1) The tarnished layer of silver amalgam consists of________________? a. Sulphides of silver b. Oxides of tin c. Chlorides of tin d. All of the above
|
||||
2) Which phase provides maximum strength in hardened mercury/silver alloy ? a. Silver / Mercury phase b. Silver / Tin phase c. Tin / Mercury phase d. Zinc / Mercury phase
|
||||
3) Copper content in low copper amalgam is________________? a. 6% b. 12-30% c. 29% d. 19%
|
||||
4) Which of the following silver amalgam alloy have the maximum strength________________? a. Lathe cut b. Spherical c. Admixed d. Single composition
|
||||
5) What is the most frequently used restorative material ? a. Silicate b. Amalgam c. Composite d. Gold
|
||||
6) How soon after a moisture contamination does a zinc containing amalgam alloy start expanding________________? a. 24 hours b. 1-2 days c. 3-5 days d. 7 days
|
||||
7) The percentage of copper in high copper alloy is______________? a. 10-12% b. 0-6% c. 13-30% d. 20-30%
|
||||
8) What is the working time of amalgam? a. One to two minutes b. Three to four minutes c. Five to six minutes d. Seven to eight minutes
|
||||
9) Advantage of zinc containing amalgam is_______________? a. Better handling property b. Dimensional Stability c. Resistance to creep d. Toxicity to pulp and dentin
|
||||
10) Discolouration of silver alloy is due to_____________? a. Tarnish b. Tarnish and corrosion c. Wet corrosion d. Dry corrosion
|
||||
11) Moisture contamination of amalgam can lead to_____________? a. Marginal breakdown b. Shrinkage c. Delayed expansion d. increased stresses
|
||||
12) In a high copper amalgam the phase, which is eliminated is_______________? a. Gamma 1 b. Gamma 2 c. Gamma 1 and 2 d. No phase is eliminated
|
||||
13) Well premeasured capsules of amalgam can release mercury vapour during_______________? a. Mulling b. Carving c. Condensation d. Trituration
|
||||
14) In spherical alloys as compared to lathe cut____________? a. Less condensing force is required b. More condensing force is required c. Both require same condensing force d. Manipulation is easy
|
||||
15) Chronic mercury toxicity results from_____________? a. Ingestion while removing old amalgam b. Skin contact c. Mercury vapour d. All of the above
|
||||
16) Increase in the residual mercury in silver amalgam filling can_____________? a. Cause fracture of the filling b. Tarnish and corrosion c. Increase the strength d. Decrease condensation pressure
|
||||
17) Which of the following statements about high copper silver alloy compared to conventional alloy is not true ? a. It has increased tensile and compressive strength b. It has poor tarnish and corrosion resistance c. It’s edge strength is greater d. Mercury content in the final restoration is less
|
||||
18) Compare to conventional amalgams, spherical amalgams_______________? a. Require more mercury b. Require heavy compection forces c. Have longer setting times d. None of the above
|
||||
19) Which of the following phases of dental amalgam has minimum strength____________? a. Gamma 1 b. Gamma 2 c. Epsilon 1 d. Gamma 3
|
||||
20) The ADA specification No 1 for composition of amalgam alloy recommends______________? a. 65% silver, 32% tin and 3% copper b. 49% silver, 32% tin and 19% cooper c. 65% silver, 29% tin and 5-6% copper d. None of the above
|
||||
21) The highest mercury concentration in amalgam filling is found_____________? a. At the margin of the restoration b. In the centre of the restoration c. In the deepest part of the restoration d. None of the above
|
||||
22) The term trituration means____________? a. Lysing amalgam alloy b. Mixing of amalgam alloy and mercury c. Removal of excess of mercury d. None of the above
|