Composite & Amalgam

Bonding of composite resins to tooth structure is by

• Covalent bond

• Ionic bond

• Micro-Mechanical bond

• Hydrogen bond

Which of the following will impart radiopacity to composite resins?

• Coupling agent

• Organic matrix

• Silica glass

• Strontium glass

Which of the following phases of dental amalgam has maximum strength?

• Ag₂Hg₄

• Ag₃Sn

• Cu₆Sn₅

• Sn₈Hg

Which of the following acts as a scavenger of oxygen during manufacturing of amalgam alloy powder?

• Silver

• Copper

• Mercury

• Zinc

Which of the following is NOT an advantage of Eames technique?

• High strength

• More plastic & good adaptation

• No squeezing of excess mercury

• Sets quickly

Which of the following is the advantage of low copper amalgam alloys as compared to high copper alloys?

• Corrosion products seal the margins

• Has low creep

• Have higher 1hr strength

• Less marginal breakdown

What is the half-life of mercury in blood?

• 15 to 30 days

• 30 to 45 days

• 45 to 60 days

• 60 to 75 days

Which of the following statement is true?

• Lathe cut amalgam require less mercury and has high 1 hr. strength

• Lathe cut amalgam require more mercury and has high 1 hr. strength

• Spherical amalgam requires less mercury and has high 1 hr. strength

• Spherical amalgam requires more mercury and has high 1 hr. strength

Which of the following fillers in composite resins have negative coefficient of thermal expansion?

• Beta-eucryptite

• Fused quartz

• Ytterbium fluoride

• Zinc glasses

Which of the following correctly denotes the filler size of midi-filled composite resins?

• 0.01 to 0.1 µm

• 0.1 to 1.0 µm

• 1.0 to 10.0 µm

• 10 to 100 µm