A. Rubber
B. Plastic
C. Organic substances
D. Glass
Related Mcqs:
- Greening occuring when porcelains are fired on silver free alloys may be attributed to________________?
A. Vaporization of silver from the walls of contaminated furnaces
B. Surface diffusion of silver from the marginal metal
C. More rapid silver diffusion in sodium containing glass
D. Silver ionization by porcelains with high oxygen potential - Chemical tempering in porcelains is done to interrupt crack propagation by______________?
A. Transformation toughening
B. Dispersion of crystalline phase
C. Inducing residual compressive strength
D. All of the above - High copper dental amalgams are superior to other amalgams because high copper dental amalgems______________?
A. Have less marginal breakdown
B. Are workable at lower Hg-alloy ratio
C. Have a higher ratio of tensile to compressive strength
D. Have less resistance to tarnish and corrosion - Powders of dental plaster and dental stone differ mainly in____________?
A. Solubility
B. Shelf life
C. Chemical formula
D. Particle porosity - The main difference between dental stone and dental plaster is______________?
A. Chemical composition
B. Self life
C. Sharpe and size of particles
D. Solubility in water - The American dental association (ADA) specification number for non-aqueous elastomeric dental impression material is______________?
A. 19
B. 20
C. 21
D. 26 - Which one of the following categories of dental materials has the highest thermal conductivity_________________?
A. Unfilled acrylic plastics
B. Gold alloys
C. Porcelains
D. Zinc phosphate cements - Which of the following properties of dental materials is time dependent_______________?
A. Creep
B. Resillience
C. Elastic limit
D. Ultimate strength - Dispersion of crystalline phase to strengthen ceramics results in_________________?
A. dispersed porcelain
B. Glazed porcelain
C. aluminium porcelain
D. All of the above - Materials which has high compressive strength and low tensile strength is classified with property of________________?
A. Ductility
B. Brittleness
C. Malleability
D. Resilient
