A tooth can be divided into two main sections; a crown (top third of the tooth) and of roots (lower two thirds of the tooth). A tooth can be thought of like an onion with layers. In the upper third of a tooth, the outer layer is the white hard enamel, next layer in is a yellow softer layer known as dentine and the center of the tooth is the pulp chamber which houses the tooth’s blood supply and nerves. In the lower two thirds of the tooth, the outer layer is root dentine followed by the root canal which extends down from the pulp chamber. The root(s) of a tooth is surrounded by cementum and periodontal ligament and finally the jaw bone. Please see the attached image of tooth anatomy.