Dental cavities, also known as carries, have been around for thousands of years. However, the problem has been steadily increasing over time. For example, scientists have discovered fossilized remains of men and women from the Iron Age in @Warwickshire, @England. These remains showed a cavity rate of only about 8 percent. When the scientists examined today's Warwickshire inhabitants, they found a remarkably high cavity rate of 48 percent. The culprit is most likely a modern diet, which consists, in large part, of highly processed, sugar-containing foods.
Dental cavities are caused by a combination of carbohydrate-containing foods and bacteria that normally live in our mouths. While there are many different types of bacteria, there are only a few that contribute to cavity formation. These bacteria reside in a film that continuously forms on and around our teeth. We call this film plaque. The bacteria use carbohydrates for food, producing acid in the process. The acid causes the @pH (a measure of acidity) on the tooth surface to drop. Before eating, the pH in the mouth is about 6.2 to 7.0, slightly more acidic than water. After eating sugary foods and other carbohydrates, the pH drops. At a pH of 5.2 to 5.5 or below, the acid begins to dissolve the hard enamel that forms the outer coating of the teeth. As the enamel wears away, a cavity results.
