Restorative & Materials · single question
A patient complains that a tooth restored 3 days ago looks darker than their natural teeth under certain lighting conditions, but it looked perfect when selected in the office. What is MOST likely responsible?
Show answer and explanation
Correct answer: A. Metamerism
Metamerism occurs when two objects appear to match in color under one light source but look different under another. When shade selection is done in the office under one light type (fluorescent or operatory light) and the patient views the restoration in a different environment (natural daylight, incandescent home lighting), a metamerism mismatch becomes apparent. Prevention: shade selection should use multiple light sources and ideally natural light.
- A. ✅ CORRECT – Metamerism explains why a restoration can look matched under one light but mismatched under another.
- B. ❌ Dehydration during shade selection causes a lighter shade selection (bleached appearance of dehydrated enamel) — results in restoration appearing too light, not too dark.
- C. ❌ Taking shade after drying causes the tooth to appear lighter (dehydrated enamel) leading to incorrect lighter shade — this is a different error.
- D. ❌ Recurrent caries does not develop within 3 days.
Practice Restorative & Materials questions Restorative & Materials study notes