Cavities are caused by tooth decay. Cavities are more common among children, but adults may develop them as well. Tooth decay occurs for several reasons including plaque formation, what you eat, the use of fluoride, how well you care for your teeth, heredity, and certain medical conditions.
Plaque plays a major role in tooth decay. It is a thin, sticky film that constantly forms over your teeth. Plaque is fueled by the sugar or starch in foods, such as candy, ice cream, soda pop, cereal, and French fries. The sugars mix with the bacteria in plaque to form destructive acids. Plaque helps to hold the acids in place against your teeth. Plaque that has hardened on your teeth is called tarter. Tartar provides plaque with an ideal growing space. When the acid comes in contact with your teeth, it works to break down their outer layers, the enamel and dentin. Eventually, the decay causes the outer layer of tooth enamel to collapse, resulting in a cavity.
Over time, the amount of plaque that you have on your teeth increases your chance of cavity formation. Plaque is removed from your teeth each time your brush or floss. Fluoride in drinking water and toothpaste helps to combat plaque. Further, some mouthwashes contain plaque-fighting material. If you do not remove plaque, it builds up. Plaque build-up is a factor that you can reduce with good oral health care.
You may have less control over other factors that contribute to tooth decay. Inherited factors, such as the shape of your teeth or the depth and number of ridges in your teeth can contribute to food accumulation and plaque formation. Certain medical conditions, medications, and medical treatments can increase the risk of cavity formation in some people. Such factors include diabetes, dry mouth, chemotherapy, and radiation therapy.