What Are Teeth Made Of?

Teeth are made up of four main parts. On the outside is a protective layer of enamel - the hardest substance in the body. Below that is a bone-like substance called dentin, which makes up the largest part of the tooth. Underneath the dentin, the tooth actually has a soft center. This is called the pulp, and it houses all of the tooth's blood vessels and nerve endings. Finally, cementum covers the roots.

Tooth decay starts with the enamel, which has no feeling. But once it reaches the dentin, it can start to cause toothache. If decay ever spreads as far as the pulp, it can be incredibly painful. Luckily, with proper brushing and regular dentist visits, you'll be able to stop decay before it causes any pain or discomfort.