A true cavity, meaning a hole in the tooth, cannot heal on its own. However, the very earliest stage of decay, when enamel is weakened but not yet broken, can be reversed with fluoride, better cleaning and less sugar. Once a hole forms, a dentist needs to remove the decay and fill the tooth.
What causes cavities?
Bacteria in plaque feed on sugars and starches from food and drink. They produce acid, which dissolves minerals from enamel. Repeated acid attacks throughout the day eventually create a hole. Risk rises with frequent snacking, sugary drinks, dry mouth, poor brushing and deep grooves in back teeth.
The stages of tooth decay
- White spots. Chalky patches show minerals have been lost. This stage is reversible.
- Enamel decay. The enamel breaks down and a small cavity forms. A filling is needed.
- Dentine decay. Decay spreads faster in the softer layer beneath and sensitivity often begins.
- Nerve involvement. Bacteria reach the pulp, causing pain and possibly infection. Root canal treatment may be needed.
- Abscess. Infection spreads to the root tip and surrounding bone.
Signs you may have a cavity
- Sensitivity to sweet, hot or cold
- Pain when biting
- A visible hole, pit or dark stain
- Food catching in the same spot
Early cavities often cause no symptoms at all, which is why regular check-ups and X-rays matter.
How to reverse early decay and prevent cavities
- Brush twice a day with fluoride toothpaste and spit, don’t rinse.
- Clean between your teeth daily.
- Keep sugary food and drinks to mealtimes rather than grazing.
- Drink water, especially fluoridated tap water where available.
- Ask about fissure sealants and fluoride varnish, especially for children.
Frequently asked questions
How fast does a cavity grow? It varies. Enamel decay can take months or years, but once it reaches dentine it can progress much faster.
Does a filling hurt? Modern fillings are done with local anaesthetic, so most people feel pressure rather than pain.
Can I stop a cavity from getting worse? You can slow it with good habits, but a cavity that has formed a hole needs a filling to stop it.
Think you might have a cavity? Book a check-up at Melrose Advanced Dentistry in Melrose, Johannesburg: 072 200 1774 or advanced-dentistry.co.za.