Dental materials and radiology basics: cobalt-chromium denture framework: practice question

A Dentistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Dentistry · Dental materials and radiology basics: cobalt-chromium denture framework

Sample item

Why is cobalt-chromium preferred to type IV gold for a removable partial denture framework?

AIts high modulus allows thin, rigid, light connectorsBIts low hardness makes finishing quicker and easierCIts high density gives better stability on the ridgeDIts greater ductility makes clasp adjustment much easier

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Its high modulus allows thin, rigid, light connectors

Cobalt-chromium-molybdenum alloys have a high modulus of elasticity, so a thin section is still rigid, and they are less dense than gold alloys, so the framework is lighter and cheaper. Their drawbacks are hardness, which makes finishing harder, and low ductility, which makes clasp adjustment difficult.

Option by option

A. Its high modulus allows thin, rigid, light connectors (correct)
Correct. High stiffness permits thin, rigid and light connectors.
B. Its low hardness makes finishing quicker and easier
It is considerably harder than gold and is more difficult to finish and polish.
C. Its high density gives better stability on the ridge
It is less dense than gold, so a framework is lighter, not heavier.
D. Its greater ductility makes clasp adjustment much easier
Cobalt-chromium is less ductile than gold, so clasps are harder to adjust.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Dentistry question

What is the answer to this Dentistry question?

The best answer is A, Its high modulus allows thin, rigid, light connectors. Cobalt-chromium-molybdenum alloys have a high modulus of elasticity, so a thin section is still rigid, and they are less dense than gold alloys, so the framework is lighter and cheaper.

Why is "Its low hardness makes finishing quicker and easier" not the answer?

It is considerably harder than gold and is more difficult to finish and polish.

Why is "Its high density gives better stability on the ridge" not the answer?

It is less dense than gold, so a framework is lighter, not heavier.

Why is "Its greater ductility makes clasp adjustment much easier" not the answer?

Cobalt-chromium is less ductile than gold, so clasps are harder to adjust.

What concept does this question test?

It tests Dental materials and radiology basics: cobalt-chromium denture framework in Dentistry. Their drawbacks are hardness, which makes finishing harder, and low ductility, which makes clasp adjustment difficult.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Dental materials and radiology basics: cobalt-chromium denture framework?

Learn the dental formula, eruption ages and tooth structure once, as tables. Then use the flashcards and the other Dentistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.