PFMs

Question 1

noble metal copings must be ___ mm

Answer 1

0.3-0.5 mm

Question 2

base metal copings must be ___ mm

Answer 2

0.2 mm

Question 3

opaquing porcelain thickness

Answer 3

0.2-0.3 mm

Question 4

porcelain thickness

Answer 4

0.5-2.0 mm

Question 5

metal alloys have a high ___ ___ and ___ ___

Answer 5

elastic modulus
yield strength

Question 6

high noble metal criteria

Answer 6

> /= 60%
at least 40% gold

Question 7

more gold = ___ alloy

Answer 7

softer

Question 8

gold-platinum-palladium contains up to ___ gold

Answer 8

88%

Question 9

___ causes greening

Answer 9

silver

Question 10

our PFM metal alloy

Answer 10

gold-palladium
(44-55% gold, 35-45% palladium)

Question 11

sag

Answer 11

resistance to deformation @ high temperatures
high elastic modulus and yield strength

Question 12

noble metal criteria

Answer 12

> /= 25% noble metals
(not having to be gold)

Question 13

PFMs are layered with ___ ___

Answer 13

feldspathic porcelain

Question 14

___ ___ is a particle-filled glass ceramic

Answer 14

lithium disilicate

Question 15

polycrystalline ceramic = ___

Answer 15

zirconia

Question 16

feldspar = ___ ___

Answer 16

glass matrix

Question 17

strong oxide that increases strength
increases viscocity

Answer 17

alumina

Question 18

alkali fluxes are ___ ___

Answer 18

glass modifiers

Question 19

includes opacifiers and colorants
increases coefficient of thermal expansion

Answer 19

glass modifiers

Question 20

brings ceramic coefficient of thermal expansion closer to metal coefficient of thermal expansion

Answer 20

leucite

Question 21

compressive forces = ___ ___

Answer 21

thermal contraction

Question 22

___ increase the wettability of the metal

Answer 22

microabrasions

Question 23

___ ___ forms oxide bond with oxide layer of metal coping

Answer 23

opaque porcelain

Question 24

the more ___, the lower the melting temperature

Answer 24

gold

Question 25

ceramic ___ is greater than metal ___

Answer 25

CTE (x2)

Question 26

contacts are made in ___

Answer 26

porcelain

Question 27

finish lines must be ___ away from occlusal contacts

Answer 27

1.5 mm

Question 28

porcelain shoulder requirements (2)

Answer 28

high fusing aluminous porcelain
2 additional firings

Question 29

metal copings are often overcontoured and thick at the gingival area

Answer 29

disappearing margin

Question 30

bond failure = ___ fracture

Answer 30

cohesive
(due to occlusion)

Question 31

de-lamination = ___ fracture

Answer 31

adhesive
(due to incorrect oxidation)

Question 32

1 reason for porcelain fracture

Answer 32

poor design

Question 33

2 reason for porcelain fracture

Answer 33

occlusion

Question 34

PFM strength comes from what?

Answer 34

bond between metal and ceramic