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Fluorine

Fluorine is a non-metallic gaseous element from the group of halogens. Its chemical symbol is F. It has the atomic number Z = 9 in the periodic table of elements. Its name is derived from the Latin verb fluere = to flow. It is a colorless and, in higher concentrations, yellowish-green gas with a pungent odor reminiscent of chlorine and is heavier than air. It was already described as fluorspar by the natural scientist Agricola in 1529 as a flux in metal smelting. It is the 17th most common element in the earth's crust. Fluorine was first obtained as an element by the French chemist Henri Moissan (1852-1907) in 1886 using electrolysis. In nature, it mainly occurs as fluorspar (calcium fluoride). Hydrofluoric acid (FCL) is the most dangerous acid of all; burns to the skin with high concentrations of this acid can cause destruction down to the bone. It is used, for example, as uranium hexafluoride in the isotope separation of natural uranium for nuclear reactors or nuclear weapons. It is also an important agent in the production of aluminium and is used as an oxidizing agent in rocket engines. In industry, fluorine is also used to make polyethylene plastics more resistant to petrol and organic solvents. In the human body, fluorine is absorbed in the form of fluorides. An adult human contains a few grams of fluoride. Fluorides are a natural building block of our body that plays a key role in bone formation and growth. With regard to caries prevention, it has been shown that an adequate supply of fluoride in the body significantly reduces the occurrence of caries. Some medicines also contain fluorides alongside other active ingredients.

Functions in the body

Fluorides contribute to the hardening of teeth and bones. It can be assumed that over 95% of the fluoride in the body is found in teeth and bones alone. The remainder is found in the skin, hair and toenails and fingernails. Fluoride is incorporated into the apatite of bones and teeth. Apatites are minerals that consist of calcium phosphate and calcium fluoride or calcium hydroxide. It should be noted that bone ash is composed of 80% apatite and 20% calcium carbonate. Apatite hardens the tooth enamel and thus contributes to the resistance of the teeth to environmental influences. Above all, it protects against the acids formed by caries bacteria.

Fluoride intake

Many regions in Germany are fluoride-deficient areas. On average, drinking water contains only about 0.3 mg of fluoride per liter of water. Oil sardines, chicken meat and black tea still contain significant amounts of fluoride. The daily fluoride intake from drinking water and food is not sufficient for effective caries protection and to strengthen the bones. Additional fluoride must therefore be supplied to the body. There are several ways to do this:

Fluoride intake

  • Toothpastes containing fluoride
  • Application of fluoride jelly (only available on prescription)
  • Brushing in a fluoride varnish (by the dentist)
  • Rinsing with fluoride solution
  • Fluoridated table salt
  • Fluoride tablets
  • fluoridated milk
  • fluoridated mineral water

The uncomplicated use of fluoridated table salt instead of conventional salt without fluoride is a very effective and inexpensive remedy that has already led to positive results in many studies. It is only sold in combination with iodine as "iodized salt with fluoride". It should be used in every household instead of normal household salt. Either fluoridated table salt or fluoride tablets should be used in the household, as using both together could cause an overdose. This does not apply to babies and small children, as they only consume very small amounts of salt. They should therefore continue to be given fluoride tablets. The fluoride content of toothpaste should also be taken into account. For adolescents and adults, the use of fluoride-containing toothpaste is advisable. Special children's toothpaste should be used for children, as the fluoride content in adult toothpaste is too high. However, it should be expressly pointed out that there are also those who reject the use of fluoridated foods or drinks or at least consider it questionable.

Deficiency symptoms

It has been clearly proven that susceptibility to tooth decay is associated with a lack of fluoride. This is particularly true for children and adolescents. Recent research has also shown a possible link between fluorine deficiency and the incidence of osteoporosis, arteriosclerosis and arteriosclerosis.

Overdose

A daily intake of up to 5 mg fluoride per day is not considered harmful for adults. Excessive intake can lead to so-called fluorosis, which, among other things, causes tooth enamel to become discolored and paradoxically soft, as well as increasing susceptibility to osteoporosis due to calcium precipitation. Acute fluoride poisoning causes vomiting and convulsions.

Requirements

The need for fluoride depends on age and gender. The German Nutrition Society recommends a daily intake of 0.25 (for infants) to 4 mg fluoride (for adults), whereby the requirement for adult women is slightly lower at around 3 mg.

Safety and side effects

Fluoride is safe and harmless for most people in the amounts added to drinking water in some countries and in the amounts contained in toothpaste and mouthwash. Low doses (up to 20 mg of elemental fluorine per day) of oral fluorine in the form of supplements also appear to be safe and harmless for most people. Higher doses are not safe and harmless and can weaken bones and ligaments, cause muscle weakness and cause nervous system problems. High doses of fluoride can cause discoloration of teeth in children who still have milk teeth. Toothpaste and mouthwashes containing fluoride should not be swallowed, especially by children. It is a good idea to ensure that children under the age of 6 only use a pea-sized amount of fluoride toothpaste to prevent swallowing larger amounts.

The maximum daily intake for elemental fluorine - the highest amount at which no harmful side effects are to be expected - has been set as follows:

  • Infants up to 6 months: 0.7 mg
  • Infants from 7 to 12 months: 0.9 mg
  • Children from 1 to 3 years: 1.3 mg
  • Children from 4 to 8 years: 2.2 mg
  • Children aged 9 and over, adults and pregnant and breastfeeding women: 10 mg

Sodium fluoride contains 45% elemental fluorine and monofluorophosphate contains 19% elemental fluorine.

Precautions and warnings

Pregnancy and lactation: Fluoride appears to be safe and harmless during pregnancy and lactation when used at doses below the maximum daily intake (see above) of 10 mg elemental fluorine and when applied directly to the teeth in the form of toothpaste and mouth rinses. Higher doses are not safe and harmless and can weaken bones and ligaments, cause muscle weakness and nervous system problems, among other things.