The Dental Pulp: Composition, Properties and Functions

Derived from neural crests, the mature pulp is due to the proliferation and condensation of apical cells implicated in root lengthening. Adult cells are bound together by intercellular junctions (desmosomes and gap junctions), forming a network. They are further transported to the crown. Root lengthening is associated to tooth eruption and to vertical sliding. Composed by type I and III collagens, fibronectin, tenascin, and other non-collagenous proteins that include a series of proteoglycans, the extracellular matrix is favoring the sliding of pulp cells. A micro-vascular network differing in the root and crown, supply the blood flow. Endothelial cells, pericytes and lymphatic vessels are contributing to direct the vascular implication to pulp development. Inflammatory and immunocompetent cells are present with in the pulp, namely dendritic cells, macrophages, lymphocytes and endothelial cells. They add to the different forms of the immune response of the dental pulp implicated in the different types of programed cell death. Nerves play role in the neutrophin family, identified within the pulp. Neuromediators are released near the nerves. Stem cells issued from the pulp of permanent and deciduous teeth, from the apical papilla and from the dental follicle, contribute to pulp healing and regeneration. Sliding of the pulp cells from the apical to the coronal pulp, and later the lateral sliding due to the effects of Wnt visualized after BIO implantation, are factors implicated in the formation of reparative and reactionary dentin, and consequently to pulp healing.