We will discuss here about the structure of a tooth.
The part of the tooth that we can see above the gum is covered with enamel and is known as the crown. The surface of the crown is made of the hardest substance in our body, which is known as the enamel. It is very difficult to scratch on the surface of this layer (i.e. enamel).
Beneath the enamel is the dentine. The dentine is not so hard. Inside the dentine is a soft portion, which has blood vessels and nerves. It is known as the pulp.
The part of the tooth that is inside the gums is known as the root of the tooth. It holds the tooth firmly in place, just like the root of a plant.
So, teeth consist of the crown, whose surface is covered with hard enamel, the dentine and the pulp.