Chapters 8 & 27 Quiz 2

Question 1

are impressions negative or positive reproductions?

Answer 1

negative

Question 2

impressions can be used to create a _______ or _________ which is a positive reproduction

Answer 2

model or cast

Question 3

used to carry the impression material into the mouth

Answer 3

impression trays

Question 4

impression trays can be ________ or _________

Answer 4

sterilized or disposable

Question 5

take an impression of a smaller area, but can impress the maxillary and mandibular arch simultaneously

Answer 5

triple trays

Question 6

dispensed onto a tray or directly on teeth and patient bites down

Answer 6

bite registration

Question 7

the type of impression material being used depends on the ______ of the impression being taken

Answer 7

purpose

Question 8

prepared teeth typically have ________

Answer 8

undercuts

Question 9

what is required to take impressions of prepared teeth?

Answer 9

more elastic material

Question 10

impressions on edentulous areas do or do not require as much detail?

Answer 10

do not

Question 11

what type of impression material is used on edentulous areas of the mouth?

Answer 11

inelastic material which is harder and more rigid

Question 12

measure of a liquids ability to flow

Answer 12

viscosity

Question 13

placed in the sulcus to pull the tissue away from a tooth during crown and bridge preparations

Answer 13

retraction cord

Question 14

impression material mixed with water

Answer 14

aqueous

Question 15

impression material mixed with something other than water

Answer 15

nonaqueous

Question 16

what are the three types of impression materials?

Answer 16

1. inelastic
2. aqueous elastomeric
3. nonaqueous elastomeric

Question 17

these materials change from a viscous liquid state called sol, to a semisolid, rubbery state called gel

Answer 17

aqueous

Question 18

what are the types of inelastic impression materials?

Answer 18

plaster, wax, and zinc oxide eugenol

Question 19

irreversible hydrocolloid

Answer 19

alginate

Question 20

set by chemical reaction to reach gelation

Answer 20

irreversible hydrocolloid

Question 21

what are the types of aqueous elastomeric impression materials?

Answer 21

alginate and agar

Question 22

reversible hydrocolloid

Answer 22

agar

Question 23

reaches gelation by means of temperature changes

Answer 23

reversible hydrocolloid

Question 24

melting and gelling at different temperatures is _______

Answer 24

hysteresis

Question 25

are alginate or agar impressions more accurate

Answer 25

agar

Question 26

potassium alginate which dissolves in water forming a _______ which is also known as a gel

Answer 26

sol

Question 27

alginate powder contains what?

Answer 27

potassium alginate, silica, antimicrobial agents, and water

Question 28

the contraction of a gel accompanied by the separating out of liquid

Answer 28

syneresis

Question 29

the absorption of one substance by another

Answer 29

imbibition

Question 30

it is important to limit the time that an impression is exposed to an aqueous disinfection solution because of _______

Answer 30

imbibition

Question 31

models should be poured shortly after an impression is taken because of __________

Answer 31

syneresis

Question 32

what are the types of non aqueous elastomeric impression materials

Answer 32

polysulfides, condensation silicones, polyethers, and addition silicones

Question 33

how do polysulfides and condensation silicones set

Answer 33

via condensation polymerization

Question 34

what does condensation polymerization produce as a by-product

Answer 34

water

Question 35

what type of system is are polysulfides

Answer 35

paste-paste

Question 36

what are more accurate than alginate but not as accurate as other nonaqueous elastomeric materials

Answer 36

polysulfides

Question 37

what type of impression materials taste and smell bad

Answer 37

polysulfides

Question 38

what by-product is produced with condensation silicones

Answer 38

alcohol

Question 39

what type of impression material is cleaner but harder to use

Answer 39

condensation silicones

Question 40

do condensation silicones have to be poured fast or slow

Answer 40

fast

Question 41

how do polyethers set

Answer 41

via cationic polymerization

Question 42

what is there by-product of polyethers

Answer 42

none

Question 43

what type of impression material is clean, tastes bad, and expensive

Answer 43

polyethers

Question 44

what is the post popular non aqueous elastomeric material

Answer 44

addition silicones

Question 45

how do addition silicones set

Answer 45

via polymerization with no by-product

Question 46

increase wetting and reduce bubbles in the stone when the impression is poured up

Answer 46

surfactants

Question 47

what impression material has surfactants added to them?

Answer 47

addition silicones

Question 48

what three impression materials are inelastic

Answer 48

plaster, wax or impression compound, and ZOE

Question 49

each tray should extend ______ to include all teeth as well as the musculature and vestibule

Answer 49

facially

Question 50

how many mm of depth of alginate should be provided beyond the occlusal surface and incisal edges

Answer 50

2-3 mm

Question 51

what can be placed around the boarders of the tray to add length/depth

Answer 51

rope wax

Question 52

should removable appliances be taken out before taking impressions

Answer 52

yes

Question 53

what temp of water increases the setting rate

Answer 53

warmer

Question 54

what water temp slows the setting reaction

Answer 54

cooler

Question 55

speeds up reaction; warm water; also potassium sulfate

Answer 55

accelerator

Question 56

slows down reaction; cooler water; also borax

Answer 56

retarder

Question 57

where should a right handed operator stand when seating a mandibular tray

Answer 57

7 oclock

Question 58

where should the operator stand when seating a maxillary tray

Answer 58

11 oclock

Question 59

what percent humidity do impressions need to be kept in if not poured up immediately

Answer 59

100 %