Dental Materials Final

Front 1

the safe interaction of dental materials with the rest of the body is defined as the materials

Back 1

biocompatibility

Front 2

the study of dental materials consist of

Back 2

the chemical reaction of the material
the physical reaction of the material
the manipulation of the material

Front 3

the internal reaction to an externally applied force is called

Back 3

stress

Front 4

which of the following restorative materials is most likely to fracture under compressive stress

Back 4

porcelain

Front 5

which of the following restorative materials is the least soluble?

Back 5

porcelain

Front 6

corrosions is of greatest concern for which of the following restorative materials

Back 6

amalgam

Front 7

surface discoloration of a metal restoration is called

Back 7

tarnish

Front 8

restorative materials with values of thermal conductivity similar to enamel include

Back 8

composite resin

Front 9

an example of galvanism is

Back 9

amalgam contacting gold

Front 10

micro leakage may be responsible for

Back 10

recurrent decay
marginal staining
post op sensitivity

Front 11

an excessive film thickness may cause

Back 11

improper seating of the restoration

Front 12

the leakage of fluids and debris extending along the tooth restoration interface is called

Back 12

microleakage

Front 13

materials used for the restoration of enamel need high

Back 13

vitality

Front 14

color shades can vary depending on the incident light or source of light. This effect is called

Back 14

metamerism

Front 15

a defining characteristic of a solid is that it has

Back 15

shape and volume

Front 16

the most stable primary bonds

Back 16

have regular crystalline structures

Front 17

the correct term for describing when an applied stress is proportional to a resulting strain is

Back 17

ultimate strength

Front 18

when the weight of a metrical increases in relationship to its volume this is described as

Back 18

dense

Front 19

hardness determines the materials ability to

Back 19

penetrate an object

Front 20

when deformation is not permanent and a material recovers it has good

Back 20

elasticity

Front 21

resistance to flow is known as

Back 21

viscosity

Front 22

thixotropic materials are those that

Back 22

flow under mechanical forces

Front 23

indirect restorative materials would include all of the following

Back 23

porcelain crowns
gold crowns
porcelain veneers

Front 24

mixing time is the length of time from

Back 24

the beginning of mixing to the beginning of working time

Front 25

a material mixed slowly on a cooled glass surface will

Back 25

have a longer working setting time

Front 26

all of the following are considered positive reproductions of the dental structures

Back 26

diagnostic cast
working cast
a die

Front 27

the manufacturing process for gypsum products includes all of the following

Back 27

the use of heat
the use of pressure
grinding of particles

Front 28

to decrease the working time of a gypsum product without a change to any physical properties, it is best to

Back 28

increase the water temperature

Front 29

the main difference between model plaster and dental stone is

Back 29

particle size and shape

Front 30

the most appropriate type of gypsum product to use for orthodontic casts is

Back 30

type III

Front 31

initial setting can be detected clinically by

Back 31

loss of gloss

Front 32

the area of the diagnostic cast that records the hard and soft tissues is called the

Back 32

anatomic portion

Front 33

all of the following statements are true of gypsum products

Back 33

excess water makes it easier to mix and manipulate gypsum product
excess water is lost in evaporation upon final set
excess water is water in excess of what is necessary to complete the chemical retain

Front 34

it is important to consider all of the following statements when pouring an impression

Back 34

when the single step method is used the material poured into the impression must reach the initial set before the base is poured

gypsum material should not be allowed to extend over the edge of the impression tray

excess gypsum should be wiped from equipment and placed into the trash

Front 35

diagnostic casts are used for all of the following

Back 35

patient education
legal documents
tracking treatment process

Front 36

a dental impression material

Back 36

allows the creation of a replica of the structures involved
forms a negative imprint of the teeth and surrounding structures

Front 37

which impression materials is/are transformed from a sol to a gel state when set?

Back 37

alginate and agar hydrocolloids

Front 38

which is an example of an inelastic impression material

Back 38

dental compound

Front 39

the types of impression materials that are considered hydrophilic are this that

Back 39

have good surface wetting characteristics

Front 40

hydrophilic impression materials

Back 40

need dry field for best results

Front 41

alginate impression material

Back 41

can be immersed in disinfectant for 24 hrs

Front 42

agar hydrocolloid

Back 42

works well in moist field

Front 43

an irreversible hydrocolloid

Back 43

cannot reverse from a gel to a sol because a chemical reaction prevents it

Front 44

polyvinyl impression materials are of the class known as

Back 44

elastomers

Front 45

polysulfide impression materials

Back 45

have excellent tear strength

Front 46

which elastomers will imbibe water when immersed in it and swell

Back 46

polyether

Front 47

which one of the following materials produces alcohol as a by product of its setting reaction and is subject to distortion as it evaporates

Back 47

condensation silicone

Front 48

which statement is true about the addition silicones

Back 48

dimensionally stabe

Front 49

the most rigid of the impression materials is

Back 49

compound

Front 50

the least accurate impression material is

Back 50

alginate

Front 51

which two of the following statements do not need to be poured with gypsum material within a few hours after the impression is made

Back 51

polyvinyl siloxane & polyether

Front 52

dental compound impression material can change from a solid to a soft material when it is heated. its greatest use today is for which procedure

Back 52

border molding custom trays and denture impressions

Front 53

which one of the following when used for denture impressions is broken into pieces to remove it from the mouth and is reassembled in the laboratory to pour the impression

Back 53

impression plaster

Front 54

zinc oxide eugenol impression material is

Back 54

used alone in a custom acrylic resin impression tray as a wash material

Front 55

disinfecting of impressions

Back 55

must be done for all impressions

Front 56

cements mixed to primary consistency are used for

Back 56

luting and low strength bases

Front 57

I'm may be necessary to place an insulating base under restorations to

Back 57

protect the pulp from sudden temperature change

Front 58

the test for a properly mixed luting cement is

Back 58

checking wether cement will hold a thin string breaking when the spatula is raised and inch

Front 59

which cement should not be used for temporary cementation of crowns to be permanently cemented with resin cements

Back 59

zinc oxide eugenol

Front 60

which cement exhibits an exothermic reaction during mixing

Back 60

zinc phosphate

Front 61

which dental cements use the bonding procedure before placement of the dental cement

Back 61

composite resin and glass ionomer

Front 62

when luting a crown it is important to

Back 62

have a film thickness that allows for complete seating

Front 63

many cements should not be dispensed until ready to mix because of

Back 63

dehydration to exposure of air
contamination from moisture in the air
materials coming in contact with each other

Front 64

which dental cement bods to dentin is kind to the pulp and resists recurrent decay

Back 64

glass ionomer

Front 65

zinc phosphate cement is mixed over a large are of glass slab to

Back 65

help lengthen working time
neutralize the chemicals
help dissipate the exothermic reaction

Front 66

proper instrumentation against cement margins includes all of the following

Back 66

avoid gouging or ditching cement margins
avoid use of air polishing on resin cement margins
only neutral sodium flouride is recommended for use on resin cement margins

Front 67

light cured cements may be used for luting each of the following

Back 67

nonmetal orthodontic retainers
nonmetal periodontal splints
porcelain veneers less than 1.5 mm in thickness

Front 68

which cement should not be used under a composite restoration because of the oil content of the liquid

Back 68

zinc oxide eugenol

Front 69

adhesion is molecular attraction between

Back 69

different molecules