Dentine
Dentine is a calcified tissue that comprises the bulk of tooth structure in vertebrates. Located between the outer enamel layer and the inner pulp chamber, dentine provides both structural support and protective function to the tooth. Composed primarily of mineral crystals embedded within an organic matrix of collagen and other proteins, dentine occupies an intermediate position in terms of hardness and mineralization—less mineralized than enamel but significantly more mineralized than bone. This composition allows dentine to be harder than bone while retaining greater flexibility than the brittle enamel layer.
Structure and Properties
Dentine contains microscopic tubules that radiate outward from the pulp chamber toward the outer surface of the tooth. These tubules contain fluid and cellular extensions called odontoblast processes, which connect the living cells at the pulp to the mineralized tissue. This tubular structure distinguishes dentine from bone and is essential for its sensory and protective functions. The tissue continues to form slowly throughout life as new dentine is deposited at the pulp-dentine interface.
Function and Clinical Significance
Dentine provides the primary structural support of the tooth and transmits sensory information from the tooth surface to the nerve within the pulp chamber. When enamel erodes or is worn away, exposed dentine can become sensitive to temperature, mechanical stimuli, and chemical irritants. Dentine caries (decay) represents a common pathological process in dentistry, as the tissue is more susceptible to bacterial acid demineralization than enamel. Understanding dentine structure and composition is fundamental to restorative dentistry and the treatment of dental disease.