Dentine

Dentine is a calcified tissue of the body, and along with enamel, cementum, and pulp, one of the four major components of teeth. It is usually covered by enamel on the crown and cementum on the root and surrounds the entire pulp.

Structure

Dentine is not quite as hard as enamel, so it wears away more quickly than enamel. However, because it is less brittle than enamel, it is less likely to fracture under the pressure of chewing. The structure of dentine is an intricate network of microscopic channels, known as dentinal tubules, which radiate outward through the dentine from the pulp cavity to the exterior cementum or enamel border.

Formation

The formation of dentine, known as dentinogenesis, begins with the differentiation of odontoblasts from the dental papilla. The odontoblasts, which are aligned along the outer pulpal wall, form a mineralized matrix by first secreting predentine, which then mineralizes to become dentine.

Types

There are several types of dentine, each with its own function. Primary dentine is formed before the eruption of the tooth. Secondary dentine is formed after the tooth has erupted and continues to form throughout life. Tertiary dentine is formed in response to stimuli, such as wear or caries.

Clinical significance

Dentine plays a crucial role in dental health. The permeability of dentine allows for the diffusion of nutrients from the pulp to the enamel, which helps to keep the tooth nourished and healthy. However, the permeability of dentine can also allow for the diffusion of toxins from caries or dental restorations into the pulp, leading to pulpitis and pulp necrosis.

See also

• Tooth enamel
• Tooth development
• Dental pulp

References

Dentine Resources
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