When Gold fused with porcelain is fired at very high temperature greenish discoloration of cervical margin is due to________________?

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. Which of the following bur is used in the preparation of cavity restored with porcelain fused to metal ?

   A. Carbide bur
   B. Diamond bur
   C. Stainless steel bur
   D. Diamond but for porcelain and carbide bur for metal

3. 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

4. Kalu, a 6- years – old child, received tetracycline. Noticeable discoloration will be seen in______________?

   A. Premolars, incisors and 1st molars
   B. Canine and 2nd molars
   C. Canines, premolars and2^nd molars
   D. Incisors and 1st molars

5. A patient with emotional problems, increased salivation; pallor of oral mucosa and a grayish blue discoloration of the gingiva. These findings are most consistent with a clinical impression of____________?

   A. Cherubism
   B. Cretinism
   C. Pierre Robin Syndrome
   D. Lead poisoning

6. Yellowish discoloration of teeth is seen in children fed on_____________?

   A. High-protein diet
   B. Tetracyclines
   C. penicillins
   D. Erythromycin

7. Green discoloration of teeth is seen in_______________?

   A. Tetracycline therapy Fluorosis
   B. Fluorosis
   C. Erythroblastosis fetalis
   D. None of the above

8. In type II gold alloys _______ Karat gold is used?

   A. 24 K
   B. 22 K
   C. 18 K
   D. 10 K

9. Pyroplastic flow of porcelain is due to___________________?

   A. High temperature during glazing
   B. Low temperature during glazing
   C. Improper condensation
   D. High firing temperature

10. Which bifurcation is closet to the cervical line (or) which surface has short root trunk length in a maxillary permanent first molar ?

    A. Buccal
    B. Mesial
    C. Distal
    D. None of the above