Tooth decay is the destruction of tooth structure, affecting both the enamel and the dentin layer. It occurs when foods containing carbohydrates, such as breads, cereals, milk, soda, fruits, cakes, or candy, are left on the teeth. Bacteria in the mouth digest these foods, turning them into acids. The bacteria, acid, food debris, and saliva combine to form plaque, which clings to the teeth. The acids in plaque dissolve the enamel surface, creating cavities. To prevent tooth decay: 1. Brush your teeth at least twice a day with fluoride toothpaste. 2. Floss daily to remove plaque from between teeth. 3. Limit sugary and starchy foods. 4. Visit your dentist regularly for check-ups and cleanings. 5. Consider dental sealants, which provide a protective coating on the teeth. 6. Drink plenty of water, especially if it contains fluoride. Researchers are also developing new methods to prevent tooth decay, such as chewing gum with xylitol, which can slow the growth of decay-causing bacteria, and materials that slowly release fluoride over time. Toothpastes and mouth rinses that can reverse early cavities are also being studied.