Tooth decay is a serious problem that affects people of all ages and backgrounds, but especially children and those who have limited access to dental care. It is the result of a complex interaction between the bacteria that live in the mouth, the food we eat, the saliva we produce, and our genetic factors. The bacteria form a sticky layer on the teeth called dental plaque or biofilm, where they feed on the sugars and starches from food and produce acids that erode tooth enamel.