Search
.Management Sciences
Category: Dental Ceramics & Miscellaneous
Coefficient of thermal expansion of metal-ceramic alloys is________________?
A. Same as porcelain
B. More than porcelain
C. Less than porcelain
D. More than or equal to porcelain but not less
Stage recognized in the firing of dental porcelain given below. Which of state is not correct ?
A. Cold stage bisque
B. Low bisque
C. Medium bisque
D. High bisque
Dicor restoration is_______________?
A. Two coloured restorations
B. Heat pressed ceramics
C. Castabel ceramic
D. None of the above
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
The most toxic form of mercury is_________________?
A. Methyl and ethyl mercury
B. Mercury vapour
C. Inorganic mercury forms
D. Mercury sulphide
Dental porcelains are crystalline materials of________________?
A. Rubber
B. Plastic
C. Organic substances
D. Glass
Porcelain binds to metal in PFM crown by_________________?
A. Metallic bind
B. Transparency
C. Chemical bond
D. B and C
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
The maximum shrinkage during firing proces in ceramic occurs in__________________?
A. High Bisque stage
B. Low Bisque stage
C. Medium Bisque stage
D. Fusion stage
Recent Comments