Subsurface porosity is due to_____________?

Related Mcqs:

1. Subsurface porosity is due to_____________?

   A. Thermal changes B. Thickness of the resin C. Lack of temperature D. Packing past the dough stage...

2. In processing methyl methacrylate, the resin may show porosity if the flask is placed too soon porosity most likely occur_____________?

   A. Throughout the denture B. Near the borders C. In the thickest part D. On the denture surface...

3. Porosity of denture base is due to_______________?

   A. Packing at dough stage B. Curing at 160°F for 9 hrs C. Inadequate pressure D. All of the above...

4. The porosity formed due to simultaneous nucleation of solid grains and gas bubbles at the first moment that metal freezes at the mold walls is called__________?

   A. Pinhole porosity B. Gas inclusion porosity C. Micro porosity D. Subsurface porosity...

5. Suck back porosity is due to_________________?

   A. Attached impurities on undersurface of casting B. Hot spot C. No rapid cooling D. Inadequate melting temperature...

6. Discolouration of silver alloy is due to_____________?

   A. Tarnish B. Tarnish and corrosion C. Wet corrosion D. Dry corrosion...

7. Glossy smooth margins of a casting are due to_____________?

   A. Shrinkage of alloy on cooling B. Investment breakdown C. Incomplete wax elimination D. Incomplete gas elimination...

8. If curing occurs at temperature more than 100°C porosity results in which area of denture______________?

   1. Hard thick central area 2. Thin Palatal area 3. Thin area of flanges 4. Porosity is uniformly distributed...

9. Porosity present in a acrylic denture is usually the result of______________?

   A. A prolonged curing cycle B. Lack of sufficient pressure applied to flask C. Insufficient acrylic resin monomer D. Prolonged bench cooling after curing...

10. To prevent porosity in self-cure acrylic resin, curing should be carried in______________?

    A. Cold water B. Hot water C. Under tap water D. Under vacuum pressure...