Localised shrinkage porosity is seen when there________________?

Related Mcqs:

1. 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

2. The linear solidification shrinkage of Type IV Ni-Cr based alloys is_______________?

   A. 2.3%
   B. 1.56%
   C. 1.37%
   D. 3%

3. Casting shrinkage is compensated by_______________?

   A. Thermal expansion
   B. Hygroscopic expansion
   C. Wax expansion
   D. All of the above

4. 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

5. 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

6. About polymerization shrinkage of composite all are true, except______________?

   A. Polymerization shrinkage is greater if bonded surface area is lesser than unbounded surface area
   B. Polymerization shrinkage is high if within the enamel margins
   C. Acid etching and priming will decrease polymerization shrinkage
   D. Microleakage can occur because of polymerization shrinkage

7. Along with polymerisation shrinkage, one of the major disadvantages of polymethyl methacrylate as denture base resin are its poor_____________?

   A. Biological properties
   B. Thermal properties
   C. Mechanical properties
   D. Esthetic properties

8. What is the polymerization shrinkage if 3:1 powder: liquid ratio is used____________?

   A. 6%
   B. 8%
   C. 10%
   D. 21%

9. The restoration which shows percolation and shrinkage along the margins is_____________?

   A. Composites
   B. Unfilled resins
   C. Amalgam
   D. Polycarboxylate

10. Back pressure porosity can be avoided by________________?

    A. Using asbestos linear
    B. Placing the sprue at least one quarter inch away form the end of casting ring
    C. Preventing rapid heating the investment in burnout oven
    D. Using a short and wide sprue