ADC Dental Materials Science

Question 1

Which property of dental amalgam describes its slow, permanent deformation under sustained compressive load?

Accepted Answer

Creep

Answer

Hardness

Answer

Compressive strength

Answer

Tarnish resistance

Question 2

Delayed expansion in zinc-containing amalgam is primarily caused by:

Accepted Answer

Contamination of the mix with moisture during condensation

Answer

Over-trituration of the alloy

Answer

High mercury-to-alloy ratio

Answer

Under-trituration of the alloy

Question 3

Which composite resin type provides the best surface polish due to its very small filler particle size?

Accepted Answer

Microfill composite

Answer

Macrofill composite

Answer

Packable composite

Answer

Flowable composite

Question 4

The setting reaction of conventional glass ionomer cement (GIC) is best described as:

Accepted Answer

Acid-base reaction between polyacrylic acid and fluoroaluminosilicate glass

Answer

Free-radical polymerization of an acrylic monomer

Answer

Hydration of calcium silicate phases

Answer

Condensation polymerization releasing water

Question 5

Among commonly used luting cements, which has the highest compressive strength?

Accepted Answer

Zinc phosphate cement

Answer

Zinc oxide eugenol cement

Answer

Polycarboxylate cement

Answer

Conventional glass ionomer cement

Question 6

The principal clinical advantage of resin-modified glass ionomer cement over conventional glass ionomer cement is:

Accepted Answer

Reduced sensitivity to early moisture contamination and improved early physical properties

Answer

Greater total fluoride release over time

Answer

Significantly lower cost of the material

Answer

Superior biocompatibility with pulp tissue

Question 7

The working time of zinc phosphate cement can be extended by:

Accepted Answer

Spatulating on a cooled glass slab and adding powder incrementally

Answer

Warming the mixing slab

Answer

Incorporating all powder at once

Answer

Using a higher powder-to-liquid ratio