Dental caries and your teeth
Let’s have a look at the structure of a typical molar. Every tooth has a crown with cusps. It is the part of the tooth you can see and feel. It also has the neck and the root, the part of the tooth that is buried in the jaw. A tooth is made of enamel. It is the hardest substance in your body. It is even harder than bone. Dentine comes after enamel. Dentine is a dense calcified substance that is composed of less animal matter than bone. Enamel and dentine both contain large amounts of the minerals calcium and phosphorus. They also contain smaller amounts of other minerals including fluoride. Inside of the tooth there is a pulp with blood vessels and nerves.
Good teeth remain strong and healthy for many years as long as the enamel on them is not damaged. If the enamel is cracked or destroyed, the much softer dentine gets exposed. The tooth will then decay rapidly. These areas of decay are called dental caries.
A tooth can be repaired by drilling out the damaged and decayed parts. The hole is then filled to seal the enamel layer again. If this is impossible the whole tooth must be removed because the decay could spread into the jaw bone.
Enamel is destroyed by acids, and this is the cause of dental caries. This may puzzle you. You don’t eat many things which contain acids, so where do they come from?
There are millions of bacteria living in your mouth. On their own they are harmless. They are found in the mouths of even the healthiest people. These bacteria combine with saliva to form an invisible material called plaque. Plaque will cover up the enamel on your teeth, if you let it, especially near the gum line and between the teeth. Like all living things, these bacteria must feed. They feed on sugar, and produce waste which contains acid. It is this acid which dissolves the enamel.