What are cavities?

Causes and Symptoms

The oral cavity is filled with a variety of bacteria, some of which can ferment foods, especially complex and simple sugars, into organic acids. A mixture of oral bacteria, organic acids, food debris, and saliva combine to form a sticky, creamy-colored substance called plaque. Plaque forms on all teeth, but some are more susceptible to plaque buildup than others. A failure to remove plaque causes it to mineralize into tartar. The combination of plaque and tartar irritates the gums, which results in gingivitis
and can ultimately cause an infection of the ligaments and bones that support the teeth (periodontitis). The acids in plaque also dissolve the enamel surface of the tooth, generating a hole that is known as a cavity.
Untreated, tooth decay can hollow out a tooth and destroy the nerves and blood vessels inside, resulting in a tooth abscess.

The earliest sign of a cavity is a chalky, white spot on the surface of a tooth, which indicates demineralization of the tooth enamel. At this point, the process is reversible, but the white spot can turn brown and develop into a breach in the enamel. Once the cavity forms, the affected tooth structure cannot be regenerated. Large cavities can cause toothache, particularly after consuming cold, hot, or sweet foods or drinks, but most cavities are typically painless until they grow large enough to affect the nerves. Dental X-rays can detect cavities even before they are visible to the naked eye, and cavities usually cause soft spots that are sticky when the tooth is pressed with a probe.

Treatment and Therapy

Treatment of dental cavities requires drilling the tooth to remove the enamel and dentin eroded by the invasion of acid-producing bacteria. Once the affected hard tissues have been removed, a dental filling made from dental amalgam, composite resin, porcelain, or gold is placed into the tooth to restore its structural integrity. For large cavities that have eroded so much of the tooth structure that restorative material cannot be placed within it, a cap called a crown, made of gold, porcelain, or porcelain fused to metal, is fitted over what remains of the tooth. Sometimes, the damage is great enough to continually stress the nerve in the tooth, leading the nerve to die and decay. Endodontic therapy is then employed. An endodontic file hollows the center of the tooth, forming a “root canal,” and removes the nerve tissue. The tissue often appears as thin wispy fibers. Endodontic therapy also involves filling the canal with gutta percha, a rubber-like substance. If the decay is too great for the tooth to be
treated and saved, the tooth must be extracted.

Conscientious personal dental hygiene consists of daily brushing and flossing, regular dental examinations at least twice a year, and diet modification that reduces the intake of simple sugars. This personal dental hygiene can reduce the risk of cavities and keep teeth and gums healthy.

Bibliography:

Alan, Rick. "Tooth Decay." Health Library, Oct. 31, 2012.

Fotek, Paul. "Dental Cavities." MedlinePlus, Feb. 22, 2012.

Frost, Helen. Food for Healthy Teeth. Mankato, Minn.: Capstone, 2006.

Sutton, Amy L, ed. Dental Care and Oral Health Sourcebook. 3d ed. Detroit, Mich.: Omnigraphics, 2008.

Taintor, Jerry F., and Mary Jane Taintor. The Complete Guide to Better Dental Care. New York: Checkmark, 1999.

UConn Health Center. “Your Dental Health: A Guide for Patients and Families.” Healthnet: Connecticut Consumer Health Information Network, Nov. 27, 2012.