Near pulp exposure
The healthy tooth is composed of two major parts: the supra-gingival portion that extends above the gingiva and is grossly visible, termed the crown, and the sub-gingival portion that extends beneath the gingiva, termed the root. A central cavity is located within the tooth, termed the pulp canal (located in the root segment) and pulp chamber (located in the crown segment). The pulp, which consists of nerves, blood vessels and connective tissues, is located within the pulp canal and chamber. It provides nutrition and sensation to the tooth. The pulp is surrounded and therefore protected by two hard layers. An inner layer composed of dentine, which is found in both the crown and root, and an outer layer of enamel and cementum. The crown is covered in enamel. The root has an outer covering of cementum. The point where the crown and root meet is termed the cemento-enamel junction. Loss of tooth structure resulting in only a thin layer of dentine covering over the pulp may produce a near pulp exposure. Treatment is aimed as indirect pulp capping to cover any exposed dentinal tubules and prevent ingress of bacteria to the pulp.