By understanding the cause of a cavity, patients might be better able to deter them. Cavities are actually caused by a chain of events, starting with food being allowed to stay on your teeth.
The worst culprit is sugar because this is most easily digested by the bacteria that naturally live in your mouth, but any food left long enough will eventually become sustenance for the bacteria. Once the bacteria (also known as plaque) digest the food, they produce an acid. It is this acid which eats away at the enamel (outer layer of tooth) eventually causing a "hole" in your tooth.
The best way to prevent cavities is by practicing good oral hygiene.
One more note: Plaque also causes gum disease, which is the major cause
of tooth loss in people over the age of 35. So, there are now at least
two good reasons for good home care!
Tooth enamel (the outer covering of a tooth) consists of a substance called hydroxyapatite. The dissolving of this substance is called demineralization, and its formation is called remineralization. In the mouth there is an equilibrium between these two processes which is established even with healthy teeth.
Do you know any chemistry? When sugar ferments on teeth, hydrogen ions are produced that upset the equilibrium between demineralization and remineralization by combining with hydroxide ions to form water. Removal of hydroxide ions causes more of the hydroxyapatite to dissolve, resulting in tooth decay.
Fluoride helps prevent tooth decay by replacing the hydroxide ions in
hydroxyapatite. The resulting chemical compound is very resistant to acid
attack!
