A cavity is not something that appears overnight. It is the end of a process that can take months or years, and that you can interrupt at many points.

How does a cavity form?

Teeth are covered by enamel, the hardest substance in the body. Plaque bacteria feed on sugars and starches and produce acid. Each acid attack dissolves a little mineral from the enamel, a process called demineralisation. Between meals, saliva neutralises the acid and helps put minerals back. If acid attacks happen too often, or plaque is not cleaned away, the balance tips towards loss, and a cavity forms.

The stages of tooth decay

  1. White spot. A chalky patch on enamel. Still reversible with fluoride and better care.
  2. Enamel decay. A hole forms in the enamel. It usually does not hurt yet, and needs a filling.
  3. Dentine decay. The softer layer beneath the enamel is affected, and decay spreads faster. Sensitivity to sweet, hot or cold may begin.
  4. Pulp involvement. Bacteria reach the nerve, causing severe pain. A root canal treatment may be needed to save the tooth.
  5. Abscess. Infection spreads to the tissues around the root, causing swelling and sometimes fever. This needs urgent attention.

How to prevent cavities

  • Brush with fluoride toothpaste twice a day, especially at night. See how fluoride works.
  • Clean between your teeth daily, where many cavities start.
  • Watch how often you have sugar. Sipping sugary tea or coffee through the day, or grazing on sweets, keeps the mouth acidic for hours. It is better to have sweet foods with a meal and then rinse with water.
  • Drink water. Especially after meals and snacks.
  • Consider sealants or fluoride varnish if you or your child are at high risk.
  • Attend regular check-ups. Early decay between teeth can only be seen on X-rays or by a trained eye.

    • Sugar is not just in sweets

    Biscuits, chips, white bread, fruit juices, sweetened chai and even “healthy” dried fruit contain fermentable carbohydrates. Read more in our guide to foods that protect and harm your teeth.

    What to do if you suspect a cavity

    Do not wait for pain. See a dentist if you notice a dark spot, a rough edge, food that keeps catching, or sensitivity to sweet foods. A small filling today can save a root canal tomorrow. Book a check-up through our general dentistry service.