13 - removal of impression materials depends on this property :
Anonymous Quiz
11%
hardness
65%
flexibility
12%
resilience
12%
impact strength
16 - fracture toughness is studied within dentistry to know how to . . .
Anonymous Quiz
15%
give orthodontic wires ability to move teeth
26%
give materials higher shelf life
32%
know energy needed to fracture material on sudden impact
26%
it is not studied! :)
17 - only property not on stress - strain curve :
Anonymous Quiz
71%
hardness
12%
flexibility
6%
toughness
12%
resilience
19 - area under the elastic and plastic portion of the stress - strain curve :
Anonymous Quiz
27%
resilience
10%
flexibility
60%
toughness
4%
hardness
20 - indicates the workability of alloys :
Anonymous Quiz
21%
ductility
12%
malleability
59%
both
8%
none
👍2
24 - impression materials are removed by sharp snap to increase tear strength
Anonymous Quiz
61%
T
39%
F
25 - impression materials must have die poured into them immediately after removal
Anonymous Quiz
41%
T
59%
F
26 - rate dependant permanent deformation :
Anonymous Quiz
13%
elasticity
68%
creep
12%
flexibility
8%
toughness
28 - which test is used to measure hardness of metals and alloys ?
Anonymous Quiz
16%
brinell
13%
knoop
12%
vickers
49%
all of the above
11%
none of the above
🥰1
29 - displays time dependent gradual recovery
Anonymous Quiz
20%
ideal elastic
55%
ideal anelastic
25%
ideal viscous
30 - which material shows partial time dependent recovery with slight permanent deformation?
Anonymous Quiz
11%
ideal viscous
19%
ideal elastic
54%
viscoelastic
17%
ideal anelastic
๋࣭ ⭑⚝ ๋࣭ ⭑ give reason :
𔓘 yield strength is of greater importance than ultimate strength (48-49)
𔓘 heating the restoration does not decrease its modulus of elasticity (50)
𔓘 long span bridges must be made of materials with high modulus of elasticity (51)
𔓘 high modulus of elasticity is an advantage in dentistry (51)
𔓘 impression materials need to be highly flexible (51)
𔓘 orthodontic wires need to be resilient (54)
𔓘 it is important to know the impact strength of a material (57)
𔓘 hardness is an advantage and a disadvantage (61)
𔓘 scratching soft materials should be avoided (61)
𔓘 amalgam undergoes creep (64)
𔓘 ceramics do not undergo creep in the oral cavity (64)
𔓘 yield strength is of greater importance than ultimate strength (48-49)
𔓘 heating the restoration does not decrease its modulus of elasticity (50)
𔓘 long span bridges must be made of materials with high modulus of elasticity (51)
𔓘 high modulus of elasticity is an advantage in dentistry (51)
𔓘 impression materials need to be highly flexible (51)
𔓘 orthodontic wires need to be resilient (54)
𔓘 it is important to know the impact strength of a material (57)
𔓘 hardness is an advantage and a disadvantage (61)
𔓘 scratching soft materials should be avoided (61)
𔓘 amalgam undergoes creep (64)
𔓘 ceramics do not undergo creep in the oral cavity (64)
❤2👍2