Search results
Results from the WOW.Com Content Network
Tertiary dentin on the surface of a gorilla tooth. The darker area indicated by the white arrow is tertiary dentin and has formed as a response to tooth wear. Wear on the surface of a tooth can lead to the exposure of the underlying dentin. When wear is severe tertiary dentin may form to help protect the pulp chamber. [4]
Cross-section of a tooth. B is dentin. Dentin (/ ˈ d ɛ n t ɪ n / DEN-tin) (American English) or dentine (/ ˈ d ɛ n ˌ t iː n / DEN-teen or / ˌ d ɛ n ˈ t iː n / DEN-TEEN) (British English) (Latin: substantia eburnea) is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth.
Dentin formation, known as dentinogenesis, is the first identifiable feature in the crown stage of tooth development. The formation of dentin must always occur before the formation of enamel. The different stages of dentin formation result in different types of dentin: mantle dentin, primary dentin, secondary dentin, and tertiary dentin. [31]
Tertiary dentin is deposited at specific sites in response to injury by odontoblasts or replacement odontoblasts from the pulp depending on the severity of the injury. Tertiary dentin can be divided into reactionary or reparative dentin. Reactionary dentin is formed by odontoblasts when the injury does not damage the odontoblast layer.
As more tertiary dentin is produced, the size of the pulp decreases. This type of dentin has been subdivided according to the presence or absence of the original odontoblasts. [85] If the odontoblasts survive long enough to react to the dental caries, then the dentin produced is called "reactionary" dentin. If the odontoblasts are killed, the ...
Dentin is the substance between enamel or cementum and the pulp chamber. It is secreted by the odontoblasts of the dental pulp. [15] The formation of dentin is known as dentinogenesis. The porous, yellow-hued material is made up of 70% inorganic materials, 20% organic materials, and 10% water by weight. [16]
Pulp acts as a security and alarm system. Slight decay in tooth structure not extending to the dentin may not alarm the pulp, but as the dentin gets exposed, due either to dental caries or trauma, sensitivity starts. The dentinal tubules pass the stimulus to the pulp's odontoblastic layer, triggering the response. This mainly responds to cold.
Odontoblasts also secrete tertiary dentin when irritated. Tertiary dentin secreted by odontoblasts is often due to chemical attack, either by chemicals diffusing through the dentin and insulting the odontoblasts, or by diffusion of toxic bacterial metabolites down the dentinal tubules in the instance of a carious attack with dental decay. This ...