Which one of the following elements is NOT added is small amount to be used as grain refiners ?
A. Iridium
B. Ruthinium
C. Indium
D. Platinum
Dental Materials
Within an hour after cementation of cast gold onlay patient complains of shooting pain every time the teeth comes together Most probable explanation is ______________?
Within an hour after cementation of cast gold onlay patient complains of shooting pain every time the teeth comes together Most probable explanation is ______________?
A. Supracocclusion of restoration
B. Retained cement in gingival sulcus
C. Excess acid in mix
D. Galvanic current caused by gold onlay occluding with a large restoration
The rate of tarnish and corrosion of class II cast material having VHN 200 is_______________?
The rate of tarnish and corrosion of class II cast material having VHN 200 is_______________?
A. 0%
B. 2 to 3%
C. 5 to 10%
D. <1%
Function of wetting agents used in casting procedure is_________________?
Function of wetting agents used in casting procedure is_________________?
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
The deoxidizing agent added to dental alloys is______________?
The deoxidizing agent added to dental alloys is______________?
A. Palladium
B. Silver
C. Copper
D. Zinc
Which of the following is function of fluoride flux in soldering process ?
Which of the following is function of fluoride flux in soldering process ?
A. It prevents the formation of copper oxide
B. It prevents the formation of chromium oxide or dissolves chromic oxide layer
C. It prevents the flow of material in undesirable area
D. Increase the strength of solder
Percentage of gold in high noble alloy is______________?
Percentage of gold in high noble alloy is______________?
A. N 25%
B. 25%
C. >40%
D. 0%
Gases dissolved in molten metals are liberated when cooled giving rise to________________?
Gases dissolved in molten metals are liberated when cooled giving rise to________________?
A. Suckback porosity
B. Gas inclusion porosity
C. Localized shrinkage porosity
D. Microporosity
Casting flux is used to_______________?
Casting flux is used to_______________?
A. Prevent the oxidation of the metal during melting
B. increase the melting point of the flux
C. Flaring the point of the sprue attachment
D. None of the above
The main ingredient of inlay wax is__________________?
The main ingredient of inlay wax is__________________?
A. Candellila wax
B. Paraffin wax
C. Carnauba wax
D. Gum dammar