Ch. 13

Question 1

ince the wax pattern will be duplicated exactly through the investing and casting technique, the definitive restoration can be no better than the ____. This pattern should possess ideal contours, contacts, occlusal anatomy, and marginal adaptation. The time spent in the wax-up phase will save much time in the finishing of the casting and will help to ensure a successful definitive restoration.

Answer 1

wax pattern

Question 2

With a small brush, place die spacer on the die. Do not place any die spacer on the die margins. Place ____ of die spacer on the die and wait for it to dry. Then place another ____ and wait for it to dry. This will yield about ____ microns of thickness which represents the space needed for the cement when the definitive restoration is completed.

Answer 2

one layer
layer
25

Question 3

Reapply lubricant ____ to avoid having the wax up adhere to the die.

Answer 3

often

Question 4

Flow Type II Inlay Wax over the entire die surface to approximately ____mm beyond the finish line using a hot No. 7A Wax Spatula.

Answer 4

1.0

Question 5

Then, if the waxed pattern is removed with forced, either the wax in the marginal areas will ____ so it can be released from the undercut or the marginal areas will ____.

Answer 5

flex

shatter

Question 6

6. To ensure that the finished restoration will have adequate proximal contact, the wax pattern must be slightly ____ mesio-distally

Answer 6

oversized

Question 7

The process consists of surrounding the wax pattern with a mold made of ____ material, eliminating the wax by heating (hence the term “lost-wax”), and then introducing molten metal through a channel called the sprue into the void left by the wax.13

Answer 7

heat resistant investment

Question 8

The sprue can be made from ____, plastic, or ____. The diameter of the sprue should be ____ than the thickest cross section of the pattern.14 The diameter and the length of the sprue affect the ____ of the casting. Common sprue diameters are 8 gauge, 10 gauge, 12 gauge and 14 gauge. The larger the gauge number, the ____ the sprue. The #10 gauge sprue will be used for the molar #19 wax pattern

Answer 8

wax
metal
density
smaller

Question 9

o ____ the wax pattern
o ____ the sprued pattern
o ____ out the invested pattern
o ____ the invested mol

Answer 9

spuing
investing
burning
casting

Question 10

The sprue design varies depending on the type of ____ being cast, the ____ used, and the ____. The requirements of a sprue for a high noble casting are:

1. The sprue must allow the molten wax to ____ from the mold.
2. It must enable the molten metal to flow into the mold with as little ____ as possible.
3. The metal within it must remain molten slightly ____ than the alloy that has filled the mold. This will provide a reservoir to compensate for the ____ that occurs during solidification of the casting

Answer 10

restoration
alloy
casting machine

escape
turbulence
longer
shrinkage

Question 11

1. To prevent distortion of the pattern, attachment of the sprue should be done while the waxed pattern is still on the ____. Any areas of the pattern that are thin should have a little wax added to it to prevent perforation during casting.
2. The 10 gauge plastic sprue is luted with inlay wax to the ____ cusp tip of the waxed pattern. This will be in an area least disturbing to the critical crown contours or to the margins. In this situation, we will be using the ____ cusp to insert the sprue.

Answer 11

stone die
non-supporting
disto-lingual

Question 12

Apply a ____ to the wax pattern to enhance the wetting of the pattern during investing.

Place a Nosbestos ring liner inside the casting ring. (This allows for the setting ____). Keep this flush with the open end and moisten it.

Place the ring over the pattern and check that it is long enough to cover the pattern. You want about ____ mm of investment over the pattern. (Figure 13b-4, Figure 13b-5 and Figure 13b-6). This provides adequate strength to the material to prevent the molten metal from perforating through the investment.

Answer 12

surfactant
expansion
6.0

Question 13

NOTE: Ideally, all sprued wax patterns should be oriented somewhat ____ to the sides of the casting ring to allow for ____ expansion of the investment and mold.

Answer 13

symmetrically

uniform

Question 14

The process starts with ____ abrasives and moves onto the ____ abrasives and polishing agents. The finishing/polishing process can be divided into:

o The ____ phase: use coarser abrasives, disks, wheels and stones.
o The ____ phase: use medium to fine disks, wheels and points.
o The ____ phase: use the finest polishing agents to provide the final shine.

Answer 14

coarser
ultra-fine
contouring
smoothing
polishing

Question 15

The process starts with ____ abrasives and moves onto the ____ abrasives and polishing agents. The finishing/polishing process can be divided into:

o The ____ phase: use coarser abrasives, disks, wheels and stones.
o The ____ phase: use medium to fine disks, wheels and points.
o The ____ phase: use the finest polishing agents to provide the final shine.

Answer 15

coarser
ultra-fine
contouring
smoothing
polishing

Question 16

Emphasis should be placed on the contouring and smoothing phases. The bulk of
the finishing procedures are performed using the low speed handpiece with the straight
nose cone. This allows for maximum ____ and control of the instruments.

Answer 16

leverage

Question 17

4.

a. Remove as much investment from the casting as possible using toothbrushes, hand instruments and water.
b. Care should be taken not to damage the crown margins.

For noble castings, pickle the casting in hot ____ to remove oxides. This is dangerous and care should be taken not to get it in eyes or on the skin or clothes. You do NOT need to pickle your castings.

a. The pickling solution is ____. Use ____ forceps to place and remove casting
b. Carefully place the casting into the heated pickling solution.
c. Pickling is complete when there are no more ____ on the surface of the casting. This may take from ____ minutes depending on the ____ and ____ of the solution.

Answer 17

acid
caustic
acid resistant
oxides
5-15
freshness
temperature

Question 18

A ____ area will appear through the alcohol and rouge (or Occlude) if there is an area of binding. Remove this shiny spot with a small round bur, preferably 1/4 or 1/2 size and try the crown on the die again. Continue until the crown is completely seated on the die. Utilize ____ on a cotton pellet to remove the Occlude from the crown.

Answer 18

shiny

alcohol

Question 19

place thin ____ paper in the interproximal contact area as you are seating the casting.

Answer 19

articulating

Question 20

NOTE: Throughout the adjustment of the occlusion, be careful not to create a thin spot (less than ____mm of metal) especially in a groove. Continuously check the thickness of
the metal with the Iwanson metal gauge.

Answer 20

0.2

Question 21

Using abrasive disks, green and white stones and carborundum separating disks to refine and smooth crown contours. Begin with the ____ disks and burs, if a lot of adjustment is needed, and proceed to the finer grit disks and stones to remove scratches and imperfections
NOTE: The finishing of the margins should be delayed until the fit of the casting is evaluated in the ____ (on the Dentoform).

Answer 21

coarser

patient’s mouth

Question 22

Once the overall contours and smoothness of the surfaces of the restoration are !acceptable, ____ wheels can be used. This will remove previously produced ! !roughness left by the finer stones. Again, the final finishing of the margins with the rubber wheel should be left to do ____.

Answer 22

rubber

chairisde

Question 23

For the occlusal surface, ____ burs can be used carefully to define occlusal anatomy, if needed. White stones, rubber wheels and points can be used to smooth the occlusal surface. Be careful not to obliterate the occlusal anatomy. The rubber wheeled casting should have no visible scratches and show a smooth, satin- like finish. At this stage, you are ready for the final polishing. The final polishing should occur after the restoration is tried in the ____ (Dentoform).

Answer 23

carbide

patient’s mouth

Question 24

The casting should be tried in on the Dentoform. If it does not seat fully, check the ____ areas FIRST

Answer 24

proximal contact

Question 25

If the casting does not seat intraorally (after adjustments), but it seats well on the die, you need to make a new ____ to fabricate a new ____.

Answer 25

impression

casting

Question 26

The marginal fit of the casting is checked with an explorer. Clinically, the marginal fit is confirmed with a radiograph as well. (Usually a ____ radiograph)

Answer 26

bitewing

Question 27

It is good practice to delay polishing until the final adjustment of margins, contacts, and occlusion are accomplished at ____

Answer 27

try-in

Question 28

The wheel should be moving in a direction ____ to the margin from cusp tip to the cervical area to avoid a catch! The casting should have a shiny, bright scratch free appearance

Answer 28

opposite

Question 29

gold rouge is the ____ abrasive

Answer 29

finest

Question 30

Final cleaning of the casting should be done using a clean soft toothbrush with ____. (Figure 13c-2 and Figure 13c-3)

Answer 30

soap and water

Question 31

NOTE: ____ will scratch and dull the high luster finish of the gold restoration. Clinically, be sure to use the ____ cleaner to remove any remnants of
rouge. Rouge contains ____, which causes ____

Answer 31

cloth and paper towels
ultrasonic
iron
corrosion

Question 32

4. Maintain isolation until cement is set (approximately ____ minutes).

Answer 32

7