lead exposure with dental caries.”

Mind you, he also cites Wiener et al., (2015) who reported:

“This study indicated a strong association of blood lead levels with increasing numbers of carious teeth in children aged 24–72 months.”

But still not evidence that lead is the major factor involved.

Pain ignores suggestions that results may suggest modification of the role of fluoride

I wonder if those who indulge in citation trawling ever actually read the papers they cite. Far from Pain’s citations being evidence of a lack of effect from fluoridation, in almost all cases they suggest the observed effects could be due to modification of the more important effect of fluoride on oral health.

For example, Martin et al., (2007) point out:

” Mechanisms which have been offered to explain the potential association include lead effects on salivary gland development and function (Watson et al., 1997; Bowen, 2001), effects on enamel formation (Lawson et al., 1971; Kato et al., 1977; Appleton, 1991; Watson et al., 1997), and an interference with fluoride uptake in saliva (Gerlach et al., 2002). “

Come on Geoff. Spend some time and actually read the articles you have trawled for your citations.

3: Fluoridation means increase lead concentration in tap water

Having rejected any beneficial role for fluoride and presented lead as the major influence on oral health Pain now puts it all together to “prove” that fluoridation actually enhances tooth decay by increasing dietary lead intake. Why? Because of:

“deliberate addition of Lead as a major contaminant of phosphate fertilizer industrial waste used in Fluoridation plus the exacerbation of Plumbosolvency by Fluoride”

The first point about lead contamination of fluoridating chemicals relies in a naive interpretation of the certificates of analysis required for these chemicals. Just because a very low concentration of lead is recorded in these certificates does not mean this causes an increase in dietary lead intake.

I showed in the article Chemophobic scaremongering: Much ado about absolutely nothing that the fluoridating chemicals contribute less than 0.05% to the lead in tap water – already present from natural sources!

Pain’s reference to “exacerbation of Plumbosolvency” relies on a limited study which reported an association between blood lead levels in children and the treatment of tap water in the US. Of course, the release of lead from pipe fittings can be a problem irrespective of water treatment – which is why authorities recommend one should let the water run for a while first thing in the morning to get rid of such impurities. However, the studies Pain relies on seem to attribute plumbosolvency to specific chlorinating chemicals rather than fluoride.

One can make a simple check, however. In New Zealand authorities regularly make chemical analyses of their tap water available. These do not show increased lead concentrations after fluoridation.


So, again, Geoff Pain has indulged in citation trawling and confirmation bias to produce this report. The citations he uses do not support his claims.

Dietary intake of lead may be one of many factors influencing dental health – but his citations do not in any way support his assertion that it is the “major factor”. Nor do they support his claim that fluoridation does not have a beneficial effect on oral health.

In fact, it is Geoff Pain, not health authorities, who is making the “false” and “absurd” claims.

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A Chinese study the anti-fluoridation crowd won’t be citing


Tooth brushing programme carried out in kindergartens in a Chinese rural area. Image credit: Supervised tooth brushing programme

Anti-fluoridation campaigners love to cite Dr Q. Y. Xiang to “prove” that community water fluoridation (CWF) can lower IQ. Trouble is – Xiang’s research on fluoride and IQ took place in an area of endemic fluorosis in China where drinking water fluoride levels were much higher than those used for CWF. That hasn’t stopped Paul Connett from making mileage out of Xiang’s data – even though the link between IQ and drinking water fluoride shown by Xiang’s data is very tenuous (see Connett fiddles the data on fluoride).

However, I suspect Connett and his activist organisation, The Fluoride Action Network (FAN), will be very quiet about the latest paper from this group. This is because the research they report supports the scientific consensus – in particular:

  • Fluoride at the concentration used in CWF does reduce tooth decay;
  • Fluoride at the concentration used in CWF does not cause the cosmetically undesirable forms of  dental fluorosis.

The paper is:

Xiang, J., Yan, L., Wang, YJ., Qin, Y., Wang, C. &  Xiang, QY. (2016). The effects of ten years of defluoridation on urinary fluoride, dental fluorosis, defect dental fluorosis, and dental caries, in Jiangsu province, PR China. Fluoride, 49(March), 23–35.

Yes, I know, it is published in Fluoride – which is hardly a credible scientific journal. And the lack of proper peer review sticks out like a sore thumb with mistakes in the text, poor data presentation and poor data statistical analysis.

Fluoride improves dental health

This is shown by data they collected in 2002 for two villages -Wamiao (a “severe endemic fluorosis village” with drinking water fluoride in the “range of 0.57 – 4.50 mg/L”) and Xinhuai (a “non-endemic fluorosis village” with drinking water fluoride in the “range 0.15 – 0.77 mg/L”). They combined the data for the 2 villages to produce the following graphic – from which they concluded that a “possible desirable range for the fluoride level for minimizing the prevalence of dental caries” . . .  [is] “approximately 1.5 – 2.5 m/L.” Considering this is just one study and has limitations the result is similar to the recommended fluoride level for CWF – 0.75 mg/L in the USA and 0.75 – 1.2 mg/L in New Zealand.

DMFT Xiang

OK, this is a poor graphic and I cannot see why they should have divided the data into the nine subgroups instead of statistically analysing the whole dataset (an indication of poor peer review by the journal?). But you get the picture. Dental decay declines as fluoride concentration in the drinking water in increased from near zero to about 1 mg/L.

CWF does not cause dental fluorosis

After 2002 the water sources used in the two villages changed:

“As a defluoridation project, water from two deep wells has been used as a tap water source of drinking water in Wamiao village since the beginning of 2003. The surface water in Yaohe river has been used as a tap water source in Xinhuai village since 2009.”

The current dental fluorosis study occurred in 2013 when the fluoride concentrations in both villages were in the range 0.85 – 0.95 mg/L. This is similar to the levels used in CWF.

In 2013, the researchers found very low levels of total dental fluorosis in both villages (3.1% in Xinhuai and 8.8% in Wamiao – no significant difference). They also measured “defect dental fluorosis” – a Chinese classification which includes some “moderate” dental fluorosis and all “severe dental fluorosis as diagnosed by Dean’s criteria (see  Water fluoridation and dental fluorosis – debunking some myths and the image below).

The prevalence of “defect dental fluorosis” in 21013 was zero for both villages.

This contrast markedly with the situation in 2002 where the prevalence of total dental fluorosis was significantly higher in Wamiao village (89%) than in Xinhuai (4.5%). The prevalence of “defect dental fluorosis” was 39% in Wamiao but zero in Xinhuai (data from Xiang, et al., 2004).

The 2013 data reported in this paper confirm what I have said again  and again in  articles here. CWF does not cause the cosmetically undesirable forms of dental fluorosis – the “moderate” and “severe” forms, or the “defect dental fluorosis” in the Chinese classification). Anti-fluoride campaigners always misrepresent this data by quoting figures for total dental fluorosis and claiming the effects are those only seen with “moderate” and “severe” forms.

Paper’s take home message

The new water supply in these two villages has solved the dental fluorosis problem while also maintaining a fluoride concentration comparable to that used in CWF and helping support a low level of dental decay in children. The data support other findings (and the current scientific consensus) showing that CWF does not cause any cosmetically undesirable dental fluorosis but does help prevent tooth decay.