When you eat, food passes through your mouth. Here it meets germs or bacteria that live in your mouth. You may have heard the dentist talk about plaque. Plaque is a sticky film of bacteria. These bacteria love sugars and starches found in many foods, like soda pop, candy, ice cream, milk, and cakes. When you don't clean your teeth after eating, plaque bacteria use the sugar and starch to produce acids that can destroy the hard surface of the tooth, called enamel. Believe it or not, even some fruits, vegetables and juices can cause cavities if you don't brush your teeth regularly. Over time, these acids break down the white covering of your tooth (called 'enamel'), leaving it weaker and less able to fight off germs and more bacteria. After a while, tooth decay occurs. The more often you eat and the longer foods are in your mouth, the more damage occurs.
If you have a cavity, it first has to be removed from your mouth. After the dentist numbs your mouth using a special medicine called anesthetic, he or she uses different things to remove the cavity. One way is to use a tiny drill that blasts the tooth decay away. After the cavity is removed, the dentist fills the space it left with a filling, which can be silvery or the color of your teeth.
This filling seals the space where the cavity once was, and keeps germs and bacteria from doing damage.