IMPRESSION MATERIALS

Question 1

Negative reproduction

Answer 1

Impression

Question 2

Positive reproduction

Answer 2

Model or cast

Question 3

Compression of tissues during impression to stimulate amount of pressure during function

Answer 3

Pressure (functional)

Question 4

Oversize tray,no border molding,Zoe impression paste

Answer 4

Non selective (mucostatic)

Question 5

Uses custom trays,best suited for withstanding forces of mastication

Answer 5

Selective

Question 6

Most common,used to any patient

Answer 6

Perforated stock trays

Question 7

Any individual jaw
Advantage: stability,lack of displacement

Answer 7

Custom trays

Question 8

Most important factor in takin accurate impression

Answer 8

Size of impression tray

Question 9

Hydrocolloid

Answer 9

Alginate
Agar hyrdrocolloid

Question 10

Elastomeric

Answer 10

Addition silicones
Polyether
Condensation silicone
Polysulfide

Question 11

Bite registration

Answer 11

Addition silicones
Polyether

Question 12

Rigid

Answer 12

Impression compond
Zinc oxide eugenol

Question 13

Types of impression materials in dentistry

Answer 13

Hydrocolloid
Elastomeric
Bite registration
Digital
Rigid

Question 14

-Flexible cross linked polymers when set

-dominate the market mainly as a result of their greater accuracy, dimensional stability with time, and
ability to record detail as compared with the hydrocolloid materials.
-The first elastomeric impression mate

Answer 14

Elastomeric impression Materials

Question 15

-AKA: polysiloxanes (VPS)
-Two paste or a two putty system
-no volatile by-product (such as water or ethanol) is formed in this reaction, minimal dimensional change occurs during polymerization.

Answer 15

Addition silicone

Question 16

It is poorly wetted by water with a contact angle of 90°

Answer 16

hydrophobic surface

Question 17

is readily wetted by water with a low contact angle.

Answer 17

hydrophilic surface

Question 18

-have properties similar to the addition silicones.
-is hydrophilic and exhibits good wetting properties, even in a moist field.
-have the disadvantage of limited dimensional stability over time and older materials had poor taste.
-supplied as a base and catalyst system.

Answer 18

Polyether

Question 19

Notes as short working times 1.5 to 3 minutes

Answer 19

Addition silicones

Question 20

• This impression material is supplied as a base and an accelerator
  -The multifunctional ethyl silicate produces a network or cross-linked structure that partly accounts for the low values of permanent deformation and flow
  -are not used commonly in the dental office but rather are used as an accurate duplicating material in the dental laboratory.
  -The setting reaction is sensitive to moisture and heat, with increases in either resulting in shorter setting and
  working times

Answer 20

Condensation silicone

Question 21

-Also called rubber base or mercaptan
-supplies as two paste
-The permanent deformation values of 2% to 3% (elastic recovery of 97% to 98%)
-shrink 0.3% to 0.4% dur- ing the first 24 hours

Answer 21

Polysulfide

Question 22

Impression compound
ZOE

Answer 22

Rigid impression material

Question 23

Impression compound is composed of?

Answer 23

-resins
-waxes
-organic acids
-fillers
-coloring agents
-sticks or cones

Question 24

Low fusing material 45c

Answer 24

Type 1

Question 25

High fusing material 70c

Answer 25

Type 2

Question 26

High fusing material 70c

Answer 26

Type 2

Question 27

Hard set of ZOE? TYPE 1 OR 2?

Answer 27

TYPE 1

Question 28

Soft set of ZOE? Type 1or 2?

Answer 28

Type 2

Question 29

-material consists of a matrix of amorphous zinc eugenolate that holds the unreacted zinc oxide particles together. -Elastomeric impression materials almost have eliminated the use of zinc oxide–eugenol impression pastes for edentulous impressions.

Answer 29

Zinc oxide eugenol

Question 30

Tube 1 base?

Answer 30

Zink oxyde 87%

Question 31

Tube 2 reactor?

Answer 31

Eugenol 12-15%

Question 32

1st impression material, least dimentionally stable

Answer 32

Hydrocolloid

Question 33

Process of absorbing water

Answer 33

Imbibition

Question 34

Process of releasing water= shrinkage

Answer 34

Syneresis

Question 35

Mixture of 2 phases

Answer 35

Colloid

Question 36

Colloid that contains water

Answer 36

Hydrocolloid

Question 37

-First successful flexible aqueous impression material use in dentistry -longest shelf life

Answer 37

Agar “irreversible hydrocolloid”

Question 38

The agar gel is converted to a sol by heating in water, usually boiling, 100° C, and becomes a gel again by cooling to 43.3° C

Answer 38

Hysterisis

Question 39

Agar hydrocolloid impression material is called a

Answer 39

reversible hydrocolloid

Question 40

Agar Component: Main component

Answer 40

Agar

Question 41

Agar Component: Strengthen the gel

Answer 41

Borax

Question 42

Agar Component: Plaster hardner

Answer 42

Sulfates

Question 43

Agar Component: Most abundant

Answer 43

Water

Question 44

Components: Fillers

Answer 44

Wax

Question 45

Agar Component: Plasticizer

Answer 45

Glycerine

Question 46

Agar Component: Bactericidal

Answer 46

Thymol

Question 47

-is one of the most widely used aqueous dental impression materials -used extensively to prepare study models of either the entire dental arch or a segment of it. -They also are used to prepare gypsum models for the preparation of athletic mouth protectors.

Answer 47

Alginate

Question 48

Function: To dissolve in water

Answer 48

Sodium or potassium alginate salt

Question 49

Function: to react with dissolve alginate to form insoluble calcium alginate

Answer 49

Calcium sulfate