Dentinogenese

Dentinogenesis is the process by which dentin, the hard tissue that makes up most of a tooth beneath the enamel, is formed. It occurs during tooth development and involves odontoblasts derived from the dental papilla.

During tooth development, odontoblasts differentiate and enter the secretory stage, synthesizing predentin, an unmineralized matrix rich in type I collagen. Predentin mineralizes, forming dentin with a mineralized collagen matrix. The dentin contains dentinal tubules formed by odontoblast processes; the growth front advances toward the pulp, producing primary dentin.

After eruption, dentin continues to form at a slower rate as secondary dentin, and in response to stimuli tertiary dentin (reactionary or reparative dentin). Mantle dentin is the outermost layer near enamel, while circumpulpal dentin makes up the bulk.

Molecularly, dentin is mainly collagen type I, with non-collagenous proteins such as dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), and others that regulate mineralization and tubule formation.

Clinical relevance: defects in dentinogenesis cause dentinogenesis imperfecta and dentin dysplasia, often linked to DSPP mutations. Clinically, teeth may appear opalescent, with altered dentin and pulp exposure risk; management focuses on protective restorations and endodontic treatment as needed.