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Dental Materials > Midterm Exam Lectures 1-7 > Flashcards

Midterm Exam Lectures 1-7 Flashcards

1
Q

_______ is the force per unit area with its units being ______ or ______ which is N/m^2

A

stress, PSI, Pa

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2
Q

strain is the change in ________ per unit length when a material is subjected to a _______ (stress)

A

length or deformation, force

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3
Q

______ is the pushing or pulling of an object

A

force

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4
Q

force has units of _______ or ______

A

NEWTONS, POUNDS

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5
Q

one newton is equal to _______ lbs

A

0.225

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6
Q

one pascal is equal to ________ PSI

A

0.000145

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7
Q

one ______ is equal to 1x10^6 PA

A

MPa

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8
Q

one ______ is equal to 1x10^9 Pa

A

GPa

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9
Q

elongation uses _______ or _______ forces to pull a material from both sides

A

axial, tension

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10
Q

compression uses _______ or _______ forces to push a material from both sides

A

axial, compression

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11
Q

shearing uses ______ force to apply a force parallel or cross sectional on the bottom and top of a material

A

shear

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12
Q

torsion uses ________ force on a material

A

twisting movement

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13
Q

bending uses _______ force on a material

A

bending

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14
Q

_________ is equal to the ratio of the stress to the strain in the linear or elastic portion of the stress strain curve

A

elastic modulus

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15
Q

elastic modulus is a measure of _______

A

stiffness

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16
Q

________ is at the point of permanent strain at the point a material is deformed plastically

A

yield strength

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17
Q

_________ is the amount of stress/strain that can be applied before a material is deformed plastically

A

proportional limit

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18
Q

the _______ is the amount of stress a material has at fracture

A

ultimate strength

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19
Q

percent elongation is the amount of _______ a material can withstand before rupture under _______

A

deformation, tensile stress

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20
Q

resilience is the energy absorbed up to the ________

A

proportional limit

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21
Q

toughness is the energy absorbed up to the _______

A

fracture point

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22
Q

the elastic region is considered to be at or around the ________

A

proportional limit

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23
Q

the plastic region is considered to be at the point that ________ is met until _______

A

yield strength, fracture

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24
Q

_______ is the amount of stress a material can withstand without fracture

A

strength

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25
Q

_________ is the ability of a material to resist deformation

A

stiffness

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26
Q

flexibility is the ability of a material to deform ________ but return to its original shape

A

elastically

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27
Q

_________ is the materials tendency to fracture with little deformation

A

brittleness

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28
Q

a weak material is one that bends, breaks or fractures easily and a ________ material is weak

A

brittle

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29
Q

a _______ material is one that is able to resist breaking and able to absorb a lot of energy

A

strong

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30
Q

ductility is a materials ability to deform _______ without fracture

A

plastically

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31
Q

a ________ material is one that can absorb energy but return to its original shape

A

resilient

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32
Q

________ is a materials ability to resist indentation

A

hardness

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33
Q

viscosity is the resistance of a fluid to ______ and a measure of _______

A

flow, internal friction

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34
Q

shear thinning is used to describe the phenomena of added stress will cause a material to become _______ viscous

A

less

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35
Q

shear thickening is used to describe the phenomena of added stress will cause a material to become _______ viscous

A

more

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36
Q

viscoelastic is when a material behaves in an ________ behavior and a _______ like manner at the same time

A

viscous, elastic

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37
Q

a viscoelastic substance _______ energy
when a load is applied, then removed

A

loses

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38
Q

Hysteresis ( is observed in the stress–strain curve), with the area of the loop being equal to the energy _______ during the loading cycle

A

lost

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39
Q

______ is defined as constant stress which in turn will _______

A

creep, increase strain

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40
Q

________ is defined as a constant strain applied will cause a _______ in stress

A

stress relaxation, decrease

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41
Q

dentin, enamel, cells, impression materials and some acrylic denture are all _______ materials

A

viscoelastic

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42
Q

the hardness test is a measure of the resistance to localized ______ deformation induced by either mechanical indentation or abrasion

A

plastic

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43
Q

the types of hardness tests include the brinell, _______, vikers, rockwell, barcol and shore A

A

Knoop (KH)

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44
Q

Knoop hardness test uses a _______ to indent the material and measures the _______ surface deformation after a load is removed

A

diamond, permanent

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45
Q

the brinell hardness test uses a _______ pressed into the sample surface with a load of 500, 1500 or 3000 kgs

A

hard ball

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46
Q

the rockwell hardness test is widely used and uses a ______ indenter that is pressed into the specimen

A

cone-shaped

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47
Q

vickers hardness test uses a _____ that is pressed into the material

A

square-based pyramid shaped tip

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48
Q

nano-indentation uses a _________ to calculate the penetration ______ the load

A

berkovich tip that is a 3 sided pyramidal shape diamond, under

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49
Q

when a hydrophilic material is used, its contact angle is______ degrees and has a ________ degree of surface detail

A

less than 90, high

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50
Q

when a hydrophobic material is used, its contact angle is _______ degrees and has ______ degree of surface details

A

greater than 90, low

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51
Q

high surface energy will have ______ adhesive wet out and examples include metal, kapton, polyester, ABS and acrylic

A

good

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52
Q

low surface energy will have ______ adhesive wet out and examples include polystyrene, acetal, EVA and teflon

A

poor

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53
Q

contaminants will _____ surface energy and inhibit wet-ability

A

decrease

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54
Q

________ is the ability of a biomaterial to perform its desired function with respect to a dental therapy, without eliciting any undesirable local or systemic effects in the recipient of that therapy

A

biocompatibility

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55
Q

there are 4 interfaces of placement in the oral cavity
1. Interface between the material and _______
2. Interface between the material and _______
3. Interface between the material and
_______
4. Interface between the material and
_______

A

oral cavity (OC), pulp (tubules), periodontium (PD), periapical bone (PA)

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56
Q

Biocompatibility is not a property of a material, but rather a property of how a material reacts with its _______

A

local environment

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57
Q

the in-vitro tests for biocompatibility include ______ and _______ tests

A

direct, indirect (barriers)

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58
Q

the tests for biocompatibility not including in-vitro tests include _____ and ______ tests

A

animal, usage

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59
Q

in-vitro tests involve placing a material in contact with a ______, _______, or some
isolated _______ system

A

cell, enzyme, biological

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60
Q

the primary cells used in in-virto tests are cells taken _______ from an animal and _______, allowed to grow for _______ time and ________ in-vivo conditions

A

directly, cultured, limited, retain

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61
Q

the cell lines used in in-vitro testing are cells that are transformed to grow _________, can keep undergoing _______, have a more ________ population but ______ in-vivo conditions

A

indefenitaly, division, homogeneous dont retain

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62
Q

the in-virto direct and indirect tests assess ________, _________ and ________

A

cytotoxicity, metabolism, mutagenesis

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63
Q

a in vitro direct test involves placing a material in _______ contact with cells

A

direct

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64
Q

during direct tests the cells can be place ______ on the material, the material and cells can be places in the same medium but ________, or the material can be incubated in a medium where the medium will then be ______ to the cells

A

directly, do not touch, transferred

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65
Q

the measuring of cytotoxicity can be microscopically for ________ evaluation or -_______ evaluation in direct testing

A

qualitative, quantitative

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66
Q

________ microscopy is used in direct testing to count the dead or alive cells

A

fluorescent

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67
Q

direct tests can use the enzymatic or biosynthetic activity of cells to determine metabolism and some of these tests include ______, ______, NBT, WST and alamarblue

A

MMT, XTT

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68
Q

in indirect tests a _______ is placed between the biomaterial and cell to better represent the in-vivo condition

A

barrier

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69
Q

the 3 indirect tests that are available include _______ method, ________ method and ______ filter assay

A

agar overlay, dentin barrier, millipore

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70
Q

the agar overlay method is an indirect test that utilizes agar to form a ______ between cells and material where the agar provides nutrients, gas and soluble ________ will diffuse into cell layer and if cells are cytotoxic they will release neutral red causing a _______

A

barrier, toxic substances, zone of inhibition

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71
Q

the dentin barrier tests are indirect tests that closely mimic the oral environment where cytotoxic materials are diffused through the _______

A

dentinal tubules

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72
Q

the advantages of in-vitro tests include they are ________, _________, and relatively fast processing of ___________ of materials and prototypes

A

cheap, controllable, large number

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73
Q

the disadvantage of in-vitro test is that they ________ the overall biocompatibility of material

A

cannot entirely predict

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74
Q

the mucous membrane irritation test performed on animals tests if the material causes _______ to the mucous membrane

A

inflammation

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75
Q

the skin sensitization test is performed on animals where materials are injected _______ to test for development of skin ________

A

intra-dermally, hypersensitivity reactions

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76
Q

the implantation test is performed on animals and is used to evaluate materials that will contact ________ or ______

A

subcutaneous tissue, bone

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77
Q

the advantages of animal testing/ in-vivo is that it allows complex systemic _______ and responses are more ________ than in-vitro

A

interactions, comprehensive

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78
Q

the disadvantages of animal testing/in-vivo are that they are ________, _________, _______ to control, and has ________ relevance to humans

A

expensive, time consuming, difficult, questionable

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79
Q

usage tests are tests done on ______ or _____ where the biomaterial is placed identically to clinical use and are _______

A

animals, humans, gold standard

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80
Q

the four main types of usage tests include ________ tests, _______ usage test, _______ usage tests, and _________ tests

A

pulp-dentin irritation, mucosa, gingival, dental implant

81
Q

dental pulp irritation tests determine the _______ of a material with the dental pulp, by preparing class Vs as ________ and fill with test material, _______ tooth after several days then margins are examined for bacterial penetration

A

compatibility, traumatic as possible, extracting

82
Q

the mucosa and gingival usage tests check for ________ in the _______ and adjacent ________ by placing material in cavity preparations with subgingival extensions

A

inflammatory cells, epithelium, connective tissues

83
Q

difficulties with the mucosa and gingival usage tests include ________, ________ and surface ______ of material

A

plaque, preexisting inflammation, roughness

84
Q

the dental implant usage tests involves implanting in jaws of dogs, miniature pigs, guinea pigs and rats and watching for ________ histologically

A

tissue reaction

85
Q

during the implant usage tests the _______ of the implant and the ________ for osseo-integration are checked while the bones are checked for _____, ______ and _______

A

mobility, radiographs, fibrous capsule formation, inrritation, inflammation

86
Q

the advantages for usage test are they have high ________ and real life _______ of the situation

A

fidelity, simulation

87
Q

disadvantages of usage tests include _____, ______, _______, _______ to control, and _______ to interpret and quantify

A

expensive, time consuming, ethical issues, difficult, difficult

88
Q

the governmental institutes that regulate dental materials include ______, ______ and _______

A

FDA, OSHA, EPA

89
Q

the non-governmental institutes thats provide standards/regulations for dental materials includes _____, ______, ______ and ______

A

ADA, ANSI, ISO, FDI

90
Q

calcium phosphate is a ______ occurring mineral and ________ is a form of calcium phosphate

A

naturally, hydroxyapitite

91
Q

enamal is the most mineralized and hardest tissue of the body composed on 96% inorganic ________, 2% organic proteins _________, and 2% _______

A

hydroxyapatite crystals, enamelins, water

92
Q

mechanical properties of enamel are strongly dependent on its _______ and only weakly dependent on its ______

A

degree of mineralization, microstructure

93
Q

demineralization is the net loss of minerals because of ________

A

ion exchange

94
Q

acid etching which contains 40-50% ________ is a process of demineralizing the enamel for 15 seconds to prep the tooth for a filling

A

posphoric acid

95
Q

the dentin-enamel junction is _______ mineralized

A

highly

96
Q

dentin constitues the largest portion of the tooth and consists by volume 25% ________, 50% _________, and 25% _______

A

organic matter (type 1 collagen), inorganic matter (hydroxyapitite), water

97
Q

the outer dentin is ______, (containing less _______) than the inner dentin

A

stronger, tubules

98
Q

________ is the most abundant protein in the human body and provides structural support for all connective tissues…….. amino acids to tropocollagen to fibrils to fibers

A

collagen type 1

99
Q

the ________ dentin contains the mineralized collagen fibers and _______ dentin is less hard

A

intertubular, peritubular

100
Q

dentin is a ______ material

A

porous

101
Q

in dentin stimuli induce rapid fluid movement affecting the nerves and leading to a sensation of ______ and operative procedures like cutting and air drying increase fluid movement

A

pain

102
Q

_______ are the most diverse class of material used because their unit structure is the branched molecule

A

polymers

103
Q

polymers are created by connecting repeating units of _______

A

monomers

104
Q

polymerization is the process of _______ linking monomers together to form a polymer chain

A

covalently

105
Q

polymerization may produce _______ and not all monomers are are polymerized which can cause shrinking of the polymer

A

by-products

106
Q

three methods to trigger polymerization include ______ curing, _______ curing and _______ curing

A

heat, chemical, light

107
Q

high degrees of polymerization lead to _______, _______ polymer networks, which is desirable in clinical applications

A

more ridgid, less soluble

108
Q

high degree of polymerization have fewer _________

A

long polymer chains

109
Q

the three steps of polymerization includes _________ by activating the monomers, –_______ by chain growth and _______ by reaction complete

A

initiation, propagation, termination

110
Q

addition polymerization begins when a _______ is formed

A

free radical

111
Q

free radicals are highly reactive molecules that have a ________ and commonly referred to as _______

A

free electron, intiators

112
Q

during addition polymerization there is no _______ formed

A

by-products

113
Q

addition polymerization is clinically preferred because there is no risk of _______ intraorally, prevents increase in ______, and prevents________ to the patient

A

by-products leaching, shrinking, toxic reactions

114
Q

modification of polymer chains includes ________ by adding a _________ agent to connect polymers where the amount of agent controls the final properties

A

cross-linking, cross linking

115
Q

cross-linking of polymers will increase _______, _______, ______ temperature, ________ to degradation by solvents and ______ resistance

A

strength, flexibility, melting, resistance, wear

116
Q

________ is one type of monomer is used and _______ are two or more types of monomers are used

A

homopolymers, copolymers

117
Q

________ are chemicals that modify the interactions between the polymer and strands

A

plasticizers

118
Q

________ are solid particles that change the polymers optical or physical properties increasing strength up to 2x

A

fillers

119
Q

fillers and plasticizers may be chemically linked to the polymer network which increases ________ and decreases _______

A

wear resistance, shrinkage

120
Q

glass transition temperature is the temperature in which a significant loss of _______ occurs aka loss of _______

A

modulus (stiffness), volume

121
Q

thermoplastic polymers usually have linear and branched structures of very long carbon main chains, _______ when heated and ______ when cooled

A

soften, harden

122
Q

thermoplastic polymers can be reheated and cooled over and over and has little change to the ________

A

polymers properties

123
Q

examples of thermoplastic polymers include _______, ________, and _________

A

polystyrene, PMMAcrylate, PVAcrylic

124
Q

thermoset polymers require heat to _______ the plastic and the reapplication of heat will ______ soften the material

A

permanently set, not

125
Q

thermoset polymers are formed into shape by temporarily disabling the ________, can be degraded or decomposed at _________ and are _______ and _______ than thermoplastic polymers

A

cross-linking, very high temperatures, harder, stronger

126
Q

examples of thermoset polymers includes _______, ________, and ________

A

silicones, X-link PMMA, polyisoprene

127
Q

common dental polymer composition includes a _________, _________, _________, and ________

A

matrix(monomers), initiators, accelerators, pigments

128
Q

in light curing of polymers, blue light triggers the initiator __________ and the organic amine accelerator _________

A

camphorquinone, DAEMA diethyl-amino-ethyl-methyacrylate

129
Q

in chemical curing of polymers, chemical activation starts with ______ catalyst, _______ initiator and an _______ activator

A

organic amine, organic benzoyl peroxide, iodonium salts

130
Q

some resins are duel cured by _____ and ______

A

light, chemical

131
Q

light curing is _________, chemical curing is _______ but mostly in the ________, and duel curing is _______

A

40 to 75%, 40-70%, 40s-50s, 70-80%

132
Q

inadequate polymerization results in poor resistance to _______, poor _______, secondary ______ and ________

A

wear, color stability, caries, soft tissue/pulp reactions

133
Q

__________ are added in small amounts to polymers to match the color of the tooth

A

inorganic pigments (oxides of iron)

134
Q

composites are provided in 10 or more shades, ________ are sometimes added to enhance optical vitality (absorbed/reemit light) which enhances the________

A

fluorescence, whitening effect

135
Q

Typical volumetric shrinkage of dental composites is generally in the range of _______, it depends on factors such as the _______ (depth high), ______, and ______ of fillers, depends on the quality of ______ (calibrated lamp) and _______ techniques to compensate

A

1–6%, amount, type, size, light, layering

136
Q

PMMA is produced by free radical polymerization and has________ due to it being an exothermic process

A

no by-products

137
Q

PMMA includes ______ or ________ as well as by the trade names Crylux, Plexiglas, Acrylite, Lucite, and Perspex and PMMA is commonly used for complete ______, portions of removable partial _______, maxillofacial ________, temporary _______, custom impression _______, and denture _______.

A

acrylic, acrylic glass, dentures, dentures, prostheses, crowns, trays, teeth

138
Q

______ is initiated by _______ forming PMMA

A

MMA, benzoyl peroxide

139
Q

some PMMA properties include
* Transparency and high _____
* Low absorption of ______ and ______ light (to 250 nm)
* Density 1.19 g/cm3
* Compression strength 90 – 100 MPa
* Very ______ - elastic modulus above 2.4 GPa
* Water sorption up to ~1.0 wt %
* ________ resistance Tg = 120 – 125C
* ________ in organic solvents (MMA, acetone, toluene, etc.)

A

clarity, visible, UV, rigid, Temperature, Soluble

140
Q

during PMMA usage _______ with ________ and _______ is very important since bacteria accumulate and grow in pores and recesses on the polymer surface

A

disinfection, clorox (hypochlorite), calgon

141
Q

Exposure to ______ or ______ will dissolve and swell the polymer network and is irreversible and even though _______ PMMA can improve this, disinfection with those products is still not recommended

A

alcohol, acetone, cross-linked

142
Q

PEMA has a ______ molecular weight than PMMA, TG=65, and the addition of plasticizers increases _______ but it can ______ easily

A

higher, stiffness, leach

143
Q

Bis-Acrylic consist of bi-functional substrates to provide ______ leading to increase in impact ______ and ______ and bis-Acrylic contains _________ monomers and inorganic ______

A

cross linkage, strength, toughness, divinyl methacrylate, fillers

144
Q

bis-acrylic composite was introduced with an aim to overcome the negatives of the _______

A

methacrylates

145
Q

Compared to PMMA, Bis-Acryl has ______ polymerization shrinkage, _______ exothermic reaction, reduced tissue _______, _______ wear resistance and strength

A

low, low, toxicity, good

146
Q

the limitations of Bis-Acrylate compared to PMMA include its more ______, ______ stain resistant, more _______, ______ hardness and limited _______

A

brittle, less, expensive, lower, shades

147
Q

Polymethyl methacrylate (PMMA) and polyethyl methacrylate (PEMA) are methacrylate resins, they were the ________ provisional methacrylate restorative material in dentistry, they ________ due to their porosity and are _________

A

first available, stain easily, color unstable.

148
Q

_______ remains the most common material for fabrication of provisional restorations and denture

A

PMMA

149
Q

PMMA is strong and lightweight with a high coefficient of thermal expansion, is relatively ________ and capable of high polish, but it has a strong ______, poor _______ and high polymerization _______

A

inexpensive, odor, durability, shrinkage

150
Q

PEMA is not as strong, durable and wear resistance as PMMA but is better for _________ fabrication and has _______ polymerization shrinkage

A

direct interim prosthesis , lower

151
Q

Bis-acrylic composite are different from methacrylate resins but is similar to composite restorative materials because it is made of ______ and _______ and its latter reduces ________

A

bis-acryl resin, inorganic fillers, polymerization shrinkage

152
Q

Bis-acrylic has a high strength because its monomers have a high ________ and has superior flexural ______ and surface _______, higher ________, better marginal adaptation and lower _______.

A

molecular weight , strength, hardness, wear resistance, shrinkage

153
Q

Provisional bis-acrylic resin restorations for long span bridges
and teeth with minimal preparation are_________ to fracture

A

too susceptible

154
Q

the resin composite composition includes:
1. Matrix: _______ polymers
2. Fillers: ________ particles (ceramics-“glass”)
3. Coupling agents: _______ compound
4. Initiator - Accelerator systems

A

organic, inorganic, inorganic

155
Q

the most common resins are dimethacrylate (_______, bisphenol A-glycidyl methacrylate) - oligomer and urethane dimethacrylate (______) - oligomer

A

Bis-GMA, UDMA

156
Q

Bis-GMA and UDMA are ______ liquids and to reduce viscosity (facilitate manipulation), _______ dimethacrylates (e.g. TEGDMA, Bis-EMA6) are added

A

viscous, low molecular weight

157
Q

the advantage of acrylic resins is that they have lower ________

A

polymerization shrinkage

158
Q

composite contain around _______ of fillers and fillers control the _________ like mechanical, water sorption, shrinkage,

A

30-70%, properties of the composite

159
Q

fillers are usually particles of glasses (ceramics) which include _______, lithium aluminum silicate and _______ (barium, strontium, zinc, ytterbium, barium borosilicates, barium aluminosilicates)

A

quartz, radiopaque

160
Q

Fillers have a significant control over mechanical properties which ______ resins, ______ properties which provides appropriate translucency, ______ resistance, _______ (packing and manipulation), they reduce ______ and control _______ (Color)

A

reinforces, optical, wear, viscosity, shrinkage, shades

161
Q

most composites have fillers with average diameters of 0.2 to 3 μm (_____ particles), 0.04 μm (_______ particles) and 1-100 nm (______ particles) which can agglomerate

A

fine, microfine, nanofine

162
Q

6 classifications of filler size are ______, ________, _______, _______, ________, and _______

A

hybrid, microfill, macrofill, nanofill, minifill, midifill

163
Q

hybrid contains fillers with _____ sized particles (10-50um + 40nm) and microfill are fillers with _______ sized particles (40-50 nm)

A

different, similar

164
Q

two types of small particle hybrids classifications include ________ (0.6-1 um + 40 nm) and _______ (1-10um + 40nm)

A

minifill, midifill

165
Q

______ is a type of nanohybrid classification for fillers with their size being around 5-100 nm

A

nanofill

166
Q

other options for fillers includes _________, _________ and _______

A

fiber-reinforced, aramid fibers, nanotubes

167
Q

fiber-reinforced fillers has two types which include glass fibers that are ______ and have _______ and polyethylene fibers that provide ______ mechanical properties but have ________

A

low cost, good adhesion, enhanced, poor adhesion

168
Q

nano-tubes are another form of ______ usually composed of carbon, halloysite, ceramics etc

A

filler

169
Q

flowable composites are obtained by reducing _______: consistency, they provide better adaptation/dispensing but increased reduction of filler quantity, reduces _______

A

filler content, mechanical properties

170
Q

packable composites allows formation of tight __________ and it has modified filler size distributions or has added other types of fillers to prevent ______

A

inter-proximal contacts, shrinkage

171
Q

smart bioactive fillers prevent _______ and regenerate ______

A

secondary caries, tissue

172
Q

Silver, QA, and Zinc fillers are smart bioactive fillers that have ________, ________ and _______ properties

A

Antibiofilm, Antibacterial, Antifungal

173
Q

Calcium Phosphate (CaP) fillers are smart bioactive fillers that have ________, _________ and _________ effects

A

Remineralizing, Regeneration, acid neutralizing

174
Q

coupling agents are the “Glue” that bonds inorganic fillers with organic resin matrix, which helps minimize ________ of the fillers from resin, _______ mechanical properties of composite, _______ water absorption (hydrophobic environment) and the most common agent is ______

A

plucking, enhances, minimizes, silane

175
Q

chemical and light dual initiated polymerization can take up to ______ to fully polymerize

A

3 days

176
Q

composites initiated by light usually uses blue light that has a wave length of around _______, uses photo initiators like _________ or ________, and uses organic amine accelerators like _______

A

465nm, camphorquinone, diketone-amine, DAEMA

177
Q

the quartz tungsten halogen is a curing lamp that contains a quartz bulb, us filtered light (_________ wavelengths), have elevated operating ________ and _______ life (100 hours)

A

400-500 nm, temperature, reduce

178
Q

the light emitting diode (LED) is a curing lamp that are __________, have a narrower light spectrum ________, have _______ heat generation and have _______ life

A

semiconductors, 440-480 nm, less, increased

179
Q

light is scattered inside the composite due to fillers (size, shape) so therefore, curing lamp should be within _______ of the surface and you must be mindful of the depth of cure, spot size, angle of tip and cleanness of tip

A

1 mm

180
Q

composites initiated by chemical reactions use an _______ catalyst, _______ initiators which produce free radicals, and the common activated setting time is around ______

A

organic amine, organic peroxide, 3-5 min

181
Q

inadequate polymerization will cause inferior mechanical properties like poor resistance to ______, _______ color stability, ________ caries, adverse soft tissue/pulp _______ and _______ (unreleased monomers)

A

wear, poor, secondary, reactions, cytotoxicity

182
Q

Volumetric shrinkage of composites results in development of contraction stresses aka ______ and ______

A

gaps, fractures

183
Q

Strength generally increases linearly with the ________ of filler and the elastic modulus (stiffness) is dominated by the _______ of filler

A

volume fraction, amount

184
Q

Opalescence varies by the _____ and _______ of filler and translucency _______ as the amount of same filler size increases

A

size, amount, decreases

185
Q

water sorption causes _______ of composite due to uptake of ______, could relieve polymerization _______ but is a slow process compared to polymerization shrinkage

A

expansion, water, stresses

186
Q

water sorption takes ______ to reach majority of expansion and ______to reach equilibrium

A

4 days, 7 days

187
Q

water sorption is greater for _______

A

uncured composites,

188
Q

water sorption is lower for _______ compared to _______

A

microhybrid, microfilled

189
Q

hardness is related exponentially to the _________ of filler and the higher filler content provides higher resistance to abrasive wear but higher hardness makes it more difficult to polish

A

volume fraction

190
Q

radiopacity is proportional to the ______ and are necessary to locate margins of tissues and detect ________

A

amount of fillers, secondary caries

191
Q

flowable composites are ______ and have lower _______ but have higher _______

A

syringeable, modulus, wear

192
Q

bulk-fill composites (packable composites) have filler loading of 66% to 70% by volume and important properties include ______ depth of cure, _____ polymerization shrinkage, ________, and ______ wear rate

A

high, low, radiopacity, low

193
Q

laboratory composites have the _______ and _______ and also has lower _______ but requires resin _______, has higher ______ and requires special equipment

A

best contact, anatomy, wear, cement, cost

194
Q

core-buildup composites can be bonded to ______, can be finished immediately, are ______ to contour, have high ______, and have _______ under all-ceramic restorations.

A

dentin, easy, rigidity, good color

195
Q

Temporary inlays, crowns, and long-span bridges typically are fabricated from ________ and the purposes of provisional restorations are to maintain the position of the prepared tooth, seal and insulate the preparation and protect the margins, establish proper vertical dimension, aid in diagnosis and treatment planning, and evaluate esthetic replacements.

A

Provisional composites

196
Q

repair of composite is accomplished by abrading of the surface of the remaining composite with _______ and then keeping the surface well isolated from saliva and moisture. The surface of the composite is treated with _______, and the new composite is added. Repair bond strength is about _______ of the cohesive strength of the original composite.

A

50 μm alumina, silane, 60% to 80%

197
Q

multipurpose composites have ______ filler and have high _______ and high ______

A

60-70%, strength, modulus

198
Q

nanocomposite has around ______ filler and high _______, high_____ and high ________

A

78%, polish, strength, modulus

199
Q

microfilled composite has around ________ filler and is best for ______ and _______ but has high _______

A

32-50%, polish, esthetics, shrinkage

Dental Materials (8 decks)

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