CTE of Dental Materials — NDEB AFK MCQ

Correct answer: A — Glass ionomer cement

Glass ionomer cement (GIC) has a coefficient of thermal expansion (CTE) that closely matches that of natural tooth structure (approximately 10-11 × 10⁻⁶/°C for dentin vs 10-11.4 × 10⁻⁶/°C for GIC). This minimises stress at the restoration-tooth interface during thermal cycling (hot and cold food/drink). Composite resin has a higher CTE (25-60 × 10⁻⁶/°C), and dental amalgam also has a higher CTE (25 × 10⁻⁶/°C) than tooth structure.

Reference: Anusavice – Phillips' Science of Dental Materials, 13th ed., 2022