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.
A tooth has three layers:
The hard outer layer is called enamel
The middle layer is called dentin
The center of the tooth is called the pulp. It contains nerves and blood vessels
The more layers that are affected by decay, the worse the damage.
What causes tooth decay?
Bacteria and food can cause tooth decay. A clear, sticky substance called plaque is always forming on your teeth and gums. Plaque contains bacteria that feed on the sugars in the food you eat
As the bacteria feed, they make acids. The acids attack the teeth for 20 minutes or more after you eat. Over time, these acids destroy tooth enamel, causing 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