Fluoride tooth decay

A familiar use of some fluoride compounds is in toothpastes. Studies show that small amounts of fluorides can help reduce tooth decay. Fluorides are deposited as new tooth material is formed, making it strong and resistant to decay. 

Studies have proven conclusively that fluoride is an effective tooth decay preventative. As a result, in the late 1960s and 1970s, many... 

Stannous fluoride (SnF ) is used as a toothpaste additive to help prevent tooth decay. 

Probably the most common use of fluorine is its addition to municipal water supphes to help prevent tooth decay. Stannous (II) fluoride (SnFj) is added to the water in proportions of about one part per million (1 ppm). In addition, many brands of toothpaste add stannous fluoride or other fluoride compounds to their product to help prevent tooth decay. Tooth enamel degenerates overtime. Fluorine promotes remineralization, essentially making a form of new enamel called fluorapatite, which is resistant to decay. 

Sodium fluoride (NaF), in the concentration of one ppm, is added to municipal drinking water to help reduce tooth decay. It is also used as an insecticide, fungicide, and rodenticide, as well as in the manufacture of adhesives, disinfectants, and dental products. 

C.M. Jones, G.O. Taylor, J.G. Whittle, D. Evans, D.P. Trotter, Water fluoridation, tooth decay in 5 year olds, and social deprivation measured by the Jarman score Analysis of data from British dental surveys. Br. Med. J. 315 (1997) 514-517. 

Fluoride ion tends to replace the isoelectronic ion OH- in solids. In particular, hydroxyapatite, Cas O OH, the chief constituent of tooth enamel, reacts slowly with aqueous fluoride to form fluoroapatite, which is harder and more resistant to tooth decay. The dental profession therefore advocates fluoride treatments at the time of regular dental checkups, and also (primarily to provide for the dental health of children) the presence of 0.7-1.0 ppm natural or added F in drinking water. Too much (>4 ppm) F in water, however, is acknowledged to cause mottling of teeth and bone sclerosis. Thus, the range of concentrations over which fluoride in public drinking water is considered to be beneficial is rather narrow. 

It is recommended that drinking water contain 1.6 ppm fluoride (F ) for prevention of tooth decay. Consider a reservoir with a diameter of 4.50 X 102 m and a depth of 10.0 m. (The volume is where r is the radius and h is the height.) How many grains of F should be added to give 1.6 ppm How many grams of sodium fluoride, NaF, contain this much fluoride ... 

Bacteria on the surface of our teeth metabolize sugars to produce lactic acid, which lowers the pH enough to slowly dissolve tooth enamel. Fluoride inhibits tooth decay because it forms fluorapatite, Cal0(PO4)6F2, which is more acid resistant than hydroxyapatite. 

There are as many salts as there are acids and bases. Sodium cyanide, NaCN, is a deadly poison. Saltpeter, which is potassium nitrate, KN03, is useful as a fertilizer and in the formulation of gunpowder. Calcium chloride, CaCl2, is used ro deice roads, and sodium fluoride, NaF in toothpaste, prevents tooth decay. The acid-base reactions forming these salts are shown in Table 10.1. 

A high sucrose diet promotes decay.11 While most people have some trouble with tooth decay, 1 or 2 per thousand remain totally free of caries and seem to be immune. Many factors must affect resistance to caries. For example, individuals vary in the kinds and numbers of bacteria present on teeth and in the structure of tooth enamel.0 Addition of fluoride ion to water supplies at a level of lppm (0.05 mM) is generally believed to reduce the incidence of tooth decay. However, caries has been declining in many developed countries at rates that are the same for water with or without fluoride.p q If teeth escape caries periodental disease, caused by bacteria, is often a major problem for older people.1... 

The introduction of fluoridated toothpaste during the 1970s caused a much greater than expected improvement in the dental health of the nation, which far outweighs dietary initiated tooth decay in those that use it. There are now very few brands of toothpaste on sale in the UK that do not contain fluoride. 

In spite of its toxicity and extreme reactivity, fluorine is widely used for the manufacture of polymers such as Teflon, (C2F4) . Fluorine is also important in the production of UF6, used in the separation of uranium isotopes for nuclear power plants, and fluoride ion is added to toothpaste in the form of NaF to help prevent tooth decay. 

The effect of pH on solubility is also important in understanding how fluoride ion reduces tooth decay. When tooth enamel comes in contact with F ions in drinking water or fluoride-containing toothpaste, OH- ions in hydroxyapatite, Ca5(PC>4)30H, are replaced by F- ions, giving the mineral fluorapatite, Ca5(PC>4)3F. Because F- is a much weaker base than OH-, Ca5(P04)3F is much more resistant than Cas(P04)30H to dissolving in acids. 

Fluorine is used in the form of fluorides in drinking water and toothpaste because it reduces tooth decay by hardening the enamel on teeth. 

Finally, a little chlorine gas is added, which sterilises the water and kills any remaining bacteria. Excess chlorine can be removed by the addition of sulfur dioxide gas. The addition of chlorine gas makes the water more acidic and so appropriate amounts of sodium hydroxide solution are added. Fluoride is sometimes added to water if there is insufficient occurring naturally, as it helps to prevent tooth decay. 

Fluoridation of water is often used to help reduce tooth decay. However, whereas levels of 1 ppm are commonly used, excessive fluoride levels (>2 ppm) can be a problem and need to be corrected. Analytical Technology Inc. manufactures a fluoride-sensitive ISE for this purpose [152]. 

The toxic nature of fluoride ion, F, is not confined to its presence in HF. It is toxic in soluble fluoride salts, such as NaF. At relatively low levels, such as about 1 ppm, used in some drinking water supplies, fluoride prevents tooth decay. At excessive levels, fluoride causes fluorosis, a condition characterized by bone abnormalities and mottled, soft teeth. Livestock are especially susceptible to poisoning from fluoride fallout on grazing land as a result of industrial pollution. In severe cases, the animals become lame and even die. 

Other important inorganic compounds of fluorine include uranium hexafluoride, UF6, a volatile substance that was used to separate 238U from the fissionable 235U by gaseous diffusion in the Manhattan Project. Sodium fluoride, NaF, is often added to drinking water and to toothpaste in order to reduce the incidence of tooth decay. 

Stannous fluoride Fluoride Treat tooth decay, prevent tooth plaque and inflammation of gums Flo-Gel, Gel-Kam 0.4... 

The tin(II) halides are much less volatile than the corresponding tin(IV) compounds in fact, they are probably ionic, containing Sn2+ and X- ions. Tin(II) chloride in aqueous solution is commonly used as a reducing agent. Tin(II) fluoride (stannous fluoride) was for many years added to toothpaste to help prevent tooth decay. It has since been replaced by sodium fluoride. 

The United States Public Health Service (USPHS) recommends the fluoridation of water as a means for preventing tooth decay. The recommended concentration is 1 mg F"/L. The presence of calcium ions in hard water can precipitate the added fluoride. What is the maximum molarity of calcium ions in hard water if the fluoride concentration is at the USPHS recommended level (Ksp for CaF2 = 4.0 X 10-11.)... 

Fluoride is a monovalent anion. It appears not to be an essential nutrient, as raising animals on a fluoride-defidenl diet over three generations has been found not to impair growth and reproduction. Fluoride has proven to be of value in reducing the rate of dental caries (tooth decay). There has been much interest in the possibility that fluoride can prevent and reverse osteoporosis, though such effects have not been proven. 

The effect of fluoride in ptevenring dental caries was recognized when it was found that levels of tooth decay were low in regions of the world where the water supply naturally contained high levels of fluoride. In some regions, the levels of fluoride are so high that they cause a harmless mottling of the teeth called "fluorosis." Both the first set and the permanent set of teeth benefit from dietary fluoride. Water and other fluids account for most of our fluoride intake. 

One of the best known uses of fluorine is in the production of fluorides, used as additives in toothpastes and municipal water supplies. Fluorides are effective in preventing tooth decay and have been widely used in the United States for this purpose since the 1950s. 

Many toothpastes contain fluoride, which helps to prevent tooth decay. However, some people worry about the long-term effects of fluoride in toothpastes as well as in the water supply. IMAGE COPYRIGHT 2009, AAAU HORNG. USED UNDER LICENSE FROM SHUTTERSTOCK.COM. 

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