Define metamerism and explain why it matters in shade matching.

• A. A chemical reaction between ceramic and metal
• B. A color change under different light sources, affecting shade matching
• C. A fixed color property independent of light
• D. A color change with temperature

Answer: (B)

Metamerism is when two colors look identical under one light but appear different under another because of how light spectra interact with the colorants. In shade matching, this matters because teeth and restorations will be viewed under different lighting in daily life—daylight, office lighting, or photos—and a shade that seems perfect in one setting can look off in another. To manage it, clinicians evaluate shades under multiple lighting conditions or use standardized lighting and shade guides designed to minimize color shifts, ensuring the restoration blends well across typical viewing environments.