metal ceramics and crowns with labial porcelain margins

Question 1

what is a ceramic

Answer 1

A product made from a non-metallic inorganic material processed by firing at a high temp to achieve desirabled properties

Question 2

what are the groups of dental ceramics

Answer 2

High fusion
MEdium Low fusion
Ultra low fusion

Question 3

temp for high fusion ceramics

Answer 3

1290-1370 degrees C

Question 4

temp for medium fusion ceramics

Answer 4

1090-1260 degrees C

Question 5

temp for low funsions ceramics

Answer 5

870-1070

Question 6

temp for ultra low fusion ceramics

Answer 6

less than 850

Question 7

what dental ceramics are used for Dnture teeth and porcelain jacket crowns

Answer 7

High fusion

Medium fusion

Question 8

what dental ceramics are used for metal-ceramic crowns

Answer 8

Low fusion

Ultra Low-fusion

Question 9

what is feldspar made of

Answer 9

A naturally occuring glass with silicas, fluxes, and alumina neatly bound together

Question 10

what does feldspar bind

Answer 10

all 3 forms of clay bodies together once fused at a high temp

Question 11

how is Frit mad

Answer 11

materials of dental porcelain are heated to a high temp then cooled fast to cause glass to fracture

Question 12

what are the chemicals of Feldspar

Answer 12

Potassium aluminum silicate orthoclase

Sodium aluminum silicate albite

Question 13

what is the chemical in quartz

Answer 13

Silicon oxide

Question 14

what is vitrification

Answer 14

Turning cystalline silica along with associated fluxes and modifiers into glass

Question 15

what does porcealin turn into after vitrification

Answer 15

Ceramic body

Question 16

what is the ceramic body made of

Answer 16

the refractory skeletal structure

feldspathic glass betwen the refractory particles

Question 17

how is the refractory skeletal structure made in a ceramic body

Answer 17

through sintering and fusing processses to help it maintain shape

Question 18

how is porcelain different than glass

Answer 18

Glass with a refractory internal structure

Question 19

do all porcelains have the same composition

Answer 19

No, have different ratios

Question 20

what are the types of dental porcelains for an MCC

Answer 20

Opaque porcelain
Body/dental porcelain
Incisal/enamel porcelain

Question 21

what does the opaque porcealin contain

Answer 21

Opacifying oxides

Question 22

can you see through body porcelain

Answer 22

Yes, it is translucent

Question 23

what is found in body porcelain

Answer 23

metalic oxides that give shade or base color selected

Question 24

how see through is the incisal/enamel porcelain

Answer 24

More translucent than body

Question 25

what are the dental porcelains mixed with

Answer 25

Water based glycerin continaing liqued

Question 26

how should enamel porcelain be added

Answer 26

over build it

Question 27

how should grind porcelain

Answer 27

Use stones or diamond burs only used to grind porcelain on a low speed

Question 28

how should shimstock feel when contact is good

Answer 28

Should drag when crown is seated, but if it holds it is too tight

Question 29

what wheels are used to adjust contact

Answer 29

Blue: course Pink: medium Gray: fine

Question 30

how to prep porcelain for a second bake

Answer 30

Clean in DI for 10 min | add porcelain to areas that are deficient

Question 31

advantage of Porcelain labial margin

Answer 31

Improve esthetics | Less plaque retention

Question 32

disadvantages of porcelain labial margin

Answer 32

- Generally inferior margin adaptation compared to cast metal - decreased strength compared to metal - more time consuming - slight more expesnive than conventional MCC

Question 33

what are the techniques for porcelain labial margin fab

Answer 33

Platinum foil matrix tech Porcelain wax technique Direct lift technique

Question 34

what is the direct lift technique

Answer 34

Apply shoulder porcelain on margin and dry with tissue paper and brush excess with large brush

Question 35

advantage of direct lift technique

Answer 35

LEast time consuming

Question 36

disadvantage of direct lift technique

Answer 36

Shoulder porcelain needed | Slightly rough margins

Question 37

when were porcelain crowns first used

Answer 37

1903 ( over 100 yeras ago)

Question 38

what is the problem with cooling porcelain

Answer 38

causes the metal to distort ( low temp is desired)

Question 39

what chem is the major component of porcelain

Answer 39

SiO2

Question 40

why should you overbuild porcelain

Answer 40

account for voids | Shrinks 45-30%

Question 41

what color should shoulder porcelain be

Answer 41

should be opaque

Question 42

what holds more plaque, ceramic or metal retainers

Answer 42

metal

Question 43

what technique is generally used to pain porcelain on the margin

Answer 43

Direct lift technique