Structure of Teeth

The three main parts of a tooth are the crown, neck and root. The crown (the part of the tooth you see - above the gums) is covered by a protective, bony layer of enamel, and the root of the tooth is covered by a sensitive, bonelike substance called cementum.
A hard substance known as dentin surrounds the pulp, which contains nerves (sensing heat, cold, pain, and pressure) and blood vessels (nourishing the tooth).