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Flashcards in Porcelain/ceramics Deck (42)
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1

why do you add metal oxides to porcelain?

mimic natural tooth shades

2

Ir/Ni

brown

3

Cu

green

4

titanium

yellow brown

5

cobalt

blue

6

manganese

lavender

7

low fusing porcelain has -- glass modifiers

a lot

8

low fusing porcelain: a lot of glass modifiers reduce --

crosslink with silicate

9

what is the melting temp of low fusing porcelain

low (850-1100C)

10

compare low fusing and high fusing porcelain strength

low fusing is weaker and less stable

11

which fusing type is more soluble in oral environment

low fusing

12

what is the thermal expansion for low fusing porcelain?

higher than high fusing

13

when would you use a low fusing porcelain?

veneer for a metal in PFM restorations

14

-- is through porcelain layer which is a metal oxide

chemical bonding

15

chemical bonding is ionic bond bond between ceramic and --

oxide layer on metal

16

chemical bonding: -- before you add porcelain

heat metal in furnace

17

thermally induced stress for --

compression fit

18

describe thermal expansion for compression fit

thermal expansion of ceramic < metal

19

metal --more during cooling

contracts

20

ceramic more attracted to metal --

irregularities

21

metal ceramic combination: coefficient of -- of ceramic slightly lower than metal

expansion

22

development of residual compressive stresses reduces -- and -- by neutralizing developing tensile stress

ceramic crack potential

tensile stresses

23

mismatch of coefficient of expansion -->

crazing, ceramic fracture, debond from metal

24

requirements of porcelain in PFM

-lower firing temp than melting temp of metal coping
-slightly lower thermal expansion coefficient than metal

25

lower firing temp than melting temp of metal coping -->

avoid overheating metal framework

26

slightly lower thermal expansion coefficient than metal -->

provide compressive stress

27

add -- to provide compressive stress

glass modifiers

28

-- is much stronger than conventional ceramic

core ceramic

29

alumina reinforced porcelain is -- embedded with alumina particles

feldspathic porcelain

30

alumina reinforced porcelain prevents --

crack propagation