Fluoride in dentistry is a cell poison

by Jan Sällström

(på svenska)

FLUORIDE IS GOOD for your teeth and reduces caries. So we have been told by campaigners for decades. Fluoride rinsing was arranged on a weekly basis in Swedish schools during the 60's, 70's and 80's, and there were discussions about whether tap water in Sweden should be generally fluoridated, like it is in many other countries. But the opponents of fluoridation claimed that fluoride is a poison and that tap water fluoridation is actually a form of compulsory medication unworthy of a democratic country. Today fluoride rinsing is on its way back in schools - while more and more countries put more and more serious warning labels on their fluoride toothpaste packages. So, what are we to believe - is fluoride beneficial or dangerous? Personally, my opinion is that fluoride prophylaxis is one of the largest experiments in medicine history. We all ingest fluoride through food and water. The daily dose among adults, consuming normal amounts of water, is estimated to 0.5-2 mg in low fluoride areas and 2-5 mg in areas with a fluoride content in water of 1 mg/liter, which is misleadingly denoted "optimum" fluoride content (1). This concentration prevails naturally in, for instance, the Swedish cities Uppsala and Eskilstuna. The National Food Administration has issued new regulations for fluoride concentration in Swedish tap water, based on an EC directive. From 25 December 2003, tap water is not allowed a higher concentration of fluoride than 1.5 mg/liter (2). The reason for this is that fluoride damages chiefly the teeth and the skeleton, since it is a potent cell poison. Big consumers of tap water, for instance diabetics and renal patients, may ingest much larger amounts. This intake is only excreted partly through the kidneys, up to a rate ranging from 20 to 80 percent. The more acidic the urine, the less excretion of fluoride (3). Individuals who eat food that lowers the pH of the urine, for instance a diet rich in meat, will therefore retain more fluoride than individuals producing a more alkaline urine. Retained fluoride will be chemically bound in different organs, principally in the hard tissues of the body, i.e. teeth and bone. Thus, the blood plasma content of fluoride will stay low at appr. 10 micrograms per liter, but will be two to three times higher in people who drink fluoridated water.   Fact box: Fluoride warnings on toothpaste     Both the Swedish National Food Administration and the American FDA nowadays require that toothpaste containing fluoride should be labeled with a special warning. This is a passage from the text on the Theramed Junior toothpaste being sold in Sweden: "The National Board of Health and Welfare recommends the use of fluoride toothpaste in children. Children under seven years of age should brush their teeth supervised by grown-ups." What it is grown-ups should look out for is not specified, however. This toothpaste contains 0.1% fluoride. If a small child were to eat all of the contents (100 g/75 ml), it would ingest 0.1 g (=100 mg) of fluoride. Aqua Fresh for Kids has the following warning: "The amount of fluoride toothpaste used by children should be limited. Use a hardly visible amount for small children, increase to a pea sized portion at the age of 6." The fluoride concentration here is 0.05%. Since the whole tube contains 63g/50 ml, the total amount of fluoride would be 31.5 mg. In the US, for instance Colgate toothpaste is labeled with this text: "Children 2-6 years: Use only a pea sized amount and supervize child's brushing and rinsing (to minimize swallowing). Warning: Keep out of reach of children under 6 years of age in case of accidental ingestion. In case of accidental ingestion, seek professional assistance or contact a Poison Control Center immediately." However, The American Dental Association's (ADA) Council on Scientific Affairs claims that this phrasing "could unnecessarily frighten parents and children, and that the label greatly overstates any demonstrated or potential danger posed by fluoride toothpastes".     Fact box: Fluorine — the chemical element     Fluorine is a greenish yellow gasiform element, which was isolated for the first time in 1886 by Henri Moissan. Fluorine, chlorine, bromine, iodine (together with the instable element astatine) make up the halogen group among the elements. Fluorine atoms have a very strong tendency to bind to other substances, so fluorine is therefore rather difficult to extract in its pure form. Fluorine can form compounds with all of the other elements, also the other halogens. There was hardly any industrial production at all of fluorine before World War II. Large amounts of fluorine has, however, been produced later, as a residual product coming out of the enrichment of uranium, manufacturing of aluminum, fertilizers, clay etc. Fluorides are to be found in nature and in water in various concentrations, so we will always be more or less exposed to them. Today there is, however, an almost unanimous agreement that fluorine is not one of the essential trace elements, that the human body needs, which for long was the position of the WHO (Handbook on Human Nutritional Requirements, WHO Monograph Series No 61, 1974), the Swedish National Board of Health and Welfare (SOSFS 1977:26), etc. The FDA in America revised its standpoint in the mid-60's (cf. Gunnar Bergström, "Åttio maximaldoser" [Eighty maximum doses], Årjäng, 1969, p. 51). Rated by degree of toxicity, fluorine would be placed somewhere between lead and arsenic. Research indicates that fluorides may cause allergies, osteoporosis, and dental fluorosis, as well as neurological damage (the latter has been described by, for instance, Dr. Phyllis Mullenix et al. in "Neurotoxicity of sodium fluoride in rats", Neurotoxicol Teratol. 17(2), 1995). Fluoride is supposed to have a hardening effect on tooth enamel. This would be due to enamel hydroxyapatite having one OH-group substituted with fluorine, thus forming fluoroapatite, Ca5(PO4)3F. The enamel gets harder, but many researchers claim that it gets more brittle as well.   This capacity of the hard tissues to bind fluoride quickly, thus keeping the serum concentration down, will decrease as one gets older, due to the accumulation of large amounts, which results in a certain saturation, especially with people living in areas high in natural fluoride (1). The risk is much higher for such individuals to get symptoms of poisoning when occasional high doses are administered. Local concentrations of fluoride in the body can get high through this enrichment process. Contents of 2-6 grams per kilo of the skeleton, or up to 10 grams per kilo in the enamel surface have been measured. This implies a 200,000 times enrichment in the skeleton compared to serum content. The deeper into the tooth, the lower the fluoride concentration. Adjacent to the soft tissue, of the tooth, i.e. the pulp, one may measure a value of about 30 mg per kilo (1, 4). Also in the soft tissues one finds an enrichment, with concentrations in, for instance, the aortic wall, the kidneys, the urinary bladder or skin, up to 10,000 times higher than in blood (5, 6). This enrichment means that the body through the years accumulates large amounts of fluorine, up to tens of grams. In general terms, the fluoride content of the skeleton in a person from a tap water fluoridated area is 2-3 times higher than in a person from a low fluoride area (1, 7). ”The lethal dose of fluoride is estimated to 1-5 grams for an adult, but the lowest registered lethal amount ingested is 105 mg.” The lethal dose of fluoride is estimated to 1-5 grams for an adult, but the lowest registered lethal amount ingested is 105 mg. Fluoride is chemically bound very strongly in the skeleton, so old people might have acquired a fluoride content in bone several times higher than the lethal dose, through years of enrichment. In cell biologic experimental research fluoride is used as a very active substance for altering the metabolism of the cell. The fluoride functions as a strong toxin in inhibiting certain enzymes, which are essential for the physiologic processes of the cell. Several enzymes, of importance to cell energy production, such as enolase phosphoglucomutase, succinodehydrogenase, or cytochrome oxidase, are inhibited by low concentration fluoride. Furthermore, the two heme containing enzymes catalase and peroxidase, which degrade hydrogen peroxide that has been produced in the cell, are inhibited, and so are also several enzymes involved in phosphate metabolism, such as acid and alkaline phosphatases, erythrocyte phosphatase and 5-nucleotidase (8). There are several other enzymes that may be inhibited by fluoride at various concentration levels. The proposed caries preventive effect of fluoride relies to a major part on the bactericidal effect of fluoride striking the bacterial enzymes. It has also been established that fluoride influences fundamental cell regulatory pathways by interacting with such messengers as calcium ions, the G-proteins (9) and cyclic AMP, the latter by stimulatory effect on the enzyme adenyl cyclase (10). Cyclic AMP is of great importance for the hormonal regulation of the cell, thus this function is being disturbed. Such basal cellular effects may explain why there appear to be a correlation between hich fluoride intake and high cancer incidence (11). The lowest levels of fluoride concentration, where the most sensitive of the above mentioned enzymes are affected, e.g. adenyl cyclase, are appr. 6-10 mg per kilo. At first sight it would seem as if this concentration is too high for there being any risk for effects from fluoridated tap water, but if one considers the capacity of fluoride to accumulate in the body, and also compares with the concentrations that might be observed in certain organs, it is understandable that fluoride is likely to bring about biological effects, even at a daily intake of 2-5 mg. The very high content of fluoride in certain prophylactic solutions like mouth rinsing and varnishes contribute to very high local concentrations in the cellular linings of the mouth, pharynx and stomach. As suspected, a number of biological effects from fluoride has also been indicated at this dose. When persons experimentally had their fluoride content in water increased from a normal surface water concentration to 0.5 or 1.0 mg per liter, or more, the alkaline phosphatase enzyme activity was significantly reduced in blood (12). In animal experimentation cell alterations were found on a biochemical level in the kidneys of monkeys given water with 1 mg fluoride per liter, during a couple of months. The activity of certain enzymes in the liver of these monkeys, and in the kidneys of guinea pigs, was also affected by such water (13, 14). It has been shown under experimental conditions that tadpoles dwelling in fluoridated water are delayed up to 14 days in their development. In this case the disturbance is probably due to a fluoride influence on the thyroid glands of the tadpoles (15). Cell geneticist A.H. Mohamed discovered that when mice, apart from food low in fluoride, was given water of so called "optimum" fluoride concentration, they were found to have more chromosome aberrations in their testicles and bone marrow than the control group of animals (16). Enamel fluorosis is the most apparent and easily visible proof of significant biological effects from fluoride, also in humans. Dentists claim, however, quite irresponsibly, that mottled enamel due to fluorosis is medically a harmless symptom, but at the same time they must admit that the underlying mechanism causing enamel fluorosis is not known in detail, even though the picture is now garadually becoming clearer. An important discovery was made by the Danish cariologist Thylstrup and his group, who through electron microscopy could prove that enamel fluorosis is actually malformed enamel with a mellow and irregular structure. In cases of severe fluorosis, the enamel is soft enough to let through contaminants from the outside, thus discoloring the tooth (17). A recent scientific report (18) further shows that fluoride disturbs the enzymes casein kinase II och alkaline phosfatase, which causes a disordered enamel formation. Thus, what dentists call innocent stains on the teeth is actually a symptom of chronic fluoride poisoning in the infant. Enamel damaged by fluorosis has been shown more susceptible to caries than normal enamel, recently in study of native children in South Africa who did never experience any type of dental care (19). When considering he biological nature of fluorosis, it is not hard to understand that children during the period of dental development should avoid fluoride as much as ever possible, i.e. they should not have fluoride tablets, fluoridated chewing gum or drink fluoridated water.   Fact box: Arvid Carlsson on fluoride     Arvid Carlsson, awarded the 2000 Nobel prize in physiology or medicine, heavily opposed water fluoridation in the 1970's and wrote several articles about fluoride and fluorosis: "It is essential to point out that enamel fluorosis is not solely a cosmetic issue. The assertion from the National Board of Health and Welfare that enamel fluorosis, from a medical point of view, is a harmless symptom, can not be supported. Swedish as well as foreign studies indicate that more severe cases of enamel fluorosis are associated with an abnormally high incidence of caries. [...]." In this context, it is worth pointing out that 'the hard evidence of the placental barrier to fluoride' (Ericsson 1970) now belongs to the history of medicine (Armstrong et al. 1970; cf. also Forsman 1974 b). There is thus reason to consider the possibility that fluoride might affect our children's somatic and mental development." "In the future, our health authorities will be increasingly engaged in the problems caused by this burden [the chemical burden on our environment], problems of very high complexity, considering the difficulty of getting a quantitative overview, the interaction between different elements etc. In our society we will need to invest more and more resources in order to keep chemical exposure down on an acceptable level." From Arvid Carlsson, "Aktuella problem rörande fluoriders farmakologi och toxikologi" [Current problems concerning the pharmacology and toxicology of fluorides], Läkartidningen [Journal of the Swedish Medical Association] 14, 1978, p. 1388-1392.   Chronic fluoride poisoning from so called "optimum" fluoride concentration in water causes several symptoms in certain individuals, that are hard to interpret but concordant with symptoms of either acute fluoride poisoning or chronic poisoning from higher doses in cattle or industrial workers. There are lots of reports in veterinary medicine, describing cases of cattle poisoning due to environmental pollution or too high fluoride concentration in animal food. On Cornwall Island in Ontario, Canada, cattle were stricken with dwarfism as a result of crops having been contaminated with airborne fluoride discharge from the Reynolds Metals Company (20). Danish physician Kaj Roholm's thesis "Fluorine Intoxication" from 1937 is fundamental in describing the damage on humans (21). The spectrum of symptoms includes loss of appetite, stomach and gut problems, allergic reactions, muscle weakness and nerve damage, joint pains and a damaged bone structure, and, in children, decomposing teeth. Similar symptoms, although not as severe but more insidious and seemingly incomprehensible, appear in chronic poisoning from lower doses of fluoride. Owing to a number of "unplanned" double-blind tests, arranged by chance, some physicians, among them allergy researcher Waldbott, have been able to associate these symptoms with chronic fluoride poisoning and describe a "chronic fluoride poisoning syndrome" (22, 23). These "unplanned" tests came about when one individual showed unexplainable symptoms, such as excessive thirst, eczematous rashes, stomach pains and muscle weakness etc, which ceased without a trace, when this person moved to another place. Not understanding the causal connection this person moved again, and got the symptoms once again, maybe after a long time without them. Such persons have not been able to point out fluoride as the common factor at those places where illness occured until they had moved several times, thus establishing the connection between water fluoridation and hypersensitivity towards fluoride. Waldbott has among his patients appr. 400 cases showing such hypersensitivity. In a thoroughly arranged double-blind study in Holland, one has been able to confirm Waldbott's finding that fluoride causes severe symptoms of hypersensitivity in certain individuals (24). Many of them get so sick that they are completely incapacitated for work. The symptoms appear as excessive thirst, eczematous and nettle rashes, stomach pains, muscle pains and cramps as well as muscle weakness, headaches and impaired sight. One may speculate that there exists a connection between the ongoing increase of allergies in the population and the indication of a successively increased intake of fluoride in our society. Although hypersensitivity towards fluoride has been descibed for decades, affecting lots of people and proven with methods meeting all requirements of objectivity, still dentists deny the existence of this side effect. They claim that it is impossible, from a physiological point of view, that the fluoride ion can cause allergies, since it is too small a chemical substance for the immune defense to detect as an alien matter. Dismissing fluoride's capacity to cause hypersensitive reactions simply on such grounds is very naive. Immunological reactions are very complex, including several biochemical control pathways, where fluoride may interfere. It has, for instance, been established that fluoride in a concentration of 20 mg/liter stimulates one of the cell types involved in allergic reactions, the mast cell, to release the substance histamine, which, as we all know, causes strong allergic symptoms (25). Even though it is not at all proven that such a mechanism is to account for fluoride's capacity to cause hypersensitivity, still this example shows that fluoride may affect the immune defense in other ways than as a direct allergen. However, the fluoride hypersensitivity syndrome, described by Waldbott, might not at all be of immunological nature. Instead it might be caused by fluoride influence upon different enzymes in the body, together with the subsequent effect also on hormonal control of different organs of the body. We escaped having tap water generally fluoridated in Sweden, but still there are efforts to add supplemental fluoride in the form of tablets, painting, gels - and last but not least toothpaste. Fluoride rinsing in schools, which the Swedish National board of health stopped recommending in 1991, has been re-introduced at the end of the 90's in several cities. To "compensate" for the "low supplement of fluoride that tap water provides", there are efforts to increase serum concentration of fluoride with tablets (26). The fluoride content in one tablet equals the fluoride content in an average sized glass of water of a fluoride concentration of 1.2 mg per liter, like in Uppsala. How many fluoride tablets will not the poor children of Uppsala take in each hot summer's day? Consequently the a very large percentage of the Uppsala children display fluorotic teeth to some extent. In 1978 the magazine "Miljš och Framtid" ("Environment and Future") featured photographs showing fluoride damage on the teeth of some children from the city of Uppsala (27). The twelve photos shown were not selected from a systematic search. Therefore one could suspect that there were many more children in Uppsala with such defective teeth. The odontological Uppsala experts in charge denied that the defects on display in the magazine could be fluorosis. A cosmetic problem only? These are the three photographs of Uppsala children's teeth from 1978, which according to the expert Lars-Eric Granath did show possible fluorosis. The whole set of twelve images are shown here. The photographs were, however, examined by Lars-Eric Granath, at the University of Lund, Sweden, and by Hans GrahnŽn, at the University of UmeŚ, Sweden, both of them professors of child dentistry. According to their opinion, three of the twelve images (number 2, 5, and 9) showed possible fluorosis, and in three more cases fluorosis could not be ruled out. The other six images were either not possible to evaluate, or, did they show cases where the possibility of fluorosis was small. The question back then was what was to happen if one were to fluoridate tap water even more. Today, the same question might be asked, regarding what happens when more fluoride is supplied in tablet form or through brushing teeth with fluoride toothpaste. Professor Dowen Birkhed at the Institute of Odontology at the University of Gothenburg suggests in an interview in Swedish daily Dagens Nyheter 1999, titled "Old teeth can never get too much fluoride", that old people should rinse their teeth with fluoride solution once or twice a day, eat fluoride tablets or chew fluoride chewing gum and brush with fluoride toothpaste twice a day (32): You should lay out a thick coat of fluoride toothpaste on your brush, and this should not be rinsed out of your mouth afterwards. The rest of the paste may remain and get absorbed, especially by the root surfaces that have been bared with the years. Unlike the tablets, which are meant to increase serum content of fluoride, thus executing a systemic effect on teeth during development, fluoride rinsing, painting and varnishing are mainly used topically. Three different concentrations of fluoride solutions are used for rinsing, 0.2%, 0.05% and 0.025% sodium fluoride, the lowest for more frequent use or for younger children (28). Studies with 6-7 year olds by Ericsson and Forsman (29) showed that under controlled circumstances the children's intake of sodium fluoride was 20%, while rinsing for 1 minute with a 7 ml solution, which equals 1.8 mg fluoride or a little more than 7 fluoride tablets, if 10 ml of a 0.2% solution is used. If all of it were to be swallowed, which probably is not unusual during less well monitored circumstances, it would equal 36 fluoride tablets. This equals 7.5 liters of Uppsala tap water and cannot be very healthy indeed, taking the aforementioned facts about fluoride toxicity into consideration. In 1976 a two-year-old boy in Austria died after having eaten 200 fluoride tablets, so the claim that fluoride is entirely harmless is absolutely false (30).   Fact box: Has fluoride really reduced caries?     From an article in Nature, 1986: "But during the period 1979-1981, especially in western Europe where there is little fluoridation, a number of dental examinations were made and compared with surveys carried out a decade or so before. [...] It soon became clear that large reductions in caries had been occurring in unfluoridated areas [...]. The magnitudes of these reductions are generally comparable with those observed in fluoridated areas over similar periods of time. [...] there would be a strong case for the scientific re-examination of the epidemiological studies which appear to demonstrate large benefits from fluoridation." Mark Diesendorf, "The Mystery of Declining Tooth Decay", Nature, Vol. 322, July 10, 1986.   From an overview of fluoridation at UNICEF's Web site: "We purposely fluoridate a range of everyday products, notably toothpaste and drinking water, because for decades we have believed that fluoride in small doses has no adverse effects on health to offset its proven benefits in preventing dental decay. But more and more scientists are now seriously questioning the benefits of fluoride, even in small amounts. [...] It has long been known that excessive fluoride intake carries serious toxic effects. But scientists are now debating whether fluoride confers any benefit at all. [...] agreement is universal that excessive fluoride intake leads to loss of calcium from the tooth matrix, aggravating cavity formation throughout life rather than remedying it, and so causing dental fluorosis. Severe, chronic and cumulative overexposure can cause the incurable crippling of skeletal fluorosis. [...] Chronic intake of excessive fluoride can lead to the severe and permanent bone and joint deformations of skeletal fluorosis. Early symptoms include sporadic pain and stiffness of joints: headache, stomach-ache and muscle weakness can also be warning signs. The next stage is osteosclerosis (hardening and calcifying of the bones), and finally the spine, major joints, muscles and nervous system are damaged. Whether dental or skeletal, fluorosis is irreversible and no treatment exists. The only remedy is prevention, by keeping fluoride intake within safe limits." From Unicef Water Environment & Sanitation: "Fluoride in water: An overview", see http://www.unicef.org/wes/fluoride.pdf.   Consequently, it is obvious that the body is supplied with high doses of fluoride through fluoride mouth rinsing. The harmful effects of this are little known. The weaker solutions provide less fluoride uptake to the body, a 0.05% solution probably equals just about two fluoride tablets per rinsing, and a 0.025% solution just one tablet. In order to decrease the fluoride burden one should use the weaker solutions, especially since Forsman has shown in one study that a 0.025% solution is as effective as one of 0.2% (31). Fluoride varnishes with up to 5% sodium fluoride are being employed in caries prophylaxis of adults. Such solutions as well as the more concentrated rinsing solutions doubtless expose the cells of the mouth, pharynx and stomach for levels of fluoride at which dysregulation of the cell will appear as described above (10). Fluoride toothpaste with 0.1% fluoride contains approximately 1 mg fluoride per inch. A Japanese study found that each brushing of teeth provided an intake of 0.3 mg fluoride, that is a little more than one tablet. Similar results were shown by a Swedish investigation (29). Brushing will thus provide a daily supply of 1-2 fluoride tablets, of which however maybe only half is absorbed in the stomach. We may conclude that all of the here mentioned local prophylactic methods contribute to a heavily increased intake of fluoride, which is unacceptable, as long as fluoride has not in a way that ensures complete safety been ruled out as a cause for illness. References: 1. Myers, H.M., Fluorides and Dental Fluorosis. Karger, Basel 1978. 2. Regulations of the Swedish National Food Administration, SLVFS 2001:30, based upon European Communities, Council Directive 98/83/EG on the quality of water for human consumption, 5 December 1998, revised 30 November, 1999. 3. Whitford, G. N. et al. Am. J. Physiol. 230:527, 1976. 4. Gründer, H.D., Zentralbl. Veterinärmed. Reihe A 19:229, 1972. 5. Waldbott, G.L., Experientia 22:835, 1966. 6. Herman, J. R. et al., J Urol. 80:263, 1958. 7. Jacksen, D. et al., J. Path. Bact. 76:451, 1958. 8. Colowick, S. P. & Kaplan, N. 0., red., Methods in enzymology, (flera volymer) 1955-1979. 9. Susa M., Int J Mol Med. 3(2):115, 1999. 10. Whitford, G.M., Allmann, D.W. & Shahed, A.R., "Topical fluorides: effects on physiologic and biochemical processes", J. Dent. Res. 66(5):1072, 1987. 11. Takahashi, K., Akiniwa, K., & Narita, K., "Regression analysis of cancer incidence rates and water fluoride in the U.S.A. based on IACR/IARC (WHO) data (1978-1992)", International Agency for Research on Cancer. J Epidemiol. 11(4):170, 2001. 12. Fergusen, D.B., Nature New Biol. 231:159, 1971. 13. Manocha, S.L. et al., Histochem. J. 7:343, 1975. 14. Sullivan, S.J., Fluoride 2:168, 1969. 15. Kuusisto, A.N. et al., Acta Odontol. Scand. 19:121, 1977. 16. Mohamed, A.H., Chem. Eng. News 54:30, 1976. 17. Thylstrup, A., Fluorids effekt på den humane emaljedannelse med særlig henblik på det primære tandset, diss., Århus, 1979. 18. Milan, A.M. et al., Arch Oral Biol. 46(4): 343, 2001. 19. Grobleri, S.R. et al., Int J Paediatr Dent. 11(5):372, 2001. 20. Krook, L & Maylin, G., Cornell Vet. 69, suppl. 8, 1979. 21. Roholm, K., Fluorine Intoxication, Copenhagen 1937. 22. Petraborg, H.T., Fluoride 7:47, 1974. 23. Waldbott, G.L. et al., Fluoridation the Great Dilemma, Lawrence, 1978. 24. Grimbergen, G.W., Fluoride 7:146, 1974. 25. Patkar, S.A. et al., Int. Arch. Allergy appl. Immunol. 55:193, 1977. 26. Socialstyrelsens kungörelse med bedömningsgrunder för konsumtionsvatten med avseende på fluoridhalten. SOSFS (M) 1977:27 och Rekommenderade bedömningsgrunder och kommentarer till olika fluoridhalter according to the proclamation of the Swedish National Board of Health and Welfare SOS FS (M) 1977:26 and 1977:27. Leaflet issued 9/22/1977. Dnr SN 1-5049:1241. 27. Sällström, A. & Sällström, J., "Fluorskadade tänder i Uppsala" [Teeth damaged by fluoride in Uppsala], Miljö och Framtid 10, 1978. 28. Socialstyrelsens kungörelse om användning av fluorider i kariesprofylaktiskt syfte. [Proclamation from the National Board of Health and Welfare on the use of fluorides for caries profylaxis] SOSF (M) 1977:26. 29. Ericsson, Y. et al., Caries Res. 3:290, 1969. 30. Ziegelbecker, R., National Fluoridation News 23 no. 4, s. 4. 31. Forsman, B., Community Dent. Oral Epidemiol. 2:58, 1974. 32. "Gamla tänder kan aldrig få för mycket fluor" [Old teeth can never get too much fluoride], Dagens Nyheter 13 January 1999. Copyright © Jan Sällström, 2003. Translated into English by Karl-Erik Tallmo. (Fact boxes interspersed in the main text were written or compiled by the Art Bin editor.)

About the author