Tooth decay (dental caries) is damage to a tooth that can happen when decay-causing bacteria in your mouth make acids that attack the tooth’s surface, or enamel. This can lead to a small hole in a tooth, called a cavity. If tooth decay is not treated, it can cause pain, infection, and even tooth loss.
Tooth decay is a common disorder, second only to the common cold. It usually occurs in children and young adults, but it can affect anyone. Tooth decay is a common cause of tooth loss in younger people.
Bacteria are normally found in your mouth. These bacteria change foods, especially sugar and starch, into acids. Bacteria, acid, food pieces, and saliva combine in the mouth to form a sticky substance called plaque. Plaque sticks to the teeth. It is most common on the back molars, just above the gum line on all teeth, and at the edges of fillings.
Plaque that is not removed from the teeth turns into a substance called tartar, or calculus. Plaque and tartar irritate the gums, resulting in gingivitis and periodontitis.
Plaque begins to build up on teeth within 20 minutes after eating. If it is not removed, tooth decay will begin.
The acids in plaque damage the enamel covering your teeth. It also creates holes in the tooth called cavities. Cavities usually do not hurt, unless they grow very large and affect nerves or cause a tooth fracture. An untreated cavity can lead to an infection in the tooth called a tooth abscess. Untreated tooth decay also destroys the inside of the tooth (pulp). This requires more extensive treatment, or possibly removal of the tooth.
Carbohydrates (sugars and starches) increase the risk of tooth decay. Sticky foods are more harmful than non-sticky foods because they remain on the teeth. Frequent snacking increases the time that acids are in contact with the surface of the tooth.
People of all ages can get tooth decay once they have teeth—from childhood through the senior years.
Young children are at risk for “early childhood caries,” sometimes called baby bottle tooth decay, which is severe tooth decay in baby teeth.
Because many older adults experience receding gums, which allows decay-causing bacteria in the mouth to come into contact with the tooth’s root, they can get decay on the exposed root surfaces of their teeth