A. Increasing the mould metal temperature difference
B. Increasing the flow of molten metal
C. Flaring the point of the sprue attachment
D. All of the above
Related Mcqs:
- Suck back porosity is due to_________________?
A. Attached impurities on undersurface of casting
B. Hot spot
C. No rapid cooling
D. Inadequate melting temperature - 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 - Impurities in casting is removed by________________?
A. Annealing
B. Degassing
C. Pickling
D. Conditioning - 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 - The effects associated with cold working can be eliminated by a heat treatment called______________?
A. Age hardening heat treatment
B. Annealing heat treatment
C. Homogenization heat treatment
D. Solution heat treatment - Addition of large amounts of platinum to a casting gold alloy will________________?
A. Decrease its strength and ability to be hardened
B. Decrease its tarnish resistance
C. Increase its fusion temperature
D. Redden the alloy - Fins and spines on the casting is seen due to_______________?
A. Prolonged heating:
B. Rapid heating me
C. Water film contamination
D. Too high pressure during casting - Asbestos liner is used in a casting ring to________________?
A. Facilitate venting of the mold
B. Retard the heating of the investment
C. Permit expansion of the world
D. All of the above - Air bubbles formed on the surface of casting is probably due to________________?
A. Improper casting pressure
B. Improper heating of the investment
C. Improper angulation of sprue
D. Improper wetting of the wax pattern by the investment - Casting shrinkage is compensated by_______________?
A. Thermal expansion
B. Hygroscopic expansion
C. Wax expansion
D. All of the above
