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White Spots on Teeth: Causes and Treatment

Chalky white patches on teeth can be early tooth decay, fluorosis from too much fluoride in childhood, or a problem with how the enamel formed. Here is how to tell them apart and what can be done.

Updated September 2026·By the OHA editorial team·8 min read·How we write
Key takeaways
  • White spots are areas where the enamel looks chalky or cloudy instead of glossy. The common causes are early tooth decay, dental fluorosis and defects in how the enamel formed.
  • A white spot can be the first sign of decay. At that stage, fluoride and good cleaning can often stop or reverse it.
  • Dental fluorosis can only develop while teeth are forming, up to about age 8. It is usually mild and does not affect how teeth work.
  • Molar incisor hypomineralisation (MIH), a common enamel defect, affects around one in eight children in the UK, according to NHS hospital leaflets.
  • A dentist can tell which cause is likely and suggest options such as fluoride varnish, microabrasion, resin infiltration or tooth-coloured fillings.

Healthy enamel, the hard outer layer of the tooth, looks smooth and glossy. The American Association of Orthodontists (AAO) explains that enamel that has lost minerals reflects light differently, so it looks chalky, cloudy or matte. Many white spots are patches of enamel that contain less mineral than the enamel around them.

The cause decides what can be done. A 2021 review abstract in Annals of Medicine makes a useful distinction: some defects form while the tooth is still developing inside the gum, while white spot lesions from early decay appear after the tooth has come through.

Early tooth decay

Tooth decay starts when bacteria in plaque turn sugars into acid, and the acid draws minerals out of the enamel. The US National Institute of Dental and Craniofacial Research (NIDCR) says a white spot may appear where minerals have been lost, and that this is a sign of early decay. healthdirect Australia says you can usually see such a spot if it is near the gumline, but not if it is in the grooves of your back teeth.

NIDCR says decay can be stopped or reversed at this point: enamel can repair itself using minerals from saliva and fluoride from toothpaste, or from fluoride applied by a dentist or dental hygienist. healthdirect says a dental professional can put fluoride paste or varnish on the teeth, alongside brushing with fluoride toothpaste and improving your diet. If more mineral is lost than is restored, the enamel breaks down and a cavity (hole) forms. See tooth decay.

White spots and braces

White marks often show up during or after treatment with braces. A Cochrane review explains that fixed braces make teeth harder to clean, so plaque builds up around the brackets and causes early decay that looks like white or brown marks, which can progress to holes needing fillings.

The AAO says braces do not cause white spots on their own; plaque and acid do. It says clear aligners can also lead to them, for example if they are worn after eating without brushing, or if you drink anything other than water while wearing them. Frequent sipping of sugary or acidic drinks speeds up mineral loss.

On extra fluoride during brace treatment, the Cochrane review found only low-certainty evidence. One study suggested a high-strength fluoride foam applied by the dentist might reduce new marks, and another that a high-strength (5,000 ppm) toothpaste might. Other ways of adding fluoride had not been shown to help. See braces and aligners.

The AAO says some early spots can fade once the enamel is strengthened and plaque is controlled, but deeper spots are harder to reverse.

Dental fluorosis

Dental fluorosis is a change in the look of the enamel caused by taking in too much fluoride while the teeth are forming. The CDC says the enamel may have white flecks, spots or lines. The American Dental Association (ADA) describes faint white lines or streaks, and says the effect is often so subtle that only a dentist would notice it.

  • Only young children can develop it. The CDC says the enamel of adult teeth is fully formed by about age 8, so older children, teenagers and adults cannot get fluorosis.
  • It is usually mild. The CDC says fluorosis in the US is mostly mild and cosmetic: it does not affect how teeth work and is not painful. Moderate and severe forms are rare.
  • It is not a disease. The ADA says fluorosis does not affect the health of your teeth, and that the type of fluorosis found in the US may even make teeth more resistant to decay.

To lower the risk, the CDC and ADA advise supervising young children's brushing, using only a small amount of toothpaste, and teaching them to spit it out. The ADA says fluoride mouthwash is not recommended for children under 6 unless a dentist advises it. It also suggests testing private well water for fluoride once a year if young children live in the home. The recommended amount of toothpaste differs between countries: see fluoride explained.

Enamel defects from development

Sometimes the enamel does not form properly in the first place. The Annals of Medicine review describes two broad kinds of developmental defect of enamel:

  • Enamel hypoplasia: the enamel is thinner than normal, showing as pits, grooves or, at worst, areas with no enamel.
  • Hypomineralisation: the enamel is its normal thickness but contains less mineral, showing as white or discoloured patches, which may have clear edges or be patchy and cloudy.

These defects can affect baby teeth, adult teeth or both. The review says they raise the risk of decay and sensitivity. The CDC also notes that tooth colour can be affected by illness and medicines in infancy and early childhood, infections in baby teeth, injury to the face, and genetics.

Molar incisor hypomineralisation (MIH)

MIH is a common form of hypomineralisation. Patient leaflets from three NHS hospital trusts (Leeds, Kent and Newcastle) say:

  • It affects the first adult back teeth (molars), which come through around age 6, and sometimes the front teeth (incisors). It is usually noticed at around 6 to 7 years old.
  • Around one in eight children in the UK have it. It ranges from mild, which people may not notice, to severe.
  • Affected teeth may look white, creamy, yellow or brown. The enamel is softer, so back teeth in particular can crumble and are more prone to decay.
  • Teeth may be sensitive to hot, cold or sweet foods, and sometimes to brushing, although many children have mild or no symptoms.
  • The cause is not fully understood. It is thought to be a disturbance while the teeth are forming, around birth or in the first few years of life. Illness, high fevers and a difficult birth have been suggested.

The Leeds leaflet advises brushing twice a day with toothpaste containing at least 1,450 ppm fluoride (UK guidance), keeping sweet foods and drinks to mealtimes, and regular check-ups. It says brushing with warm rather than cold water can help with sensitivity, and a dentist may prescribe a fluoride mouthwash from age 7 or a higher-strength toothpaste from age 10.

What can a dentist do about white spots?

The AAO advises having new white spots checked to confirm the cause and look for active decay. Depending on the cause, options include:

  • Fluoride. Fluoride varnish or paste to help early decay heal (healthdirect, NIDCR). For MIH, varnish helps with sensitivity (Leeds, Kent) and protects back teeth, and the Kent leaflet says it may be applied every three to six months.
  • Microabrasion, which uses a mild acid and polishing to remove the outermost layer of enamel. The Leeds leaflet says it may take a few visits and is not suitable where the patch is large, as it can make the appearance worse. The ADA says it is limited to marks that do not go deeper than the enamel.
  • Resin infiltration, where a tooth-coloured resin soaks into the white spot to improve its appearance. The Leeds and Kent leaflets say this suits some cases only.
  • Whitening. The ADA says white marks from fluorosis or braces may become less noticeable as the rest of the tooth lightens. For children, the UK leaflets differ slightly: Leeds and Newcastle say whitening is only for over-18s, while Kent says it may be considered in special circumstances for under-18s at some dental hospitals. See stained teeth for whitening rules in each country.
  • Tooth-coloured fillings over the affected area (Leeds, Kent, Newcastle).
  • For back teeth with MIH: sealants (see dental sealants), fillings, preformed metal crowns, or, where a tooth is in poor condition, removal at an age that lets the next molar move into the gap (Leeds, Kent).
When to see a dentist
  • You notice new white spots, especially near the gumline or around braces or aligners (healthdirect, AAO).
  • Your child's new adult teeth come through with white, creamy, yellow or brown patches, or seem to crumble (NHS trust MIH leaflets).
  • Teeth are sensitive to hot, cold or sweet food, or to brushing.
  • You are worried your child is getting too much fluoride.

Frequently asked questions

Are white spots always a sign of decay?

No. They can be early decay, but also fluorosis or a developmental defect such as MIH. A dentist can tell them apart and check for active decay.

Can white spots go away?

Spots from early decay can often be stopped or reversed with fluoride and good cleaning (NIDCR). Fluorosis and developmental defects do not go away, but their appearance can often be improved.

Can adults get fluorosis?

No. The CDC says only children whose teeth are still forming, up to about age 8, can develop it, though marks from childhood remain.

Will whitening get rid of white spots?

Not always. The ADA says white marks from fluorosis or braces may become less noticeable as the rest of the tooth lightens, rather than disappearing.

Sources

  1. Tooth decay, National Institute of Dental and Craniofacial Research, accessed September 2026
  2. Tooth decay, healthdirect Australia, accessed September 2026
  3. White spots after braces: how to prevent teeth staining, American Association of Orthodontists, accessed September 2026
  4. Fluorides for preventing early tooth decay (demineralised lesions) during fixed brace treatment, Cochrane (Benson and others, 2019), accessed September 2026
  5. About dental fluorosis, CDC, accessed September 2026
  6. Fluorosis, American Dental Association (MouthHealthy), accessed September 2026
  7. Whitening, American Dental Association, accessed September 2026
  8. Differential diagnosis of developmental defects of enamel: a review, Castro MJ and others, Annals of Medicine, 2021, accessed September 2026
  9. Molar-incisor hypomineralisation (MIH), Leeds Teaching Hospitals NHS Trust, accessed September 2026
  10. Molar incisor hypomineralisation, Kent Community Health NHS Foundation Trust, accessed September 2026
  11. Molar incisor hypomineralisation (MIH) in your child's teeth, Newcastle Hospitals NHS Foundation Trust, accessed September 2026

This article is general information about oral health. It is not a diagnosis or a substitute for advice from a dentist or doctor who knows your situation. If you have pain, swelling, bleeding that does not settle, or a problem that is getting worse, see a dental professional. In an emergency, contact your local emergency service.

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