Dental Fluorosis – Causes, Treatment And Prevention

Dental fluorosis is the name for a mottling condition of the teeth, usually whitish in color, caused by excessive amounts of fluoride becoming incorporated into the outer enamel layer of a tooth. The damage occurs as the enamel is developing in the young child.

Fluorosis was first described early in the 20th century when in the US and UK it was noticed that children in certain areas tended to show whitish or brown discoloration of their teeth . This was eventually established as due to excessive amounts of naturally occurring fluoride in the drinking water.


Moderate fluorosis

Moderately affected teeth, showing characteristic white ‘mottling’. Image source

Signs and symptoms

Fluorosis is not a disease and does not physically harm the dentition, but unfortunately it can cause psychological problems if moderate to severe by spoiling a person’s natural smile.

Fluorosis can vary in its severity and hence in the degree to which it affects the appearance of a tooth.In its mildest form, it appears as barely noticeable tiny white spots or streaks in the surface enamel layer. Very mild, slightly whitish spots in the enamel are thought by some to make teeth look more attractive – but if the marks are actually distinguishable then the effect is considered rather unattractive.

Dentists classify the severity of fluorosis by the degrees of white opacity, the size of affected areas and the percentage of tooth area affected. A typical classification is:

  • Very mild – The enamel shows slight changes ranging from a few barely noticeable white flecks to occasional white spots, and less than 25% of the tooth area is affected.
  • Mild – There are more extensive white patches visible, but over less than half the tooth surface.
  • Moderate – There are white patches over more than half the tooth surface, and some brown patches may also be evident.
  • Severe – There are patches on all or most teeth, some of them brownish, and there may also be pitting of the enamel in places. The overall appearance of a tooth can be as if it has been corroded, exhibiting an irregular surface and loss of shape definition.



Severe fluorosis

Severe damage, with heavy brown staining. Image source


Fluoride can be taken up by a developing tooth as it forms within the jaw and it can change the chemical structure of the tooth’s enamel, leading to a more pronounced white appearance rather than the creamy white of normal enamel.

It is slightly ironic that a very tiny amount of fluoride is considered beneficial for a tooth since it strengthens the enamel against decay, but an excessive concentration can alter the enamel composition enough to adversely affect its appearance. It is a fine line between what is considered too much and what is considered to be an acceptable level of fluoride as far as teeth are concerned.

Certainly a young child, from a baby through to about eight years of age, should not be exposed to excessive amounts of fluoride. Otherwise it can be absorbed by the growing teeth within the jaws giving rise to a mottling or discoloration of the tooth surface, which may vary from very mild to quite disfiguring (as explained above).  The period between twenty to thirty months of age is reckoned to be the most critical as regards excessive fluoride intake.

Once the teeth have actually come through and are visible in the mouth the risk is minimal.

Fluorosis may occasionally affect the first set of teeth, but is only really of concern when it appears in the second or permanent set of teeth because the discoloration is itself permanent.

The likelihood of dental fluorosis in general in the population seems to be directly in proportion to the concentration of fluoride in drinking water. One part per million is the optimum for prevention of dental decay, but anything over three parts per million can induce noticeable enamel flecking.

Of course fluoride from toothpastes and mouthwashes can contribute to the amounts consumed, especially by younger children who are more likely to swallow some.




Fortunately many cases of fluorosis are fairly mild and affect only a few teeth. In such instances the whitish marks may become less obvious as the patient gets older anyway or may be so slight that no treatment is considered necessary. In more severe cases, however, the marks may become darker over time and present a cosmetic problem.

Fluorosis is estimated to affect nearly one in every four Americans who are between the ages of 6 to 49 years, but is mild enough in most cases not to require treatment.

Moderate to severe fluorosis can however be psychologically upsetting, and treatment can be provided to cover or mask the discoloration.

Sometimes deep surface cleaning and/or whitening treatment is sufficient to improve the teeth’s appearance, but in more severe cases it is often necessary to cover the enamel with bonded tooth-colored resin materials or a porcelain veneer. A porcelain veneer is a very thin piece of porcelain made to the shape of the tooth and then bonded on to the front surface. Even a porcelain veneer which is very thin can be made to successfully cover quite bad discoloration and make a tooth look as good as new.

If the fluorosis is very severe, with multiple areas of deep pitting of the enamel or loss of the proper shape of a tooth, it may be necessary to provide a full crown or cap in order to properly restore the tooth. A crown can be made of porcelain or porcelain bonded to a precious metal backing.




It is wise for a parent to be aware of the dangers of too much fluoride.

The concentration of fluoride in your local drinking water should to a large extent determine the steps you take for prevention of fluorosis in your children.

It is often possible to find out the concentration of fluoride in your daily drinking water and if it’s too high it may well be worth buying bottled water. If it is very low and your child is beginning to get his or her second teeth you might consult your dentist with regard to a suitable fluoride supplement to give caries protection without risk of discoloration of teeth.

Oral hygiene instructions with fluoride toothpaste

Proper oral hygiene instructions and supervision is vital


The following points of advice are important to reduce any risks:

  • Parents should supervise their children while they are brushing until the age of about 7.
  • The correct strength of toothpaste should be used as per the child’s age.
  • Use only pea-sized smear of toothpaste.
  • Make sure children do not swallow toothpaste when brushing.
  • Keep tubes of toothpaste, bottles of mouthwash and fluoride supplements out of the reach of children.
  • Children under the age of 6 should not be given fluoride mouthwashes.
  • Fluoride supplements should be given in the dose advised by your dentist.  They are not needed if the water supply is sufficiently fluoridated in your area.



A very tiny amount of fluoride provides protection for teeth, but too much at an early age can have adverse effects which although treatable, are best avoided in the first place.

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