Tissue Management, Impression Making, Definitive Casts and Dies (Pt. II)

Question 1

Definitions

Solid Definitive Cast (or master or working
cast): replica of ____, ridge areas, and other parts of the ____

Die: positive reproduction of ____ tooth. Consists of a suitable hard substance of sufficient ____(usually improved stone, resin, or metal)

Answer 1

prepared teeth
dental arch
prepared
accuracy

Question 2

Definitions

To learn to properly use virtual casts, the
underlying principles of conventional definitive cast and die systems must be understood

Virtual systems model the same information in
three dimensional formats that enable the technician to use virtual tools for certain phases of the restoration fabrication process

Virtual systems offer significantly improved ____.

Answer 2

efficiency

Question 3

The accuracy of a cast and die is a function of the ____ of the impression.

The cast cannot contain ____ information than the impression from which it was made

Answer 3

completeness

more

Question 4

Prerequisites of Definitive Cast

oMust exactly reproduce ____ tooth surfaces
oUnprepared teeth immediately adjacent to preparation must be free of ____
oSurfaces of teeth involved in ____ and occlusal surfaces of all unprepared teeth must allow for precise articulation
oAll relevant ____ should be reproduced
n including all ____ spaces and residual ridge contours involved in fixed prosthesis

Answer 4

prepared and unprepared
voids
anterior guidance
soft tissues
edentulous

Question 5

Prerequisite of Die

oMust reproduce prepared tooth exactly
oAll surfaces must be accurately duplicated
n No bubbles or voids acceptable
oUnprepared tooth
structure immediately
\_\_\_\_ to finish line
should be easily discernible on die
n Ideally \_\_\_\_ visible oAdequate access to margin imperative

Answer 5

cervical

0.5-1mm

Question 6

Die Materials
oDifferent materials
n (1)\_\_\_\_
n(2)\_\_\_\_ (epoxy resin) n(3)\_\_\_\_ 
n(4)\_\_\_\_ materials
psimilar to heavy body silicone or polyether impression materials

Answer 6

gypsum
resin
electroplated
flexible die

Question 7

Die materials

ADA Type IV stone
Advantages: \_\_\_\_
Straightforward technique
\_\_\_\_ cost
Straightforward in-office procedure
Disadvantages: Will be \_\_\_\_ if not handled carefully (poor resistance to abrasion)
Use: Most \_\_\_\_
Precautions: Accurate \_\_\_\_ essential
Recommend vacuum mix

Answer 7

dimensional stability
low
damaged
situations
proportioning

Question 8

Die materials

ADA Type V stone
Advantages: \_\_\_\_ technique
\_\_\_\_ cost
Straightforward in-office procedure
Harder than \_\_\_\_
Disadvantages: Increased \_\_\_\_
Use: Most \_\_\_\_
Precautions: Accurate \_\_\_\_ essential
Recommend vacuum mix

Answer 8

straightforward
low
type IV
expansion
situations
proportioning

Question 9

Die materials

Expoxy
Advantages: High \_\_\_\_
Good abrasion resistance
Disadvantages: \_\_\_\_
\_\_\_\_-consuming complex procedure
More \_\_\_\_ than stone
Prostheses fit more \_\_\_\_
Use: \_\_\_\_ crowns
Precautions: Not compatible with \_\_\_\_ or hydrocolloid

Answer 9

strength
polymerization shrinkage
time
expensive
tightly
polysulfide

Question 10

Die material

Electroplating
Advantages: High \_\_\_\_
Good abrasion resistance
Disadvantages: \_\_\_\_- consuming
\_\_\_\_ equipment needed
Use: \_\_\_\_ crowns
Precautions: Silver entails use of \_\_\_\_, which is toxic
Incompatible with many \_\_\_\_ materials

Answer 10

strength
time
special
complete ceramic
cyanide
impression

Question 11

Die Materials
Selection Criteria
oMust allow dimensionally \_\_\_\_ cast** 
oStrong and resistant to abrasion** 
oEasy to \_\_\_\_ and trim
oCompatible with separating agent 
oReproduce \_\_\_\_ accurately oColor to contrast wax to visualize margin 
oEasily \_\_\_\_ by wax
oCompatible with impression material

Answer 11

accurate
section
surface detail
wettable

Question 12

Available Methods (1)Removable Dies

oDie is integral component of ____
n Can be lifted from cast for access
oPrecise ____ of die in definitive cast is crucial
n ____ or dowels
n Need resistance to rotation
o2 pours of ____ colors n First forms ____
n Second forms ____

Answer 12

definitive cast
relocation
brass pins
contrasting
teeth
base

Question 13

Available Methods (1)Removable Dies

o____ of dowels are critical
n If improperly placed, the dowels do not allow die of
prepared teeth to be withdrawn from the cast
oThis will be done in the preclinic
n Pindex

Answer 13

location and orientation

Question 14

Available Methods
(1)Removable Dies

o Advantages
n Removable die
facilitates ____
n Cast pouring ____

o Disadvantages
Extra \_\_\_\_ involved in making cast with dowels
\_\_\_\_ equipment
Care needed with dowel placement
\_\_\_\_ difficult 
pGetting dies to seat 
p\_\_\_\_ die
nDamage to interproximal margins

Answer 14

waxing and porcelain
unimpeded
steps
special
technically
sawing

Question 15

Available Methods
(2)Solid Cast with Individual Die

o􏰀Multiple pour technique􏰁
o____ than removable die
oMay be slightly more ____
oImpression poured in stone in area of preparation
n Trimmed to die with handle pSimilar to tooth root
oThen, second pour of the ____ made

Answer 15

simpler
accurate
entire arch

Question 16

Available Methods
(2)Solid Cast with Individual Die

o____ started on die (first pour)
oTransferred to ____ to contour and anatomy
oReturned to die for ____

Answer 16

wax pattern
articulated cast
margins

Question 17

Available Methods
(2)Solid Cast with Individual Die

o Advantages
n Definitive cast requires
\_\_\_\_ trimming
n Gingival tissues intact can be used as a guide for \_\_\_\_ restoration
n \_\_\_\_ procedure

o Disadvantages
n May be difficult to transfer wax pattern from ____
n Seating pattern on second pour more difficult due to second pour slightly ____ than first
n Only use with impression materials which could be poured more than once
pNot ____ hydrocolloid

Answer 17

minimum
contouring
straightforward
cast to die
larger
reversible

Question 18

Available Methods (3)Alternative Die Systems

oAccu-Trac technique. Di-Lok
n Many other systems available
n Utilizes a precision tray with a \_\_\_\_
n Impression is poured and seated on the \_\_\_\_ 
n Following setting, the tray is \_\_\_\_
and stone cast removed
n Dies are sectioned
n Cast and die reassembled and mounted on \_\_\_\_

Answer 18

magnetic indexer
tray
disassembled
articulator

Question 19

Accu-trac technique

tables!

Answer 19

ya

Question 20

Available methods
Alternative die systems

o Advantages
n ____ die
n Cast pouring unimpeded
n Less ____ than pindex

o Disadvantages 
n \_\_\_\_
n Care needed during reassembly
n \_\_\_\_ equipment needed
n Care needed when pouring to get proper orientation

Answer 20

removable
costly
bulky
special

Question 21

Available Methods
Choice of Die Systems

oDepends upon
n____ preference
nDental technician preference
nAssessment of ____

If used properly, all available systems achieve clinically acceptable ____

Answer 21

operator
advantages/disadvantages
accuracy

Question 22

Pindex Model Overview

Refer to video and laboratory manual for specific information

oPour final impression oWait for stone to set
n ____minutes
oSeparate impression
oTrim excess stone with cast trimmer
n Base thickness ____ inch
n Integral router and sandpaper point to trim lingual
oUse pindex to drill holes

Answer 22

40

3/4 - 1

Question 23

Pindex Model Overview
Refer to video and laboratory manual for specific information
oPlace dowel pins into drilled holes with cyanoacrylate
oWait ____ minutes for cyanoacrylate to dry
oPlace sleeves on dowel pins
oApply separating medium
oPour base using pre-fabricated rubber mold and vacuum mix

Answer 23

5

Question 24

Pindex Model Overview
Refer to video and laboratory manual for specific information
oLet base harden for ____ minutes oSeparate the rubber mold and trim
n ____mm land
oSeparate dies (#19 preclinically)
oTrim dies with acrylic bur oReturn dies to ____
oMount casts on articulator
n Preclinically, mount to previously mounted maxillary cast

Answer 24

30
3
master cast

Question 25

Procedure (in preclinic)
Pouring Definitive Cast

o Measure proper proportions of Type IV stone and water
n \_\_\_\_ placed into mixing bowl first
n Then, add \_\_\_\_
pPre-packaged in
preclinic 
o Mix stone
n Vacuum mixer strongly recommended
pHand mix in preclinic

Answer 25

water

powder

Question 26

Procedure (in preclinic)
Pouring Definitive Cast

o Holding tray on vibrator, use small brush or instrument to place stone in areas of preparation
n Slowly tease stone into preparation along axial walls by tilting impression
n Visualize stone going into preparation
n Continue until preparation is filled
o Fill remainder of tray at least ____mm above impression border

Answer 26

5

Question 27

Procedure (in preclinic)
Pouring Definitive Cast
oSeparate cast and trim n Base must be prepared
\_\_\_\_
n Vestibular area must be trimmed
\_\_\_\_ to the flat base

Answer 27

flat

perpendicular

Question 28

Die Preparation
oPreclinically, section #19 for die
oTo section dies, the saw cuts should ____ slightly toward eachother, or the die will be locked in by undercuts

Answer 28

converge

Question 29

Trimming Dies
oTrimmed dies should not have a ___ apical to margin
n May lead to poor gingival contour
oHandle dies very carefully

Overtrimming will result in ___ restorations

Answer 29

ditch

overcontoured

Question 30

Summary

oAccurate definitive casts and dies are essential to successful indirect restorations
oVarious materials and techniques provide precise reproduction of prepared teeth
n ____ stone usually recommended
pCareful to avoid chipping and abrading
margins
n ____ are durable alternatives
oDifferent systems are available for die fabrication
n If done accurately, each is an acceptable method

Answer 30

type IV

epoxy or electroplating

Question 31

Summary
oDefinitive cast must accurately articulate with opposing cast
oVirtual casts may be acquired from data captured with ____ or solid casts scanned in the dental laboratory

Answer 31

optical intraoral scanners