Tooth

Enamel, the hardest calcified tissue in the body, covers the surface of the crown of the tooth.  Enamel is formed before tooth eruption and is not replenished after the tooth erupts.

Dentin, another mineralized tissue, provides the bulk and general form of the tooth.  Dentin underlies both the enamel and the cementum and is formed continuously throughout life.

Cementum, a much thinner layer than either the enamel or dentin, is the mineralized dental tissue covering the anatomic roots of the tooth.  Cementum is formed continuously throughout life, passively pushing the tooth toward the oral cavity as it does so.

In the living tooth the pulp chamber is filled with connective tissue, blood vessels, nerves and lymphatics; odontoblasts are located in the pulp chamber immediately adjacent to the dentin, into which their processes extend.  The volume of the pulp cavity decreases throughout life with the continued deposition of dentin by odontoblasts.