Fluoride is a naturally occurring element in water, soil, foods, and a variety of minerals such as fluorite and fluorapatitie. It is considered the 13th most abundant element on earth’s crust, though it is also manufactured in laboratories and added to toothpaste, drinking water, mouthwashes, and a variety of other chemical products.
Fluoride is effective in preventing tooth decay and promoting bone growth.
The majority of fluoride intake comes from fluoridated water, food and beverages prepared with fluoridated water, and dental products containing fluoride, including toothpaste.
Most of the orally ingested fluoride is absorbed by the gastrointestinal tract, about half of which is stored in bones and teeth, while the other half is excreted. Young children take up more fluoride in their bones and teeth than in adults.
There are no established criteria for determining adequate, high, or low levels of fluoride in the body, although fluoride levels can be measured in various bodily fluids and tissues, including plasma, bones, teeth, nails, hair, and urine.
Recommended Fluoride intake
The Food and Nutrition Board (FNB) has come up with certain recommendations for the daily Adequate Intake (AI) of fluoride, which has been provided in the Dietary Reference Intakes (DRIs), as is assumed to ensure nutritional sufficiency.
Depending on age, daily AI may vary as follows:
Birth to 6 months
7 – 12 months
1 – 3 years
4 – 8 years
9 – 13 years
14 – 18 years
19 + years
NB: The fluoride requirement for women doesn’t necessarily change when pregnant or lactating.
The use of fluoride in drinking water
Water authorities across the globe used to add fluoride to tap water based on the assumption that it was useful in reducing the prevalence of decay in their population.
However, many developed nations have completely stopped water fluoridation, with the exception of the US, since they consider fluoride a highly toxic product from industrial waste. But is this argument valid?
According to the World Health Organisation (WHO), there is negligible difference in tooth decay between fluoridated countries and non-fluoridated countries.
Reports indicate that most people in the US drink fluoridated water, while 97 percent of the Western Europe population takes non-fluoridated water, yet the reduction of tooth decay incidents in the last 60 years in the US (linked to the use of fluoride in water) has also occurred in Western Europe.
Importance of Fluoride
Corroborating the report from the WHO, multiple studies have repeatedly shown that the addition of fluoride to drinking water in populations where the levels of this element are low helps to decrease tooth decay.
How does this work?
Every day, minerals are lost and added to the tooth’s enamel layer through the process of demineralisation and remineralisation, respectively.
Demineralisation occurs when sugars and plaque bacteria in your mouth form acids that attach the teeth’s enamel layer, while remineralisation occurs when minerals, such as calcium, phosphate, and fluoride, from foods and water consumed, are re-deposited onto the enamel layer and strengthen it.
Tooth decay occurs when the rate of demineralisation is faster than that of remineralisation.
Fluoride is critical in the prevention of cavities and strengthening teeth, though it is not as effective if the cavity has already formed. It helps prevent tooth decay by increasing the tooth’s resistance to acid attacks, and reverses early decay.
Fluoride is particularly important during the development of permanent teeth, at the age of 6 – 16 years, as it prevents demineralisation by disrupting acid production and facilitating re-mineralisation.
How to achieve optimal fluoride intake
Fluoride is available in water and foods, as well as fluoridated toothpastes and mouth rinses. It can also be applied in high concentrations as a gel by a dentist. These sources are effective in delivering topical fluoride to prevent dental caries, according to various evidence-based recommendations.
In the event that you lack adequate access to topical fluoride from either fluoridated toothpaste or water, a dental professional can recommend additional fluoride products in the form of chewable tablets, drops, or lozenges, though their effectiveness in preventing tooth decay is not high in school-aged children, while any pros and cons for infants and toddlers are unknown.
Some people tend to be at greater risk of getting tooth decay, perhaps due to hormones, genetics, or environment, such that topical fluorides alone are deemed to be insufficient in preventing caries. In such cases, your dental professional can recommend other measures such as antibacterial therapy, diet changes, or even a fluoride varnish.