What traverses the region between the dentinoenamel junction and the pulp?

• A. Dentinal tubules
• B. Enamel prisms
• C. Blood vessels
• D. Nerve fibers

Answer: (A)

Dentin contains tubular channels that run from the pulp chamber up to the dentin–enamel junction. These are dentinal tubules. Each tubule houses the cytoplasmic process of an odontoblast and is filled with dentinal fluid, making it the main pathway through the region between the pulp and the DEJ. This tubular system explains how sensory signals from the dentin can reach the pulp and contribute to dentin sensitivity when dentin is exposed.

Enamel prisms belong to enamel, not dentin, and lie outside this region. Blood vessels are located in the pulp itself, not traversing dentin. Nerve fibers are primarily in the pulp; while nerves may be associated with tubules near the pulp, they do not form the channels that extend through dentin the way dentinal tubules do.