A single ceramic crown appears too WHITE compared with the adjacent natural tooth. The same appearance results from under-reduction of the axial walls, leaving insufficient depth to mask the opaque layer. Which colour dimension is at fault?

Correct answer: B. Value

• A. Translucency is affected as well — an under-reduced, opaque-dominated crown is too opaque and loses incisal translucency — but the recognised descriptor for the crown being too WHITE and too bright is high VALUE.
• B. CORRECT. VALUE — the brightness or greyness of the colour — is the dimension at fault. When the preparation is UNDER-REDUCED there is not enough space for an adequate thickness of dentin and enamel porcelain over the opaque layer, so the opaque shows through and the restoration reads as excessively BRIGHT and monolithic. Value is also the dimension the human eye judges most acutely, which is why a value mismatch is the single most common reason a technically acceptable crown is rejected at try-in.
• C. Chroma is the SATURATION of the hue. A chroma error makes the crown look too pale or too intense within its colour family, but the specific complaint of an opaque, too-white unit from inadequate reduction is a value problem.
• D. Hue is the basic colour family. A hue error would make the crown look too yellow or too grey relative to its neighbour, not too bright.

Note: The remedy is at the preparation stage, not the laboratory. Ensure adequate reduction (roughly 1.5-2.0 mm incisally, 1.2-1.5 mm facially for an all-ceramic anterior crown) and use depth-cutting burs and a reduction matrix to verify it. Once the crown is too high in value, staining can lower it slightly, but a remake is usually required.