Medical & Health Encyclopedia

The hardest substance in the human body is the enamel that covers the exposed surface of a tooth. Below the gum, the tooth's outside surface is composed of somewhat softer cementum. Beneath enamel and cementum is a bonelike substance, call dentin, which covers the soft interior of the tooth, called pulp. Pulp is serviced by blood vessels and nerves through the root or roots of the tooth. The passageway of nerves and blood vessels that lead up through the tooth from the gum sockets is called a root canal. Tooth and gum are stuck to each other by a tough, adhesive tissue called periodontal (or peridental- "surrounding the tooth") membrane.