Stage recognized in the firing of dental porcelain given below. Which of state is not correct ?

Related Mcqs:

1. For porcelain fused to metal crown, the porcelain should have ______________?

   A. High fusion expansion
   B. High fusion temperature
   C. Linear coefficient of thermal expansion less than that of metal
   D. Linear coefficient of thermal expansion more than that of metal

2. Condensation shrinkage of porcelain during firing depends on__________________?

   A. Rate of arriving at firing temperature
   B. Uniformity of particle size
   C. Shape and size of particle
   D. Type of investment used

3. In method of firing: A shorter firing period at a higher temperature is considered better_______________?

   A. A large time period at a lower temperature is preferred
   B. A long firing period at a very high temperature is preferred
   C. A short firing period at a very low temperature is preferred
   D. none of these

4. Quartz is Dental porcelain is______________?

   A. Strengthener
   B. Binder
   C. Pigment
   D. Crack minimzer

5. To prevent porosity in dental porcelain it should be backed________________?

   A. Boric oxide
   B. In vacuum
   C. For long period
   D. Under pressure

6. Porosity in porcelain at condensation stage depends on_________________?

   A. Shape and size of particle
   B. Uniform distribution of particle size
   C. Number of particles
   D. None of the above

7. 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

8. Powders of dental plaster and dental stone differ mainly in____________?

   A. Solubility
   B. Shelf life
   C. Chemical formula
   D. Particle porosity

9. 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

10. The American dental association (ADA) specification number for non-aqueous elastomeric dental impression material is______________?

    A. 19
    B. 20
    C. 21
    D. 26