Dental fluorosis

In the United States, rates of dental fluorosis continue to rise to alarming levels. But in heavily-fluoridated Australia, with a higher fluoride concentration than the US, strangely, fluorosis rates appear to have fallen. But have they really fallen? Find out what radical steps Australia’s NHMRC took to conceal the real underlying damage of dental fluorosis.
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"By 1983 I was thoroughly convinced that fluoridation caused more harm than good. I expressed the opinion that some of these children with dental fluorosis could, just possibly, have also suffered harm to their bones"
Dr. John Colquhoun
Former Principal Dental Officer for Auckland New Zealand
  • The damage to our teeth from fluoride has been known since the early 1930s;
  • Even Dean himself was concerned: any level above his first category was not acceptable and believed that only 10 per cent of children would be affected;
  • Numerous major studies over decades show the direct link between fluoride and dental fluorosis;
  • Dental fluorosis in the US is out of control, raising to 65% amongst teenagers;
  • Fluorosis rates in Australia, with more fluoride, are strangely lower;
  • But it’s not hard to see why: dental fluorosis rates pose a serious threat to our fluoridation program, so NHMRC changed the measurements to cover up the real damage;
  • Dental fluorosis is associated with other systemic damage;
  • No amount of dental fluorosis is acceptable.
A brief history of fluorosis

Dental fluorosis is a very common condition where the tooth enamel is compromised or damaged directly by excessive fluoride intake during childhood. The effect of fluorosis ranges from a mild, barely-noticeable discolouration or ‘mottling’, to serious physical damage to the tooth surface.

The damage fluoride can cause to the teeth has long been known. By the early 1930s, several researchers in the United States had linked this ugly blotching or mottling to naturally-occurring fluoride in water supplies. At that stage, Alcoa, the country’s largest fluoride polluter, had also discovered this damage was not restricted to nature’s fluoride, with children living near the company’s large aluminium plant in Massena suffering from this unsightly ‘mottled-teeth’ condition.

In 1932, 10 years before he conducted the famous “21-city Dean study”, Dr H Trendley Dean surveyed the whole of the United States for dental fluorosis and created the Dean’s Fluorosis Index. These four main categories of damage to the teeth caused directly by fluoride are still used today:

  1. Very mild (mottling of 25 per cent of the tooth surface)
  2. Mild (mottling of 50 per cent)
  3. Moderate (mottling, some pitting and discolouration of 100 per cent)
  4. Severe (mottling, more pitting and brittleness often turning brown of 100 per cent)

By then Dean was already concerned. He found that natural levels of fluoride were causing mottled teeth in hundreds of areas in the Unites States. As for artificial fluoridation, he felt that any level above his first category – very mild – was not acceptable and believed that at 1ppm, fluorosis in the mild form would only affect 10 per cent of children.

In 1933, Floyd DeEds, a senior toxicologist, published a comprehensive review, on behalf of the US Department of Agriculture, about fluoride’s many harmful effects, including dental and skeletal fluorosis.

In 1937, Kaj Roholm, a scientist and researcher, conducted a comprehensive study involving workers at a metal smelting factory in Copenhagen who were suffering from fluoride poisoning. He published a 364-page review titled Fluoride Intoxication, reporting that toxic fluoride accumulated in the teeth, bones and quite possibly the kidneys and lungs and that 84 per cent of the workers developed signs of osteosclerosis and other serious forms of skeletal damage. Roholm stated in his report:

The once general assumption that fluorine is necessary to the quality of the enamel rests upon an insufficient foundation. Our present knowledge most decidedly indicates that fluorine is not necessary to the quality of that tissue, but that on the contrary the enamel organ is electively sensitive to the deleterious effects of fluorine.”

Kaj Roholm, "Fluoride Intoxication"

In 1951, JAMA Medical Literature reported the symptoms of chronic fluoride poisoning, stating “Chronic intoxications resulting from prolonged intake of smaller amounts of fluorides include dental fluorosis. Fluoride also tends to accumulate in bones, leading to hypercalcification and brittleness.”

In 1979, in a book titled “Continuing Evaluation of the Use of Fluorides”, Dr. Harold Hodge, wrote: “The most important and widely disregarded fact about dental fluorosis is that no safe established daily intake exists, i.e., the maximal amount in mg fluoride which consumed daily does not produce cosmetically damaging white areas or brown stain in some areas has not been fixed.”

Figure 1: Dean's Fluorosis Index: Very mild, mild, moderate and severe.
“For the last 15 years I have carried out research showing what damage fluoride accumulation can do to human teeth and bones. At the same time, it is obvious that the benefit of fluoridation is next to nil. After spending 3 years on the US National Research Council panel reviewing the damage that fluoride can do to other tissues, I am even more convinced that fluoride should be banned as a systemic drug (which includes water fluoridation) and classified as a prescription drug for topical use on teeth that only dentists can prescribe.”
Hardy Limeback, PhD, DDS
Associate Professor and Head of Preventive Dentistry, University of Toronto, past president of the Canadian Association for Dental Research, and Member of the 2006 National Research Council panel which reviewed the toxicology of fluoride, Mississauga, Canada
Major studies

Over the last 70 years, many studies have been conducted revealing the damage fluoride causes to our teeth in the form of dental fluorosis. This damage is acknowledged by fluoridation proponents and opponents. Here are some of the major studies:

In 1990 Dr. John Colquhoun, former Chief Dental Officer for Auckland New Zealand, conducted a study on 60,000 school children and found no difference in tooth decay rates between fluoridated and unfluoridated areas. Additionally, he found that a substantial number of children in fluoridated areas suffered from dental fluorosis. After announcing the results of this study he was forced into early requirement.

In 1997, the US Centres for Disease Control (CDC) released the results of the National Health and Nutrition Examination (NHANES) 1986-1987 Survey, revealing that nearly 29.6 per cent of children living in fluoridated areas had dental fluorosis on at least two teeth. This was already three times the rate anticipated by Dean. The study also found that in non-fluoridated areas, with natural fluoride at 0.3 – 0.7mg/L, a surprising 21.7 per cent of children had fluorosis on at least two teeth. In areas with less than 0.3mg/L natural fluoride, 13.5 per cent of children had fluorosis on at least two teeth.

In 2000, the York Review estimated that 48 per cent of children in areas of 1ppm fluoride (often referred to as “optimally fluoridated”) had any form of dental fluorosis and 12.5 per cent had fluorosis of aesthetic concern.

In 2005, the 1999-2002 NHANES survey showed that US school children had a dental fluorosis rate of 32 per cent – an increase of 9 per cent since the previous survey in 1986-1987.

Since then, the fluorosis alarm bells have continued to ring, only louder. In 2009, New Zealand’s Ministry of Health Oral Health Survey found nearly 50 per cent of children in both fluoridated and non-fluoridated areas have some form of dental fluorosis.

In 2009 Lida and Kumar again examined 1986-1987 NIDR data and showed that 7- to 17-year-olds have similar cavity rates in their permanent teeth whether their water supply is fluoridated or not. The study also revealed that as the concentration of fluoride increased from less than 0.3mg/L to 1.2mg/L, tooth decay remained almost static, while the damage of dental fluorosis increased from around 14 per cent to nearly 40 per cent.

Figure 2: The Association between enamel fluorosis and dental caries in US school children; Lida & Kumar (2009)

In 2010 the results of the 1999-2004 NHANES survey revealed that 41 per cent of American adolescents have some form of fluorosis — an increase of over 400 per cent from the rates found 60 years previously, before the widespread use of fluoride. In some areas the rate was much higher.

In 2015, the Cochrane Review analysed 90 studies with 180,530 participants and estimated that with a fluoride level of 0.7ppm (at the lower end of the Australian range), 40 per cent of participants had fluorosis of any level and 12 per cent had fluorosis of aesthetic concern.

In 2016 the results of the 2011-2012 NHANES survey showed that adolescents with any form of fluorosis had jumped to a staggering 65 per cent. Even more concerning was the huge increase in combined moderate and severe fluorosis, from 3.7 per cent previously to a massive 30.4 per cent.


Figure 3: NHANES dental fluorosis rates for children ages 12-15 years, comparing changes across the three national surveys in the USA 1986 - 2012.
Figure 4: Dental Fluorosis Trends in United States Oral Health Surveys: 1986–2012; C. Neurath et al, March 2019. Full paper available here.

In March 2019, a study titled “Dental Fluorosis Trends in United States Oral Health Surveys: 1986–2012” highlighted the dramatic increases in dental fluorosis and widespread fluoride overexposure with risk of neurotoxicity. According to lead author, Chris Neurath: “These extremely high rates are unprecedented and far beyond what were considered acceptable when water fluoridation was started 75 years ago.”

Although we were not able to determine what specific sources of fluoride caused these large increases in fluorosis, likely contributors include increases in water fluoridation, especially when used for mixing infant formula, and swallowed fluoride toothpaste."

Chris Neurath, Lead Author, "Dental Fluorosis Trends in United States Oral Health Surveys: 1986 - 2012."
Dental fluorosis in Australia

While dental fluorosis rates are soaring in the United States, the prevalence of fluorosis in Australia is somewhat of a misnomer, with an apparent decline from around 40 per cent in the 1990s to less than 17 per cent more recently.

It is relevant at this point to mention that in 2015, in response to the significant increase in fluorosis rates in the United States between 1986 and 2004, the US Public Health Service recommended a reduction in the level of fluoride added to drinking water from 0.7 – 1.2mg/L down to 0.7mg/L.  Meanwhile, Australia’s fluoride concentration remains around 1mg/L, within a range of 0.6 – 1.1mg/L.

But it’s not hard to see why our fluorosis rates have miraculously fallen. For starters, dental fluorosis in Australia is always downplayed, with fluoridation proponents often referring to an “optimum level” for water fluoride concentration and “achieving a balance between decay and fluorosis”. The tactics used to hide the real damage of fluorosis, however, don’t stop there.

While there has been a large number of children’s dental surveys conducted in Australia, most have only measured tooth decay; very few surveys have measured dental fluorosis. When dental fluorosis is measured, surveys have often recorded fluorosis on one single tooth or just the front teeth, ignoring the damage fluorosis has caused to the middle and rear teeth. Also, if there is any doubt about the level of fluorosis it is normally downgraded to a lower grading.

In 2007, a large children’s dental survey which did measure fluorosis, showed that nearly 25 per cent of children in fluoridated NSW areas had some level of fluorosis and of these 3.3 per cent had moderate fluorosis.

In 2017, fluoride promoters who reviewed fluoridation for Australia’s National Health and Medical Research Council (NHMRC) claimed that children’s fluorosis rates had decreased to 16.8 per cent and the level of moderate fluorosis was only 0.8 per cent. But this is just an apparent trend. 

The decrease was achieved via two main tactics:

Firstly, fluorosis results from fluoridated and non-fluoridated areas were intentionally combined, including Queensland which had only just commenced fluoridation. Secondly, even more egregiously, NHMRC intentionally engineered a more favourable outcome by re-classifying the fluorosis grading of TF3 (Thylstrup and Fejerskov (TF) Index) from the universal moderate grade down to a mild grade. NHMRC also simultaneously upgraded the threshold level for fluorosis of aesthetic concern from TF 3 up to a level of TF 4.  This means our fluorosis rates are simply not revealing the true extent of fluoride’s damage to the teeth.

Dental Fluorosis rates pose a serious risk for fluoridation programmes, so by downplaying fluorosis and then claiming fluorosis is not a concern, NHMRC masks the real effects of fluorosis and thereby helps protect fluoridation."

Merilyn Haines, from her article titled "Can the NHMRC be trusted?"

NHMRC has also downplayed the true extent of fluorosis by:

  • Claiming that fluorosis does not cause children psychological harm despite a previous report concluding “children with mild fluorosis showed a significant adverse psychological response to their dental appearance.”
  • Withholding fluorosis data collected from the 2004 – 2006 National Adult Oral Health Survey and the 2012 – 2014 National Child Oral Health Survey;
  • Claiming that fluorosis is only a small risk until a child reaches the age of six, even though a child’s permanent teeth are still forming until the age of eight;
  • Specifically excluding numerous fluorosis studies in their review that would have emphasised the damage caused by fluoridation, while providing unacceptable if not absurd reasons for doing so.

For more details of the above points, see the article: Can the NHMRC be trusted?

But misleading tactics used to hide dental fluorosis are not exclusive to our national health body. Another example is a dental study conducted in Western Australia where the author deliberately avoided using the word “fluorosis”. In 2008, a study conducted by Dr Peter Arrow, who has promoted fluoridation for the WA Health Department, published the results of his study “Prevalence of Developmental Enamel Defects of the First Permanent Molars Among School Children in WA”. 

The study concluded:

“At the individual level, 71 per cent had permanent molars with enamel defects, 47 per cent with white diffuse opacities and 22 per cent with demarcated opacities. “
“A prevalence of one in five children affected at least with a demarcated opacity and one in 17 with a defect severe enough to require clinical intervention.”
The systemic effect of fluoride

Unfortunately fluorosis is not limited to our teeth, which are often regarded as ‘biomarkers’ for our entire physiology. If fluoride is damaging our teeth – to any degree – then it can also be damaging our bones. That’s because calcium is so susceptible to fluoride. But the damage extends well beyond the teeth and bones.

In response to the latest research showing dental fluorosis is continuing to climb in the United States, Paul Connett, PhD, co-author of The Case Against Fluoride, says “The defenders of water fluoridation are missing the real story. Dental fluorosis is a biomarker of over-exposure to fluoride and the ‘elephant in the room’ is what damage fluoride is doing to other tissues.”

Connett goes on to say; “This is compelling evidence that fluoride exposure, linked to lowered IQ in children, has skyrocketed.  Fluorosis is a permanent marker of excessive early life exposure to fluoride.  The US Public Health Service (PHS) has promoted fluoridation since the 1950s, but now must recognize fluoride exposure is out of control.  The emerging evidence of harm to developing brains can no longer be dismissed.”

Several studies have revealed the association between dental fluorosis and other health effects. One study conducted by Khandare et al (2017) involved 824 Indian school children aged 8 to 15 years. The study revealed that dental fluorosis was significantly higher in affected (fluoridated) than control (non-fluoridated) area children. There was also a significant decrease in thyroid-stimulating hormone (TSH) in the affected area children compared to control. The authors stated, “fluorotic area school children were more affected with dental fluorosis, kidney damage, along [with] some bone indicators as compared to control school children.”

This is compelling evidence that fluoride exposure, linked to lowered IQ in children, has skyrocketed.  Fluorosis is a permanent marker of excessive early life exposure to fluoride.  The US Public Health Service (PHS) has promoted fluoridation since the 1950s, but now must recognize fluoride exposure is out of control.  The emerging evidence of harm to developing brains can no longer be dismissed.”

Paul Connett, PhD.

Other adverse health effects associated with dental fluorosis can be found here.

According to the late Dr. John Colquhoun, “Common sense should tell us that if a poison circulating in a child’s body can damage the tooth-forming cells, then other harm also is likely.” If a child has a thin blue line on their gum (Burton’s Line) it represents over-exposure to lead or another heavy metal. No one would say it is “only cosmetic”.


Given the huge increase in the prevalence of dental fluorosis in America over the last 70 years, plus the misleading if not deceptive tactics used in Australia to downplay, downgrade and intentionally conceal the real extent of fluorosis, it is well time that our health authorities understand and acknowledge that dental fluorosis is the first sign of fluoride poisoning, that there are various other adverse consequences of fluoride ingestion and therefore no amount of dental fluorosis is acceptable.

Fluoride is a slow poison, causes dental, skeletal and non-skeletal fluorosis. It affects almost all the organs in the body. Most serious is its damage to the brain. There is strong evidence that it lowers IQ in children.”