It is said that prevention is better than cure and if we talk about the prevention of dental caries the first thing that we talk about is the fluoride. The dentist also advises to use fluoridated tooth paste. Now the question arises what is fluoride. How it is available in environment and how it affects the teeth to prevent them from caries. To find out about fluoride first thing is what is fluoride? Total intake in adults is 5mgF/day. Total intake in infants-0.2mgF/day. We will discus in the following paragraphs we will discuss the importance and need for fluoride in dentistry.


The word FLUORIDE is derived from Latin term “FLUORE” meaning “TO FLOW”. Fluoride ion comes from fluorine. Fluorine is a member of the halogen family with a relative atomic weight of 19 and atomic number 9.It is pale yellow green gas. It always exists in combination with other elements such as a fluoride compound. It is combined chemically in the form of fluorides and fluorine and it is the 17th most abundant element in earth’s crust.

Fluoride In The Environment - Fluoride enters atmosphere by volcanic action & by the entrapment of soil & water particles due to action of wind on these surfaces. It is returned to earth’s surface by deposition as dust or in rain, snow & fog.

  1. Total intake in adults-5mgF/day
  2. Total intake in infants-0.2mgF/day 

Fluoride in The Lithosphere 

In lithosphere Fluorine is present as inorganic fluorides. More than 50 fluoride containing minerals are present, many of which are silicates. Fluoride average conc. in earth crust is about 300ppm   or we can say about 0.087% of its weight.First several inches of soil contain about 20-500ppm of fluoride. In deep soil the fluoride level increases.

Fluorides in Biosphere 

In biosphere fluoride is present in different concentrations in different plants, vegetables or the animals. Normal level of fluorides in plants is about 2-20mg/g of weight. In leafy vegetables the level of fluoride is about11-26mgF.In animals the fluoride level is almost same conc. as present in plant, in dried fish- 10-20ppmF. Sea food is rich in fluorine since ocean have 1ppm of fluorine.

Fluorides In The Hydrosphere

In hydrosphere that is in water bodies the level of fluoride varies. Concentration of fluoride in water varies not only from place to place but also with in the same locality. In rain water the fluoride level is negligible. In lakes & wells the fluoride level is high. In sea water the fluoride level is 0.5-1.4mg/l. In river water the fluoride level is 0.5mg/l

Fluorides in Atmosphere 

Fluoride is present in the atmosphere but in very small amount. Non urban areas showed no detectable levels of fluorides. The highest level of water soluble fluoride found in the air sample was 0.16mg/m3.In industrialized urban areas, the range of values for airborne fluorides conc. Was 0.05-1.89mg/m3.

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