Dental emergency? Here’s what to do and who to call
Dentist Disaster

Decay & gums

Tooth decay

See a dentist soon6 treatment options

Decay often starts silently and ends in holes, pain or infection. How it develops, the early warning signs and the treatments at each stage.

How urgent is it? See a dentist soon

See a dentist as soon as possible if you think you or your child has tooth decay. Seek urgent care if you have swelling, a high temperature or severe pain that painkillers do not control.

When to call 999, NHS 111 or your dentist

What it is

Tooth decay (also called dental caries) happens when bacteria in plaque turn sugars into acid. Each sugary snack or drink sets off an acid attack that softens the tooth surface; saliva helps repair early damage, but frequent sugar leaves teeth under near-constant attack.

Early decay often causes no symptoms at all, which is why regular check-ups matter. As it spreads into the softer dentine the tooth may become sensitive, and if it reaches the pulp - the living centre of the tooth - it can cause severe pain and a dental abscess.

The NHS explains that very early decay can sometimes be reversed with fluoride treatments. Once a hole has formed, it will need a filling, and deeper decay may need root canal treatment or, if the tooth cannot be saved, an extraction.

Signs and causes

Common signs

  • No symptoms at all in the early stages
  • Sensitivity or sharp pain with hot, cold or sweet food and drink
  • Toothache
  • White, brown or black spots on a tooth
  • A visible hole or food catching in a tooth

Usual causes

  • Having sugary food and drink often, especially between meals
  • Not brushing and cleaning between the teeth regularly
  • Sugary medicines taken regularly
  • A dry mouth, which reduces the protective effect of saliva
  • Smoking and regularly drinking more than 14 units of alcohol a week, which the NHS lists among things to avoid

Ways to fix it

The options a dentist may discuss with you, and when each one tends to be used. Which one suits you depends on an examination.

  1. Fluoride treatments and fissure sealants

    Very early decay that has not yet formed a hole - fluoride varnish or high-fluoride products may help reverse it; sealants help protect children's back teeth.

    Available on the NHSPreventive

  2. Fillings

    Small to moderate cavities.

    Available on the NHSRestorative

  3. Inlays and onlays

    Larger areas of decay on back teeth where a filling would not be strong enough.

    Available on the NHSRestorative

  4. Root canal treatment

    When decay has reached and infected the pulp.

    Available on the NHSRestorative

  5. Crowns

    To protect a heavily filled or root-treated tooth.

    Available on the NHSRestorative

  6. Tooth extraction

    When the tooth is too badly damaged to restore.

    Available on the NHSSurgical

What you can do now

  • Take paracetamol or ibuprofen for pain while you wait to be seen, following the pack instructions
  • Avoid very hot, cold or sweet food and drink if the tooth is sensitive
  • Keep brushing gently around the tooth with fluoride toothpaste

Preventing it

  • Brush twice a day with fluoride toothpaste - last thing at night and one other time - then spit, do not rinse
  • Clean between your teeth every day with floss or interdental brushes
  • Keep sugary foods and drinks to mealtimes
  • Choose sugar-free medicines where possible
  • Have regular check-ups at the interval your dentist recommends

Common questions

Can tooth decay be reversed?

Only at the very earliest stage, before a hole forms. The NHS says a dentist can prescribe fluoride treatments such as varnish or mouthwash to help reverse early decay.

Why doesn't my decay hurt?

Decay confined to the enamel usually causes no pain. Symptoms tend to appear once it reaches the dentine or the nerve, which is why check-ups are important.

Is NHS dental treatment free?

Not for most adults in England, who pay a band charge. It is free for some people, including under-18s, under-19s in full-time education, people who are pregnant or have had a baby in the last 12 months, and people receiving certain benefits.

Products that may help at home

These support good daily care; they don’t replace treatment from a dentist. Some links may be affiliate links.

Sources we used

Checked September 2026. Guidance changes, so always follow the advice of your own dental team. About our sources.