What is tooth decay, and what causes it?

Tooth decay is the disease known as caries. Unlike other diseases, however, caries is not life threatening and is highly preventable, though it affects most people to some degree during their lifetime. Tooth decay occurs when your teeth are frequently exposed to foods containing carbohydrates (starches and sugars) like soda pop, candy, ice cream, milk, cakes, and even fruits, vegetables and juices. Natural bacteria live in your mouth and form plaque. The plaque interacts with deposits left on your teeth from sugary and starchy foods to produce acids. These acids damage tooth enamel over time by dissolving, or demineralizing, the mineral structure of teeth, producing tooth decay and weakening the teeth.

How is caries prevented?

The acids formed by plaque can be counteracted by simple saliva in your mouth, which acts as a buffer and remineralization agent. Dentists often recommend chewing sugarless gum to stimulate your flow of saliva. However, though it is the body's natural defense against caries, saliva alone is not sufficient to combat tooth decay. The best way to prevent caries is to brush and floss regularly. To rebuild the early damage caused by plaque bacteria, we use fluoride, a natural substance which helps to remineralize the tooth structure. Fluoride is added to toothpaste to fight cavities and clean teeth. The most common source of fluoride is in the water we drink. Fluoride is added to most community water supplies and to many bottled and canned beverages. If you are at medium to high risk for caries, your dentist may recommend special high concentration fluoride gels, mouthrinses, or dietary fluoride supplements. Your dentist may also use professional strength anti-cavity varnish, or sealants- thin, plastic coatings that provide an extra barrier against food and debris.

Who is at risk for caries?

Because we all carry bacteria in our mouths, everyone is at risk for caries. Those with a diet high in carbohydrates and sugary foods and those who live in communities without fluoridated water are likely candidates for caries. The area around a restored portion of a tooth is a good breeding ground for bacteria, those with a lot of fillings have a higher chance of developing tooth decay. Children and senior citizens are the two groups at highest risk for caries.

What can I do to help protect my teeth?

The best way to combat caries and cavities is to follow three simple steps:

1. Cut down on sweets and between-meal snacks. Remember, it's these sugary and starchy treats that put your teeth at extra risk.

2. Brush after every meal and floss daily. Cavities most often begin in hard-to-clean areas between teeth and in the fissures and pits- the edges in the tooth crown and gaps between teeth. Hold the toothbrush at a 45-degree angle and brush inside, outside and between your teeth and on the top of your tongue. Be sure the bristles are firm, not bent, and replace the toothbrush after a few weeks to safeguard against reinfecting your mouth with old bacteria that can collect on the brush. Only buy toothpastes and rinses that contain fluoride. Children under six should only use a small pea-sized dab of toothpaste on the brush and should spit out as much as possible because a child's developing teeth are sensitive to higher fluoride levels. Finally, because caries is a transmittable disease, toothbrushes should never be shared, especially with your children.

3. See your dentist at least every six months for checkups and professional cleanings. Because caries can be difficult to detect, a thorough dental examination is very important. If you get a painful toothache, if your teeth are very sensitive to hot or cold foods, or if you notice signs of decay like white spots, tooth discolorations or cavities, make an appointment right away. The longer you wait to treat infected teeth the more intensive and lengthy the treatment will be. Left neglected, caries can lead to root canal infection, permanent deterioration of decayed tooth substance and even loss of the tooth itself.

Sources: The medical management of dental caries, by Burton L. Edelstein, DDS, Journal of the American Dental Association, Jan. 1994; How severe is the threat of caries to old teeth? by M.l. MacEntee, et al., Journal of Prosthetic Dentistry, May 1994; Tooth decay, American Dental Association, 1994; Modern management of dental caries: the cutting edge is not the dental bur, by Maxwell H. Anderson, DDS, et. al., JADA, June 1993; Changing paradigms in caries management, by Maxwell H. Anderson, DDS, Periodontology and Restorative Dentistry, March 1992; Preventing dental caries: breaking the chain of transmission, by Ernest Newbrun, DMD, JADA, June 1992; Prevention of dental caries, by Andrew J. RuggGunn, Dental Update, Jan/Feb 1990; Preventive dentistry: dental caries, by John C. Greene, DMD, et al., Journal of the American Medical Association, Dec. 22/29, 1989. This information was compiled for you by the Academy of General Dentistry Your dentist cares about long-term dental health for you and your family and demonstrates that concern by belonging to the Academy of General Dentistry As one of the 36,000 general dentists in the United States and Canada who are members of the AGD, your dentist participates in an ongoing program of professional development and continuing education to remain current with advan ces in the professio n and to provide quality patient treatment.

Back to Health Library menu