dentinoenamel

Dentinoenamel, commonly referred to in dental literature as the dentin-enamel junction (DEJ), is the boundary between the enamel that covers the crown of a tooth and the underlying dentin. It is not a separate tissue but a specialized interface that forms during tooth development when enamel-producing ameloblasts and dentin-producing odontoblasts meet.

The DEJ often exhibits a scalloped, interdigitated morphology, with enamel and dentin extending in complementary projections that interlock. This interfacial architecture helps to secure the brittle enamel to the more resilient dentin, distributing stresses and reducing the likelihood that cracks will propagate from enamel into dentin under masticatory forces.

Enamel is the outermost, highly mineralized tissue, roughly 96% hydroxyapatite, and is formed by enamel rods. Dentin lies beneath enamel and is less mineralized, about 70%, containing a substantial organic matrix rich in type I collagen and a network of dentinal tubules. The DEJ thus marks a transition zone where mineral content and mechanical properties change, yet are connected through the interfacial structure.

Clinically, the integrity of the dentinoenamel junction influences bonding procedures, restorative outcomes, and resistance to fracture. Disturbances in enamel or dentin formation can alter DEJ architecture and affect how enamel and dentin respond to caries, wear, and restorative interventions. In research, the DEJ remains a focal point for understanding tooth resilience and improving adhesive dentistry.