Prosthodontics & Occlusion · single question
A complete denture patient says their crowns look 'too white.' You realize the shade selection error occurred. Which of the following would NOT explain this error?
Show answer and explanation
Correct answer: A. Shade was selected at the start of the preparation appointment
Selecting shade at the start of the preparation appointment is actually the correct technique — the tooth is still hydrated and not influenced by dehydration from air drying or preparation. This would NOT cause an error. The errors are: selecting shade under fluorescent light only (no natural light comparison → metamerism); selecting after preparation (dehydrated tooth appears lighter → selects too light a shade); or the patient viewing under different lighting (metamerism).
- A. ✅ CORRECT – Selecting shade at the START of the appointment (before preparation, tooth is hydrated) is the CORRECT technique and would NOT cause an error.
- B. ❌ Selecting shade under only one light source (fluorescent) without checking under natural light IS an error — leads to metamerism mismatch.
- C. ❌ Metamerism (different appearance under different light sources) IS a cause of this complaint.
- D. ❌ Selecting shade after preparation when the tooth is dehydrated IS an error — dehydrated enamel appears lighter, causing incorrect shade selection.
Practice Prosthodontics & Occlusion questions Prosthodontics & Occlusion study notes