Fluorine mineral is the most abundant element in nature being so highly reactive. It is never found in its elemental gaseous forms but only in combined form. About 96% of the fluoride in the body is found in bones and teeth.
It occurs widely distributed in nature as fluorides. The principal sources of fluorine available to man are
- Drinking Water: The major sources of fluorine to man is drinking water. The fluorine content of water is found to be 0.4mg/L but in fluorosis-endemic areas, it may be as high as 3-11mg/L.
- Foods: It occurs in traces of many foods but some foods such as sea fish, cheese and tea are found to be rich in fluorides.
- Fluorine is the inhibitor of several enzymes.
- It is essential for normal mineralization of bones and formation of enamel. Fluorine produces hardening of teeth and bones. Its deficiency has shown to results in an abnormal increase in the incidence of dental caries and possibly osteoporosis.
- Fluorides are being added to the toothpaste and even applied as such in children as a prophylactic against dental caries and it, therefore, prevent decay or cavity formation in them.
- It is found to be important in preventing certain heart diseases.
Fluorine is often considered a two-edged sword. Its deficiency is associated with tooth decay and delay in the mineralization of bones, therefore, leading to dental caries as well as osteoporosis of the bones respectively.
Prolonged ingestion of fluoride through drinking water in excess of the daily requirement is associated with dental and skeletal fluorosis. Fluorosis is a condition due to a very high intake of fluorine. It produces brown staining of teeth or even leads to dental mottling. The bones of the skeletal system show excessive density. The fluorosis may lead to calcification of the ligament and the vertebral spine is usually more affected by this disease. Nausea, abdominal pain, vomiting, diarrhea, tetany and cardiovascular collapse may be seen in this condition.
The recommended and optimum level of fluorides in drinking water has been placed at 3.75 parts/million. In temperate countries where the water intake is low, the optimum level of fluorides in drinking water is accepted as 1-2 mg per liter.