Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Fixed Prosthodontics I > Quiz 1 Review > Flashcards

Quiz 1 Review Flashcards

1
Q

what is the result of overdrying a preparation?

A

it can dessicate the dentinal tubules

in other words, it’s bad

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

pain can stimulate/increase ___

A

salivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

is esthetics an acceptable reason to do a full coverage zirconia crown?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the appropriate method for caries removal?

A

slow speed with a large round bur and/or a hand instrument (spoon excavator)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the reduction measurements for a full zirconia crown preparation?

A
  • occlusal reduction/clearance
    • functional cusp: 1.5-2.0mm
    • non-functional cusp: 1.5-2.0mm
    • functional cusp bevel: 1.5-2.0mm
  • axial reduction: 1.0mm at margin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the two typical margin types for a full zirconia crown preparation?

A

rounded shoulder or chamfer design

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the target measurement of the margin above the gingiva?

A

0.5mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what should the width of the non-functional cusp bevel be for a full coverage zirconia crown preparation?

A

about 1.0mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

for a full coverage zirconia crown preparation, all line and point angles should be ___

A

rounded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is an undercut?

A

under-tapered preparation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the implications of an undercut?

A
  • wasted chair time
  • impression distortion
  • difficulty with provisional
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the 3 mechanical considerations for full coverage zirconia crown preparations?

A
  • retention form
  • resistance form
  • anti-deformation form

*these are what keep the crown “fixed”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

___ form prevents dislodgement of the restoration parallel to the path of insertion

A

retention form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the 4 factors that influence retention?

A
  • magnitude of the dislodging forces (ex. caramel, taffy, gum, etc.)
  • geometry of the tooth preparation
  • roughness of intaglio (underside of fixed restoration) surface of fixed restoration
  • material being cemented or bonded
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

geometrically speaking, what 3 things can increase retention?

A
  • increased axial surface area
  • increased preparation height
  • decreased taper of axial walls (aka make walls more parallel)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

the ideal axial wall taper is ___ degrees

A

6-10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what can increase intaglio surface roughness?

A

airborne particle abrasion (micro-etch) and acid etch with hydrofluoric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

___ form prevents dislodgement of the restoration along a path other than the path of insertion

A

resistance form

this is resistance to tipping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

which 3 factors influence resistance?

A
  • magnitude and direction of dislodging forces
  • geometry of the tooth preparation
  • physical properties of the luting agent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are 4 examples of factors that affect the magnitude and direction of dislodging forces?

A
  • design occlusion to load tooth/implant axially
  • parafunction
  • habits (pipe smoking, nail biting, etc.)
  • misuse of prosthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

geometrically speaking, what are 5 things that can increase resistance?

A
  • decreased preparation diameter
  • decreased axial wall taper
  • increased crown height
  • proximal grooves and boxes
  • definite line and point angles (not rounded) - remember that you want these rounded though…
22
Q

what are 5 luting agent considerations that increase resistance?

A
  • complete seating of restoration (decreased cement thickness)
  • luting agents with increased compressive strength
  • luting agents with increased modulus of elasticity
  • chemically bonded restoration
  • micro-mechanically bonded restoration
23
Q

___ form prevents dislodgement of the restoration due to permanent deformation (bending) of the restoration during function

A

anti-deformation

24
Q

what are 4 factors that influence deformation?

A
  • material selection
  • adequate tooth reduction
  • proper occlusal or lingual concavity reduction form
  • margin design
25
Q

occlusal reduction creates ___ for strength, should conserve ___, should be uniform and follow ___ planes, and includes which 3 cusps?

A
  • corrugated effect
  • tooth structure
  • cuspal planes
  • functional cusp, non-functional cusp, and functional cusp bevel
26
Q

alginate is a ___ impression material

A

irreversible hydrocolloid

27
Q

is alginate expensive?

A

no, it is inexpensive

28
Q

is alginate easy to use and manipulate?

A

yes

29
Q

does alginate have a fast or slow set time?

A

fast

30
Q

why is alginate not an appropriate impression material to create die models?

A

it is lacking in fine detail that is necessary to create die models

31
Q

alginate impression material includes ___ which react with calcium to form ___

A
  • sodium and potassium and other salts of alginic acid
  • calcium alginate
32
Q

what component of alginate is added to provide a source of calcium ions to cross-link the alginic acid?

A

calcium sulfate dihydrate

33
Q

what component of alginate is added as a retarder and its concentration is adjusted to control set time?

A

sodium phosphate

34
Q

___ is a naturally occurring hydrophilic colloidal polysaccharide obtained from brown seaweed

A

alginic acid

35
Q

describe the sol-to-gel reaction of alginate impression material

A
  • forms a sol when the powder is first added to water
  • as the alginic acid becomes cross-linked via the calcium ions, the gel is formed (this is the set material)
36
Q

the function of the ___ in alginate impression material is to dissolve in H2O and react with calcium

A

potassium alginate

37
Q

the function of the ___ in alginate impression material is to react with potassium alginate to form an insoluble calcium alginate gel

A

calcium sulfate

38
Q

the function of the ___ in alginate impression material is to counteract the inhibiting effect of the hydrocolloid on the fluoride, silicates, or borates setting of gypsum, giving a high quality surface to the die

A

potassium sulfate and potassium zinc

39
Q

the function of the ___ in alginate impression material is to react preferentially with calcium ions to provide working time before gelation

A

sodium phosphate

40
Q

the function of the ___ in alginate impression material is to control the consistency of the mixed alginate and the powder flexibility of the set impression

A

diatomaceous earth or silicate

41
Q

the function of the ___ in alginate impression material is to make the powder dustless

A

organic glycols

42
Q

the function of the ___ in alginate impression material is to produce a pleasant taste

A

wintergreen, peppermint, or anise

43
Q

the function of the ___ in alginate impression material is to provide color

A

pigments

44
Q

the function of the ___ in alginate impression material is to help in disinfection

A

disinfectants (quaternary ammonium salts and chlorhexidine)

45
Q

how can you minimize permanent deformation of alginate impressions?

A
  • use a quick snap motion when removing impressions - preferably in 5 seconds or less
  • wait about 10 minutes before pouring to allow for elastic recovery
46
Q

the space between the impression tray and the teeth allows for ___mm of alginate material

A

4-5

47
Q

what happens to alginate impressions when they are exposed to air?

A

they lose water by evaporation and shrink

aka desiccation

48
Q

what is the best method to prevent the desiccation of alginate?

A

either wrap them in a moist towel or disinfect in a plastic bag for 8-10 minutes, then pour immediately

49
Q

what is imbibition?

A

the uptake of water by hydrocolloid when immersed in water, causing distortion

50
Q

T or F:

you should never make an alginate impression if you cannot pour it immediately after (up to 10 minutes) the disinfection period

A

true

Fixed Prosthodontics I (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions