11/6: Definitive Casts Flashcards

1
Q

A replica of the tooth surfaces, residual ridge areas, and/or other parts of the dental arch and/or facial structures used to fabricate a dental restoration or prosthesis

A

defintive (master or working) cast

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2
Q

The positive reproduction of the form of a prepared tooth in any suitable substance

A

die

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3
Q

A metal pin used in stone casts to remove die sections and replace them accurately in the original position

A

die pin

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4
Q

what are the requirements for a good cast?

A

bubble and distortion free
captures both the prep and unprepped surfaces
all occlusing surfaces must allow for appropriate articulation
all soft tissues be captured

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5
Q

what are the Die requirements?

A

reproduce the prepared tooth
all surfaces
uprepared tooth structure apically to finish line
adequate access for carving wax pattern margins

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6
Q

what is the primary material used for dies?

A

gypsum

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7
Q

what is the advantage to using gypsum?

A

compatible with all impression material
can replicate fine details
dimensional accuracy and stability
easy to use

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8
Q

what is negative about gypsum?

A

abrasive can affect it

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9
Q

ADA die classification

A

type 1 and 2: Impression plaster and mounting plaster
type 3: dental stone
type 4: high strength/low expansion
type 5: high strength/high expansion

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10
Q

what types of gypsum are die stone?

A

type 4 and 5

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11
Q

what are the desirable properties of die materials?

A

accuracy
reproduce fine detail
strength and durability
color

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12
Q

what strength and durability do we want in die materials?

A

dry versus wet strength
resistance to shearing forces (edge strength)
abrasion resistance

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13
Q

why is color important in die materials?

A

so CAD/CAM can scan it

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14
Q

should you add powder to water or water to powder?

A

powder to water

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15
Q

what is directly proportional to water?

A

setting time and fluidity

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16
Q

what is inversly related to water?

A

compressive strength
setting expanion

17
Q

is a wet cast or dry cast stronger?

A

dry cast

18
Q

what should be used for surface impregnation?

A

cyanoacrylate cement

19
Q

(T/F) the final impression should be only poured once

A

false, need to be pour twice so we can get dies and working cast to be mounted

20
Q

should a trimmed die have the same contour as the tooth?

A

yes

21
Q

how much margin do you need to carve the wax to the proper emergence profile?

A

5mm to finish line

22
Q

this is used to provide space for cement while cementing final restoration in mouth

A

die spaces

23
Q

where should a die-spacer be placed?

A

5mm coronally to finish line

24
Q

this is necessary to orient dies of prepared teeth to the opposing occlusion

A

interocclusal records

25
Q

allu wax should

A

not be used for FPD

26
Q

when placing the interocclusal record, where should it be?

A

between prepped and opposing teeth only

27
Q

this dye system requires less manipulation of wax pattern and reduces chances of breakage and distortion

A

removable die system

28
Q

epoxy resin is superior to gypsum in terms of

A

abrasion resistance

29
Q

what is the best interocclusal record materials?

A

rigid, fast-setting VPS

30
Q

gypsum should be set in what position?

A

upright position

31
Q

which die system provides a rigid relation for the FPD component

A

solid cast -die system