What are the uses of fluoride ?

Fluoride reinforces the enamel of the teeth and helps to prevent tooth decay and cavities.

The enamel protected by fluoride will dissolve slower in an acid environment (especially the acidity produced after a meal).

The enamel is made of crystals, called carbonate substituted hydroxyapatite crystallites. When the enamel contains fluoride we can observe fluorapatite crystals.

Hydroxyapatite dissolves with a PH of 5.5
Fluorapatite dissolves with a PH of 4.6 (more acid)

(Reminder: neutral PH is 7, the lower the PH, the more acid it is)

Nevertheless, even if fluoride decreases the risk of caries, it cannot remove it entirely. It is essential to reduce the number of meals, sweet foods and have a correct tooth brushing technique.

Is fluoride dangerous?

In a normal use, fluoride is not dangerous; in the contrary it can be beneficial for your teeth.

Certain foods contain fluoride, such as fish and shell-fish, tea and certain mineral waters. We can swallow a small amount daily with no risks.

 Advised daily intake of fluoride mg per day
Children from 0 to 6 months 0,1
Children from 6 months to 1 year 0,2
Children from 1 to 3 years 0,5
Children from 4 to 8 years 1
Children from 9 to 13 years 1,5
Teenagers from 14 to 18 years 2
Women 2
Men 2,5
Pregnant or breast-feeding 2

A.Martin et al. « Apports nutritionnels conseillés pour la population française » Ed Lavoisier, Tec&Doc.2001

 Fluoride contains in mg/litre
According to manufacture
Quézac 2,2
Badoit 1,2
Saint-Yorre 1
Vichy Célestins 0,5
San Pellegrino 0,5
Wattwiller < 0,5
Hépar 0,4
Contrex 0,36
Perrier < 0,2
Vittel 0,16
Evian 0,12
Mont Roucous < 0,1

Unfortunately, the floride swallowed will not protect adult patient’s teeth. It is only in children of which the tooth germ in still growing that the fluoride can integrate the enamel.

Where can I find fluoride to protect my teeth?

The source of fluoride such as tooth paste, mouth wash or gels and varnish are not swallowed. Their action is local and deposits itself on the surface of the teeth. The protective layer containing fluoride is very thin (approx.. 6 microns). Studies have shown the teeth get worn by 3 microns per day. Fluoride must be supplied regularly to obtain a continuous protection.

The easiest way to protect your teeth is to use a fluoride based tooth paste.

Supermarket adult toothpaste contains between 1000 to 1500ppm (which is 1-1.5mg of fluoride per gram of toothpaste). In the chemist you can find toothpastes with up to 2500ppm of fluoride (which is 2.5mg of fluoride per g of toothpaste).

Young children that are unable to spit correctly must use toothpaste suitable for their age, of which the content of fluoride is lower, in order not to overdose the recommended daily intake of fluoride.

Does fluoride stain the teeth?

It was common practice some time ago to give fluoride drops or tablets to strengthen the teeth. In certain cases white or brown marks appeared on the permanent teeth (fluorosis). These marks were due to an excess of fluoride swallowed during the formation of the teeth. This means that on top of the drops/tablets the children ingested originating from other sources (food, beverage, toothpaste…). The total quantity of ingested fluoride was over the recommended daily intake.

Today, the prescription of this medication is recommended only in certain specific cases. Usually children do not receive fluoride drops anymore.

The updated recommendations are to use topical fluoride, which means using fluoride directly on the surface of the teeth, without swallowing it: toothpaste, dental varnish… the fluoride, not swallowed, is not absorbed in the tooth germ and only protects the teeth present in the mouth. This way is it impossible to create white or brown stains on the teeth.

The very young children do not spit out all the toothpaste and swallow a small amount. This is why toothpaste for children contains a lower amount of fluoride than the ones for adults, which take into account the recommended daily intake.

Only purchase toothpaste that is suitable for the age of your child.

Use a very small quantity of toothpaste on the toothbrush for your child:

  • Before the age of 3: the equivalent of a grain of rice once per day
  • Between 3 to 6 years: the equivalent of a grain of rice twice per day
  • After 6 years: the equivalent of a green pea 2 to 3 times per day.

Be careful to the water that your child drinks. By mineral water that has low levels of minerals. The content of tap water is always available at the local town hall.