Dental Materials: Test 2

Question 1

Classification for Impression Materials

Answer 1

Elastic: pick-up undercuts
Ridge: will not pick-up undercuts

Question 2

Classification for elastic impression

Answer 2

Irreversible: will not return to original state (powder/liquid)
Reversible: will return to original state. ( only one impression is reversible)

Question 3

Types of impression trays

Answer 3

Metal Perforated, Rim, Disposable plastic perforated trays, bite registration, triple trays, custom trays

Question 4

Postitive impression

Answer 4

Poured impression in the stone known as diagnostic cast

Question 5

die

Answer 5

replica of prepared tooth from working cast

Question 6

Alginate composition

Answer 6

Agar (seaweed)

Question 7

Polyvinyl composition?

Answer 7

Polyvinyl siloxane- ex. calking around a window

Question 8

Polyvinyl armamentarium?

Answer 8

cartridges with mixing tip and mixing gun

Question 9

polyvinyl tray?

Answer 9

disposable or quadrant

Question 10

Alginate trays?

Answer 10

Max. 1-6 (1: smallest)

Mand. 20-26 ( 20-26) *20-24 most commonly used

Question 11

Polysulfid Composition

Answer 11

Sulfide *oldest on market

Question 12

Polysulfid Armamentarium

Answer 12

Catalyst and base, diamond head spatula, used in dentures

Question 13

Polysulfid tray

Answer 13

Custom

Question 14

Synersis

Answer 14

loss of water in an impression (alginate)

Question 15

inhibition

Answer 15

uptake of water in an impression (alginate)

Question 16

humidore

Answer 16

vessel used to store an impression (alginate) ex. tupperware container

Question 17

Uses of dental waxes

Answer 17

lab work, cast, to hold things together, boxing, patterns

Question 18

Composition of waxes

Answer 18

Mix of synthetic (fats, oils, resins, gums) and natural (minerals, beeswax, keratin,reason) waxes

Question 19

Melting range of waxes

Answer 19

Range of temps that cause each component of the wax to go thru sulfide state

Question 20

flow of waxes

Answer 20

Flows over what it needs to once in softened state

Question 21

excess residue of waxes

Answer 21

remains after wax is removed

Question 22

Classifications of waxes

Answer 22

Pattern, Inlay, Casting, Baseplate

Question 23

Processing waxes

Answer 23

boxing, utility, sticky

Question 24

Cons of Impression waxes

Answer 24

not accurate bite registration, almost obsolete, they distort

Question 25

Rigid impression material composition

Answer 25

Resins, waxes, talcum, plastics

Question 26

Rigid impression material uses

Answer 26

Border Mold

Question 27

How do you soften rigid impression material?

Answer 27

open flame, compound heater (reversible, thermoplastic)

Question 28

gypsum

Answer 28

mineral found in nature used for making dental casts

Question 29

what are the physical and chemical properties of gypsum?

Answer 29

Dihydrate- mixing powder with water

Hemihydrate- fluffy powder

Question 30

Calcining

Answer 30

heat up & drive water off

Question 31

Classification of gypsum

Answer 31

impression plaster, model plaster, dental stone, die stone, high strength stone

Question 32

how do you manipulate gypsum

Answer 32

hand or vacuspat

Question 33

setting of gypsum

Answer 33

working time- 1 min
Initial set- losing gloss
Final set- hardens in bowl

Question 34

Methods of pouring cast

Answer 34

single step- 1 mix
double pour- comes to hard state & pour again: 2mins
boxing- using boxing wax or paper towel

Question 35

slurry water

Answer 35

water running out of hose during trimming, combo of water and stone

Question 36

Angle: pointed outline max. cast

Answer 36

30 degrees

Question 37

Angle: max. sides

Answer 37

65 degrees

Question 38

Angle: heel angle

Answer 38

115 degrees

Question 39

Angle: mand. sides

Answer 39

55 degrees

Question 40

Angle: heel bevel

Answer 40

15-20 mm or 1/2