A. To felicitate wetting of ring liner
B. To felicitate mixing investment
C. To reduce contact angle of liquid with max surface
D. For better wax elimination
Related Mcqs:
- The wetting of an adherent surface by an adhesive is related to________________?
A. Surface energy of the adherent
B. Surface texture of the adherent
C. Surface tension of the adherent
D. Nature of the adherent that is crystalline or amorphous - A five-year old child presents with chronic bed wetting and bilateral loose deciduous first molars. His mother says that she want to drink of water several times during each night. Which of the following is the most likely diagnosis ?
A. Hand-Schuller Christian disease
B. Marble bone diasease
C. Nieman pick disease
D. Polyostotic fibrous dysplasia - 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 - Incomplete casting is the result of_____________?
A. More porous investment in the mould
B. Narrow sprue diameter
C. Hollow sprue pin
D. Large reservoir - Crucible indicated for casting base metal alloys is______________?
A. Carbon crucible
B. Clay crucible
C. Quartz crucible
D. High melting plastic crucible - 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 - Impurities in casting is removed by________________?
A. Annealing
B. Degassing
C. Pickling
D. Conditioning - The gold alloys used for casting contain at least…. percent of precious metal according to ADA specification number 5________________?
A. 55
B. 65
C. 75
D. 85 - Casting shrinkage is compensated by_______________?
A. Thermal expansion
B. Hygroscopic expansion
C. Wax expansion
D. All of the above
