What is the purpose of a base?

• A. Aesthetic enhancement
• B. Bonding surface for dentin
• C. Conduction of heat to pulp
• D. Thermal protection and stress distribution

Answer: (D)

Bases provide thermal protection for the pulp and help distribute stresses from the restoration. In deep cavities, dentin is thin and pulp is vulnerable to temperature changes and mechanical forces. A base acts as an insulating cushion, reducing heat or cold reaching the pulp, and spreads occlusal stresses to prevent concentrated loads that could cause dentin fracture or pulp irritation. Aesthetic enhancement isn’t the purpose, and bonding to dentin is handled by bonding agents or liners rather than the base itself. The goal is to protect the pulp and support the tooth structure during function.