Toronto Total Health Show 07-April-2013, Dr. Hardy Limeback Presentation – Is There a Natural Way to Fight Dental Decay
Infant formula made with fluoridated tap water causes dental fluorosis: Where are the warnings from Health Canada?
In a previous blog I talked about how serious and widespread the problem of dental fluorosis is in Canada and how it is being ignored by Health Canada.
Recall that dental fluorosis is irreversible ‘scarring’ of the permanent teeth causing children to be self-conscious and costing families thousands of dollars to repair (see photo).
It would be best to prevent dental fluorosis in the first place.
The main cause of dental fluorosis
Dental fluorosis occurs because infants ingest too much fluoride from birth to age three years when their bodies are small. Fluoride can come from any or all of the following (1,2):
- infant formula made with fluoridated tap water
- early use and ingestion of fluoridated toothpaste
- any fluoride supplementation (pills, lozenges, vitamins, drops)
Remember it is the TOTAL ingestion that places a child at risk. The sources are additive. Fluoride from one source might cause very mild fluorosis but when another source is added, not only does the prevalence (the percentage of kids with fluorosis) increase, so does the severity.
Don’t let ANY public health person blame toothpaste alone. That’s like a doctor blaming lung cancer on a patient because he lives in a polluted city, while ignoring the fact that he’s a 2-pack-a-day smoker.
Is fluoride added to water a drug?
Health Canada is very specific in terms of its definition of what is a drug. (3)
“According to the Food and Drug Act, a drug includes any substance or mixture of substances manufactured, sold or represented for use in:
- the diagnosis, treatment, mitigation or prevention of a disease, disorder, abnormal physical state, or the symptoms thereof in man or animal
- restoring, correcting or modifying organic functions in man or animal, or
- disinfection in premises in which food is manufactured, prepared or kept”
All doctors (family physicians, pediatricians, dentists and pediatric dentists) know they have to adjust the dosage of drugs for children (due to smaller body mass). Babies, especially, should not receive adult doses of drugs. This is essential to avoid unnecessary and sometimes very serious side effects.
Therefore, pediatric drugs are all administered by adjusting the dosage according to the weight of the child.
For example, a dentist or pediatrician might prescribe the following for an oral infection in a baby:
[<3 mo] Dose: 20-30 mg/kg/day by mouth divided into two doses per day. Max: 30 mg/kg/day. (4)
Every drug has a therapeutic window of effectiveness that should be balanced with the risk of any negative side effects if too much drug is administered and/or metabolized.
Fluoride’s (topical) effectiveness against dental decay has declined over the years. Ingestion of fluoride has no benefit. It might still be effective (e.g. in very high concentrations in toothpaste) but only topically, when it bathes the teeth after they erupt into the oral cavity. It is the ingested fluoride that causes unwanted side effects such as permanent tooth damage (dental fluorosis).
So, what do authorities recommend as safe levels for fluoride intake during those critical years of tooth development (birth to age three years)? The maximum fluoride ingestion to avoid dental fluorosis, as has been adopted by the Canadian Dental Association (5), is as follows:
“the total daily fluoride intake from all sources should not exceed 0.05-0.07 mg F / kg body weight in order to minimize the risk of dental fluorosis.”
Has a pediatrician ever asked about the fluoride intake at home by any member of your family? Has your dentist ever calculated, on your behalf, the estimated total intake of fluoride of your child?
If you wanted to protect your baby from too much fluoride intake, how would you go about determining the fluoride content of his/her diet?
If you are feeding your baby exclusively infant formula and making it up with fluoridated tap water, your baby is likely already past the maximum recommended fluoride intake and will likely end up with some fluorosis on the permanent teeth.
Here’s a simple calculation (we’ll use fluoridated water at 1.0 ppm since not all communities have lowered their fluoride levels to 0.7 ppm, as recently recommended by the US EPA and Health Canada).
Fluoridated tap water at 1.0 ppm = 1 mg fluoride/liter
Some babies have a fluid intake as high as 1 L/day (6). A baby at 3 mo. weighing 5 kg (7) could consume 1 L liquid formula in one day. (8)
The calculation for total fluoride intake per day is, therefore, (1 L X 1.0 mg fluoride/L ) /5 kg = 0.2 mg fluoride/kg/day
This is clearly 3 to 4 times the maximum fluoride intake recommended to avoid dental fluorosis. Moms who exclusively breastfeed their babies do not expose their babies to this high level of fluoride because breast milk is almost completely lacking in fluoride
In fact many studies, including ours (9, 10) have shown that breastfeeding reduces the risk for dental fluorosis in children.
This being the case why doesn’t Health Canada issue warnings to moms, who don’t breast feed, that using fluoridated tap water to make formula can cause dental fluorosis in their babies?
The US state of New Hampshire recently passed legislation (11) that requires cities in the state to add the following warning to their water bills.
“Your public water supply is fluoridated. According to the Centers for Disease Control and Prevention, if your child under the age of 6 months is exclusively consuming infant formula reconstituted with fluoridated water, there may be an increased chance of dental fluorosis. Consult your child’s health care provider for more information.”
However, Health Canada has not taken ANY step to warn mothers of this problem and continues to insist that artificial fluoridation causes no harm.
What about weaning babies and introducing foods?
Suppose you either breastfed your baby, or made efforts to avoid fluoridated water to make up infant formula, but now you have to introduce solid foods to your baby’s diet. Will your child still be susceptible to fluorosis?
The short answer is yes, especially if fluoridated water is used to reconstitute foods and beverages and to cook with.
How much fluoride will be introduced in foods used when you start weaning your baby off exclusive milk feeding?
An easy guide is provided by Zohoori et al (12). Any beverage or food made or cooked with fluoridated water will end up with the same amount of fluoride contained in the volume of water used to cook: cereals and vegetables cooked in 1 ppm fluoridated tap will have 1 ppm or more fluoride. These authors recommend that parents be educated about the added fluoride intake in their children.
“Therefore, it is important that parents receive appropriate information on the F [fluoride] content of infant foods and drinks as well as guidelines regarding appropriate waters suitable for the preparation of infant food and drinks.”
Take home message for the reader: Health Canada is failing to do its job. It should warn against using fluoridated tap water to reconstitute infant formula. It should require fluoride labeling on prepackaged and reconstituted foods. Families have to learn on their own how to protect their newborns from developing dental fluorosis.
Challenge to the reader: Talk to your local municipal council representative. Let him/her know Health Canada is not protecting its citizens. Remind him/her that it is the municipality that is responsible for drinking water and council members have the power to stop water fluoridation.
- Brothwell D, Limeback H. Breastfeeding is protective against dental fluorosis in a nonfluoridated rural area of Ontario, Canada. J Hum Lact. 2003 Nov;19(4):386-90.
- Brothwell DJ, Limeback H. Fluorosis risk in grade 2 students residing in a rural area with widely varying natural fluoride. Community Dent Oral Epidemiol. 1999 Apr;27(2):130-6.
- Zohoori FV, Moynihan PJ, Omid N, Abuhaloob L, Maguire A. Impact of water fluoride concentration on the fluoride content of infant foods and drinks requiring preparation with liquids before feeding. Community Dent Oral Epidemiol. 2012 Oct;40(5):432-40.
The decay rates in children have declined dramatically all over the world in developed countries.
How was this achieved?
Was it because of fluoridation? No. Fluoridation is not practiced in Europe except in Ireland (where it is mandatory) and a few small pockets of the UK. All other European countries either never started or stopped adding fluoridation chemicals to the drinking water years ago. In fact, the practice was ‘banned’ in some countries. See http://www.fluoridealert.org/content/europe-statements/
Proponents of fluoridation say that dental decay rates will skyrocket if fluoridation is halted. The exact opposite has happened. When they stopped adding fluoride to the drinking water dental decay rates continued to decline sometimes faster than in control cities that still fluoridated. See http://cof-cof.ca/2001/12/maupome%C2%B4et-al-patterns-of-dental-caries-following-the-cessation-of-water-fluoridation/
Here is a composite graph indicating the overall trend to dental decay in fluoridated and non-fluoridated counties.
There are so many reasons for the decline of dental decay in the developed world.
When the electric refrigerator was introduced fresh fruit and other foods were possible and there was less reliance on fruits preserved in jars with sugar.
Penicillin was introduced just in time to save countless of lives during WWII. Penicillin also kills the bacteria that cause dental decay.
Vitamin D is essential for strong teeth and bones. A deficiency in Vitamin D not only causes rickets but increases dental decay. Rickets is less common these days because of milk that is fortified with Vitamin D but some parents feel that the natural way to get Vitamin D (outdoor exposure to sun) is best for their children. Aboriginal peoples really don’t need Vitamin D because they get enough sun and eat Vitamin D rich foods in the winter. Recently there has been a trend to increasing dental decay in fluoridated cities because of the substitution of milk with sugar-laden soda pop and sport drinks.
Before fluoridation was introduced, artificial sweeteners made their debut. Replacing raw sugar in the diet drastically curtails dental decay (as demonstrated by the dashed black line in the diagram – Japan’s decay rate went to nil during WWII when their sugar supply was cut off).
Most experts now believe that fluoridated toothpaste was an important factor in the non-fluoridated countries in lowering decay rates, but that was not the only factor. Better diets, improved dental hygiene and better access to dental care (and professional preventive dentistry) played important roles (Bratthall et al, 1996).
Products containing chlorhexidine (an antibacterial agent) and xylitol (a natural anti-cavity sugar substitute) were also introduced in the 70’s and 80’s in addition to fluoridated toothpaste.
Finally, dental sealants, especially those placed on highly susceptible pits and fissures (those surfaces that usually decay), made a significant contribution to declining dental decay.
[A detailed discussion with references can be found in Limeback et al, 2012]
Current studies suggest that fluoridation might have contributed to perhaps a savings of 0.5 tooth surfaces from needing dental treatment. One has to weigh health risks of twenty years of fluoridating the entire population in order to save 0.5 tooth surfaces.
Is it worth it?
When it is pointed out to fluoridation supporters that Europeans experience better dental health than North Americas without fluoridation, it is often claimed that they get their fluoride from ‘other’ sources, such as fluoridated salt, milk and supplements.
It is important to remember that fluoride does NOT work by ‘strengthening’ the enamel from within. You don’t have to swallow it (see previous blog). Fluoride, if anything, works topically AFTER the tooth appears in the mouth. Ingested fluoride is actually quite useless.
Add to this that when fluoridated water (or milk or salt) is ingested from birth until age 6 years it causes dental fluorosis. It is hard to understand, then, why dental researchers continue to try to inject fluoride into the food system in Europe. Even if people were willing to accept permanent ‘scarring of the teeth’ to achieve some minor benefit against dental decay, there is no evidence that fluoridated salt works and there is only ONE study that suggests fluoridated milk might provide a slight benefit to the primary dentition. (Cagetti et al, 2012).
I received this interesting email from Declan Waugh, an environmental risk assessor in Ireland, who wrote a detailed critique of Ireland’s fluoridation policy:
Milk fluoridation programmes targeted at children are currently in operation in Bulgaria and the UK. (http://www.borrowfoundation.org/community-programmes/programme-details.html#Russia). In Bulgaria where, in addition to milk, yogurt is fluoridated in a few regions of the country. The total number of children receiving these products is 5000 [this program has ceased to operate]. In the UK there were in 2004 eleven education authorities in England offering fluoridated milk, with approximately 32,000 children drinking it (Riley et al, 2005), and in June 2005 this number amounted to over 40,000 children in 510 establishments. [The figures for 2012 are 30,000 children age 3-11 years]. Hungary attempted a trial on a small level in 1978 but subsequently discontinued it. That’s it- no other country [in Europe]. To read more see WHO Report: http://www.who.int/oral_health/publications/milk_fluoridation_2009_en.pdf
Challenge to the reader: Question when proponents of fluoridation say adding a toxic byproduct to the drinking water is ‘safe and effective’. Remember that dental decay is not a fluoride-deficiency disease. Learn about the other ways that we have achieved better dental health in developed countries. Don’t let fluoridation proponents bully you and tell you that fluoridation is necessary- it’s not.
Take home message for the reader: The next time you hear someone claim that the Europeans have better dental health than us in North America because they consume fluoridated salt and milk, tell them they are wrong and point them to this blog.
1. Hardy Limeback, Jim Yuan Lai, Grace Bradley, and Colin Robinson. A brief introduction to oral diseases: caries, periodontal disease, and oral cancer. (2012) in: Comprehensive Preventive Dentistry (H. Limeback ed), Wiley-Blackwell (Ames Iowa, USA).
2. Cagetti MG, Campus G, Milia E, Lingström P. A systematic review on fluoridated food in caries prevention. Acta Odontol Scand. 2012 Jul 25.
3. Bratthall D, Hänsel-Petersson G, Sundberg H. Reasons for the caries decline: what do the experts believe? Eur J Oral Sci. 1996 Aug;104(4 ( Pt 2)):416-22; discussion 423-5, 430-2.
4. Riley JC, Klause BK, Manning CJ, Davies GM, Graham J, Worthington HV. Milk fluoridation: a comparison of dental health in two school communities in England. Community Dent Health. 2005 Sep;22(3):141-5.
Fluoridation and baby bottle tooth decay
Can breast feeding cause early childhood caries (rampant dental decay in toddlers)?
Does fluoride in the drinking water reduce the incidence of early childhood caries?
Can adding fluoride to drinking water reduce the prevalence or severity of baby bottle tooth decay?
When I first announced that I was publicly opposed to water fluoridation I received many heated phone calls and emails from upset dental care professionals, even from friends. I was distraught. My dental office routine was disrupted. My family was negatively affected (my wife is my dental office manager). I discovered that criticizing fluoridation produced a lot of emotional and negative reactions within the dental community.
I received an email from a dental hygienist working for public health in the province of BC (almost the entire province is unfluoridated). She sent me a picture of baby bottle tooth decay and asked how I could be against fluoridation when there were so many toddlers suffering from rampant dental decay. The reaction was understandable since that dental hygienist probably did not know that fluoridation does little to help toddlers with baby bottle tooth decay (more below…)
When I was invited to Salem, Oregon to help the citizens fight a mandatory water fluoridation bill, a pediatric dentist showed a video of a screaming toddler who was being treated for rampant dental decay. It was a clear attempt to elicit sympathy from the audience … and it did.
Parents don’t want their kids to suffer. Videos intended to pull on the heart strings of parents are effective. Videos and photos of toddlers with rampant dental decay are often shown at hearings where the city council or citizens have to decide on the policy of whether or not to add fluoridation chemicals to the drinking water. In my opinion, the tactic of using a traumatic dental visit where a toddler with baby bottle tooth decay has to have several teeth repaired at once is disingenuous and merely a scare tactic.
Breast vs. bottle milk
Prehistoric dental decay in children
Baby bottle tooth decay and early childhood caries are modern diseases. Dr. Brian Palmer, who recently passed away, was a dentist in Kansas who studied the benefits of breast feeding in relationship to jaw development and early childhood caries. He went to the Smithsonian Natural Museum in Washington D.C. to examine the skulls of prehistoric Native Americans. Out of 1344 ‘baby teeth’, only 1.4% had any signs of decay. Only FOUR teeth had large cavities. The following is a typical image of the prehistoric native infant found in the Plains of South Dakota.
Breast milk never did cause any tooth decay in prehistoric children. It was Dr. Palmer’s contention that “It would be evolutionary suicide for breast milk to cause decay.”
It is now well known that indigenous populations eating processed food (a ‘western diet’) have dental decay problems. Decay rates are extremely high now in some regions where aboriginal people live, largely if not entirely because of the change in diet from the ‘hunter-gatherer’ traditional diet to one of processed food high in sugars and low in nutrition. This was well documented in the book by Weston A. Price, first published in 1939 (Nutrition and Physical Degeneration, 6th edition, Price-Pottenger Nutrition Foundation). I personally experienced how difficult it was to manage dental decay problems in children when I worked as a young dentist in the Sioux Lookout region near James Bay in Ontario. I was told by the local nurse practitioner that families were in the habit of putting their toddlers to bed with a bottle filled with sugar water or cola soft drinks, because they could not afford to purchase fresh cows’ milk or formula powder.
Why the baby bottle damages teeth
Baby bottle tooth decay can be very serious. As shown in this example image, graciously provided with permission from Dr. Palmer’s widow, one can see how every single baby tooth has severe tooth decay. A number of those baby teeth would have to be extracted because they are infected.
Most mothers realize that putting babies to bed with a bottle containing sugary drinks is a mistake. Even milk from a baby bottle can cause severe dental decay because of the natural sugar content. Milk contains the disaccharide lactose. It isn’t as dangerous as table sugar (sucrose) but it still can cause tooth decay.
The difference between breast milk and the baby bottle, according to Dr. Palmer, is that the baby requires some effort to ‘latch on’ and work with a forceful sucking motion to express the breast milk. Breast milk is expressed further in the back of the oral cavity past the teeth. With commercial bottles, there is no effort to drink milk from the rubber nipples, which tend to leak resulting in the pooling of milk on the teeth as baby falls asleep. Once asleep, saliva flow diminishes and does not fight off the acid produced by the metabolism of lactose by plaque bacteria. Furthermore, there are important anti-cavity factors that are in human breast milk (Erickson & Mazhari, 1999).
Research shows that prolonged nighttime feeding with breast milk does not increase the risk for ‘nursing caries’ (I find the term nursing caries to be a misnomer because some dentists believe that early childhood caries can be caused by nighttime feeding at the breast). The large National Health and Nutrition Examination Survey (NHANES) study in the US concluded: “these data provide no evidence to suggest that breastfeeding or its duration are independent risk factors for early childhood caries, severe early childhood caries, or decayed and filled surfaces on primary teeth.” Iida (2007)
Weerheijm (1998) reported that in Holland “… prolonged demand breast-feeding does not lead to a higher caries prevalence”
In the UK, Cartwright argued that breast milk does not cause dental decay.
Nunes (2012) reported that, “the present results showed that prolonged breast-feeding was not a risk factor for ECC after adjustment for a handful of important confounders.”
In fact, from the largest lactation study ever conducted it was concluded that, “Extended breast feeding (to 12 mo.) did not provide any significant benefit or harm” (Kramer et al, 2007).”
Abbey expressed this position in an article in the Journal of the American Dental Association as early as 1979 and yet the American Dental Association continues to offer the following statement on their website: “Unrestricted, at-will nocturnal breastfeeding after eruption of the child’s first tooth can lead to an increased risk of caries”. http://www.ada.org/2057.aspx
What else causes early childhood tooth decay?
We know breast milk doesn’t cause early childhood dental decay but putting the baby to bed at night with a bottle filled with sugary liquid or even milk can cause rampant dental decay.
What are other reasons why toddlers get rampant tooth decay?
About 5 toddlers/preschoolers out of 100 have severe dental decay (Al-Jewair & Leake, 2010).
This prevalence seems to have increased recently in 2-5 year olds (Kagihara et al. 2009)
There are many risk factors that predispose a preschooler to dental decay in the primary dentition. These include
1. low vitamin D levels (Schroth et al, 2012)
2. enamel defects (Caufield et al, 2012),
3. second hand smoke (Hanioka et al, 2011)
4. social disparities which result in more frequent sugar intake, more soda pop intake, less milk consumption, and less access to dental services (Vadiakas, 2008; Mobley et al, 2009).
Severe dental decay can occur even when the above risk factors are not present
Once the child is weaned off the bottle or breast and introduced to ‘adult’ foods, the risk for caries increases. Substituting milk for juices is the first obvious problem because of the loss of calcium intake and a switch to the more destructive sugars fructose and, in most cases, added sucrose. Allowing the child to have on demand access to drinks sweetened with sucrose through a ‘sippy cup’ increases the risk even further. Lack of oral hygiene and increased consumption of other carbohydrates rather than foods rich in protein and fibre, compounds the problem. Of course, many toddlers who express their dissatisfaction through crying are often ‘comforted’ by treats sweetened with sugar. So often I see parents capitulating to a crying child at the check-out counter in the grocery stores offering that child a candy or chocolate treat to avoid the stress and embarrassment of the child causing a disturbance in a public place. Dentists often report preschoolers coming to the office with chocolate bars in hand. Parents admit to using candy treats at every turn to ‘bribe’ their kids. On top of all this, medications administered at nighttime are laced with sugar (to entice the preschoolers to take them).
No wonder that the dental profession thinks we need fluoridation. But will fluoridation at 0.7 ppm really help early childhood caries? Not according to the research literature.
Fluoridation does little to reduce Early Childhood Caries
Looking at the children in the Head Start Program in the US, Barnes discovered that, “children attending centers showed no significant differences based on fluoride status for the total sample or other variables.” (Barnes et al, 1992).
Howard Pollick, a profluoridation spokesperson for the American Dental Association, has written articles in favour of fluoridation but in this study which he co-authored, it was reported that fluoridated water had no influence on early childhood caries. “Our analysis did not appear to be affected by whether or not children lived in an area with fluoridated water.” (Shiboski et al, 2003).
Community water fluoridation did not appear to provide a cost benefit in the UK (Kowash et al, 2006).
In Brazil, living in a fluoridated community did not make any difference in early childhood caries (Tiano 2009).
However, in a recent small study in Australia, fluoridated water used in infant formula reduced caries risk marginally but only in those infants fed longer than 6 months (Do et al, 2012). It must be remembered that infant formula made with tap water increases the risk of dental fluorosis (see blog on fluorosis) and fluorosis is associated with lowered intelligence (Choi et al, 2012).
Even if there were small positive effects on baby bottle tooth decay by living in a community with fluoridated water, the other health risks from ingesting fluoride are not worth it.
A much more effective way to reduce early childhood caries is to educate low income families on how to prevent it (Feldens et al, 2010)
New moms, once empowered with science-based knowledge, will do everything in their power to properly protect their kids from the pain and suffering that rampant caries brings. No mother wants to see her child placed under general anesthetic and then pay thousands of dollars in dental repair costs.
Rather than put millions of dollars into fluoridation programs, cities would be better off providing oral health education, dietary advice and assistance to families in need.
Challenge to the reader: If there is a new mom in the family, send her the link to this blog so that she can read about how important breast feeding is and how damaging it is to allow babies to sleep with a bottle in their mouth. Confront health care professionals who believe water fluoridation will prevent baby bottle tooth decay, and also send them the link to this blog.
Take home message for the reader: Breast milk does not cause decay in baby teeth and water fluoridation does not prevent baby bottle tooth decay.
Abbey LM (1979) Is breast feeding a likely cause of dental caries in young children? J Am Dent Assoc. 98(1):21-3.
Al-Jewair TS, Leake JL. (2010) The prevalence and risks of early childhood caries (ECC) in Toronto, Canada. J Contemp Dent Pract. 11(5):001-8.
Barnes GP, Parker WA, Lyon TC Jr, Drum MA, Coleman GC. (1992) Ethnicity, location, age, and fluoridation factors in baby bottle tooth decay and caries prevalence of Head Start children. Public Health Rep. 1992.
Cartwright A. (2008) Breast is Best. British Dental Journal 204: 351 – 352.
Caufield PW, Li Y, Bromage TG. (2012) Hypoplasia-associated severe early childhood caries–a proposed definition. J Dent Res. 91(6):544-50.
Choi AL, Sun G, Zhang Y, Grandjean P. (2012) Developmental Fluoride Neurotoxicity: A Systematic Review and Meta-Analysis. Environ Health Perspect. Jul 20. (Ahead of print)
Do LG, Levy SM, Spencer AJ. (2012) Association between infant formula feeding and dental fluorosis and caries in Australian children. J Public Health Dent.72(2):112-21.
Erickson PR, Mazhari E. (1999) Investigation of the role of human breast milk in caries development. Pediatr Dent. 21(2):86-90.
Feldens CA, Giugliani ER, Duncan BB, Drachler Mde L, Vítolo MR.(2010) Long-term effectiveness of a nutritional program in reducing early childhood caries: a randomized trial. Community Dent Oral Epidemiol. 38(4):324-32.
Hanioka T, Ojima M, Tanaka K, Yamamoto M. (2011) Does second hand smoke affect the development of dental caries in children? A systematic review. Int J Environ Res Public Health. 8(5):1503-19.
Iida H, Auinger P, Billings RJ, Weitzman M. (2007) Association between infant breastfeeding and early childhood caries in the United States. Pediatrics. 120(4):e944-52.
Kagihara LE, Niederhauser VP, Stark M. (2009) Assessment, management, and prevention of early childhood caries. J Am Acad Nurse Pract. 21(1):1-10.
Kim Seow W. (2012) Environmental, maternal, and child factors which contribute to early childhood caries: a unifying conceptual model. Int J Paediatr Dent. 22(3):157-68.
Kowash MB, Toumba KJ, Curzon ME. (2006) Cost-effectiveness of a long-term dental health education program for the prevention of early childhood caries. Eur Arch Paediatr Dent. 7(3):130-5.
Kramer MS, Vanilovich I, Matush L, Bogdanovich N, Zhang X, Shishko G, Muller-Bolla M, Platt RW. (2007) The effect of prolonged and exclusive breast-feeding on dental caries in early school-age children. New evidence from a large randomized trial. Caries Res 41(6):484-8.
Mobley C, Marshall TA, Milgrom P, Coldwell SE. (2009) The contribution of dietary factors to dental caries and disparities in caries. Acad Pediatr. 2009 9(6):410-4.
Nunes AM Alves CMC, Arau´ jo FB, Ortiz TML, Ribeiro MRC, Silva AAM, Ribeiro CCC. (2012) Association between prolonged breast-feeding and early childhood caries: a hierarchical approach. Community Dent Oral Epidemiol. Online Jun 23 (ahead of print).
Schroth RJ, Jeal NS, Kliewer E, Sellers EA. (2012) The relationship between vitamin D and severe early childhood caries: a pilot study. Int J Vitam Nutr Res. 82(1):53-62.
Shiboski CH, Gansky SA, Ramos-Gomez F, Ngo L, Isman R, Pollick HF. (2003) The association of early childhood caries and race/ethnicity among California preschool children. J Public Health Dent. 63(1):38-46.
Tiano AV, Moimaz SA, Saliba O, Saliba NA. (2009) Dental caries prevalence in children up to 36 months of age attending daycare centers in municipalities with different water fluoride content. J Appl Oral Sci. 17(1):39-44.
Vadiakas G. (2008) Case definition, aetiology and risk assessment of early childhood caries (ECC): a revisited review. Eur Arch Paediatr Dent. 9(3):114-25.
Weerheijm KL, Uyttendaele-Speybrouck BF, Euwe HC, Groen HJ. (1998) Prolonged demand breast-feeding and nursing caries. Caries Res.32(1):46-50.
Dr. Hardy Limeback BSc PhD (Biochemistry) DDS — Dental Fluorosis: Permanent tooth scarring caused by fluoridation
Dental Fluorosis: Permanent tooth scarring caused by fluoridation
What is dental fluorosis?
Dental Fluorosis caused by water fluoridation is irreversible, disfiguring, psychologically damaging and costly to repair. In essence, it is medical assault on children.
When children are exposed to increased fluoride intake from birth to age 6 years, fluoride interferes with normal tooth development and their teeth develop dental defects on the enamel surfaces that vary from
- barely visible white lines or spots (very mild) to
- coalescing chalky white opaque areas (mild) to
- chalky enamel on all teeth that start to ‘pit’ and stain brown (moderate) to
- mottling of all teeth, with enamel pitting and staining (severe)
Researchers have often categorized the various severities of dental fluorosis with indices, two of which are shown in this composite diagram.
How big a problem is dental fluorosis?
I was astounded by the high prevalence of fluorosis in my local area, but there is nothing special about my area. It was fluoridated for years. Dental fluorosis is rampant in fluoridated communities like mine.
When epidemiologists in the UK did a systematic review of all the relevant studies on dental fluorosis (the well known York Review), many of them conducted in the US, it was concluded that every eighth child had objectionable dental fluorosis as a result of fluoridation. (McDonagh MS, Whiting PF, Wilson PM, et al. Systematic review of water fluoridation. BMJ. 2000 Oct 7;321(7265):855-9.)
In a recent US large scale study about 10% of children have fluorosis that needs to be treated (Beltrán-Aguilar ED, Barker L, Dye BA. Prevalence and severity of dental fluorosis in the United States, 1999-2004. NCHS Data Brief. 2010 Nov;(53):1-8.). The Center for Disease Control in the US reports that dental fluorosis has been increasing throughout the years. Fluorosis is always worse in fluoridated communities.
There have been several studies conducted in Canada to estimate fluorosis prevalence.
Twenty years ago dental fluorosis was found in nearly 70% of the children in fluoridated communities (Ismail AI, Shoveller J, Langille D, MacInnis WA, McNally M. Should the drinking water of Truro, Nova Scotia, be fluoridated? Water fluoridation in the 1990s. Community Dent Oral Epidemiol. 1993 Jun;21(3):118-25).
The prevalence of fluorosis was about 60% in Courtenay and Comox in BC but this declined significantly when fluoridation was halted (Clark DC, Shulman JD, Maupomé G, Levy SM. Changes in Dental Fluorosis Following the Cessation of Water Fluoridation. Community Dent Oral Epidemiol. 2006 Jun;34(3):197-204)
In 1999, Dr. David Locker, now deceased, conducted a review of fluoridation for the Ontario Ministry of Health and the First Nations and Inuit Health Branch. He reported, “current studies support the view that dental fluorosis has increased in both fluoridated and non-fluoridated communities. North American studies suggest rates of 20 to 75% in the former and 12 to 45% in the latter.”
It was after the Locker Report that Ontario decided to recommend a range of fluoride in drinking water from 0.5 ppm to 0.8 ppm.
The dental public health department in Toronto in a follow-up survey looked at whether fluorosis was still a problem in Toronto. It was. The authors reported
“Dental fluorosis of moderate severity (Tooth Surface Index of Fluorosis 2) was found among 14.0% of 7-year-olds, 12.3% of 13-year-olds and 13.2% of the 2 age groups combined.” (Leake J, Goettler F, Stahl-Quinlan B, Stewart H. Has the level of dental fluorosis among Toronto children changed? J Can Dent Assoc. 2002 Jan;68(1):21-5).
The authors even admitted “Nonetheless, the prevalence and severity of dental ﬂuorosis among those we could identify as having been born in Toronto support the August 1999 decision to reduce Toronto’s water ﬂuoride concentration to 0.8 ppm from the former 1.2 ppm.”
How did Toronto end up having 1.2 ppm fluoride in its drinking water in the first place?
It turns out that picking that level was based on a silly calculation that suggested children living in cities in hot climates (Texas, Nevada, Arizona) would consume a lot more water than those in moderate climates (the ‘optimum fluoride level was arbitrarily set at a nice round figure of 1.0 ppm) and those children living in colder cities (e.g. Toronto) would consume less water.
But wait a minute.
It is well known that fluoride, if it has any benefit, provides its benefit through topical means, by exposing the teeth AFTER they erupt into the mouth, not systemically, through ingestion. (CDC 1999. Achievements in Public Health, 1900-1999: Fluoridation of Drinking Water to Prevent Dental Caries. Mortality and Morbidity Weekly Review (MMWR), 48(41);933-940 October 22, 1999.)
Someone messed up… and now they are reducing the fluoride in the drinking water without a peep to the public.
Dr. Dick Ito, in 2007, confirmed the observations I made in my own patients and found that in our region every tenth child had dental fluorosis that needed treatment (Ito D. A Cross-sectional Study to Compare Caries and Fluorosis in 7-year-old Schoolchildren from a Fluoridated Area with Those in a Neighbouring Non-fluoridated Area in Ontario. 2007, MSc Thesis, University of Toronto).
An attempt was made recently by the Chief Dental Officer of Canada to conduct a survey of fluorosis in Canada but this survey was not scientifically conducted. Non-fluoridated communities were selected at a ratio of two to one over fluoridated communities, it was not blinded or randomized, and there was no attempt to adjust for life-long fluoride exposure. The survey remains unpublished in an internationally-recognized journal and has not been peer-reviewed. Even so the Chief Dental Officer of Canada concluded that “the prevalence (of moderate to severe fluorosis) is too low to permit reporting”. http://cof-cof.ca/wp-content/uploads/2012/09/Oral-Health-Statistics-2007-2009-Canadian-Health-Measures-Survey-CHMS-Health-Canada.pdf
In my opinion, the Canadian Health Measures Survey did little to add to our knowledge of dental fluorosis and its national prevalence pattern.
The psychosocial effects of dental fluorosis.
Having treated dozens of children for dental fluorosis I can say from my own experience as a practicing dentist that these children are psychologically and socially affected by their dental ‘scarring’. Similar to how children are psycologically and socially impacted by acne scarring from years of acne. Both such children are often ridiculed or ostricized simply because of the way they look.
How would society react to a medication added to the drinking water that was supposed to prevent skin infections but left 4% to 10% of the population with irreversible acne scars? Public health might say, we’re lowering more severe skin infections by 10%. Most teens get acne. Acne is just a cosmetic side effect of the medication that we are putting in your drinking water– the scars can be covered up by make-up.
Society looks down on children who have ‘scarred’ teeth. The study by Bennett concluded, “…participants were significantly more likely to make negative judgments involving health, aesthetic, and person attributions about faces with high levels of fluorosis, and to make negative judgments more quickly and positive judgments more slowly than those with lower levels of fluorosis.” (Bennett P, Williams D, Chestnutt I, Hood K, Lowe R. A reaction-time study of social, health, and personal attributions in relation to fluorosed teeth. Psychol Health Med. 2008 Jan;13(1):75-86.)
The cost of treating dental fluorosis.
It costs a LOT of money to treat dental fluorosis.
If you have to cap the teeth with porcelain crowns or cover the front of the teeth with porcelain veneers it can cost tens of thousands of dollars!
See http://cof-cof.ca/wp-content/uploads/2012/09/Osmunson-Water-Fluoridation-Intervention-Dentistry%E2%80%99s-Crown-Jewel-Or-Dark-Hour-Guest-Editorial-Fluoride-404214%E2%80%93221-Oct-Dec-2007.pdf for a discussion and some images.
I showed that some minor dental fluorosis can be treated with microabrasion and bleaching (Limeback H, Vieira AP, Lawrence H. Improving esthetically objectionable human enamel fluorosis with a simple microabrasion technique. Eur J Oral Sci. 2006 May;114 Suppl 1:123-6; discussion 127-9, 380.)
However, because repairing dental fluorosis is considered ‘cosmetic’ dental insurance companies do not pay for these repairs.
In my estimate, repairing all those teeth with objectionable fluorosis costs families (on average) more money than it costs to treat the dental decay that fluoridation supposedly prevents.
Ingested fluoride makes teeth brittle and fracture more easily.
The next time you have to go to the dentist for a fractured tooth, ask yourself… Have I been drinking fluoridated water my whole life? Am I a post-fluoride baby?
If the answer is yes to either question, then your teeth are undoubtedly a little more brittle than your pre-fluoride parents. Fluoride accumulates in dentin, the mineralized tissue that supports the outer layer, the enamel. If dentin becomes brittle, entire portions of the tooth are at risk for breaking off, especially if you clench or grind your teeth.
Fluoride is toxic to the cells that make teeth. It alters the expression of genes. It interferes with cellular enzymes. Fluoride that is ingested changes teeth as they develop. If children from birth to age 6 years avoid ingestion of fluoride they do not get dental ‘scarring’.
Challenge to the reader: Look at kids’ teeth when they smile. See if you can identify dental fluorosis. Learn more about the condition. Tell the municipal councillor in your ward that you do not want your kids scarred for life by fluoride medication added to your drinking water by your municipality.
Take home message of blog: Dental fluorosis caused by water fluoridation is scarring our kids’ teeth for life. The practice is morally and ethically indefensible and it has to end.
Future blog topics:
1.Why infants are most at risk for dental fluorosis and developmental problems related to fluoridation.
2. Fluoridation increases lead uptake in children: the consequences.
3. Fluoridation has no effect on baby bottle tooth decay.
Why this dental researcher became concerned that fluoridation can harm human bone.
As a professor, I was fortunate enough to receive years of government funding to analyse the proteins that were responsible for the formation of teeth. I became intrigued by how fluoride interfered with normal tooth development and caused dental fluorosis. Dental fluorosis can range from very mild, almost undetectable white streaking or flecking of the enamel, to a more moderate chalky white discolouration (often with orange permanent staining) to a more severe kind where the enamel seems to be very fragile and ‘flakes off’ the surface leaving behind stained, mottled enamel (a topic of a future blog).
It made sense to me that if too much fluoride ingestion can interfere with the mineralization of teeth, then it could interfere with the process that makes the mineral in bone; both tissues are mineralized with the same fluoride-containing mineral called fluorapatite.
It had been well documented in animals that too much fluorapatite in bone changes the bone’s physical properties making it more brittle and more susceptible to fracture. There had been some human epidemiological studies linking increased fluoride intake from drinking water to increased hip fractures but there were also studies that showed no effect. Clinical drug trials using massive daily doses of fluoride (25 to 50 mg per day) to treat osteoporosis were a disappointment. The side effects were horrendous. Also, researchers found that although large doses of fluoride made bone thicker the bone became more brittle and fractured more easily. The use of fluoride as a bone ‘strengthening’ agent was abandoned.
But fluoridation wasn’t supposed to affect anything except teeth!
Most fluoride ingestion comes from drinking fluoridated water. Fluoride accumulates in bone and the older you get the more ends up in your bones. The concern that fluoridation was weakening bones and increasing the risk for hip fractures in the elderly was heightened by the publication of studies such as this one from Utah.
“We found a small but significant increase in the risk of hip fracture in both men and women exposed to artificial fluoridation at 1 ppm (1 mg/L), suggesting that low levels of fluoride may increase the risk of hip fracture in the elderly.” (Danielson, C., Lyon, J.L., Egger, M., and Goodenough, G.K. 1992. Hip fractures and fluoridation in Utah’s elderly population. Journal of the American Medical Association. 1992, 268:746-748.)
Hip fractures are devastating for the elderly. Up to 36% of the elderly with hip fractures are dead within a year. http://www.ncbi.nlm.nih.gov/pubmed/19421703
If just one hip fracture is attributed to fluoridation, that’s one too many, in my mind. Almost 20 years ago I proposed that Canada consider reducing or eliminating fluoride from drinking water to reduce the risk of bone damage in Canadians (Limeback, H. Fluoride accumulation in human teeth and bones: Is dose adjustment now required? Canadian Journal of Public Health 1993, 84:78-81).
There was really no data in North America that looked at the quality of human bone exposed to low levels of fluoride (fluoridation). So, I decided to secure the help of a well-known bone researcher, Dr. Marc Grynpas of Mt. Sinai Hospital in Toronto, to apply for federal funding to study the effect of fluoride on human bone quality.
Our “Toronto-Montreal Bone Study”
The study, conducted primarily by a PhD student by the name of Debbie Chachra, was simple: she collected donated femoral heads (the tops of the leg bones) from patients at the Mt. Sinai Hospital in Toronto (a fluoridated city since 1964) undergoing total hip replacement, and examined the changes in anatomy and biomechanical properties, comparing the Toronto bones to donated bones from patients at the Montreal Jewish General Hospital (Montreal has never been fluoridated).
Here are some of the observations from that study (her thesis was published in 2001 but the peer-reviewed paper from that study did not appear until 2010) http://www.ncbi.nlm.nih.gov/pubmed/20858781
- Toronto bone samples contained significantly more fluoride than the Montreal bones (1033 ± 438 ppm vs 643 ± 220 ppm)
- fluoride accumulates with age (confirming other published studies)
- “the strength of the bone (was) lower for the more fluoridated group” [the ultimate compressive strength and yield to compressive stress declined with increasing fluoride (p < 0.05)]
- variability of results made it difficult to be certain of the fluoride effect (Debbie managed to secure a total of 92 femoral heads in total; it would have been nice to have collected a lot more specimens)
I suspect if this study were to be repeated with a greater number of patients, with a more homogenous group and limited to only the elderly who have been ingesting fluoridated drinking water for 60 or more years, the results would have been striking.
The York Review: Limitations of Ecological Studies
A group of epidemiologists in the UK, after systematically reviewing the quality of the various epidemiological studies, reported in the ‘York Review’ that fluoridation was not associated with an increased risk of bone fracture. http://www.york.ac.uk/inst/crd/CRD_Reports/crdreport18.pdf
Quite often, the York Review is quoted as the final word that fluoridation does not result in increased bone fractures. Can one really say that? The York reviewers used the meta-analysis technique, which is a systematic and statistical analysis of several studies combined. For an explanation see http://www.medicine.ox.ac.uk/bandolier/painres/download/whatis/meta-an.pdf
However, ecological studies have a huge potential for bias and errors (called ecological fallacy) http://www.nap.edu/openbook.php?record_id=11571&page=439
Using the GIGO principle (“garbage in, garbage out”) I’m not convinced the York reviewers proved much at all regarding the safety of fluoridation and bone quality. Inferences can be made about individuals from the ecological studies at the population level but so many variables still have to be accounted for that we really should be funding properly conducted clinical trials using outcome measures such as serum, urine and bone fluoride levels, bone biomechanics and bone histology.
What about people who retain more fluoride?
Susceptible subgroups of the population retain more fluoride because…
- they either drink a lot more water (diabetes, construction workers in hot climates, athletes),
- consume more fluoride on a dose/kg basis because they are smaller (infants and toddlers) or
- because they are unable to excrete fluoride properly (the elderly, people with renal failure).
With respect to renal patients, Dr. Grynpas’ group found in a study of 153 iliac crest bone biopsies taken from patient with renal osteodystorphy (ROD), a pathological change in bone, the following:
“These results suggested that in ROD, bone fluoride may diminish bone microhardness by interfering with mineralization.” (Ng AH, Hercz G, Kandel R, Grynpas MD. Association between fluoride, magnesium, aluminum and bone quality in renal osteodystrophy. Bone 2004, 34(1):216-24.)
I served on the US National Academies of Sciences Committee on Fluoride in Drinking Water (National Research Council). Our findings, Fluoride in Drinking Water: A Scientific Review of EPA’s Standards, were published in March of 2006 and can be found here: http://www.nap.edu/catalog.php?record_id=11571
We recommended that more research is needed on bone concentrations of fluoride in people with altered renal function, as well as other potentially sensitive populations (e.g., the elderly, postmenopausal women, people with altered acid-balance) to better understand the risks of musculoskeletal effects in these populations.
Fluoridation wasn’t supposed to affect the bones of our kids.
Our NRC committee concluded…
“Dose-response (biological gradient): For the most part, the observational studies discussed above observed higher fracture risk with higher exposure compared with 1 mg/L. The combined findings of Kurttio et al. (1999), Alarcón-Herrera et al. (2001), and Li et al. (2001) lend support to gradients of exposure and fracture risk between 1 and 4 mg/L.”
Dr. Steven Levy, a public health dentist, and his coworkers, started to look at bone health in a cohort of families they have been following in Iowa for many years.
In their 2009 publication looking at whether small daily fluoride exposures can affect kids’ bones they admit, “comparing results for girls and boys, we found consistently small positive associations of fluoride with bone outcomes for boys, but more commonly slight negative associations for girls.” (Levy SM, Eichenberger-Gilmore J, Warren JJ, Letuchy E, Broffitt B, Marshall TA, Burns T, Willing M, Janz K and Torner JC. Associations of fluoride intake with children’s bone measures at age 11. Community Dentistry and Oral Epidemiology 2009, 37: 416–426.)
Public Health’s continuing denial that our bones are at risk.
On Feb.17, 2011, the Association of Local Public Health Agencies (alPHa), in a press release, had this to say.
TORONTO — “The use of fluoride in drinking water is a safe, effective, and economical way to help prevent dental cavities with no scientifically proven adverse health impacts, according to Ontario public health agencies who voted overwhelmingly in support of the fluoridation of community drinking water at an Association of Local Public Health Agencies (alPHa) conference in Toronto last week.”
The use of fluoride in drinking water is safe? …with no scientifically proven adverse health impacts?… really?
Valid studies that show changes to the skeleton as a result of fluoridation have been published. More continue to accumulate in the literature. Public health must be unaware they exist or they interpret them completely differently. I suspect they give them no credence at all because these studies seem to contradict the “safe and effective” message.
Challenge to the reader: Ask your local public health representatives to provide the studies THEY have to prove that ‘the use of fluoride in drinking water is a safe, effective and economical way to prevent dental cavities’. Ask them why they are not monitoring fluoride levels even though municipalities insist on medicating their residents with the drug fluoride (to treat dental decay). Ask your doctor to have your fluoride levels checked.
Take home message for the reader: There ARE studies that show that fluoridation can have adverse health effects on bone.
Dr. Hardy Limeback is a recently retired full professor and former head of Preventive Dentistry at the Faculty of Dentistry, University of Toronto, a position he served for 18 years. His career started with a BSc and PhD in Biochemistry, followed by dental school with graduation in 1983. As a professor, he conducted laboratory research on the proteins responsible for tooth development and studied the effects of fluoride on teeth and bone. An author (and co-author) of over 150 papers, book chapters and abstracts, Dr. Limeback served as president of the Canadian Association for Dental Research (1998-99) and served on the US National Academy of Sciences Subcommittee on Fluoride in Drinking Water. He recently authored and edited a textbook in preventive dentistry (Comprehensive Preventive Dentistry – Wiley-Blackwell, June 2012). His clinical experience included working part-time as an associate general dentist and as Chief Dentist for the Metropolitan Toronto Homes for the Aged. Since 1993 he has been operating his own dental office. Dr. Limeback continues to practice today as a solo practitioner in Mississauga, Ontario, Canada.
We are honoured and delighted to have Dr. Limeback’s wealth of experience and knowledge shared on our informational website.
Robert J. Fleming, President / Spokesperson
Canadians Opposed to Fluoridation ~ Canadiens Opposés à la Fluoration (COF-COF)
Dr. Hardy Limeback BSc PhD (Biochemistry) DDS – Why I am now officially opposed to adding fluoride to drinking water.
To whom it may concern:
Why I am now officially opposed to adding fluoride to drinking water.
Since April of 1999, I have publicly decried the addition of fluoride, especially hydrofluosilicic acid, to drinking water for the purpose of preventing tooth decay. The following summarize my reasons.
New evidence for lack of effectiveness of fluoridation in modern times.
1. Modern studies (published in the 1980’s 1990’s) show dental decay rates are so low in North America that the effects of water fluoridation cannot be measured. Because of the low prevalence of dental decay, water fluoridation studies today must be carefully conducted to correct for mobility of subjects between fluoridated and non-fluoridated areas, access to fluoride from other sources, the lack of blinding and problems with the `halo’ effect. Even when very large sample sizes are used to obtain statistically significant results, the benefit of water fluoridation is not a clinically relevant one (the number of tooth surfaces saved from dental decay per person is less than one half). Recent studies show that halting fluoridation will either result in only a marginal increase in dental decay which cannot be detected or no increase in dental decay at all.
2. The major reasons for the general decline of tooth decay worldwide, both in non-fluoridated and fluoridated areas, is the widespread use of fluoridated toothpaste, improved diets, and overall improved general and dental health (antibiotics, preservatives, hygiene etc).
3. There is now a better understanding of how fluoride prevents dental decay. What little benefit fluoridated water may still provide is derived primarily through topical means (after the teeth erupt and come in contact with fluorides in the oral cavity). Fluoride does not need to be swallowed to be effective. It is not an essential nutrient. Nor should it be considered a desirable `supplement’ for children living in non-fluoridated areas. Fluoride ingestion delays tooth eruption and this may account for some of the differences seen in the past between fluoridated and non-fluoridated areas (i.e. dental decay is simply postponed). No fluoridation study has ever separated out the systemic effects of fluoride. Even if there were a systemic benefit from ingestion of fluoride, it would be miniscule and clinically irrelevant. The notion that systemic fluorides are needed in non-fluoridated areas is an outdated one that should be abandoned altogether.
New evidence for potential serious harm from long-term fluoride ingestion.
1. Hydrofluorosilicic acid is recovered from the smokestack scrubbers during the production of phosphate fertilizer and sold to most of the major cities in North America, which use this industrial grade source of
fluoride to fluoridate drinking water, rather than the more expensive pharmaceutical grade sodium fluoride salt. Fluorosilicates have never been tested for safety in humans. Furthermore, these industrial-grade
chemicals are contaminated with trace amounts of heavy metals such as lead, arsenic and radium that accumulate in humans. Increased lead levels have been found in children living in fluoridated communities.
Osteosarcoma (bone cancer) has been shown to be associated with radium in the drinking water. Long-term ingestion of these harmful elements should be avoided altogether.
2. Half of all ingested fluoride remains in the skeletal system and accumulates with age. Several recent epidemiological studies suggest that only a few years of fluoride ingestion from fluoridated water increases
the risk for bone fracture. The relationship between the milder symptoms of bone fluorosis (joint pain and arthritic symptoms) and fluoride accumulation in humans has never been investigated. People unable to
eliminate fluoride under normal conditions (kidney impairment) or people who ingest more than average amounts of water (athletes, diabetics) are more at risk to be affected by the toxic effects of fluoride accumulation.
3. There is a dose-dependent relationship between the prevalence/severity of dental fluorosis and fluoride ingestion. When dental decay rates were high, a certain amount of dental fluorosis was considered an
acceptable `trade off’ of providing an `optimum’ dose of 1.0 ppm fluoride in the water. However, studies published in the 1980’s and 1990’s have shown that dental fluorosis has increased dramatically in North
America. Infants and toddlers are especially at risk for dental fluorosis of the front teeth since it is during the first 3 years of life that the permanent front teeth are the most sensitive to the effects of fluoride. Children fed formula made with fluoridated tap water are at higher risk to develop dental fluorosis. A relatively small percentage of the children affected with dental fluorosis have the more severe kind that requires extensive restorative dental work to correct the damage. The long-term effect of fluoride accumulation on dentin colour and biomechanics is also unknown. Generalized dental fluorosis of all the permanent teeth indicates that the bone is a major source of the excess fluoride. The effect of this excess amount of fluoride in bone is unknown. Whether stress bone fractures occur more often in children with dental fluorosis has not been studied.
4. A lifetime of excessive fluoride ingestion will undoubtedly have detrimental effects on a number of biological systems in the body and it is illogical to assume that tooth enamel is the only tissue affected by low
daily doses of fluoride ingestion. Fluoride activates G-protein and a number of cascade reactions in the cell. At high concentrations it is both mitogenic and genotoxic. Some published studies point to fluoride’s
interference with the reproductive system, the pineal gland and thyroid function. Fluoride is a proven carcinogen in humans exposed to high industrial levels. No study has yet been conducted to determine the
level of fluoride that bone cells are exposed to when fluoride-rich bone is turned over. Thus, the issue of fluoride causing bone cancer cannot be dismissed as being a non-issue since carefully conducted animal
and human cancer studies using the exact same chemicals added to our drinking water have not been carried out. The issue of mass medication of an unapproved drug without the expressed informed consent of each individual must also be addressed. The dose of fluoride cannot be controlled. Fluoride as a drug has contaminated most processed foods and beverages throughout North America. Individuals who are
susceptible to fluoride’s harmful effects cannot avoid ingesting this drug. This presents a medico-legal and ethical dilemma and sets water fluoridation apart from vaccination as a public health measure where doses and distribution can be controlled. The rights of individuals to enjoy the freedom from involuntary fluoride medication certainly outweigh the right of society to enforce this public health measure, especially when the evidence of benefit is marginal at best. Based on the points outlined briefly above, the evidence has convinced me that the benefits of water fluoridation no longer outweigh the risks. The money saved from halting water fluoridation programs can be more wisely spent on concentrated public health efforts to reduce dental decay in the populations that are still at risk and this will, at the same time, lower the incidence of the harmful side effects that a large segment of the general population is currently experiencing because of this outdated public health measure.
Dr. Hardy Limeback BSc PhD (Biochemistry) DDS
Head, Preventive Dentistry
Water fluoridation less effective in the late 1980’s and the 1990’s.
Water fluoridation cessation studies:
Attwood D, Blinkhorn AS. Dental health in school children 5 years after water fluoridation ceased in southwest. Scotland. Dent J. 1991 Feb;41(1):43-8.
Kobayashi S, Kawasaki K, Takagi O, Nakamura M, Fujii N, Shinzato M, Maki Y, Takaesu Y. Caries experience in subjects 18-22 years of age after 13 years’ discontinued water fluoridation in Okinawa. Community Dent Oral Epidemiol. 1992 Apr;20(2):81-3.
Kalsbeek H, Kwant GW, Groeneveld A, Dirks OB, van Eck AA, Theuns HM. Caries experience of 15-year old children in The Netherlands after discontinuation of water fluoridation. Caries Res. 1993;27(3):201-5.
Seppa L, Karkkainen S, Hausen H. Caries frequency in permanent teeth before and after discontinuation of water fluoridation in Kuopio, Finland. Community Dent Oral Epidemiol. 1998 Aug;26(4):256-62.
Kunzel W, Fischer T. Caries prevalence after cessation of water fluoridation in La Salud, Cuba. Caries Res. 2000 Jan-Feb;34(1):20-5.
Burt BA, Keels MA, Heller KE. The effects of a break in water fluoridation on the development of dental caries and fluorosis. J Dent Res. 2000 Feb;79(2):761-9.
Comparison of fluoridated and non-fluoridated communities.
Brunelle JA, Carlos JP. Recent trends in dental caries in U.S. children and the effect of water fluoridation. J Dent Res. 1990 Feb;69 Spec No:723-7; discussion 820-3.
Ismail AI, Shoveller J, Langille D, MacInnis WA, McNally M. Should the drinking water of Truro, Nova Scotia, be fluoridated? Water fluoridation in the 1990s. Community Dent Oral Epidemiol. 1993 Jun;21(3):118-25.
Jackson RD, Kelly SA, Katz BP, Hull JR, Stookey GK. Dental fluorosis and caries prevalence in children residing in communities with different levels of fluoride in the water. J Public Health Dent. 1995 Spring;55(2):79-84.
Slade GD, Davies MJ, Spencer AJ, Stewart JF. Associations between exposure to fluoridated drinking water and dental caries experience among children in two Australian states. J Public Health Dent. 1995 Fall;55
Kumar JV, Swango PA, Lininger LL, Leske GS, Green EL, Haley VB. Changes in dental fluorosis and dental caries in Newburgh and Kingston, New York. Am J Public Health. 1998 Dec;88(12):1866-70.
Angelillo IF, Torre I, Nobile CG, Villari P. Caries and fluorosis prevalence in communities with different concentrations of fluoride in the water. Caries Res. 1999;33(2):114-22.
Decline of caries is not all due to fluoride.
Bratthall D, Hansel Petersson G, Sundberg H. (1996) Reasons for the caries decline. What do the experts believe? Euro J Oral Sci 104:416-422 de Liefde B. The decline of caries in New Zealand over the past 40 years. N Z Dent J. 1998 Sep;94(417):109-13.
Birkeland JM, Haugejorden O, Ramm Von Der Fehr F. Some factors associated with the caries decline among norwegian children and adolescents: age-specific and cohort analyses. Caries Res. 2000 Mar-Apr;34
Krasse B. From the art of filling teeth to the science of dental caries prevention: a personal review. J Public Health Dent. 1996;56(5 Spec No):271-7.
Dental fluorosis is now an epidemic.
Leverett D. Prevalence of dental fluorosis in fluoridated and nonfluoridated communities—a preliminary investigation. J Public Health Dent. 1986 Fall;46(4):184-7.
Pendrys DG, Stamm JW. Relationship of total fluoride intake to beneficial effects and enamel fluorosis. J Dent Res. 1990 Feb;69 Spec No:529-38; discussion 556-7.
Szpunar SM, Burt BA. Evaluation of appropriate use of dietary fluoride supplements in the US. Community Dent Oral Epidemiol. 1992 Jun;20(3):148-54.
Riordan PJ. Perceptions of dental fluorosis. J Dent Res. 1993 Sep;72(9):1268-74.
Clark DC. Appropriate use of fluorides in the 1990’s. J Can Dent Assoc. 1993 Mar;59(3):272-9.
Clark DC. Trends in prevalence of dental fluorosis in North America. Community Dent Oral Epidemiol. 1994
Lalumandier JA, Rozier RG. The prevalence and risk factors of fluorosis among patients in a pediatric dental practice. Pediatr Dent. 1995 Jan-Feb;17(1):19-25.
Pendrys DG, Katz RV, Morse DE. Risk factors for enamel fluorosis in a nonfluoridated population. Am J Epidemiol. 1996 Apr 15;143(8):808-15.
Limeback H, Ismail A, Banting D, DenBesten P, Featherstone J, Riordan PJ. Canadian Consensus Conference on the appropriate use of fluoride supplements for the prevention of dental caries in children. J Can Dent Assoc. 1998 Oct;64(9):636-9.
Kumar JV, Swango PA. Fluoride exposure and dental fluorosis in Newburgh and Kingston, New York: policy implications. Community Dent Oral Epidemiol. 1999 Jun;27(3):171-80.
Rozier RG. The prevalence and severity of enamel fluorosis in North American children. J Public Health Dent. 1999 Fall;59(4):239-46.
Fluoride ingestion delays tooth eruption and may simply delay tooth decay.
Kunzel VW. [Cross-sectional comparison of the median eruption time for permanent teeth in children from fluoride poor and optimally fluoridated areas]. Stomatol DDR. 1976 May;5:310-21.
Virtanen JI, Bloigu RS, Larmas MA. Timing of eruption of permanent teeth: standard Finnish patient documents. Community Dent Oral Epidemiol. 1994 Oct;22(5 Pt 1):286-8.
Campagna L, Tsamtsouris A, Kavadia K. Fluoridated drinking water and maturation of permanent teeth at age 12. J Clin Pediatr Dent. 1995 Spring;19(3):225-8.
Nadler GL: Earlier dental maturation: fact or fiction? Angle Orthod 1998 Dec;68(6):535-8
Krook L, Maylin GA, Lillie JH, Wallace RS. Dental fluorosis in cattle. Cornell Vet. 1983 Oct;73(4):340-62.
Smith CE, Nanci A, Denbesten PK. Effects of chronic fluoride exposure on morphometric parameters defining the stages of amelogenesis and ameloblast modulation in rat incisors. Anat Rec. 1993 Oct;237(2):243-58.
The anti-caries benefit from swallowed fluoride is miniscule compared to the post-eruptive topical effects.
Heifetz SB, Proskin HM. Serendipitous results of a pilot study: precaution indicated. J Clin Dent. 1995;6(1):117-9.
Burt, B.A. (1994). Letter. Fluoride, 27, 180-181.
Carlos, J.P. (1983). Comments on Fluoride. J.Pedodontics. Winter, 135-136.
Fejerskov O, Thylstrup A, Larsen MJ. Rational use of fluorides in caries prevention. A concept based on possible cariostatic mechanisms Acta Odontol Scand.1981;39(4):241-9.
Levine, R.S., (1976). The action of fluoride in caries prevention: a review of current concepts. Brit. Dent. J. 140, 9-14.
Martens LC, Verbeeck RM. [Mechanism of action of fluorides in local/topical application]. Rev Belge Med Dent. 1998;53(1):295-308.
Featherstone JD. Prevention and reversal of dental caries: role of low level fluoride. Community Dent Oral Epidemiol. 1999 Feb;27(1):31-40.
Limeback H. A re-examination of the pre-eruptive and post-eruptive mechanism of the anti-caries effects of fluoride: is there any anti-caries benefit from swallowing fluoride? Community Dent Oral Epidemiol. 1999Feb;27(1):62-71.
Fluoridated water is associated with an increase risk for bone fracture.
Jacobsen SJ, Goldberg J, Miles TP, Brody JA, Stiers W, Rimm AA. Regional variation in the incidence of hip fracture. US white women aged 65 years and older. JAMA. 1990 Jul 25;264(4):500-2.
Sowers MF, Clark MK, Jannausch ML, Wallace RB. A prospective study of bone mineral content and fracture in communities with fluoride exposure. Am J Epidemiol. 1991 Apr 1;133(7):649-60.
Cooper C, Wickham CA, Barker DJ, Jacobsen SJ. Water fluoridation and hip fracture. JAMA. 1991 Jul 24-31;266(4):513-4.
Danielson C, Lyon JL, Egger M, Goodenough GK. Hip fractures and fluoridation in Utah’s elderly population. JAMA. 1992 Aug 12;268(6):746-8.
Jacobsen SJ, Goldberg J, Cooper C, Lockwood SA. The association between water fluoridation and hip fracture among white women and men aged 65 years and older. A national ecologic study. Ann Epidemiol. 1992 Sep;2(5):617-26
Jacqmin-Gadda H, Commenges D, Dartigues JF. Fluorine concentration in drinking water and fractures in the elderly. JAMA. 1995 Mar 8;273(10):775-6.
Hillier S, Inskip H, Coggon D, Cooper C. (1996) Water fluoridation and osteoporotic fracture. Community Dent Health Suppl 2:63-8
Karagas MR, Baron JA, Barrett JA, Jacobsen SJ. Patterns of fracture among the United States elderly: geographic and fluoride effects. Ann Epidemiol. 1996 May;6(3):209-16.
Papadimitropoulos EA, Coyte PC, Josse RG, Greenwood CE. Current and projected rates of hip fracture in Canada. CMAJ. 1997 Nov 15;157(10):1357-63.
Feskanich D, Owusu W, Hunter DJ, Willett W, Ascherio A, Spiegelman D, Morris S, Spate VL, Colditz G. Use of toenail fluoride levels as an indicator for the risk of hip and forearm fractures in women. Epidemiology. 1998 Jul;9(4):412-6.
Allolio B, Lehmann R. Drinking water fluoridation and Exp Clin Endocrinol Diabetes. 1999;107(1):12-20.
Kurttio P, Gustavsson N, Vartiainen T, Pekkanen J. Exposure to natural fluoride in well water and hip fracture: a cohort analysis in Finland. Am J Epidemiol. 1999 Oct 15;150(8):817-24.
Hillier S, Cooper C, Kellingray S, Russell G, Hughes H, Coggon D. Fluoride in drinking water and risk of hip fracture in the UK: a case-control study. Lancet. 2000 Jan 22;355(9200):265-9.
Fluorosilicates, lead, arsenic, radium and other harmful contaminants in our fluoridated water are toxic
Denzinger HF, Konig HJ, and Kruger GE 1979 No. 103 sept/Oct issue of ‘Phosphorus and Potassium’
Lyman GH, Lyman CG, Johnson W. Association of leukemia with radium groundwater contamination. JAMA. 1985 Aug 2;254(5):621-6.
Finkelstein MM. Radium in drinking water and the risk of death from bone cancer among Ontario youths. CMAJ. 1994 Sep 1;151(5):565-71.
Moss ME, Kanarek MS, Anderson HA, Hanrahan LP, Remington PL. Osteosarcoma, seasonality, and environmental factors in Wisconsin, 1979-1989. Arch Environ Health. 1995 May-Jun;50(3):235-41.
Maki-Paakkanen J, Kurttio P, Paldy A, Pekkanen J. Association between the clastogenic effect in peripheral lymphocytes and human exposure to arsenic through drinking water. Environ Mol Mutagen. 1998;32(4):301-13.
Masters RD, Coplan M. Water treatment with Silicofluorides and Lead Toxicity. Intern J of Environ Studies 1999 56:435-449
Moss ME, Lanphear BP, Auinger P. Association of dental caries and blood lead levels. JAMA. 1999 Jun 23-30;281(24):2294-8.
Kurttio P, Pukkala E, Kahelin H, Auvinen A, Pekkanen J. Arsenic concentrations in well water and risk of bladder and kidney cancer in Finland. Environ Health Perspect. 1999 Sep;107(9):705-10.
Finkelstein MM. Silica, silicosis, and lung cancer: a risk assessment. Am J Ind Med. 2000 Jul;38(1):8-18.
Saffiotti U, Ahmed N. Neoplastic transformation by quartz in the BALB/3T3/A31-1-1 cell line and the effects of associated minerals. Teratog Carcinog Mutagen. 1995 15(6):339-56.
Studies reporting a link between fluoride and cancer – some show a trend for increase risk of bone cancer in young males.
Zeiger E, Shelby MD, Witt KL. Genetic toxicity of fluoride. Environ Mol Mutagen. 1993;21(4):309-18.
Cohn, P.D. (1992). “An Epidemiologic Report on Drinking Water and Fluoridation”. New Jersey Department of Health, Trenton, NJ.
Bucher JR, Hejtmancik MR, Toft JD 2d, Persing RL, Eustis SL, Haseman JK. Results and conclusions of the National Toxicology Program’s rodent carcinogenicity studies with sodium fluoride. Int J Cancer. 1991 Jul 9;48(5):733-7.
Hoover RN “Fluoridation of Drinking Water and Subsequent Cancer Incidence and Mortality” In Review of Fluoride: Benefits and Risks, Report of the Ad Hoc Committee on Fluoride of the Committee to Coordinate Environmental Health and Related Programs. US Public Health Service, pp E1-E51.
Tohyama E. Relationship between fluoride concentration in drinking water and mortality rate from uterine cancer in Okinawa prefecture, Japan. J Epidemiol. 1996 Dec;6(4):184-91.
Lee JR. Fluoridation and Bone Cancer. Fluoride 1993;26(2):79-82.
Yiamouyiannis JA. Fluoridation and cancer: The biology and epidemiology of bone and oral cancer related to fluoridation. Fluoride 1993;26(2):83-96.
Galanti MR, Sparen P, Karlsson A, Grimelius L, Ekbom A. Is residence in areas of endemic goiter a risk factor for thyroid cancer? Int J Cancer. 1995 May 29;61(5):615-21.
Grandjean P, Olsen JH, Jensen OM, Juel K. Cancer incidence and mortality in workers exposed to fluoride. J Natl Cancer Inst. 1992 Dec 16;84(24):1903-9.
Tsutsui T, Ide K, Maizumi H. Induction of unscheduled DNA synthesis in cultured human oral keratinocytes by sodium fluoride. Mutat Res. 1984 May;140(1):43-8
Aardema MJ, Gibson DP, LeBoeuf RA. Sodium fluoride-induced chromosome aberrations in different stages of the cell cycle: a proposed mechanism. Mutat Res. 1989 Jun;223(2):191-203.
Scott D, Roberts SA. Extrapolation from in vitro tests to human risk: experience with sodium fluoride clastogenicity. Mutat Res. 1987 Sep;189(1):47-58
Publications arguing against the link between fluoride and cancer. Why? – failure to recognize in most cases that hydrofluosilicic acid (and its radium and arsenic contaminants), not pure sodium fluoride, was used to fluoridate water -the increase in risk from 1 ppm fluoridated water for all cancers is low, for osteosarcomas, it is extremely low, but it should still be detectable with sufficient sample sizes.
Chilvers C. Cancer mortality and fluoridation of water supplies in 35 USA cities. Int J Epidemiol 1983;12(4):397-404.
Shupe JL, Bruner RH, Seymour JL, Alden CL. The pathology of chronic bovine fluorosis: a review. Toxicol Pathol. 1992;20(2):274-85; discussion 285-8.
Freni SC, Gaylor DW. International trends in the incidence of bone cancer are not related to drinking water fluoridation. Cancer 1992;70(3):611-618.
Clemmesen J. Alleged association between artificial fluoridation of water supplies and cancer: review. Bull. WHO 1983;61(5):871-883.
Cook-Mozaffari P, Doll R. Fluoridation of Water Supplies and Cancer Mortality 2. Mortality Trends After Fluoridation. J Epidemiol Community Health 1981;35(4):233-238.
Doll R, Kinlen L. Fluoridation of water and cancer mortality in the U.S.A. Lancet 1977;1(Jun):1300-1302.
Griffith GW. Fluoridation and Cancer Mortality in Anglesey Wales Uk. J Epidemiol Community Health 1985;39(3):224-226.
Kinlen L, Doll R. Fluoridation of Water Supplies and Cancer Mortality 3. a Reexamination of Mortality in Cities in the Usa. J Epidemiol Community Health 1981;35(4):239-244.
Hoover RN, McKay FW, Fraumeni JFJ. Fluoridated drinking water and the occurrence of cancer. J Natl Cancer Inst 1976;57(4):757-768.
Walker AR, Cleaton-Jones PE, Richardson BD. Fluoridation and Cancer. S Afr Med J 1981;60(23):878-879.
Thomson WM. Dental health: water fluoridation, hip fracture, osteosarcoma–recent evidence. N. Z. Pharm. 1997;17(Nov):40-42.
Jackson RD, Kelly SA, Noblitt TW, Zhang W, Wilson ME, Dunipace AJ, Li Y, Katz BP, Brizendine EJ, Stookey GK. Lack of effect of long-term fluoride ingestion on blood chemistry and frequency of sister chromatid exchange in human lymphocytes. Environ Mol Mutagen. 1997;29(3):265-71.
Fluoride is neurotoxic.
Hu YH, Wu SS. Fluoride in cerebrospinal fluid of patients with fluorosis. J Neurol Neurosurg Psychiatry. 1988 Dec;51(12):1591-3.
Holland, R.I. Fluoride inhibition of protein synthesis. Cell Biol. Int. Rep. 1979 3:701-705
Jope RS. Modulation of phosphoinositide hydrolysis by NaF and aluminum in rat cortical slices. J. Neurochem. 1988 51:1731-1736.
Kay AR, Miles R, Wong RKS. Intracellular fluoride alters the kinetic properties of calcium currents facilitating the investigation of synaptic events in hippocampal neurons. J. Neurosci. 1986 6: 2915-2920.
Varner JA, Jensen KF Isaacson RL. Toxin-induced blood vessel inclusions caused by the chronic administration of aluminum and sodium fluoride and their implications for dementia. Ann. N.Y. Acad. Sci. 1997 825: 152-166.
Mullenix PJ, Denbesten PK, Schunior A, Kernan WJ. Neurotoxicity of sodium fluoride in rats. Neurotoxicol Teratol. 1995 Mar-Apr;17(2):169-77.
Varner JA, Jensen KF, Horvath W, Isaacson RL. Chronic administration of aluminum-fluoride or sodiumfluoride to rats in drinking water: alterations in neuronal and cerebrovascular integrity. Brain Res. 1998 Feb16;784(1-2):284-98.
Varner JA, Horvath WJ, Huie CW, Naslund HR, Isaacson RL. Chronic aluminum fluoride administration. I. Behavioral observations. Behav Neural Biol. 1994 May;61(3):233-41.
Zhao LB, Liang GH, Zhang DN, Wu XR. Effect of high fluoride water supply on children’s intelligence. Fluoride 1996 29:190-192.
Li, XS, Zhi JL, RO. Effect of fluoride exposure on intelligence in children. Fluoride 1995 28(4):189-192.
Luke JA. Effect of fluoride on the physiology of the pineal gland. CariesResearch 1994 28:204.
Bahavior not affected by fluoride?
Morgan L, Allred E, Tavares M, Bellinger D, Needleman H. Investigation of the possible associations between fluorosis, fluoride exposure, and childhood behavior problems. Pediatr Dent. 1998 Jul-Aug;20
Fluoride affects reproduction.
Dominguez L, Diaz A, Fornes MW, Mayorga LS. Reagents that activate GTP-binding proteins trigger the acrosome reaction in human spermatozoa. Int J Androl. 1995 Aug;18(4):203-7.
Hoffman DJ, Pattee OH, Wiemeyer SN. Effects of fluoride on screech owl reproduction: teratological evaluation, growth, and blood chemistry in hatchlings. Toxicol. Lett. 1985 26: 19-24.
Eckerlin, R.H., Maylin, G.A., Krook, L., and Carmichael, D.T. Cornell Ameliorative effects of reduced foodborne fluoride on reproduction in silver foxes.Vet. 1988 78 75-91.
Narayana MV, Chinoy NJ Reversible effects of sodium fluoride ingestion on spermatozoa of the rat Int J Fertil Menopausal Stud 1994 Nov-Dec;39(6):337-46
Messer HH, Armstrong WD, Singer L. Fertility impairment in mice on a low fluoride intake. Science. 1972 Sep 8;177(52):893-4
Haesungcharern A, Chulavatnatol M. Inhibitors of adenylate cyclase from ejaculated human spermatozoa. J Reprod Fertil. 1978 May;53(1):59-61
Susheela AK, Jethanandani P. Circulating testosterone levels in skeletal fluorosis patients. J Toxicol Clin Toxicol. 1996;34(2):183-9.
Kumar A, Susheela AK. Effects of chronic fluoride toxicity on the morphology of ductus epididymis and the maturation of spermatozoa of rabbit. Int J Exp Pathol. 1995 Feb;76(1):1-11.
Nicol CJ, Zielenski J, Tsui LC, Wells PG. An embryoprotective role for glucose-6-phosphate dehydrogenase in developmental oxidative stress and chemical teratogenesis. FASEB J. 2000 Jan;14(1):111-27.
No fluoride effect on reproduction?
Merkley JW, Sexton TJ Reproductive performance of White Leghorns provided fluoride Poult Sci 1982 Jan;61(1):52-6
Fluoride can affect thyroid hormones and, therefore, many other organs.
Susa M. “Heterotrimeric G proteins as fluoride targets in bone (Review). Int J Mol Med 3(2):115-126 (1999)
Caverzasio J, Palmer G, Suzuki A, Bonjour JP. Mechanism of the mitogenic effect of fluoride on osteoblastlike cells: evidences for a G protein-dependent tyrosine phosphorylation process. J Bone Miner Res. 1997 Dec;12(12):1975-83.
Susa M, Standke GJ, Jeschke M, Rohner D. Fluoroaluminate induces pertussis toxin-sensitive protein phosphorylation: differences in MC3T3-E1 osteoblastic and NIH3T3 fibroblastic cells. Biochem Biophys Res
Commun. 1997 Jun 27;235(3):680-4.
Galletti PM, Joyet G – “Effect of fluoride on thyroidal iodine metabolism in hyperthyroidism” J Clin Endocrinol 18:1102-1110 (1958)
Gedalia I, Brand N. The relationship of fluoride and iodine in drinking water in the occurrence of goiter. Arch Int Pharmacodyn 1963;142:312-5.
Gorlitzer von Mundy. Einfluss von Fluor und Jod auf den Stoffwechsel, insbesondere auf die Schilddrüss. Münch Med Wochenschrift 105:234-247 (1963)
Litzka G – “Die experimentellen Grundlagen der Behandlung des M. Basedow und der Hyperthyreose mittels Fluortyrosin” Dtsch Med Wochenschr 63:1037-1040 (1937)
Gordonoff T. – Fluor und die Schilddrüse, Toxikology des Fluors Basel/Stuttgart, pp.111-123 (1964)
May W. Antagonismus zwischen Jod und Fluor im Organismus. Klin Wochenschr 14:790-792 (1935)
May W. Behandlung der Hypothyreosen einschließlich des schweren genuinenMorbus Basedow mit Fluor” Klin Wochenschr 16:562-564 (1937)
Haddow JE, Palomaki GE, Allan WC, et al. -“Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child.” N Engl J Med 341:549-55 (1999)]
Eckerlin, R.H.,Maylin, G.A., and Krook, L. Cornell Vet. 76 403-404 (1986). Milk production of cows fed fluoride contaminated commercial feed.
Balabolkin MI, Mikhailets ND, Lobovskaia RN, Chernousova NV. [The interrelationship of the thyroid and immune statuses of workers with long-term fluorine exposure]. Ter Arkh. 1995;67(1):41-2.
Krishnamachari KA Skeletal fluorosis in humans: a review of recent progress in the understanding of the disease. Prog Food Nutr Sci 1986;10(3-4):279-314
Tezelman S, Shaver JK, Grossman RF, Liang W, Siperstein AE, Duh QY, Clark OH. Desensitization of adenylate cyclase in Chinese hamster ovary cells transfected with human thyroid-stimulating hormone
receptor. Endocrinology. 1994 Mar;134(3):1561-9.
Fluoride enters the placenta and may cause birth defects.
Malhotra A, Tewari A, Chawla HS, Gauba K, Dhall K. Placental transfer of fluoride in pregnant women consuming optimum fluoride in drinking water. J Indian Soc Pedod Prev Dent. 1993 Mar;11(1):1-3
Armstrong WD, Singer L, Makowski EL. Placental transfer of fluoride and calcium. Am J Obstet Gynecol. 1970 Jun 1;107(3):432-4.
Erickson JD. Fluoridation and Down Syndrome. J Dental Res 58a 1979;228.
Erickson JD. Down Syndrome, Water Fluoridation, and Maternal Age. Teratology 1980;21(177-180).
Gupta SK, Gupta RC, Seth AK, Chaturvedi CS. Increased incidence of spina bifida occulta in fluorosis prone areas. Acta Paediatr Jpn. 1995 Aug;37(4):503-6.
Fluoride may affect the immune system.
Loftenius A, Andersson B, Butler J, Ekstrand J. Fluoride augments the mitogenic and antigenic response of human blood lymphocytes in vitro. Caries Res. 1999;33(2):148-55.
Gutierrez J, Liebana J, Ruiz M, Castillo A, Gomez JL. Action of sodium fluoride on phagocytosis by systemic polymorphonuclear leucocytes. J Dent. 1994 Oct;22(5):279-82.
Sutton PR. Is the ingestion of fluoride an immunosuppressive practice? Med Hypotheses. 1991 May;35(1):1-3.
Spittle B. Allergy and hypersensitivity to fluoride. Fluoride 1993 26: 267-273.
Gabler WL, Mugrditchian M, Creamer HR, Bullock WW. Effect of fluoride on movement of concanavalin Aacceptor molecules of human neutrophils. Inflammation. 1989 Jun;13(3):317-28.
Gabler WL, Creamer HR, Bullock WW. Fluoride activation of neutrophils: similarities to formylmethionylleucyl-phenylalanine. Inflammation. 1989 Feb;13(1):47-58.
Gabler WL, Hunter N. Inhibition of human neutrophil phagocytosis and intracellular killing of yeast cells by fluoride. Arch Oral Biol. 1987;32(5):363-6
Gomez-Ubric JL, Liebana J, Gutierrez J, Castillo A. In vitro immune modulation of polymorphonuclear leukocyte adhesiveness by sodium fluoride. Eur J Clin Invest. 1992 Oct;22(10):659-61
Lewis A, Wilson CW. Fluoride hypersensitivity in mains tap water demonstrated by skin potential changes in guinea-pigs. Med Hypotheses. 1985 Apr;16(4):397-402
Hirano S, Ando M, Kanno S. Inflammatory responses of rat alveolar macrophages following exposure to fluoride. Arch Toxicol. 1999 Aug;73(6):310-5.
O’Shea JJ, Urdahl KB, Luong HT, Chused TM, Samelson LE, Klausner RD. Aluminum fluoride induces phosphatidylinositol turnover, elevation of cytoplasmic free calcium, and phosphorylation of the T cell antigen receptor in murine T cells. J Immunol. 1987 Nov 15;139(10):3463-9
Gutierrez J, Liebana J, Ruiz M, Castillo A, Gomez JL. Action of sodium fluoride on phagocytosis by systemic polymorphonuclear leucocytes. J Dent. 1994 Oct;22(5):279-82.