Which dental material experiences the highest degree of marginal leakage due to temperature fluctuations?

Explanation

Among dental restorative materials, unfilled resin exhibits the greatest marginal leakage when exposed to temperature changes. This is because unfilled resins have higher polymerization shrinkage and lack filler particles that help reduce thermal expansion differences, leading to compromised marginal integrity compared to materials like amalgam, composite resin, or direct gold fillings.