Free Metals and Alloys MCQs with Answers
125 Metals and Alloys MCQs from Dental Materials, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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125 questions · page 7 of 7
121. Mercury rich condition in a slow setting amalgam alloy system in a resoration in______________?
- A. All of the above
- B. Fracture of the restoration
- C. Merginal damage
- D. Accelerated corrosion
Explanation: Excess mercury in a slow-setting amalgam leaves more matrix and promotes gamma-2 formation, causing increased corrosion, marginal…
Correct answer: All of the above- A. Reduces contraction
- B. Increases the strength of lathe cut alloy but reduces the strength of spherical alloy amalgam
- C. Decreases creep
- D. Gives al dull and crumbly amalgam
Explanation: Over-trituration affects alloy types differently: it can increase the strength of lathe-cut amalgam but may reduce the strength of…
Correct answer: Increases the strength of lathe cut alloy but reduces the strength of spherical alloy amalgam- A. Direct contact with the mercury
- B. None of the above
- C. Ingestion of mercury
- D. Inhalation of mercury vapours
Explanation: Mercury is volatile at room temperature, so occupational exposure in a dental office mainly occurs by inhaling mercury vapour, especially…
Correct answer: Inhalation of mercury vapours- A. 0.05 mg / m3
- B. mg / m3
- C. mg / m3
- D. mg / m3
Explanation: The commonly cited threshold limit value for mercury vapour in dental occupational exposure is 0.05 mg/m³.
Correct answer: 0.05 mg / m3- A. Oxides of tin
- B. Sulphides of silver
- C. Chlorides of tin
- D. All of the above
Explanation: The characteristic tarnish of silver-containing amalgam is mainly due to formation of silver sulfide, which produces a dark surface film.
Correct answer: Sulphides of silver