Question: Over-trituration of silver alloy and mercury_______________?

• 1. Reduces contraction
• 2. Increases the strength of lathe cut alloy but reduces the strength of spherical alloy amalgam
• 3. Decreases creep
• 4. Gives al dull and crumbly amalgam

Question: Mercury intoxication in dental office mainly results from____________?

• 1. Direct contact with the mercury
• 2. Inhalation of mercury vapours
• 3. Ingestion of mercury
• 4. None of the above

Question: The threshold limit value of mercury exposures is_______________?

• 1. mg / m3
• 2. 0.05 mg / m3
• 3. mg / m3
• 4. mg / m3

Question: The tarnished layer of silver amalgam consists of________________?

• 1. Sulphides of silver
• 2. Oxides of tin
• 3. Chlorides of tin
• 4. All of the above

Question: Which phase provides maximum strength in hardened mercury/silver alloy ?

• 1. Silver / Mercury phase
• 2. Silver / Tin phase
• 3. Tin / Mercury phase
• 4. Zinc / Mercury phase

Question: Copper content in low copper amalgam is________________?

• 1. 6%
• 2. 12-30%
• 3. 29%
• 4. 19%

Question: Which of the following silver amalgam alloy have the maximum strength________________?

• 1. Lathe cut
• 2. Spherical
• 3. Admixed
• 4. Single composition

Question: What is the most frequently used restorative material ?

• 1. Silicate
• 2. Amalgam
• 3. Composite
• 4. Gold

Question: How soon after a moisture contamination does a zinc containing amalgam alloy start expanding________________?

• 1. 24 hours
• 2. 1-2 days
• 3. 3-5 days
• 4. 7 days

Question: The percentage of copper in high copper alloy is______________?

• 1. 10-12%
• 2. 0-6%
• 3. 13-30%
• 4. 20-30%