Gold Onlay Thickness — ORE Part 1 MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: C — 1.5 mm
Explanation lettering: B = shown as A · D = shown as B · A = shown as C · E = shown as D · C = shown as E
The correct answer is A: 1.5 mm. Contemporary restorative dentistry guidelines establish 1.5 mm as the minimum thickness for indirect restorations covering functional cusps. Gold alloys, with their high modulus of elasticity and fatigue resistance, require this threshold to resist flexure and occlusal wear. Options B (0.5 mm) and C (0.3 mm) are too thin and would risk deformation under mastication. Options D (3 mm) and E (4 mm) are excessive and violate the principle of conservative preparation design, unnecessarily destroying sound tooth structure. The 1.5 mm standard balances mechanical adequacy with preservation of remaining tooth tissue.
Reference: Clinical Performance of Chairside CAD/CAM Restorations (NCT04279574); operative dentistry principle of minimum functional cusp thickness applied across indirect restoration types.