Prismatik UniPack Technique Manual - Glidewell Dental Labs

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Prismatik UniPack Technique Manual - Glidewell Dental Labs

Dental Technology

Reference Guide

CLINICAL AND LABORATORY PRODUCTS

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Dental Technology

Reference Guide

Prismatik UniPack Ceramic

Technique Manual

Written support material for video training programs.

Prismatik Dentalcraft, Inc. is not responsible for any damages or other liabilities (including attorney fees) resulting, or

claimed to result in whole or in part, from actual or alleged problems arising out of the use of this information. The

techniques, procedures and theories presented herein are provided in good faith and believed to be correct as of the

date hereof. Any dental professional viewing this presentation must make his or her own decisions about the use of

the materials and techniques for specific situations.

No representations as to the completeness or accuracy of this information is given, and no representations or warranties,

either express or implied, of merchantability, fitness for a particular purpose or of any other nature are made

hereunder with respect to the information or the product to which information refers.

Copyright © 2006, Prismatik Dentalcraft, Inc.


TABLE OF CONTENTS

Chapter 1 – Beneficial Properties of the Prismatik Ceramic System

Opalescent Properties........................................................................................ 1

Color and Shading Properties ........................................................................... 1

Coefficient of Thermal Expansion (CTE) Data ................................................. 2

Wear and Opposing Compatibility Factors....................................................... 3

Time and Temperature/Optical and Physical Characteristics .......................... 3

Prismatik Firing Chart........................................................................................ 5

Prismatik Shade Indicator ................................................................................. 6

Chapter 2 – Understanding the Prismatik Ceramic System

The UniPack System .......................................................................................... 7

Opaque Powders................................................................................................ 7

Margin Powders ................................................................................................. 7

Opaceous Dentin Powders ................................................................................ 8

Pre-blended Dentin & Incisal Powders............................................................. 8

Opal Incisal Powders......................................................................................... 8

Add-On Powders................................................................................................ 9

Stain and Glaze Powders................................................................................... 9

Universal Stain & Glaze Liquids........................................................................ 9

Universal Build-up and Opaque Liquids .......................................................... 9

Chapter 3 – UniPack Techniques

Posterior Opaque Technique ........................................................................... 10

Posterior Build-up Technique.......................................................................... 13

Posterior Stain & Glaze Techniques ................................................................ 15

Anterior Opaque Technique ............................................................................ 17

Anterior Build-Up Technique .......................................................................... 20

Anterior Stain and Glaze Techniques.............................................................. 22

Anterior Shoulder Butt Margin Technique...................................................... 24

Opaceous Dentin Technique ........................................................................... 28

Multiple-Unit Restorations ............................................................................... 29

Prismatik Ceramic Kits .............................................................................................30

Troubleshooting Guide....................................................................................................31


Chapter 1 – Beneficial Properties of the

Prismatik Ceramic System

Welcome to the world of Prismatik TM Ceramics. Glidewell Laboratories Research

and Development has developed three new prismatically blended high-strength

ceramics in the form of Prismatik UniPack TM , Prismatik NetPress TM and Prismatik

ThinPress TM . These ceramics have incisal pre-blended with dentin that will save

valuable production time and improve upon the shade fidelity of your ceramic

restorations. Prismatik Ceramics eliminate the need for layering of multiple powders

to achieve accurate shades and natural-looking esthetics. This exciting new

system has proven very successful in laboratory production with over 100,000

restorations for more than a two-year period.

Opalescent Properties

The Opal Incisal ceramic contains opalescent particles

that match the patient’s natural teeth when

exposed to a variety of light sources. The particles

refract, reflect and scatter light that results in

an opalescence that appears orange in light transmission

and blue when it reflects light. This property

results in a restoration that reflects, absorbs

and blends like natural dentition.

Color and Shading Properties

Prismatik Ceramics have been spectrophotometrically

designed to ensure that the shades

provide predictable hue, value and chroma

consistent with the Vita Classic Shade Guide.

Prismatik Ceramic Powders have been formulated

according to translucency/opacity ratios.

This results in the ability to eliminate incisal

cutback procedures, saving valuable time during

the fabrication process. If increased incisal

translucency is indicated or desired, normal

incisal cutback and translucent layering techniques

lend themselves readily to this technique.

1


Normal staining and glazing procedures are applied after final contour and contact

adjustment of the restoration is completed.

Coefficient of Thermal Expansion (CTE) Data

Coefficient of Thermal Expansion data varies considerably with the same ceramic

material regardless of the manufacturer. This is due to time and temperature conditions

when sintering any material. Therefore all CTEs reflect a coefficient range

rather than one set coefficient parameter. (See Figure 1 – Prismatik CTE Data

Chart.)

Prismatik UniPack

Figure 1 – Prismatik CTE Data Chart

Delta-L(evaluated) [µm]

Delta-L(evaluated)[pu61705M]

Linear Expansion

Alpha-tech[pu61705M]

Coefficient of Thermal Expansion

500.0°C 12.82E-6/K

20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520

Temperature(smoothed) [C°]

Figure 1 reflects the variance of CTE time and temperature tests conducted with

Prismatik Ceramic materials.

2


We may conclude from these tests that Prismatik Ceramic powders are compatible

with a wide variety of frequently used alloys with the thermal expansion ratios

covering a broad range from 13.6 ppm to 14.8 ppm (25-500ºC). Due to the vast

number of ceramic alloys on the market today it is impossible to recommend compatible

alloys that can be successfully employed in partnership with the Prismatik

Ceramic System. Please contact your alloy manufacturer’s technical department for

a list of CTE compatible alloys in accordance with the CTE data chart.

Wear and Opposing Compatibility Factors

One of the prime considerations when selecting a ceramic material has to be the

wear factor of the material and how it affects the opposing dentition. Prismatik

Ceramic exhibits much less wear loss compared to conventional porcelain-fusedto-metal

restorations because of the small leucite crystals. Many dental patients

with Prismatik restorations in place are already benefiting from its superior kindness

to opposing dentition and low ceramic wear.

Time and Temperature/Optical and Physical Characteristics

Most of the desired esthetics in ceramic materials is established during the first

body bake. (See Figure 2 - Prismatik UniPack Firing Parameters.) The firing chart

is provided to give you a recommended starting point in order to achieve the

proper high sintering temperature in your furnace. To achieve a natural glaze on

the restoration if desired and to ensure proper sintering of the porcelain mass it is

always better to err on the higher end of the ideal sintering temperature rather

than the lower end. Overfusion reduces porosity but it also lowers value. Repeated

firings at the high end of the proper sintering phase will also lower the coefficient

of thermal expansion of the porcelain.

Under-fusion results in more opacity of the material and it lowers chroma. It also

produces higher value restorations. Underfiring produces a weak restoration

3


ecause it doesn’t reduce porosity in the porcelain mass. This could lead to fractures

or a poor bond. An underfired restoration after the first bisque bake will also

make natural glazing very difficult. An excellent standard when determining proper

time and temperature sintering parameters for a first firing is to compare it to the

glaze on a shade tab. If it is too dull or too shiny after the first bake adjust your

furnace up or down to compensate until you achieve the desired shade tab gloss.

Overfired Underfired Perfect

To compensate for variances in furnace firings for opaque, dentin and stain and

glaze bakes, raise the final temperature either up or down in increments of 41°F

(5°C) until a visual match of the shade guide surface texture is achieved.

4


Figure 2 – Prismatik UniPack Firing Parameters

1st Opaque 2nd Opaque Margin 1st Bake 2nd Bake Glaze Add-On

Low Temp.

538°C

1000°F

538°C

1000°F

482°C

900°F

380°C

716°F

380°C

716°F

482°C

900°F

482°C

900°F

Pre-Dry Time 6 min. 6 min. 4 min. 6 min. 6 min. 6 min. 6 min.

Heat Rate

55°C/min.

100°F/min.

55°C/min.

100°F/min.

39°C/min.

70°F/min.

55°C/min.

100°F/min.

55°C/min.

100°F/min.

55°C/min.

100°F/min.

55°C/min.

100°F/min.

Vac. Level Full Full Full Full Full Full Full

Vac. Start

538°C

1000°F

538°C

1000°F

538°C

1000°F

570°C

1058°F

570°C

1058°F

N/A

538°C

1000°F

Vac. Release

1070°C

1958°F

965°C

1769°F

959°C

1758°F

870°C

1598°F

865°C

1589°F

N/A

774°C

1425°F

High Temp.

1070°C

1958°F

1020°C

1868°F

960°C

1760°F

870°C

1598°F

865°C

1589°F

860°C

1580°F

815°C

1499°F

Hold Time 0 0 1 min. 0 0 0 0

Cool Time 3 min. 3 min. 1 min. 1 min. 1 min. 1 min. 1 min.


Figure 3 – Prismatik UniPack Shade Indicator


Chapter 2 – Understanding the UniPack Ceramic System

The Prismatik UniPack System

Prismatik UniPack Ceramic is a high-strength (>110 mpa flexural strength) ceramic

powder in 19 shades (refer to Fig. 3) that are conventionally wet layered upon

metal copings. The dentin powders are pre-blended with incisal to eliminate cutbacks

and layering. This unique blending saves time, improves esthetic value,

maintains shade integrity and consistency.

Opaque Powders

Opaque powder is available in 18 shades that

correspond to the shades available in the Vita

Classic Shade Guide. UniPack opaques lend

themselves well with spray opaque techniques

as well as conventional application techniques.

Two bleached opaques are also provided for

use with three Bleach Shades. The opaques are

coordinated in hue, value and chroma to lend

shade integrity with its corresponding body

shade. The opaques, when properly fired, should exhibit a slightly shiny eggshell

appearance.

Margin Powders

Margin powder is available in five hues to match

all 19 shades. This ceramic material fuses at a

temperature slightly lower than the opaque temperature

ensuring stability and thus resisting

shrinkage, slumping and deformation during

subsequent body bakes.

7


Opaceous Dentin Powders

In cases where insufficient reduction at the gingival

will result in an opaque halo or a “dead

looking” restoration, or in cases where short

clinical preps are present, application of

Prismatik UniPack Opaceous Dentin Powders

will correct the situation. The powders are color

matched to blend between the opaque and body

porcelains with no line of demarcation. The

powders are available in 13 shades of A, B, C, D,

Modifier White and Bleach hues to complement the Prismatik UniPack Margin

Porcelain. They may also be blended with Prismatik UniPack Powders to create

custom shades if desired.

Pre-blended Dentin & Incisal Powders

Opal Incisal Powders

Opal powders are available in Clear, Light, White,

Blue White, Blue and Ivory. These powders are

made available in the event that the technician

determines that more translucency is required

above the translucency that the pre-blended

shades offer.

Pre-blended powders are available in all shades

contained in the Vita Classic Shade Guide and

three Vita Bleach Shades. The powders are preblended

with dentin and incisal according to

degrees of opacity and translucency designed

specially for each shade. This makes it possible to

build a restoration utilizing a wet layering technique

without the time-consuming procedure of

cutback and application of incisal materials.

8


Add-On Powders

Add-On powders in Body and Incisal Light are

intended for use when minor corrections

become necessary and an additional body bake

is not desired. They may also be used successfully

with the Prismatik NetPress System and are

available separately. If the correction is a minor

add-on the case can be fired without vacuum

and completed during the stain and glaze cycles.

It is recommended that if large corrections are

indicated the restoration should be fired under full vacuum to eliminate porosity.

Stain and Glaze Powders

Prismatik Stain and Glaze Powders are provided

in A, B, C, D, Blue, White, Crème, Violet, Pink,

Dark Brown and Yellow/Orange hues. The fine

particle size of the stain powders mix to a

smooth consistency, ensuring easy application

without streaking. The Prismatik Glaze Powder

is a universal glaze allowing coefficient compatibility

with all components of the Prismatik

Ceramic System.

Universal Stain & Glaze Liquid

Universal Build-Up

& Opaque Liquids

Prismatik Universal Stain and

Glaze Liquid is available in a

60ml. quantity.

This liquid is available for

purchase in 60ml., 8 oz. or

16 oz. bottles.

9


Chapter 3 – UniPack Techniques

Posterior Opaque Techniques

Finish the metal substructure according

to the manufacturer’s instructions.

Sandblast with aluminum oxide and steam

clean or ultrasonic clean the substructure.

Degas the metal substructure to form oxides for

a better bond to opaque, also to get rid of gases

and contaminants on the metal.

10


Mix opaque powder with universal build-up

liquid. Opaque powder has light reflective properties

and opacity to mask metal substructure.

Apply a thin coat of opaque to the metal

substructure for the first firing.

1st Opaque Firing Parameters

Low Temp.

538ºC

1000°F

Vac. Level

Full

High Temp.

1070ºC

1958ºF

Pre-Dry Time

6 min.

Vac. Start

538ºC

1000ºF

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

1070ºC

1958ºF

Cool Time

3 min.

Apply another coat of opaque in a paste-like

consistency, making sure its not too thick.

11


2nd Opaque Firing Parameters

Low Temp.

538ºC

1000°F

Vac. Level

Full

High Temp.

1020ºC

1868ºF

Pre-Dry Time

6 min.

Vac. Start

538ºC

1000ºF

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min

Vac. Release

965ºC

1769ºF

Cool Time

3 min.

Final result of opaque should have a slight

eggshell sheen, and should achieve good metal

coverage not thicker than 0.1mm - 0.2mm.

Alternate spray opaque technique

UniPack opaque powder

is mixed with a spray

opaque liquid then placed

into sprayer.

Spray opaque allows for

an even and consistent

coat.

12


Posterior Build-up Technique

Mix pre-blended powder with universal build-up

liquid. Pre-blended Dentin & Incisal allow for

better light diffusion and vitality throughout the

restoration.

Proceed with application of porcelain,

building to occlusion.

Overbuild the porcelain to

compensate for shrinkage.

13


Keep internal aspect of crown

clean and fire the restoration.

1st Bake Firing Parameters

Low Temp.

380ºC

716°F

Vac. Level

Full

High Temp.

870ºC

1598ºF

Pre-Dry Time

6 min.

Vac. Start

570ºC

1058ºF

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

870ºC

1598ºF

Cool Time

1 min.

After firing, adjust the restoration to final anatomical contour and fit.

14


Posterior Stain & Glaze Techniques

Increased Depth

Stains are great tools for individualizing ceramic

teeth and adding character to a restoration.

Increased Height

Not Stained

Stained

Stains are mixed to help achieve an ideal final

shade. Staining liquid is used to mix the stain

powder into a thin, brushable form. The mixture

should be free of bubbles.

The mixture must be the correct consistency.

If it is too thin it will puddle during application.

And if it is too thick it will be hard to

apply, and will puddle as it melts.

Stain Dark

Brown

Stain White

UniPack Powder

A2

Stain Blue

Stain

A

To give the illusion of depth add Dark Brown

stain to the grooves.

To achieve the effect of translucency add Blue

stain to the cusps, and White stain to mimic

decalcification.

Add the corresponding stain A, B, C or D at

the gingival if increased chroma is desired.

15


Always use the shade tab to check your color

before you do your final glaze bake.

Glaze Firing Temperatures

Low Temp.

482ºC

900°F

Vac. Level

Full

High Temp.

860ºC

1580ºF

Pre-Dry Time

6 min.

Vac. Start

N/A

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

N/A

Cool Time

1 min.

The finished UniPack restoration

after firing.

16


Anterior Opaque Technique

Finish and sandblast the metal according to

the alloy manufacturer’s instructions.

Oxidize according to the

alloy manufacturer’s instructions.

Mix opaque powder with universal build-up

liquid. Opaque powder has light reflective properties

and opacity to mask metal substructure.

Apply a thin wash of

opaque for the first opaque firing.

17


1st Opaque Firing Parameters

Low Temp.

538ºC

1000°F

Vac. Level

Full

High Temp.

1070ºC

1958ºF

Pre-Dry Time

6 min.

Vac. Start

538ºC

1000ºF

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

1070ºC

1958ºF

Cool Time

3 min.

The wash coat opaque after

the first opaque firing.

Apply a second opaque layer utilizing the

desired opaque application technique.

18


2nd Opaque Firing Parameters

Low Temp.

538ºC

1000°F

Vac. Level

Full

High Temp.

1020ºC

1868ºF

Pre-Dry Time

6 min.

Vac. Start

538ºC

1000ºF

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

965ºC

1769ºF

Cool Time

3 min.

Prismatik UniPack Opaque should have a slight

eggshell sheen when properly sintered.

Alternate spray opaque technique

UniPack opaque powder is mixed with a spray opaque

liquid then placed into a sprayer. Spray opaque allows

for an even and consistent coat.

19


Anterior Build-up Technique

Proceed with normal application of the Preblended

Dentin & Incisal powder.

Completed dentin application overbuilt to

compensate for normal shrinkage after firing.

UniPack powders are pre-blended, therefore, no

incisal cutback is required unless more translucency

is desired. If more translucency is needed

you may cut back and add opal incisal powder.

Opal incisal powders were selected to match a

variety of Prismatik Ceramics.

Opal Incisal

CLEAR LIGHT WHITE

BLUE/

WHITE IVORY BLUE

20


1st Bake Firing Parameters

Low Temp.

380ºC

716°F

Vac. Level

Full

High Temp.

870ºC

1598ºF

Pre-Dry Time

6 min.

Vac. Start

570ºC

1058ºF

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

870ºC

1598ºF

Cool Time

1 min.

After firing, the UniPack should

exhibit a shade tab gloss.

Fit and adjust the restoration’s

anatomical contour.

21


Anterior Stain and Glaze Techniques

Stains are great tools for individualizing ceramic

teeth and adding character to a restoration.

Stains may be mixed to achieve ideal final shade.

Staining liquid is used to mix the powder into a

thin, brushable form. The mixture should be free

of bubbles. It is important for the mixture to be

the correct consistency. If too thin it will puddle

during application. If too thick it will be hard to

apply and will puddle as it melts.

Add blue stain to the incisal edge to give t

the appearance of translucency.

22


Add chroma stains A, B, C, D at the

gingival if increased chroma is desired.

Always use the shade tab to check your color

before you do your final glazing bake.

Fire according to stain

and glaze parameters.

Glaze Firing Parameters

Low Temp.

482ºC

900°F

Vac. Level

Full

High Temp.

860ºC

1580ºF

Pre-Dry Time

6 min.

Vac. Start

N/A

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

N/A

Cool Time

1 min.

23


The finished UniPack restoration

after firing.

Anterior Shoulder Butt Margin Technique

Prepare the coping to receive shoulder materials

as you normally would .

Apply separator to the areas that will

receive the Prismatik Margin material.

24


Apply the Prismatik Margin material

where indicated.

Lightly tap to bring excess

moisture to the surface.

Remove the excess

moisture with a tissue.

Lightly brush excess margin

powder from the first application.

25


The margin material should not be overbuilt. It

should blend into the opaqued coping for the

first firing.

Margin Firing Parameters

Low Temp.

482ºC

900°F

Vac. Level

Full

High Temp.

960ºC

1760ºF

Pre-Dry Time

4 min.

Vac. Start

538ºC

1000ºF

Hold Time

1 min.

Heat Rate

39ºC/min.

70ºF/min.

Vac. Release

959ºC

1758ºF

Cool Time

1 min.

After firing, areas to receive additional

margin material will be evident.

26


Apply a thin layer of porcelain separator prior to

the second application of margin material.

Add a second layer of margin

material to open areas. Do not over build.

Remove excess moisture with a tissue.

Brush away any loose particles.

Remove from the die and fire.

27


Margin Firing Parameters

Low Temp.

482ºC

900°F

Vac. Level

Full

High Temp.

960ºC

1760ºF

Pre-Dry Time

4 min.

Vac. Start

538ºC

1000ºF

Hold Time

1 min.

Heat Rate

39ºC/min.

70ºF/min.

Vac. Release

959ºC

1758ºF

Cool Time

1 min.

Check for open or insufficient margins.

Add and re-fire if necessary.

Opaceous Dentin Technique

In cases where insufficient tooth structure results in increased and unwanted

translucency, Prismatik Opaceous Dentin is used to build-out the dentin-form of

the restoration.

28


Opaceous Dentin Firing Parameters

Low Temp.

380ºC

716°F

Vac. Level

Full

High Temp.

870ºC

1598ºF

Pre-Dry Time

6 min.

Vac. Start

570ºC

1058ºF

Hold Time

0

Heat Rate

55ºC/min.

100ºF/min.

Vac. Release

870ºC

1598ºF

Cool Time

1 min.

Multiple-Unit Restorations

The Prismatik UniPack technique provides the technician the benefit of building

multiple-unit bridges or multiple single-unit restorations without having to spend

valuable production time cutting back and adding incisal powders.

29


Prismatik Ceramic Kits

Starter Kit

Trial Kit

5 - 50g UniPack Powders (A2, A3, B1, C2, D3)

5 - 50g Opaque Powders (A2, A3, B1, C2, D3)

1 - 60ml Stain & Glaze Liquid

1 - 60ml Build-Up & Opaque Liquid

1 - 10g Add-On Body Light

1 - 10g Add-On Incisal Light

5 - 4g Stain Powder (A, B, C, D and Blue)

1 - 4g Glaze Powder

1 - Technique Manual

1 - 50g UniPack Powder (A2)

1 - 50g Opaque Powder (A2)

1 - 60ml Stain & Glaze Liquid

1 - 60ml Build-Up & Opaque Liquid

1 - 10g Add-On Body Light

1 - 10g Add-On Incisal Light

1 - 4g Glaze Powder

1 - 4g Stain Powders (A, Blue)

1 - Technique Manual

Stain Kit

11 - 4g Stain Powders (Blue, White, Créme,

Violet, Pink, Dark Brown, Yellow/Orange,

Stain A, Stain B, Stain C, Stain D)

Opaceous Dentin Kit

15 - 10g Opaceous Dentin Powders (A1,

A2, A3, A3.5, B1, B2, B3, C1, C2, C3,

D2, D3, D4, Modifier White, Bleach)

Opal Incisal Kit

6 - 10g Opal Incisal Powders (Clear, Light,

White, Blue White, Ivory, Blue)

Margin Kit

5 - 10g Margin Powders (A1, A3, C1, C3,

White)

30


Troubleshooting Guide

PROBLEM KNOWN CAUSES SOLUTIONS

Opaque is separating off Under-fired opaque The opaque should have

the metal substructure

an eggshell sheen after

firing. Increase the temperature

until this is

achieved. Verify the accuracy

of the oven and

calibrate as necessary.

Opaque is bubbling Insufficient dry time Use at least 6 min.

for powder opaque and

at least 6-8 min. for

paste opaque.

Heat rate is too high

Heat rate should be

55°C/min. (100°F/min.)

If this does not work,

continue to lower the

rate as necessary.

Opaque is pooling at Incompatible opaque The high temperature of

the margin area of the

the porcelain is likely to

coping/framework

be too high and the

opaque is “running.”

Double check the firing

schedule and what

opaque was used. Verify

the accuracy of the

oven and calibrate as

necessary.

During build-up, Too much moisture Dry the porcelain more

porcelain tends to

before applying it. If

“slump” or “lose

using water, try build-up

its shape”

liquid instead.

31


PROBLEM KNOWN CAUSES SOLUTIONS

Bubbles in porcelain Metal finishing was not Follow the manufacturer

done correctly. There is recommendations for

likely to be trapped air in properly preparing the

the metal surface

frameworks.

Trapped air during

build-up

If the bubbles do not

show metal, this means

air was trapped during

build-up. Build-up was

done too quickly or in

too large of chunks.

Green/Gray Framework alloys with Check the manufacturer

Discoloration of too high a content of specs on the alloy you

Porcelain silver and/or copper can are using. There should

lead to discoloration not be higher than a

5% content of silver or

copper.

After firing, the Over-fired porcelain Verify that our recomporcelain

is losing its

mended firing temperashape/is

slumping/has

tures were used for the

an overly shiny

first bake. Decrease the

appearance

high temperature as necessary

until the proper

appearance is achieved.

If necessary, decrease

hold time. Verify the

accuracy of the oven and

calibrate as necessary.

“Tearing of porcelain” Dry time is too short Dry time should be 6

min. as a minimum

32


PROBLEM KNOWN CAUSES SOLUTIONS

Milky Appearance Too much moisture Dry the porcelain

during build-up

mixture more before

adding to the build-up.

Follow the proper set-

tings on our firing chart.

Try releasing the vacuum

1°C below the high

temperature.

Vacuum was released too

early OR applied too

soon

Re-wetting dried porcelain

with more build-up liquid

Only distilled water

should be used for rewetting

dried porcelain.

An underglazed or dull/ First bake was under-fired Verify that our recomrough

surface is present

mended firing temperaafter

the glazing cycle

tures were used for the

first bake. Increase the

high temperature as necessary

until the proper

appearance is achieved.

If necessary, increase

hold time. Verify the

accuracy of the oven and

calibrate as necessary.

Separation of add-on Insufficient dry time Dry time should be 6

porcelains from

min. as a minimum.

underlying porcelain

33


PROBLEM KNOWN CAUSES SOLUTIONS

Cracks/Fractures in Sharp edges in coping In framework design,

Porcelain

never have sharp

edges/corners.

Double check the appro-

priate data on the CTE

of the alloy you are

using for your substructures.

Try to use alloys

that are at the most 1.0

higher than the listed

CTE value for Prismatik

UniPack.

Insufficient metal support

CTE incompatibility

between porcelain

and alloy

Have at least 1mm. of

space beyond opaqued

alloy in all areas. Try not

to go beyond 3 mm. of

porcelain in any areas.

34

01-1507-0106

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