Tooth decay


Tooth decay
Tooth decay

Tooth decay is damage to a tooth caused by dental plaque turning sugars into acid.

If plaque is allowed to build up, it can lead to problems, such as holes in the teeth (dental caries) and gum disease.

This can lead to dental abscesses. These are collections of pus at the end of the teeth or in the gums.

Symptoms of tooth decay

Tooth decay may not cause pain but you might have:

  • toothache – either continuous pain keeping you awake, or occasional sharp pain without an obvious cause
  • tooth sensitivity – you may feel tenderness or pain when eating or drinking something hot, cold or sweet
  • grey, brown or black spots appearing on your teeth
  • bad breath
  • an unpleasant taste in your mouth

Use our Dental Symptom Checker.

Seeing a dentist

If you think that you have tooth decay, call your dental practice.

If you do not have a regular dentist call the dental helpline number for your area.

Visit your dentist for check-ups as regularly as they recommend so that they can identify tooth decay as early as possible.

Tooth decay is easier and cheaper to treat in the early stages.

Dentists can identify tooth decay and further problems during an examination or by taking an X-ray.

Find your nearest dentist here.

Treatments for tooth decay

Early-stage tooth decay

Early-stage tooth decay, which is before a hole (or cavity) has formed in the tooth, can be reversed by:

  • reducing how much and how frequently you have sugary foods and drinks
  • brushing your teeth twice a day with fluoride toothpaste

Your dentist may apply a fluoride gel or varnish to the affected tooth.

Fluoride strengthens the enamel making teeth more resistant to acids from plaque that cause tooth decay.

Treatments for holes in teeth

When there's a hole in the tooth, treatment may include:

  • a filling or crown – this involves removing the dental decay and filling the hole or covering the tooth
  • root canal treatment – to remove decay that's spread to the middle of the tooth where the blood vessels and nerves are (the pulp)
  • removing all or part of the tooth – this is advised when the tooth is badly damaged and cannot be restored.

Cost of NHS treatment

NHS charges are set by the government and are standard for all NHS patients. Charges are assessed each year and usually change every April.

Some people do not have to pay for dental treatment, including children, pregnant women and new mothers.

Financial help may also be available to those on a low income.

Read more about:

NHS dental charges and getting help with dental charges.

The cost of private dental treatment varies. There is no set charge. If you choose to see a private dentist, agree the cost before having treatment.

Preventing tooth decay in adults

Tooth decay is preventable.

The best way to avoid tooth decay and keep your gums as healthy as possible is to:

  • visit your dentist regularly – your dentist will decide how often they need to see you
  • cut down on sugary and starchy food and drinks
  • Avoid snacking between meals or eating within an hour of going to bed
  • Some medicines contain sugar, so look for sugar-free alternatives where possible
  • Brush your teeth with a fluoride toothpaste twice a day
  • Use floss and an interdental brush once a day
  • See your dentist or a GP if you have a persistently dry mouth – this may be caused by certain medicines, treatments or medical conditions

Protecting your child's teeth

Establishing good eating habits can help your child avoid tooth decay. Limit how many sugary snacks and drinks they consume.

Children should brush their teeth twice a day using fluoride toothpaste. Children under 8 need help with brushing their teeth. They may need help beyond this depending on the individual child's needs.

For more information see the Designed to Smile website.

What causes tooth decay

Bacteria that live in the mouth form a sticky film over the teeth called dental plaque.

When you eat food and drinks containing sugar, bacteria in plaque turn the sugar into energy. At the same time they produce acid which can damage teeth.

The acid can break down the surface of your tooth, causing holes known as cavities. Without treatment, the hole can get deeper and become painful.

Eventually, the bacteria can cause an infection in the tooth called a dental abscess. If not treated, the infection can spread into the bone at the end of the tooth. This can lead to a swelling.

The videos below have more advice

Easing toothache.

When and where to seek advice on dental care.


The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website
Last Updated: 21/05/2024 11:10:24