CTE Match to Enamel — NDEB AFK MCQ
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Correct answer: E — Porcelain (feldspathic)
Feldspathic porcelain has a coefficient of thermal expansion (CTE) of approximately 6.5-8.0 × 10⁻⁶/°C, which is closest to enamel (~11.4 × 10⁻⁶/°C, though some sources cite ~8-10). By comparison: amalgam ~25; composite ~25-60; gold ~14; GIC ~10-11 (closest to dentin). A close CTE match between the restoration and tooth structure minimises thermally induced stress at the interface during temperature changes (hot/cold food), reducing microleakage and marginal gap formation.
Reference: Anusavice – Phillips' Science of Dental Materials, 13th ed., 2022