Dental Materials - Restorative Resins (1)

Front 1

What is a compound of two or more distinctly different materials such that the compound has superior (or intermediate) properties of the individual materials being combined?

Back 1

composite

Front 2

What is unique about the strength of a composite?

Back 2

It's stronger than the individual strengths of the materials that make it up

Front 3

What are two examples of naturally occurring composite?

Back 3

enamel, dentin

Front 4

What is the composition of enamel?

Back 4

1% wt enamelin, 90-92% wt hydroxyapatite and water

Front 5

What is the composition of dentin?

Back 5

18% wt collagen, 75% wt hydroxyapatite and water

Front 6

True or False, restorative resins are not considered synthetic composites

Back 6

False, they ARE

Front 7

In what decades were Acrylic resins developed?

Back 7

1940s and 1950s

Front 8

Acrylic resin has (high, low) polymerization shrinkage (PS) and (high, low) coefficient of thermal expansion (CTE)

Back 8

high, high

Front 9

What was added to acrylic resin to decrease polymerization shrinkage and coefficient of thermal expansion?

Back 9

Quartz filler

Front 10

What are the 6 components of a composite resin?

Back 10

Resin matrix, filler particles, coupling agent, activator-initiator, inhibitor, modifiers/opacifiers/UV absorbers

Front 11

In composite resin, the resin matrix is what phase? Filler particles are what phase?

Back 11

continuous phase, dispersed phase

Front 12

Bis-GMA is one of the most widely used ___. What does this stand for?

Back 12

monomers; bisphenol A-glycidyl methacrylate

Front 13

Bis-GMA is (high, low) molecular weight, (high, low) viscosity, (cross-linked, linear) multifunctional dimethacrylate resin

Back 13

high, high, cross-linked

Front 14

Bis-GMA has proportionately (more, less) polymerization shrinkage than methyl methacrylate

Back 14

less

Front 15

Bis-GMA has (5 times, 1/5th) the molecular weight and (5 times, 1/5th) the density of methacrylate double bonds

Back 15

5 times, 1/5th

Front 16

What does UDMA stand for?

Back 16

urethane dimethacrylate

Front 17

UDMA contains how many urethane groups and how many methacrylate end groups?

Back 17

one or more, 2

Front 18

What does TEGDMA stand for?

Back 18

triethylene glycol dimethacrylate

Front 19

TEGDMA is (high, low) molecular weight, permits (high, low) filler content, it (increases, decreases) polymerization shrinkage and wear of resin and forms (10-25%, 25-50%, 50-75%, almost 100%) of the resin

Back 19

low, high, increase, 25-50%

Front 20

True or False, in a resin with Bis-DMA and TEGDMA, more TEGDMA will cause the resin to be less viscous

Back 20

True.

Front 21

Of the resin monomers Bis-GMA, UDMA, and TEGDMA, which has 2 carbon rings in it?

Back 21

Bis-GMA

Front 22

What are three examples of inorganic filler particles? What are their size ranges in micrometers?

Back 22

quartz, glass, amorphous silica; .1-100

Front 23

Quartz was originally used as an inorganic filler particle but it had two downsides, what are they?

Back 23

hard and abrasive

Front 24

Microfillers are how big? What is the process called that makes them?

Back 24

.04 micrometers, precipitation or pyrolytic process

Front 25

Microfillers are added in concentrations that are (less than, equal to, greater than) 5% weight

Back 25

less than

Front 26

Microfillers (raise, lower) viscosity and (improve, worsen) consistency

Back 26

raise, improve

Front 27

What is the primary purpose of filler?

Back 27

strengthen composite resin and reduct amount of matrix material

Front 28

Increasing filler concentration: (increases, decreases) hardness and strength, (increases, decreases) wear, (reduces, increases) polymerization shrinkage, (reduces, increases) thermal expansion coefficient

Back 28

increases, decreases, reduces, reduces

Front 29

Increasing filler concentration: (increases, decreases) viscosity, (reduces, increases) water sorption, softening, and staining, (increases, decreases) radioopacity, incorporates compounds like (Ba and Sr, S and N, Se and Br)

Back 29

increases, reduces, increases, Ba and Sr

Front 30

Filler-matrix chemical bonding will lower polymerization shrinkage in proportion to the ___ fraction of filler

Back 30

volume

Front 31

Filler-matrix chemical bonding lowers coefficient of thermal expansion compared to unfilled resin, which produces (more, less) interfacial stress

Back 31

less

Front 32

Filler-matrix chemical bonding (improves, worsens) compression and tensile strength, stiffness and abrasion resistance

Back 32

improves

Front 33

Name two organosilanes

Back 33

gamma-MPS, vinyl trichlorosilane

Front 34

gamma-MPS and vinyl trichlorosilane coupling agents have ___ bonds between solanol groups on filler surface and coupling agent

Back 34

siloxane

Front 35

Coupling agents have ___ bonds between methacrylate groups on coupling agent and on resin

Back 35

covalent

Front 36

Coupling agents permit transfer of what from matrix to stiffer filler particles?

Back 36

stresses

Front 37

Coupling agents provide hydro(static, lytic, phobic) stability

Back 37

hydrolytic

Front 38

What are the four types of activator-initiator systems?

Back 38

chemical, light, and heat activated, as well as dual-cured

Front 39

Describe a chemically activated activator-inhibitor system

Back 39

two paste system containing benzoyl peroxide initiator and tertiary amine activator in the other that are mixed

Front 40

In a chemically activated activator-initiator system, the (initiatior, activator) is benzoyl peroxide and the (initiator, activator) is tertiary amine

Back 40

initiator, activator

Front 41

True or False, a chemically activated system is a one paste system and a light activated system is a two paste system

Back 41

False. Chemically activated is 2, light is 1.

Front 42

What is the wavelength of sensitivity of the camphoroquinone in a light activated system?

Back 42

about 470nm

Front 43

What is the photosensitizer molecule in the light activated system?

Back 43

camphoroquinone

Front 44

A dual cured system is like having the capabilities of (pick 2: heat, light, chemical) activated systems in one

Back 44

light, chemical

Front 45

What is added to minimize spontaneous or premature polymerization of monomers?

Back 45

inhibitor

Front 46

How does the inhibitor minimize spontaneous and premature polymerization?

Back 46

terminates ability of free radicals to start polymerization process

Front 47

What two specific compounds can be added in trace amounts to impart color and translucency/opacity?

Back 47

TiO2 and Al2O3

Front 48

Darker and more opaque shades are (more, less) difficult to polymerize and should be places in (thinner, thicker) layers

Back 48

more, thinner

Front 49

What is one issue that is common in chemically-activated resins because they are mixed?

Back 49

air bubbles may inhibit polymerization due to presence of O2

Front 50

What kind of control over the working time do you have in a chemically activated resin once the mixing starts?

Back 50

no control

Front 51

True or False, a chemically activated resin should be left alone for several minutes because messing with it can disturb polymerization

Back 51

True.

Front 52

You should cure a light activated resin (before, after) you contour it

Back 52

after

Front 53

What is the wavelength of light used for light activated resins?

Back 53

400-500

Front 54

What is the curing time for 2mm work of light curing resin?

Back 54

40-60 sec

Front 55

Light activated resins shrink (towards, away from) the light source

Back 55

towards

Front 56

The Quartz-Tungsten Halogen lights have a ___ bulb with a ___ filament in a ___ environment

Back 56

quartz, tungsten, halogen (go figure, it's in the name)

Front 57

True or False, Quartz-Tungsten Halogen lights are the most widely used

Back 57

True.

Front 58

Quartz-Tungsten Halogen lights emit light in what range?

Back 58

400-500 (broad spectrum)

Front 59

Blue Light-emitting Diode (LED) lights emit light in what range?

Back 59

440-480 (narrow)

Front 60

Which type of light system is the least expensive?

Back 60

Quartz-Tungsten Halogen

Front 61

Plasma-arc curing lights share their wavelength range with what other type of light?

Back 61

Quartz-Tungsten Halogen

Front 62

Plasma-arc curing lights generate very (high, low) intensity light

Back 62

high

Front 63

Argon-ion laser lights have a narrow wavelength spectrum at about ___nm

Back 63

490

Front 64

With increase in light intensity output, you (increase, decrease) depth of cure, (increase, decrease) curing time, (improve, worsen) flexural strength

Back 64

increase, decrease, improve

Front 65

With increase in light intensity, you have two bad things happen. You polymerization shrinkage stresses (increase, decrease) and temp. of resin by radient heat energy (increases, decreases)

Back 65

increase, increases