What is a cavity?

A cavity is a hole in a tooth that develops from tooth decay. Cavities form when acids in the mouth wear down, or erode, a tooth’s hard outer layer (enamel). Anyone can get a cavity. Proper brushing, flossing and dental cleanings can prevent cavities (sometimes called dental caries).

Anatomy of a tooth | Cleveland Clinic

How common are cavities?

More than 80% of Americans have at least one cavity by the time they enter their mid-30s. Cavities are one of the most common chronic diseases that affect all ages.

Who might get a cavity?

Tooth decay can happen at any age, although cavities are more common in children. They may not brush properly and consume more sugary foods and drinks.

Adults also get cavities. Sometimes, new decay develops around the edges of cavities treated in childhood. Adults also are more likely to have receding gums. This condition exposes the lower parts of teeth to cavity-causing plaque.

What are the types of cavities?

Tooth decay can affect all layers of a tooth. It can take three years for a cavity to form in the strong outer layer of tooth enamel. Decay progresses more quickly through the dentin (middle layer) to pulp (innermost layer). Pulp contains a tooth’s nerve endings and blood supply. Types of tooth decay include:

  • Smooth surface: This slow-growing cavity dissolves tooth enamel. You can prevent it — and sometimes reverse it — with proper brushing, flossing and dental cleanings. People in their 20s often develop this form of tooth decay between their teeth.
  • Pit and fissure decay: Cavities form on the top part of the tooth’s chewing surface. Decay also can affect the front side of back teeth. Pit and fissure decay tends to start during the teenage years and progresses quickly.
  • Root decay: Older adults who have receding gums are more prone to root decay. Gum recession exposes the tooth’s root to plaque and acid. Root decay is difficult to prevent and treat.

What causes cavities?

Many factors play a role in the development of cavities. These steps typically occur:

  • Bacteria in the mouth feed on sugary, starchy foods and drinks (fruit, candy, bread, cereal, sodas, juice and milk). The bacteria convert these carbohydrates into acids.
  • Bacteria, acid, food and saliva mix to form plaque. This sticky substance coats the teeth.
  • Without proper brushing and flossing, acids in plaque dissolve tooth enamel, creating cavities, or holes.

What are the risk factors for cavities?

Certain factors increase your risk of cavities:

What are the signs of cavities?

Tooth decay on the outer enamel surface doesn’t usually cause pain or symptoms. You’re more likely to experience symptoms as decay progresses into the dentin and root. Signs of cavities include:

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