Dental Materials

a gold alloy that is 50% gold has how many karats
A. 24
B. 14
C. 18
D. 12

the ada recognizes which three major categories of alloys?
A. class I II and III
B. high noble, noble, base metal
C. precious, semiprecious and nonprecious
D. high noble, noble and low noble

high noble metal classification must contain what pecent by wieght of gold
A. 60%
B. 90%
C. 75%
D. 40%

noble metal elements include all ofthe following except
A. silver
B. palladium
C. platinum
D. gold

porcelain bonding alloys form oxides on their surfaces that chemically bond with the porcelain at high temperatures. which of the following metals may be added to the alloys to help form these oxides?
A. silver or copper
B. cobalt or chromium
C. indium or tin
D. lead or beryllium

metal that is formed by casting into an ingot or bar and then is altered in its form by extruding or pressing it is known as
A. stainless steel
B. milled metal
C. transformed metal
D. wrought metal

high noble alloys usually have which metals added to increase their strength
A. chromium or cobalt
B. iron or aluminum
C. silver or copper
D. nickel or beryllium

which type of orthodontic wire is more difficult to adapt as an arch wire becasue of its springiness and tendency to maintain its original shape?
A. gold
B. stainless steel
C. cobalt-chrome nickel
D. nickel-titanium

allergy to nickel
A. is associated more often with parital denture framworks than with crowns
B. occurs 10 times more often in women than in men
C. occurs in less than 3% of the population
D. is seen only in the oral cavity

solder has all of the following uses except
A. joining a wire loop to a band to make a space retainer
B. adding a contact to crown
C. repairing a hole in the occlusal surface of a crown discovered at the periodic oral examination
D. joining a pontic to a bridge retainer

the purpose of a flux used during soldering is to
A. lower the metling point of the solder
B. make the solder harden quickly
C. remove oxides from the surfaces of the metals to be soldered so the solder can flow and wet the surfaces better
D. prevent the solder from flowing to areas where the solder is not needed

preformed metal posts are vailable in all of the following materials except
A. stainless steel
B. titanium
C. titanium alloy
D. gold

the purpose of a post is to
A. put a permanent seal over the root canal filling material
B. retain the core material
C. strengthen the core material
D. strengthen the root

which one of the following statements about cast posts is false
A. they are formed from a wax or acrylic resin patter
B. they usually ahve the core attached as part of the casting
C. they can be cast using high-noble, noble or base metal alloys
D. the are used in practice far more often than preformed posts