What is tooth decay?

Tooth decay is damage that occurs when germs (bacteria) in your mouth make acids that eat away at a tooth. It can lead to a hole in the tooth, called a cavity. If not treated, tooth decay can cause pain, infection, and tooth loss.

What causes tooth decay?

Things that make you more likely to have tooth decay include:

- Not brushing and flossing your teeth regularly and not seeing a dentist for checkups and cleanings.
- Eating foods that are high in sugar and other carbohydrates, which feed the bacteria in your mouth.
- Not getting enough fluoride. Fluoride helps prevent tooth decay by making teeth more resistant to acids produced by plaque. Fluoride is added to many public water supplies.
- Not having enough saliva. Saliva washes away food and harmful sugars, so it helps protect your teeth from decay. A dry mouth may be caused by a condition such as xerostomia or Sjögren's syndrome, by taking certain medicines, or by breathing through your mouth. Older adults are more likely to have a dry mouth.
- Having diabetes.
- Smoking, using spit (smokeless) tobacco, or breathing secondhand smoke.

What are the symptoms?

Tooth decay usually doesn't cause symptoms until you have a cavity or an infected tooth. When this happens, you may have:

- A toothache, which is the most common symptom.
- Swelling in your gums near a sore tooth. This can be a sign of severe tooth decay or an abscessed tooth camera.gif.
- Bad breath or a bad taste in your mouth.
- White, gray, brown, or black spots on your teeth.