Type III Gold Alloy Composition — MFDS 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 — Approximately 75%
Option C is correct. A conventional high-gold Type III casting alloy contains about three-quarters gold by mass. Elemental analysis of such an alloy found 72.4–75.7% gold, with the remainder principally silver, copper and palladium, plus a small amount of zinc. These alloying elements provide the mechanical properties required of a Type III or “hard” casting alloy used for restorations such as full cast crowns. Approximately 65% or 50% would better suggest lower-gold formulations rather than the conventional high-gold alloy specified. Approximately 85% is higher than the representative Type III composition, while 99% would be essentially pure gold and would not represent a conventional hard dental casting alloy.
Reference: Ayad MF, Ayad GM. Corrosion behavior of as-received and previously cast type III gold alloy. Journal of Prosthodontics. 2010;19(3):194–199. https://pubmed.ncbi.nlm.nih.gov/20210863/