Which type of dentine is laid down in layers as a repair mechanism?

The type of dentine that is laid down in layers as a repair mechanism is reparative dentine. This form of dentine is produced in response to injury or trauma, such as caries or dental procedures. When the dental pulp is stimulated due to damage, the odontoblasts (the cells responsible for dentin formation) can become activated to deposit this secondary layer of dentine. It serves to protect the pulp and maintain the integrity of the tooth structure.

Reparative dentine is characterized by its irregular structure and is typically formed more rapidly than primary or secondary dentine. It is essential in tooth defense against further damage or infection, effectively acting as a natural barrier and support for tooth longevity.

While both primary and secondary dentine contribute to the overall structure and functionality of the tooth, they do not play a direct role in the repair process as reparative dentine does. Primary dentine forms during tooth development, and secondary dentine is formed slowly throughout life, adding to the tooth's structure but without the specific purpose of repair. Peritubular dentine, on the other hand, is found within the dentinal tubules and is not involved in repair mechanisms.

Understanding the role of reparative dentine highlights the body's ability