A crown is returned from the laboratory and appears slightly too light. Which dimension of color CANNOT be altered chairside by external characterization or glazing?

Correct answer: C. Hue

• A. Value (lightness/darkness) CAN be lowered chairside with grey or blue-grey surface stains. Note that value is the most important dimension for a natural match and the hardest to raise — raising value requires internal opaquing, i.e., a remake.
• B. Chroma (saturation) CAN be increased chairside with external stains in the same hue family.
• C. CORRECT. HUE — the basic family of the color (the A, B, C, D groups on the Vita shade guide) — is established by the body porcelain during fabrication and cannot be meaningfully changed with surface stains. Correcting hue requires remaking the restoration.
• D. Translucency CAN be modified with translucent or opalescent surface glazes.

Note: Practical rule: you can go DARKER and MORE saturated at the chair; you cannot go LIGHTER or change the hue family. Those need a remake.