Fluorosis Overview

Medically Reviewed by Renee A. Alli, MD on September 04, 2023
5 min read

Fluorosis is a cosmetic condition that affects the teeth. It’s caused by overexposure to fluoride during the first eight years of life. This is the time when most permanent teeth are being formed.

After the teeth come in, the teeth of those affected by fluorosis may appear mildly discolored. For instance, there may be lacy white markings that only dentists can detect. In more severe cases, however, the teeth may have:

  • Stains ranging from yellow to dark brown
  • Surface irregularities
  • Pits that are highly noticeable

Fluorosis first attracted attention in the early 20th Century. Researchers were surprised by the high prevalence of what was called “Colorado Brown Stain” on the teeth of native-born residents of Colorado Springs. The stains were caused by high levels of fluoride in the local water supply. This was fluoride that occurred naturally in the ground water. People with these stains also had an unusually high resistance to dental cavities. This sparked a movement to introduce fluoride into public water supplies at a level that could prevent cavities but without causing fluorosis.

Fluorosis affects nearly one in every four Americans ages 6 to 49. It’s most prevalent in those ages 12 to 15. The vast majority of cases are mild, and only about 2% are considered “moderate.” Less than 1% are “severe.” But researchers have also observed that since the mid-1980s, the prevalence of fluorosis in children ages 12 to 15 has increased.

Although fluorosis is not a disease, its effects can be psychologically distressing and difficult to treat. Parental vigilance can play an important role in preventing fluorosis.

A major cause of fluorosis is the inappropriate use of fluoride-containing dental products such as toothpaste and mouth rinses. Sometimes, children enjoy the taste of fluoridated toothpaste so much that they swallow it instead of spitting it out.

But there are other causes of fluorosis. For example, taking a higher-than-prescribed amount of a fluoride supplement during early childhood can cause it. So can taking a fluoride supplement when fluoridated drinking water or fluoride-fortified fruit juices and soft drinks already provide the right amount.

 

Fluoride occurs naturally in water. Natural fluoride levels above the currently recommended range for drinking water may increase the risk for severe fluorosis. In communities where natural levels exceed 2 parts per million, the CDC recommends that parents give children water from other sources.

Prompted by concerns that children may be getting too much fluoride, the Health and Human Services Department in January 2011 lowered its recommended level of fluoride in drinking water. And the Environmental Protection Agency is reviewing its rules on the upper limit of fluoride levels in drinking water.

Symptoms of fluorosis range from tiny white specks or streaks that may be unnoticeable to dark brown stains and rough, pitted enamel that is difficult to clean. Teeth that are unaffected by fluorosis are smooth and glossy. They should also be a pale creamy white.

Contact your dentist if you notice that your child’s teeth have white streaks or spots or if you observe one or more discolored teeth.

Since the 1930s, dentists have rated the severity of fluorosis using the following categories:

  • Questionable. The enamel shows slight changes ranging from a few white flecks to occasional white spots.
  • Very mild. Small opaque paper-white areas are scattered over less than 25% of the tooth surface.
  • Mild. White opaque areas on the surface are more extensive but still affect less than 50% of the surface.
  • Moderate. White opaque areas affect more than 50% of the enamel surface.
  • Severe. All enamel surfaces are affected. The teeth also have pitting that may be discrete or may run together.

 

In many cases, fluorosis is so mild that no treatment is needed. Or, it may only affect the back teeth where it can’t be seen.

The appearance of teeth affected by moderate-to-severe fluorosis can be significantly improved by a variety of techniques. Most of them are aimed at masking the stains.

Such techniques may include:

  • Tooth whitening and other procedures to remove surface stains; note that bleaching teeth may temporarily worsen the appearance of fluorosis.
  • Bonding, which coats the tooth with a hard resin that bonds to the enamel
  • Crowns
  • Veneers, which are custom-made shells that cover the front of the teeth to improve their appearance; these are used in cases of severe fluorosis.
  • MI Paste, a calcium phosphate product that is sometimes combined with methods like microabrasion to minimize tooth discoloration

 

Parental vigilance is the key to preventing fluorosis.

If your water comes from a public system, your doctor or dentist -- as well as your local water authority or public health department -- can tell you how much fluoride is in it. If you rely on well water or bottled water, your public health department or a local laboratory can analyze its fluoride content. Once you know how much fluoride your child is getting from drinking water and other sources such as fruit juices and soft drinks, you can work with your dentist to decide whether or not your child should have a fluoride supplement.

At home, keep all fluoride-containing products such as toothpaste, mouth rinses, and supplements out of the reach of young children. If a child ingests a large amount of fluoride in a short period of time, it may cause symptoms such as:

Although fluoride toxicity usually doesn’t have serious consequences, it sends several hundred children to emergency rooms each year.

It’s also important to monitor your child’s use of fluoridated toothpaste. Only place a pea-sized amount of toothpaste on your child’s toothbrush. That is sufficient for fluoride protection. Also teach your child to spit out the toothpaste after brushing instead of swallowing it. To encourage spitting, avoid toothpastes containing flavors that children may be likely to swallow.