Caries, or tooth decay, is a preventable disease. When teeth and gums are consistently exposed to large amounts of starches and sugars, acids may form that begin to eat away at tooth enamel. Carbohydrate-rich foods such as candy, cookies, soft drinks and even fruit juices leave deposits on the teeth. Those deposits bond with the bacteria that normally survive in the mouth and form plaque. The combination of deposits and plaque forms acids that can damage the mineral structure of teeth, with tooth decay resulting.