Dentin

Dentin (Latin dentinum) is the hard calcified tissue that makes up the bulk of the tooth. It is located under the enamel in the crown area and under the cementum in the root area of the tooth, surrounding the pulp chamber and root canals. In terms of its physical properties, dentin is stronger than bone but more elastic than enamel.

Etiology and pathophysiology

Dentin is permeated by millions of microscopic dentinal tubes, within which are outgrowths of odontoblast cells and dentinal fluid. The presence of these tubes makes dentin a permeable tissue capable of transmitting irritants and bacterial toxins to the nerve endings of the pulp.

During the life of the tooth, odontoblasts continue to slowly produce secondary dentin, reducing the volume of the pulp chamber. In response to stimuli at the enamel-dentin interface, the formation of tertiary (reparative or replacement) dentin is activated;

Clinical significance

Dentin and pulp function as a single complex. Exposed dentin due to decay, trauma or abnormal abrasion leads to fluid movement in the tubules, which irritates the pulp receptors and causes tooth sensitivity (hyperesthesia). When treating dental caries, preserving a layer of healthy dentin over the pulp is a priority in order to preserve the viability of the tooth.