Tubule density near the pulp is closest to which value per square millimeter?

• A. 20,000/mm2
• B. 50,000/mm2
• C. 100,000/mm2
• D. 5,000/mm2

Answer: (B)

Dentinal tubule density near the pulp is high, creating many diffusion pathways from dentin toward the pulp. This high density means a large number of tubules per unit area, which in turn increases the potential for substances to reach the pulp. The value that best matches typical near-pulp measurements is about 50,000 tubules per square millimeter. The other numbers fall short or exceed the usual range for this region, so 50,000/mm^2 is the closest estimate. This high density helps explain why materials in restorative procedures can diffuse more readily toward the pulp and influence pulpal response.