Metal free ceramics /lingual orthodontics courses

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METAL FREE CERAMICSMETAL FREE CERAMICS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

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Introduction :
Ceramics in dentistry is a recent phenomenon, theCeramics in dentistry is a recent phenomenon, the
desire for a durable and esthetic material isdesire for a durable and esthetic material is
ancient. Although metals have manyancient. Although metals have many
characteristics that make them useful in dentistrycharacteristics that make them useful in dentistry
they do not look like natural teeth. In contrast athey do not look like natural teeth. In contrast a
superb esthetic and biocompatible result can besuperb esthetic and biocompatible result can be
achieved with ALL CERAMICS’s.achieved with ALL CERAMICS’s.
Ceramic is the most natural appearing prostheticCeramic is the most natural appearing prosthetic
restorative material for missing tooth substance.restorative material for missing tooth substance.

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Dental porcelain play an important role in theDental porcelain play an important role in the
fabrication of the most esthetic fixed partialfabrication of the most esthetic fixed partial
dentures. Translucency, light transmission,dentures. Translucency, light transmission,
and biocompatibility give dental ceramicsand biocompatibility give dental ceramics
highly desirable esthetic properties.highly desirable esthetic properties.
However, the brittle nature of dentalHowever, the brittle nature of dental
porcelains, which are basicallyporcelains, which are basically
noncrystalline glasses composed ofnoncrystalline glasses composed of
structural units of silicon and oxygen (SiOstructural units of silicon and oxygen (SiO44
tetrahedra) limit the use of this material.tetrahedra) limit the use of this material.

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Selection :
 The primary advantage of using metal freeThe primary advantage of using metal free
ceramic system is to increase the depth ofceramic system is to increase the depth of
translucency and light transmission in thetranslucency and light transmission in the
crown either deep into the crown or acrosscrown either deep into the crown or across
the entire crown.the entire crown.
 Esthetic results vary from system to system,Esthetic results vary from system to system,
and in a laboratory setting several factorsand in a laboratory setting several factors
influence the choice one crown system overinfluence the choice one crown system over
another….another…. www.indiandentalacademy.com

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Factors influence the selection of
crown system :
 Strength.Strength.
 Simplicity of fabrication.Simplicity of fabrication.
 Potential for high volume production.Potential for high volume production.
 Marginal and internal fit.Marginal and internal fit.
 Cost-benefit analysis.Cost-benefit analysis.
 Personal experience.Personal experience.
 Esthetic performance.Esthetic performance.

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Indications :
The fracture resistance of all-ceramic crown isThe fracture resistance of all-ceramic crown is
based on adequate support by thebased on adequate support by the
preparation, proper patient selection,preparation, proper patient selection,
strength of crown material and type ofstrength of crown material and type of
luting cement.luting cement.
Indications include….Indications include….
♣ All anterior teeth where esthetics is ofAll anterior teeth where esthetics is of
prime factor.prime factor.

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♣ Conservation of tooth structure andConservation of tooth structure and
maintenance of periodontal health.maintenance of periodontal health.
♣ Lower incisors where space is available.Lower incisors where space is available.
♣ Limited use on the premolar teeth where theLimited use on the premolar teeth where the
occlusion allows some protection of theocclusion allows some protection of the
buccal shearing cusps.buccal shearing cusps.

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Contra-indications:
 In the cases of parafunctional activity of theIn the cases of parafunctional activity of the
mandible,e.g. bruxism. Or any deflectivemandible,e.g. bruxism. Or any deflective
malocclusions remain uncorrected.malocclusions remain uncorrected.
 Where occlusal clearance after after toothWhere occlusal clearance after after tooth
preparation is less than 0.8 mm, e.g. very thinpreparation is less than 0.8 mm, e.g. very thin
teeth, deep incisal over jets with lingual wearteeth, deep incisal over jets with lingual wear
facets.facets.
 Insufficient tooth support or where the preparationInsufficient tooth support or where the preparation
design causes sudden changes of thickness in thedesign causes sudden changes of thickness in the
porcelain.porcelain.
 Molar teeth.Molar teeth. www.indiandentalacademy.com

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Aluminous Porcelain
Vs
Metal Ceramics

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Aluminous porcelain :
Advantages :Advantages :
1.1. Good esthetics is easily obtained if theGood esthetics is easily obtained if the
core porcelain is placed correctly.core porcelain is placed correctly.
2.2. Full lingual core porcelains protect theFull lingual core porcelains protect the
crown against opposing incisors.crown against opposing incisors.
3.3. The resistance to pyroplastic flow orThe resistance to pyroplastic flow or
slump of the core porcelain can produceslump of the core porcelain can produce
better fits than regular porcelains.better fits than regular porcelains.
4.4. Greater depth of translucency obtained.Greater depth of translucency obtained.www.indiandentalacademy.com

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Aluminous Porcelain :
Disadvantages :Disadvantages :
1.1. Cannot be used in posterior regions.Cannot be used in posterior regions.
2.2. Parafunctional movements.Parafunctional movements.
3.3. Long span bridges.Long span bridges.
4.4. Tooth preparation is even more.Tooth preparation is even more.

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Metal Ceramics :
Advantages :Advantages :
1.1. Very high strength due to prevention ofVery high strength due to prevention of
crack propagation.crack propagation.
2.2. Improved fit.Improved fit.
3.3. Long span bridges.Long span bridges.
4.4. Availability.Availability.
5.5. Economical.Economical.

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Disadvantages :Disadvantages :
 Increased opacity and light reflectivity.Increased opacity and light reflectivity.
 Risk of over contouring – metal .5 mm and theRisk of over contouring – metal .5 mm and the
rest is ceramic material.rest is ceramic material.
 Metal margin exposure.Metal margin exposure.
 The fit of long span bridges may be affected byThe fit of long span bridges may be affected by
the creep of the metal during successive bakes ofthe creep of the metal during successive bakes of
porcelain.porcelain.
 Difficult to obtain good esthetics.Difficult to obtain good esthetics.
 Porcelains used in the metal-ceramic techniquePorcelains used in the metal-ceramic technique
are more liable to devitrify which can produceare more liable to devitrify which can produce
cloudiness.cloudiness. www.indiandentalacademy.com

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Constituents of Dental
Porcelain :
Silicon dioxide – SiO2 – Glass forming matrix,Silicon dioxide – SiO2 – Glass forming matrix,
glass formers.glass formers.
Boric oxide –B2O3 – (Glass modifiers /Flux)Boric oxide –B2O3 – (Glass modifiers /Flux)
Lowers the softening point, lower viscosity,Lowers the softening point, lower viscosity,
higher expansion.higher expansion.
Oxides of potassium, Sodium, calcium, lithium,Oxides of potassium, Sodium, calcium, lithium,
magnesium (Glass modifiers).magnesium (Glass modifiers).
Aluminum oxide – Al2O3 – (intermediate oxides)Aluminum oxide – Al2O3 – (intermediate oxides)
reduces viscosity, lowers firing temperature.reduces viscosity, lowers firing temperature.
Phosphorus pentoxide – P2O5 – opalescence,Phosphorus pentoxide – P2O5 – opalescence,
glass forming oxide.glass forming oxide.www.indiandentalacademy.com

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Properties of Dental Porcelain :
 Low fusing temperature.Low fusing temperature.
 High viscosity.High viscosity.
 Resistance to devitrification.Resistance to devitrification.
 Translucent.Translucent.

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Strength of All Ceramic Crowns :
The objective of fabricating all ceramic crown is toThe objective of fabricating all ceramic crown is to
provide the patient with lasting esthetic restorations.provide the patient with lasting esthetic restorations.
New materials are been advocated as replacementNew materials are been advocated as replacement
for metal ceramic restoration.for metal ceramic restoration.
The strength of ceramic is greatly influenced by theThe strength of ceramic is greatly influenced by the
presence of surface flaws acting as stress initiatorspresence of surface flaws acting as stress initiators
and causing widening and propagation ofand causing widening and propagation of
microcracks through the material from the surface.microcracks through the material from the surface.
Therefore dental porcelain is much weaker inTherefore dental porcelain is much weaker in
tension than in compression and is prone to brittletension than in compression and is prone to brittle
fracture.fracture.

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Dental porcelain is also susceptible to “staticDental porcelain is also susceptible to “static
Fatigue”which is generally caused by aFatigue”which is generally caused by a
stress dependent chemical reaction betweenstress dependent chemical reaction between
water vapor and the surface flaws in thewater vapor and the surface flaws in the
restoration. This causes flaws to grow torestoration. This causes flaws to grow to
critical dimensions, allowing spontaneouscritical dimensions, allowing spontaneous
crack propagation, resulting in a fracturecrack propagation, resulting in a fracture
with comparatively little occlusal loading,with comparatively little occlusal loading,
particularly over long periods.particularly over long periods.

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Surface Flaws :
A high strength ceramic with a badly flawed surfaceA high strength ceramic with a badly flawed surface
may perform worse in a clinical situation than amay perform worse in a clinical situation than a
weaker ceramic with comparatively flaw-freeweaker ceramic with comparatively flaw-free
surface.surface.
The fracture pattern of cast glass ceramic, aluminousThe fracture pattern of cast glass ceramic, aluminous
porcelains is always initiated at the surfaces andporcelains is always initiated at the surfaces and
usually at the locations involving porosities.usually at the locations involving porosities.
Kelley et al classified porcelain defects intoKelley et al classified porcelain defects into
Processing defects – Machining scratches, porosities,Processing defects – Machining scratches, porosities,
and impurity inclusions.and impurity inclusions.
Inherent material defects – large grains, residualInherent material defects – large grains, residual
stresses and microcracks.stresses and microcracks.www.indiandentalacademy.com

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Core Thickness :
The rigidity and thickness of the ceramic core playThe rigidity and thickness of the ceramic core play
an essential role in the flexural strength of thean essential role in the flexural strength of the
whole restoration.sections less than 1mm shouldwhole restoration.sections less than 1mm should
be avoided, and ideally dentist should aim forbe avoided, and ideally dentist should aim for
cross sections of 1.5 mm.cross sections of 1.5 mm.
The ideal aluminous porcelain coping for incisorsThe ideal aluminous porcelain coping for incisors
should exhibit: * a lingual surface atleast 1 mmshould exhibit: * a lingual surface atleast 1 mm
thick: *a lingual collar extended proximally,thick: *a lingual collar extended proximally,
similar to a metal coping: *the incisal labial areasimilar to a metal coping: *the incisal labial area
thinned to 0.3 mm for esthetics.thinned to 0.3 mm for esthetics.

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Strengthening Mechanisms :
Crack-tip interactions :Crack-tip interactions :
Dispersion strengthening with Alumina,Dispersion strengthening with Alumina,
Leucite, Zirconia and MagnesiumLeucite, Zirconia and Magnesium
aluminum oxide spinell crystals. Obstaclesaluminum oxide spinell crystals. Obstacles
in the microstructure impede crackin the microstructure impede crack
propagation by reorienting and deflectingpropagation by reorienting and deflecting
the plane of fracture.the plane of fracture.

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Crack-tip Shielding :Crack-tip Shielding :
Events triggered by the high stresses in the crack tipEvents triggered by the high stresses in the crack tip
region act to reduce the stresses.region act to reduce the stresses.
Dispersion strengthening by Glass Infusion of slipDispersion strengthening by Glass Infusion of slip
cast alumina ceramics, (Micro-crack toughening).cast alumina ceramics, (Micro-crack toughening).
Dispersion strengthening of PSZ ceramics,Dispersion strengthening of PSZ ceramics,
(Transformation toughening).(Transformation toughening).

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Crack Bridging :
The second phase crystalline structure acts asThe second phase crystalline structure acts as
a “bandage”to prevent crack from openinga “bandage”to prevent crack from opening
further.Crystallization of Glasses byfurther.Crystallization of Glasses by
Ceramming.Ceramming.

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Crystalline dispersion
Strengthening :
StrengtheningStrengthening
methodmethod Clinical systemClinical system CharacteristicsCharacteristics
Fused AluminaFused Alumina
sintered into asintered into a
matched expansionmatched expansion
glass.glass.
Hi – CeramHi – Ceram
(Vident)(Vident)
Alumina reinforcedAlumina reinforced
ceramicsceramics
Leucite crystalsLeucite crystals
dispersed throughdispersed through
the body of thethe body of the
crowncrown
Optec(Jeneric/PentOptec(Jeneric/Pent
ron)ron)
IPS EmpressIPS Empress
(ivoclar)(ivoclar)
Leucite reinforcedLeucite reinforced
Heat pressedHeat pressed
leucite-reinforcedleucite-reinforced
CrystallizedCrystallized
magnesiunmagnesiun
aluminum oxedealuminum oxede
spinellspinell
Al-Ceram (InnotekAl-Ceram (Innotek
Dental Corp.)Dental Corp.)
formerly Cerestore.formerly Cerestore.
Shrik-freeShrik-free
aluminaalumina
ceramic.ceramic.

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Glass infiltration strengthening :
ReinforcingReinforcing
crystalscrystals
Clinical SystemClinical System CharestresticsCharestrestics
AluminaAlumina In-CeramIn-Ceram
Alumina (Vita)Alumina (Vita)
High aluminaHigh alumina
coping infused withcoping infused with
a low fusing glassa low fusing glass
ZirconiaZirconia In-CeramIn-Ceram
Zirconia (Vita)Zirconia (Vita)
High ZirconiaHigh Zirconia
a low fusing glassa low fusing glass
MagnesiumMagnesium
oxide spinelloxide spinell
In-CeramIn-Ceram
Spinell (Vita)Spinell (Vita)
High SpinellHigh Spinell
a low fusing glassa low fusing glasswww.indiandentalacademy.com

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Crystallization of Glasses :
StrengtheningStrengthening
methodmethod
Clinical systemClinical system CharacteristicsCharacteristics
Conversion byConversion by
“Ceramming”“Ceramming”
DicorDicor
(Dentsply)(Dentsply)
Castable glassCastable glass
ceramic withceramic with
tetrasilic fluormicatetrasilic fluormica
crystalscrystals
Conversion byConversion by
“Crystallization”“Crystallization”
CerapearlCerapearl
(Kyocera(Kyocera
america Inc.)america Inc.)
Castable apatiteCastable apatite
ceramicceramic

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Classification of Dental Porcelain
A lu m in a M ag n esiu n sp in ell
Z ircon iu m L eu cite
Z irconia W h iskers H ig h A lu m in a
R ein forcin g M aterial
P ow d er slu rry C astab le
P ressab le In filtrated
M achin ab le
G en aral S ystem
H ihg F usin g M ed iu m F u sin g
L ow F u sin g
F irin g Tem p eratu re
A L L -C E R A M IC S
Summarywww.indiandentalacademy.com

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Firing Temperature :
High Fusing : 1290`C – 1370`CHigh Fusing : 1290`C – 1370`C
These are used for the manufacture ofThese are used for the manufacture of
porcelain teeth.porcelain teeth.
Composed of Feldspar=70%-90%, Quart=Composed of Feldspar=70%-90%, Quart=
11%-18%, Kaolin= 1%-10%.11%-18%, Kaolin= 1%-10%.

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Low / Medium Fusing Porcelains
Low and medium fusing porcelains areLow and medium fusing porcelains are
manufactured by a process called Fritting.manufactured by a process called Fritting.

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General ClassificationGeneral Classification
1.Conventional powder ceramics
2.Castable ceramics
3.Pressable ceramics
4.Infiltrated ceramics
5.Machinable ceramics

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Castable Ceramics :
These products are supplied as solid ceramic ingots,These products are supplied as solid ceramic ingots,
which are used for fabrication of cores or fullwhich are used for fabrication of cores or full
contour restorations using a lost wax andcontour restorations using a lost wax and
centrifugal casting technique. Generally, onecentrifugal casting technique. Generally, one
shade of material is available. Which is coveredshade of material is available. Which is covered
by conventional feldspathic porcelain or is stainedby conventional feldspathic porcelain or is stained
to obtain proper shading and characterization ofto obtain proper shading and characterization of
the final restoration.the final restoration.
e.g. DICOR (Corning glass, Dentsply).e.g. DICOR (Corning glass, Dentsply).
CERAPEARL (Bioceram, Kyocera)CERAPEARL (Bioceram, Kyocera)

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Powder Slurry Ceramics :
These products are supplied as powders to which theThese products are supplied as powders to which the
technician adds distilled water to produce a slurry,technician adds distilled water to produce a slurry,
which is build up in layers on a die material towhich is build up in layers on a die material to
form the contours of the restoration. The powdersform the contours of the restoration. The powders
are available in different shades andare available in different shades and
translucencies, and are supplied withtranslucencies, and are supplied with
characterizing stains and glazes.characterizing stains and glazes.
e.g. OPTEC H.S.P (Jeneric/Pentron)e.g. OPTEC H.S.P (Jeneric/Pentron)
DUCERAM L.F.C (Ducera Inc)DUCERAM L.F.C (Ducera Inc)
Vita Hi-Ceram (Vita Zahnfabrik)Vita Hi-Ceram (Vita Zahnfabrik)www.indiandentalacademy.com

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Pressable Ceramics :
These are also supplied as ingots, these product areThese are also supplied as ingots, these product are
melted at higher temperatures and pressed into amelted at higher temperatures and pressed into a
mould using a lost wax technique. These pressedmould using a lost wax technique. These pressed
form can be made into full contour, or can be usedform can be made into full contour, or can be used
as a substrate for conventional feldspathicas a substrate for conventional feldspathic
porcelain buildup, or can be built up by layeringporcelain buildup, or can be built up by layering
technique.technique.
e.g. IPS Empress I, II (Ivoclar vivadent)e.g. IPS Empress I, II (Ivoclar vivadent)
OPC (Optec Pressable Ceramic)OPC (Optec Pressable Ceramic)
ALCERAM (Cerestore, Innotek dental corp)ALCERAM (Cerestore, Innotek dental corp)

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Infiltrated Ceramics :
These are glass infiltrated core ceramics. ThisThese are glass infiltrated core ceramics. This
involves slipcasting technique for makinginvolves slipcasting technique for making
the core, and the contours of the restorationthe core, and the contours of the restoration
are obtained by individual layering andare obtained by individual layering and
staining techniques.staining techniques.
e.g. In-CERAM (Vita Zahnfabrik)e.g. In-CERAM (Vita Zahnfabrik)
AluminaAlumina
ZirconiaZirconia
SpinellSpinell

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Machinable Ceramics
These products are supplied as ingots in variousThese products are supplied as ingots in various
shades and are milled into desired form. Theseshades and are milled into desired form. These
machined restorations can be stained and glazed tomachined restorations can be stained and glazed to
obtain desired characterization. They are of twoobtain desired characterization. They are of two
types :types :
CAD-CAM =CAD-CAM = Computer Aided Designing – ComputerComputer Aided Designing – Computer
Aided MillingAided Milling. e.g. CEREC (Sirona). e.g. CEREC (Sirona)
Ivoclar ProCAD (Ivoclar, Spring)Ivoclar ProCAD (Ivoclar, Spring)
Dicor M.G.C (Dentsply)Dicor M.G.C (Dentsply)
Copy Milling = CELAY (Mikrona Technologies)Copy Milling = CELAY (Mikrona Technologies)www.indiandentalacademy.com

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Preparations for All-Ceramic Crowns :
The role of the tooth preparation for aThe role of the tooth preparation for a
porcelain jacket crown is to provide supportporcelain jacket crown is to provide support
for the prosthesis with uniform porcelainfor the prosthesis with uniform porcelain
thickness. It was recognized that the mostthickness. It was recognized that the most
frequent cause of JC failure was improperfrequent cause of JC failure was improper
tooth preparation.tooth preparation.

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The Design :
The design of an ideal all-ceramic crown preparation is toThe design of an ideal all-ceramic crown preparation is to
provide maximum strength of the crown by establishing flatprovide maximum strength of the crown by establishing flat
planes at right angles to the forces of mastication andplanes at right angles to the forces of mastication and
avoiding sharp line angles. A shoulder margin is alsoavoiding sharp line angles. A shoulder margin is also
required because it offers superior strength as compared torequired because it offers superior strength as compared to
chamfer.chamfer. www.indiandentalacademy.com

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Length of the preparation :
When a load is applied from a lingual direction, the labialWhen a load is applied from a lingual direction, the labial
shoulder is placed under compression and only the lengthshoulder is placed under compression and only the length
of the preparation at the incisal lingual aspect providesof the preparation at the incisal lingual aspect provides
significant resistance to this force.short preparations causesignificant resistance to this force.short preparations cause
considerable stresses and may lead to fracture.considerable stresses and may lead to fracture.www.indiandentalacademy.com

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Length of the preparation :
The ideal incisal reduction 2 mm and must not exceed moreThe ideal incisal reduction 2 mm and must not exceed more
than 1/3than 1/3rdrd
of the anatomical crown . If the incisal reductionof the anatomical crown . If the incisal reduction
is too thin, it should be thickened and placed at a rightis too thin, it should be thickened and placed at a right
angle to the direction of stress by reducing the preparationangle to the direction of stress by reducing the preparation
to a length of 2/3to a length of 2/3rdrd
of the anatomical crown.of the anatomical crown.www.indiandentalacademy.com

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Shoulder :
A well defined shoulder with adequate width improves theA well defined shoulder with adequate width improves the
fracture resistance of the crown because it providesfracture resistance of the crown because it provides
additional bulk at the margins that is placed at right anglesadditional bulk at the margins that is placed at right angles
to the direction of stressesto the direction of stresses
The more the intimate the contact between the preparationThe more the intimate the contact between the preparation
and the ceramic crown higher the resistance to fracture onand the ceramic crown higher the resistance to fracture on
occlusal loading.occlusal loading.www.indiandentalacademy.com

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Shoulder / Chamfer :
When the shoulder angle of the preparation to theWhen the shoulder angle of the preparation to the
longitudinal axis of the tooth is greater than 90`,longitudinal axis of the tooth is greater than 90`,
the risk if porcelain fracture increases.the risk if porcelain fracture increases.
The internal shoulder angle should be rounded toThe internal shoulder angle should be rounded to
reduce the stress concentration factor up to 50%reduce the stress concentration factor up to 50%
and because sharp internal line angles cannot beand because sharp internal line angles cannot be
easily reproduced with porcelain. Similarly , theeasily reproduced with porcelain. Similarly , the
internal rounded shoulder is recommended for theinternal rounded shoulder is recommended for the
In-Ceram* crown to facilitate the adaptation of theIn-Ceram* crown to facilitate the adaptation of the
aluminous oxide slip on the die.aluminous oxide slip on the die.

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Shoulder / Chamfer :
A chamfer is conservative and simpler toA chamfer is conservative and simpler to
execute and has been described as an optionexecute and has been described as an option
for cast glass ceramic restorations.for cast glass ceramic restorations.

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Shoulder width :
A shoulder of uniform thickness may roundA shoulder of uniform thickness may round
the preparation excessively and compromisethe preparation excessively and compromise
resistance form. For a maxillary centralresistance form. For a maxillary central
incisor, the lingual and facial shoulderincisor, the lingual and facial shoulder
width should be I mm with a minimum ofwidth should be I mm with a minimum of
0.8 mm, and the interproximal width should0.8 mm, and the interproximal width should
be 0.5 mm because the proximal walls ofbe 0.5 mm because the proximal walls of
the crown flare out and provide sufficientthe crown flare out and provide sufficient
strength in the proximal areastrength in the proximal area

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Shoulder width :
These specifications for a shoulder of non uniformThese specifications for a shoulder of non uniform
width provide for conservatism, support, andwidth provide for conservatism, support, and
resistance of the preparation to stresses.resistance of the preparation to stresses.

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Shoulder curvature (interproximally) :
The finish lines should follow a smooth curvatureThe finish lines should follow a smooth curvature
that it is not too steep inter-proximally to avoid athat it is not too steep inter-proximally to avoid a
potential v shaped notch that could split the labialpotential v shaped notch that could split the labial
off the lingual aspect of the crown.off the lingual aspect of the crown.www.indiandentalacademy.com

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Facial & Lingual reduction :
The minimal acceptable facial thickness of porcelainThe minimal acceptable facial thickness of porcelain
from an esthetic standpoint is 1.0mm, and thefrom an esthetic standpoint is 1.0mm, and the
ideal depth of reduction on the midfacial aspect ofideal depth of reduction on the midfacial aspect of
a typical maxillary central incisor for ana typical maxillary central incisor for an
aluminous porcelain jacket crown should be 1.3aluminous porcelain jacket crown should be 1.3
mm. Facial depths of reduction up to 1.5mm havemm. Facial depths of reduction up to 1.5mm have
also been recommended for molded, castable, andalso been recommended for molded, castable, and
slip-cast ceramics. Lingual thickness values of 1.5slip-cast ceramics. Lingual thickness values of 1.5
mm are ideal but are difficult to achieve routinely.mm are ideal but are difficult to achieve routinely.

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Facial & Lingual reduction :
Practically lingual thickness should be in thePractically lingual thickness should be in the
1 – 1.3 mm range, and the absolute1 – 1.3 mm range, and the absolute
minimum should be 0.8 mm. The lingualminimum should be 0.8 mm. The lingual
aspect of the preparation should be shapedaspect of the preparation should be shaped
to avoid uneven sections of the crowns andto avoid uneven sections of the crowns and
sharp line angles must be avoided.sharp line angles must be avoided.

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Taper :Minimal taper is recommended for maximum surfaceMinimal taper is recommended for maximum surface
area and support of the preparation. Excessivearea and support of the preparation. Excessive
taper of the preparation correlates with a reductiontaper of the preparation correlates with a reduction
in breaking strength and increase in stressin breaking strength and increase in stress
concentration in the area where support is lacking.concentration in the area where support is lacking.
A 5`taper is ideal and would ensure maximumA 5`taper is ideal and would ensure maximum
resistance form with only one path of insertion ofresistance form with only one path of insertion of
the crown but it is also difficult to achieve withoutthe crown but it is also difficult to achieve without
producing undercuts.producing undercuts.
The safest and most practical convergence angle ofThe safest and most practical convergence angle of
all-ceramic preparations is 10`taper, whichall-ceramic preparations is 10`taper, which
represents an acceptable compromise betweenrepresents an acceptable compromise between
taper and strength.taper and strength.

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Taper :
Excessive porcelain bulk has an adverse effect onExcessive porcelain bulk has an adverse effect on
strength. It is not the bulk that gives the strength tostrength. It is not the bulk that gives the strength to
the crown, it is the resistance to flexure providedthe crown, it is the resistance to flexure provided
by the support from the preparation and theby the support from the preparation and the
accuracy of the fit.accuracy of the fit.www.indiandentalacademy.com

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CASTABLE CERAMICS
DICOR*DICOR*
CERAPEARL*CERAPEARL*
Summary

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DICOR
The castable glass ceramic system
 HistoryHistory
MaterialMaterial
Advantages & DisadvantagesAdvantages & Disadvantages
Indications & ContraindicationsIndications & Contraindications
Clinical proceduresClinical procedures
Laboratory proceduresLaboratory procedures

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History :
 The DICOR castable glass ceramic is one of theThe DICOR castable glass ceramic is one of the
pyoceram ceramics manufactured by Corningpyoceram ceramics manufactured by Corning
glass ware.glass ware.
 Founded in the year 1978, after 6 years ofFounded in the year 1978, after 6 years of
intensive research this ceramic system wasintensive research this ceramic system was
introduced to dentistry.introduced to dentistry.
 The present system represents the cumulativeThe present system represents the cumulative
efforts of Peter.J.Adair of BIOCOR Inc., Davidefforts of Peter.J.Adair of BIOCOR Inc., David
Grossman Ph.D of the Corning Glass ware &Grossman Ph.D of the Corning Glass ware &
Dentsply International.Dentsply International.

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Composition

Consists of three crystalline forms,Consists of three crystalline forms,
SiOSiO22, = 45% -70% (w/w), = 45% -70% (w/w)
KK22O, = 20% (w/w)O, = 20% (w/w)
MgO, = 3% - 13% (w/w)MgO, = 3% - 13% (w/w)
MgFMgF22 == 4% - 9%4% - 9% (w/w)(Fluoride as a nucleating(w/w)(Fluoride as a nucleating
agent forming nucleation sites to aid the crystal growthagent forming nucleation sites to aid the crystal growth
during the process of ceramming, ;eading to a growth ofduring the process of ceramming, ;eading to a growth of
approx 1 micron small tetrasilicic crystals).approx 1 micron small tetrasilicic crystals).
Small amounts of AlOSmall amounts of AlO33, ZrO, ZrO22,BaO,BaO
Fluorescing agents.Fluorescing agents.

53
Material :

Technically described as Tetrasilicic fluoromicaTechnically described as Tetrasilicic fluoromica
glass ceramic.glass ceramic.

Tetrasilicic fluoromica crystalsTetrasilicic fluoromica crystals 55% vol55% vol
GlassGlass 45% vol45% vol

These miniscule crystals lie interlaced within theThese miniscule crystals lie interlaced within the
glass phase in the direction of the casting. On theglass phase in the direction of the casting. On the
surface of the cerammed glass are Enstatitesurface of the cerammed glass are Enstatite
crystals of thickness microns. These occur throughcrystals of thickness microns. These occur through
fluorine depletion which occurs through thefluorine depletion which occurs through the
interaction with the embedment material neededinteraction with the embedment material needed
for the ceramming process. These crystals are infor the ceramming process. These crystals are in
orthogonal in direction to the surface and areorthogonal in direction to the surface and are
whitish and opaque.whitish and opaque.www.indiandentalacademy.com

54
Advantages :

Strength -Strength -
 Feldspathic porcelains and some all porcelains, areFeldspathic porcelains and some all porcelains, are
glasses, and they are subject to the inherentglasses, and they are subject to the inherent
frailties of glass (super cooled liquids).frailties of glass (super cooled liquids).
 The tetrasilicic mica crystals(KThe tetrasilicic mica crystals(K22MgMg55SiSi88OO2020FF44) are) are
similar to mica.similar to mica.
 These crystals stop the propagation Griffith flaws.These crystals stop the propagation Griffith flaws.

55
Marginal adaptation :
 Dicor casting are statistically more consistent inDicor casting are statistically more consistent in
terms of “fit”than were the gold crowns.terms of “fit”than were the gold crowns.
 The thermal expansion of coefficient of cast glassThe thermal expansion of coefficient of cast glass
ceramic is close to that of natural enamel. Thisceramic is close to that of natural enamel. This
means expansion and contraction during normalmeans expansion and contraction during normal
temperature fluctuations, thus maintaining a goodtemperature fluctuations, thus maintaining a good
marginal seal.marginal seal.

56
Biocompatibility :
 Lesser plaque accumulation.Lesser plaque accumulation.
 good marginal fit.good marginal fit.
 Fluoride content inhibits bacterialFluoride content inhibits bacterial
colonization.colonization.
 The surface of the restoration is smooth andThe surface of the restoration is smooth and
non porous.non porous.

57
Wear Potential :
 This system has a microhardness closely matchedThis system has a microhardness closely matched
to enamel, while the microhardness of feldspathicto enamel, while the microhardness of feldspathic
porcelains is one third greater.porcelains is one third greater.
 Cast Ceramic (KHN) = 362.Cast Ceramic (KHN) = 362.
 EnamelEnamel (KHN) = 343.(KHN) = 343.
contd….

58
Wear potential…..
 The surface can be polished to a veryThe surface can be polished to a very
smooth non porous finish smoother thansmooth non porous finish smoother than
glazed feldspathic porcelain.glazed feldspathic porcelain.
 Lingual contours that represent aLingual contours that represent a
physiologic anterior guidance are also aphysiologic anterior guidance are also a
crucial factor in minimizing wear.crucial factor in minimizing wear.

59
Thermal conductivity :
 Low thermal conductivity that insulates theLow thermal conductivity that insulates the
underlying tooth from temperature changes.underlying tooth from temperature changes.
SimplicitySimplicity

60
Esthetics : There is a close match in translucency between theThere is a close match in translucency between the
cast ceramic material and enamel.cast ceramic material and enamel.
 The numerous, small mica crystals that constituteThe numerous, small mica crystals that constitute
the structure of the castable ceramic are looselythe structure of the castable ceramic are loosely
matched in the index of refraction to thematched in the index of refraction to the
surrounding glass phase that bonds the material.surrounding glass phase that bonds the material.
Thus the intensity of light scattering at each glassThus the intensity of light scattering at each glass
crystal interface is less, that is more suitable.crystal interface is less, that is more suitable.
Increase in crystalinity ensures more scattering.Increase in crystalinity ensures more scattering.
 Veneering porcelains also can be used to modifyVeneering porcelains also can be used to modify
translucency and better color depth.translucency and better color depth.
 This material is capable of producing chameleonThis material is capable of producing chameleon
effect, where part of the color of the restoration iseffect, where part of the color of the restoration is
picked up from the adjacent teeth as well as thepicked up from the adjacent teeth as well as thewww.indiandentalacademy.com

61
Disadvantages :
 Special equipment and cost.Special equipment and cost.
 Moderate strength.Moderate strength.
 No fixed partial denture application.No fixed partial denture application.
 High failure rate in posterior regions of theHigh failure rate in posterior regions of the
mouth, as well as recent developments ofmouth, as well as recent developments of
other materials, led to the phasing of thisother materials, led to the phasing of this
product.product.

62
Indications :
 Anterior PJC.Anterior PJC.
 Inlays, onlays, three quarter crowns.Inlays, onlays, three quarter crowns.
 Partial veneers, especially in periodontallyPartial veneers, especially in periodontally
compromised teethcompromised teeth

63
Contraindications :
 Clinical crown length is short.Clinical crown length is short.
 FPD.FPD.

64
Clinical Procedure :
 The tooth structure is sufficiently removedThe tooth structure is sufficiently removed
to allow an adequate thickness of theto allow an adequate thickness of the
material for strength and color saturation.material for strength and color saturation.
 For castable ceramics, the tooth reductionFor castable ceramics, the tooth reduction
on all surfaces must be no less than 1.2mm.on all surfaces must be no less than 1.2mm.
 Heavy chamfer (135`)`or shoulder margin.Heavy chamfer (135`)`or shoulder margin.
 6`- 8`taper and all line angles rounded.6`- 8`taper and all line angles rounded.
 Standard impression procedures areStandard impression procedures are
followed.followed.

65
Tooth preparation :
 Incisal or occlusal - 1.5 mm- 2.0 mm.Incisal or occlusal - 1.5 mm- 2.0 mm.
 Facial or lingual - 1.0 mm – 1.5 mm.Facial or lingual - 1.0 mm – 1.5 mm.www.indiandentalacademy.com

66
Laboratory Procedures :
 Die preparation.Die preparation.
 Waxing & Spruing.Waxing & Spruing.
 Investing & Mold conditioning.Investing & Mold conditioning.
 Casting.Casting.
 Divesting.Divesting.
 Sprue removal.Sprue removal.
 Embedding.Embedding.
 Ceramming & post ceram divesting.Ceramming & post ceram divesting.
 Finishing, coloring.Finishing, coloring.www.indiandentalacademy.com

67
Die Preparation :
Casts shoulb free of 0cclusal artifacts,air bubbles andCasts shoulb free of 0cclusal artifacts,air bubbles and
other inaccuracies.other inaccuracies.
Dies must be prepared with proper indexing. TheDies must be prepared with proper indexing. The
dies should be sectioned, trimmed and refineddies should be sectioned, trimmed and refined
with care.with care.
Any existing undercuts must bu blocked out toAny existing undercuts must bu blocked out to
ensure wax pattern removal without distortion.ensure wax pattern removal without distortion.
Die sealant should be used.Die sealant should be used.
A die spacer of appropriate shade is applied onA die spacer of appropriate shade is applied on
evenly to the die to within 1 mm of margin.evenly to the die to within 1 mm of margin.www.indiandentalacademy.com

68
Prepared Die :

69
Waxing :
 Die lubricant is applied over the die spacer toDie lubricant is applied over the die spacer to
prevent adherence of the wax to the die.prevent adherence of the wax to the die.
 All contours of the wax crown should have aAll contours of the wax crown should have a
minimum thickness of at least 1mm to ensureminimum thickness of at least 1mm to ensure
adequate strength of the crown.adequate strength of the crown.
 A smooth and completely formed internal surfaceA smooth and completely formed internal surface
of the waxed crown is necessary.of the waxed crown is necessary.
 A wild-Leitz stereomicroscope with fibre opticA wild-Leitz stereomicroscope with fibre optic
light can be used to avoid any over extensions inlight can be used to avoid any over extensions in
the margins.the margins.

70
Wax Pattern :

71
Spruing :
 One 8 or 10 gauge wax sprue, attached to theOne 8 or 10 gauge wax sprue, attached to the
incisal surface of the anterior patterns, provides anincisal surface of the anterior patterns, provides an
adequate gate for the ingress of the ceramicadequate gate for the ingress of the ceramic
material.material.
 Posterior patterns are usually require 10 gaugePosterior patterns are usually require 10 gauge
sprues attached to the lingual and buccal cusp tips.sprues attached to the lingual and buccal cusp tips.
 Sprue placement on molar patterns should beSprue placement on molar patterns should be
diagonally opposed for more uniform flow of thediagonally opposed for more uniform flow of the
fluid ceramic.fluid ceramic.
 A sprue design incorporating a perpendicularA sprue design incorporating a perpendicular
reservoir has also produced adequate casting.reservoir has also produced adequate casting.www.indiandentalacademy.com

72
Spruing :
 Length must be approx 3 – 4 mm.Length must be approx 3 – 4 mm.
 The pattern should be located so that itsThe pattern should be located so that its
most distal point is approx 6 – 7 mm frommost distal point is approx 6 – 7 mm from
the open end of the casting ring to allowthe open end of the casting ring to allow
adequate diffusion of the mold glassadequate diffusion of the mold glass
through the investment.through the investment.

73
Spruing :

74
Investment :
 Wax pattern must be cleansed with a debublizingWax pattern must be cleansed with a debublizing
agent, any excess must be removed.agent, any excess must be removed.
 Non-corroding casting rings that are resistant toNon-corroding casting rings that are resistant to
oxidation at high temperature must be used.oxidation at high temperature must be used.
 2 layers of Kaoliner* a ring liner material (an2 layers of Kaoliner* a ring liner material (an
asbestos liner)is placed inside the ring,to permitasbestos liner)is placed inside the ring,to permit
suffficient expansion.suffficient expansion.
 The ring liner is saturated eith water for about 10The ring liner is saturated eith water for about 10
sec before ceating the ring on to the cruciblesec before ceating the ring on to the crucible
former.former.
 A special phosphate bonded investment is usedA special phosphate bonded investment is usedwww.indiandentalacademy.com

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Castable ceramic investment* :

76
Investment :
 This material exhibits no setting expansion butThis material exhibits no setting expansion but
produces approx 1.5% thermal expansion at highproduces approx 1.5% thermal expansion at high
temperatures.temperatures.
 8 ml of distilled water must be mixed with 60 gm8 ml of distilled water must be mixed with 60 gm
of investment powder for 30 sec under vacuumof investment powder for 30 sec under vacuum
with power spatulation.with power spatulation.
 After spatulation additional vibration underAfter spatulation additional vibration under
vacuum is carried for 20 – 30 sec.vacuum is carried for 20 – 30 sec.
 The mixed investment should be carefully appliedThe mixed investment should be carefully applied
on to the wax pattern with a camel’s hair brush.on to the wax pattern with a camel’s hair brush.www.indiandentalacademy.com

77
Investment :
 After the wax pettern is carefully filled andAfter the wax pettern is carefully filled and
coated, the remaining material should becoated, the remaining material should be
vibrated into the ring allowing an excess tovibrated into the ring allowing an excess to
remain above the open ends of the ring.remain above the open ends of the ring.
 After bench setting for 1 hr the excessAfter bench setting for 1 hr the excess
material should be trimmed even with thematerial should be trimmed even with the
top of the casting flask.top of the casting flask.

78
Investment :

79
Mold conditioning :
 A two stage mold conditioning is employed.A two stage mold conditioning is employed.
 The invested pattern is placed in a cold furnace,The invested pattern is placed in a cold furnace,
the temperature is raised to 249`C, and maintainedthe temperature is raised to 249`C, and maintained
for 30 min (heat soak), 10 min of additional timefor 30 min (heat soak), 10 min of additional time
for each ring should be added if more than threefor each ring should be added if more than three
rings are placed at a time.rings are placed at a time.
 The temperature is raised to 899`C, andThe temperature is raised to 899`C, and
maintained for 2 hrs (heat soak), similarly 10 minmaintained for 2 hrs (heat soak), similarly 10 min
added for each ring.added for each ring.

80
Casting :
A 4 gm ceramic ingot is loaded in the ceramicA 4 gm ceramic ingot is loaded in the ceramic
crucible.crucible.
The amount of ceramic material required toThe amount of ceramic material required to
make a good casting can be determinedmake a good casting can be determined
when multiplied by a conversion factor ofwhen multiplied by a conversion factor of
2.6, the weight of the wax pattern, sprues2.6, the weight of the wax pattern, sprues
and button should not exceed 4gm .and button should not exceed 4gm .
Two patterns can be cast into one flask.Two patterns can be cast into one flask.

81
Ceramic ingot; Ceramic crucible:

82
Casting Machine :
 The Dentsply DICOR casting machineThe Dentsply DICOR casting machine
features a platinum electric resistance-typefeatures a platinum electric resistance-type
muffle mounted on a electrically drivenmuffle mounted on a electrically driven
straight centrifugal casting arm.straight centrifugal casting arm.
 The machine is fitted with a specialThe machine is fitted with a special
receptacle to hold the Dicor crucible.receptacle to hold the Dicor crucible.

83
Dentsply DICOR Casting
Machine :

84
Dentsply DICOR Casting
Machine :

85
Casting Procedure :
 An ideal temperature of 1100`C is maintained forAn ideal temperature of 1100`C is maintained for
10 min to stabilize the muffle.10 min to stabilize the muffle.
 The crucible containing the ceramic ingot isThe crucible containing the ceramic ingot is
inserted through the rear muffle door.inserted through the rear muffle door.
 The crucible is properly positioned in the muffleThe crucible is properly positioned in the muffle
for melting the glass by the help if a special tool.for melting the glass by the help if a special tool.
 The rear door is closed, the melting temperature isThe rear door is closed, the melting temperature is
adjusted to 1360`C, and the melt switch is turnedadjusted to 1360`C, and the melt switch is turned
on.on.
 After reaching the determined temperature, thisAfter reaching the determined temperature, this
will be maintained for 6 min.will be maintained for 6 min.www.indiandentalacademy.com

86
Casting Procedure :
 The rear muffle door is opened .The rear muffle door is opened .
 The casting ring is removed from the burnoutThe casting ring is removed from the burnout
furnace and placed in the cradle with the cruciblefurnace and placed in the cradle with the crucible
and gate facing the muffle.and gate facing the muffle.
 The front muffle door is opened and the muffleThe front muffle door is opened and the muffle
assembly is slid forward towards the casting ringassembly is slid forward towards the casting ring
until it is seated.until it is seated.
 The casting machine cover is shut and the castingThe casting machine cover is shut and the casting
switch is turned on. The casting arm spinsswitch is turned on. The casting arm spins
automatically for 4 ½ min and then stops. By theautomatically for 4 ½ min and then stops. By the
end of the spin cycle the casting will cool downend of the spin cycle the casting will cool downwww.indiandentalacademy.com

87
Casting Procedure :
 The casting ring is removed form theThe casting ring is removed form the
machine and allowed to dool for 45 minmachine and allowed to dool for 45 min
before divesting.before divesting.
Divesting :
•After cooling, the investment is removed from
arround the edges of the casting ring to a depth of
approx 6 –8 mm. The investment mass can be
forced out of the retaining ring by pushing with the
fingers. www.indiandentalacademy.com

88
Divesting :
 The bulk of the investment material can be brokenThe bulk of the investment material can be broken
away from the casting with finger pressure.away from the casting with finger pressure.
 The remaining casting should be removed with anThe remaining casting should be removed with an
air abrasive tool using 25 micron aluminum oxideair abrasive tool using 25 micron aluminum oxide
at 40 p.s.I.at 40 p.s.I.
 The margin areas should be protected by coveringThe margin areas should be protected by covering
with the finger to prevent chipping.with the finger to prevent chipping.

89
Sprue removal :
 The cast crown is cut off at the junction ofThe cast crown is cut off at the junction of
sprue and button using a suitable single orsprue and button using a suitable single or
double side diamond disc.double side diamond disc.
 The sprue is cut near the glass button toThe sprue is cut near the glass button to
avoid chipping.avoid chipping.
 The remaining button must be dicsarde andThe remaining button must be dicsarde and
cannot be reused because the glass is alteredcannot be reused because the glass is altered
during melting cycle.during melting cycle.
 The casting at this stage is non-crystalline.The casting at this stage is non-crystalline.

90
Casting :

91
Embedding :
 The casting is embedded in the ceramicThe casting is embedded in the ceramic
embedment material, so that the cerammingembedment material, so that the ceramming
process can take place.process can take place.
 During this ceramming procedure the glass isDuring this ceramming procedure the glass is
concerted into a 55% crystalline form.concerted into a 55% crystalline form.
 The glass casting is embedded in a mixture of 18The glass casting is embedded in a mixture of 18
ml distilled water and 50gm of embedmentml distilled water and 50gm of embedment
powder. Hand mixing is sufficient.powder. Hand mixing is sufficient.
 The inside of the crown is carefully filled with theThe inside of the crown is carefully filled with the
embedment mix and then it is placed on a trayembedment mix and then it is placed on a tray
with a concave receptacle in which additionalwith a concave receptacle in which additional
material is placed.material is placed.www.indiandentalacademy.com

92
Embedding :
 Additional embedment is used to cover andAdditional embedment is used to cover and
protect the glass crown. The material should beprotect the glass crown. The material should be
allowed to set for 45 – 60 min.allowed to set for 45 – 60 min.

93
Ceramming :
 This process is accomplished by a preciselyThis process is accomplished by a precisely
controlled ceramming furnace.controlled ceramming furnace.
 The furnace temperature is gradually increased toThe furnace temperature is gradually increased to
1075`C for 3 ½ hrs, this temperature should be1075`C for 3 ½ hrs, this temperature should be
maintained for 6 hrs. the furnace is cooled tomaintained for 6 hrs. the furnace is cooled to
200`C and the embedment tray is removed.200`C and the embedment tray is removed.
 The ceramming process involves a two-stage heatThe ceramming process involves a two-stage heat
treatment. The first heat treatment is carried at thetreatment. The first heat treatment is carried at the
temperature for maximum nucleation of crystals,temperature for maximum nucleation of crystals,
so maximum no: of crystals are formed. Theso maximum no: of crystals are formed. The
temperature is held for some time for the crystaltemperature is held for some time for the crystal
growth to take place, to attain the maximum size.growth to take place, to attain the maximum size.www.indiandentalacademy.com

94
DICOR Ceramming Furnace :

95
Ceramming tray :

96
DICOR Ceramming Furnace :

97
Ceramming
 The proper ceram cycle is verified by the use of aThe proper ceram cycle is verified by the use of a
pyrometric cone.pyrometric cone.
 The characteristic droop will provide verificationThe characteristic droop will provide verification
that proper time and temperature has allowed thethat proper time and temperature has allowed the
development of the desired crystalline propertiesdevelopment of the desired crystalline properties
in the casting.in the casting.

98
Ceramming verification :

99
Postceram divesting :
 The tray is allowed to cool to roomThe tray is allowed to cool to room
temperature.temperature.
 The embedment is broken.The embedment is broken.
 The crown is cleaned by air-blasting withThe crown is cleaned by air-blasting with
25 micron aluminum oxide at 40 p.s.I at a25 micron aluminum oxide at 40 p.s.I at a
distance of approx 6inches.distance of approx 6inches.
 The margins should be protected fromThe margins should be protected from
chipping during air-blasting.chipping during air-blasting.

100
Wax pattern – Glass form - crystalline form - finished crown

101
Crown finishing :
 Crystalline glass crown is inspected for internalCrystalline glass crown is inspected for internal
nodules or irregularities, which may interfere withnodules or irregularities, which may interfere with
seating of the casting on the die. Theseseating of the casting on the die. These
irregularities csn be removed with extrafineirregularities csn be removed with extrafine
diamond points.diamond points.
 The crows is seated on to the die and examined forThe crows is seated on to the die and examined for
marginal overextensions. If any, must be removedmarginal overextensions. If any, must be removed
with fine white point or rubber wheel rotating atwith fine white point or rubber wheel rotating at
low speed.low speed.
 The remaining sprue is removed with a doubleThe remaining sprue is removed with a double
sided diamond disc rotating at slow speed.sided diamond disc rotating at slow speed.

102
Crown finishing :
 The fine opaque white skin covering the crownThe fine opaque white skin covering the crown
must be removed. The sprue is finished and themust be removed. The sprue is finished and the
skin is lightly removed with a fine rubber abrasiveskin is lightly removed with a fine rubber abrasive
wheel.wheel.
 After removal of the skin the crown is air blastedAfter removal of the skin the crown is air blasted
with 25 microns aluminum oxide at 40 psi.with 25 microns aluminum oxide at 40 psi.
 The primary and secondary occlusal anatomy canThe primary and secondary occlusal anatomy can
be defined with small round and inverted cone T.Cbe defined with small round and inverted cone T.C
burs.burs.
 Corrections can be done with an add-on material.Corrections can be done with an add-on material.
The casting is dried in front of the open muffle atThe casting is dried in front of the open muffle at
593`C and introduced into muffle under vacuum593`C and introduced into muffle under vacuum
to a temperature of 968`C for 1 min and can beto a temperature of 968`C for 1 min and can be
shaped and adjusted to desired contours.shaped and adjusted to desired contours.

103
Characterization & Glazing :
 After the ceramming process the casring isAfter the ceramming process the casring is
achromatic, the desired hue is decided by theachromatic, the desired hue is decided by the
shading porcelains.shading porcelains.
 The blending of enamel and body colors mustThe blending of enamel and body colors must
occur while they are wet.occur while they are wet.
 The first and the second shading porcelains shouldThe first and the second shading porcelains should
be fired at a slightly lower temperature to preventbe fired at a slightly lower temperature to prevent
over glazing and glassy appearance of the crown.over glazing and glassy appearance of the crown.
 Castable ceramics can be fired repeatedly in aCastable ceramics can be fired repeatedly in a
conventional glazing oven without affecting theconventional glazing oven without affecting the
physical properties or marginal integrity of thephysical properties or marginal integrity of the
materialmaterial www.indiandentalacademy.com

104
Characterization & Glazing :

105
Unglazed & Glazed crowns :

106
Completed crown :

107
Cementation :
 The color value is modified by a series odThe color value is modified by a series od
dentsply shaded cements.these cements are colordentsply shaded cements.these cements are color
coordinated with the die spacers that are earliercoordinated with the die spacers that are earlier
used.used.
 If a natural colored tooth preparation exists, aIf a natural colored tooth preparation exists, a
translucent glass ionomer cement is indicated. Intranslucent glass ionomer cement is indicated. In
those cases the tooth structure or a metal core isthose cases the tooth structure or a metal core is
present, the use of properly colored cement can bepresent, the use of properly colored cement can be
of good esthetic value.of good esthetic value.
 During cementation process, controlled, positiveDuring cementation process, controlled, positive
finger pressure should be used to seat the crownfinger pressure should be used to seat the crown
onto the prepared tooth. Excess cement isonto the prepared tooth. Excess cement is
completely removed after the setting is complete.completely removed after the setting is complete.www.indiandentalacademy.com

108
Dicor shaded cements :

109
CERAPEARL :
 IntroductionIntroduction
 CompositionComposition
 PropertiesProperties
 Lab techniqueLab technique

110
Introduction :
 Bioceram group have developed castableBioceram group have developed castable
ceramic material (Hobo & Kyocera) whichceramic material (Hobo & Kyocera) which
may be classified as CaO.Pmay be classified as CaO.P22OO55.MgO.SiO.MgO.SiO22
glass ceramic.glass ceramic.
 Its crystalline structure is similar to that ofIts crystalline structure is similar to that of
enamel.enamel.
 Biocompatible and is indicated for crownsBiocompatible and is indicated for crowns
and inlays.and inlays.

111
Composition :
 It is composed of CaO.PIt is composed of CaO.P22OO55.MgO.SiO.MgO.SiO22 plusplus
traces of other elements.traces of other elements.
 CaO.PCaO.P22OO55 - are the main ingredients and aid- are the main ingredients and aid
in glass formation. Essential to formin glass formation. Essential to form
hydroxyapatite crystals.hydroxyapatite crystals.
 Mg O. CaO – decrease the viscosity.Mg O. CaO – decrease the viscosity.
 SiOSiO22 in combination with Pin combination with P22OO55 – form the– form the
matrix.matrix.

112
Properties :
 Melts at 1460`C and can be cast. TheMelts at 1460`C and can be cast. The
casting has an amorphous microstructurecasting has an amorphous microstructure
and when it is reheated at 870`C for 1 hr, itand when it is reheated at 870`C for 1 hr, it
forms crystalline oxyapatite. This apatite isforms crystalline oxyapatite. This apatite is
clinically unstable and when exposed toclinically unstable and when exposed to
moisture becomes crystalline hydro-moisture becomes crystalline hydro-
oxyapatite.oxyapatite.
 It has similar crystalline arrangement asIt has similar crystalline arrangement as
enamel but the crystals are irregularenamel but the crystals are irregular
providing superior mechanical strength.providing superior mechanical strength.www.indiandentalacademy.com

113
Lab Technique :
 Casts are poured in type IV dental stone.Casts are poured in type IV dental stone.
 After the die sealant,spacer and separator isAfter the die sealant,spacer and separator is
applied, the wax up is done and sprue isapplied, the wax up is done and sprue is
attached.attached.
 Invested in phosphate bonded investment in aInvested in phosphate bonded investment in a
silicone mold.silicone mold.
 After seraration of the silicone mold 60 minAfter seraration of the silicone mold 60 min
later, it is dried in an oven at temperature lesslater, it is dried in an oven at temperature less
than 100`C for 30 min.than 100`C for 30 min.
 Then the temperature is raised to 500`C and thenThen the temperature is raised to 500`C and then
to 800`C for 30 min.to 800`C for 30 min.www.indiandentalacademy.com

114
Lab Technique :
 The investment mold is transferred to a high heatThe investment mold is transferred to a high heat
processor specially developed for this system.processor specially developed for this system.
 8 – 10 gm of new Cerapearl is placed in the8 – 10 gm of new Cerapearl is placed in the
ceramic crucible and melted under vacuum atceramic crucible and melted under vacuum at
1400`C and cast into a mold.1400`C and cast into a mold.
 Upon completion of casting the ring is transferredUpon completion of casting the ring is transferred
to crystallization mold. The process by which theto crystallization mold. The process by which the
casting is re-heated under appropriate conditionscasting is re-heated under appropriate conditions
to develop the micro-crystals of apatite is termedto develop the micro-crystals of apatite is termed
crystallization.crystallization.
 It makes the casting highly dense, strong, hard andIt makes the casting highly dense, strong, hard and
chemically stable.chemically stable.

115
Lab Technique :
 The crystalization starts at 750`C thenThe crystalization starts at 750`C then
maintained for 15 min =, then reached atmaintained for 15 min =, then reached at
870`C for 1 hr.870`C for 1 hr.
 Translucency is similar to enamel.Translucency is similar to enamel.
 External stains can also be given afterExternal stains can also be given after
cooling.cooling.

116
Conventional
POWDER SLURRY
CERAMICS
Vita Hi-Ceram*Vita Hi-Ceram*
Optec HSP*Optec HSP*
Duceram LFC*Duceram LFC*
Summary

117
VITA Hi-Ceram :
 Material propertiesMaterial properties
 Laboratory procedures.Laboratory procedures.

118
Material :
 This is a aluminum oxide reinforced hardThis is a aluminum oxide reinforced hard
core porcelain.core porcelain.
 Alumina reinforced core consists of 50% ofAlumina reinforced core consists of 50% of
aluminous crystals in a matrix of low fusingaluminous crystals in a matrix of low fusing
glass of matching thermal expansion.glass of matching thermal expansion.
 Aluminous core porcelains are twiceAluminous core porcelains are twice
stronger than regular porcelains.stronger than regular porcelains.

119
A comparision of the bending strengths of vita Hi-Ceram
and Vitadur-N core porcelains

120
Merits :
 Highly accurate margins.Highly accurate margins.
 Higher melting points and greater stability.Higher melting points and greater stability.
 For both anterior and posterior crowns,For both anterior and posterior crowns,
veneers.veneers.

121
Clinical Procedures :
 Heavy chamfer or shoulder with internalHeavy chamfer or shoulder with internal
angles rounded.angles rounded.
 Regular impression procedures.Regular impression procedures.

122
Lab Procedures :
 Preparing the refractory die.Preparing the refractory die.
 Hard core porcelain framework.Hard core porcelain framework.
 Crown buildup.Crown buildup.

123
Refractory Die :
 Prepared die on thePrepared die on the
master model.master model.

124
 To create theTo create the
necessarynecessary
space for thespace for the
cement,cement,
apply Vitaapply Vita
interspaceinterspace
varnish on tovarnish on to
the die in 2the die in 2
or 3 coatings.or 3 coatings.

125
 Apply aApply a
coat of thincoat of thin
insulatinginsulating
grease ontogrease onto
thethe
duplicatingduplicating
base andbase and
ring, fix thering, fix the
die into thedie into the
base andbase and
then placethen place
the ringthe ring
intointo
position.position.

126
 The hi-ceramThe hi-ceram
paste consistspaste consists
of paste, liquidof paste, liquid
and catalyst,and catalyst,
should beshould be
stirred quicklystirred quickly
to obtain ato obtain a
homogenoushomogenous
mix. NOTE :mix. NOTE :
first mix thefirst mix the
paste and liquidpaste and liquid
together andtogether and
then stir in thethen stir in the
catalyst.catalyst. www.indiandentalacademy.com

127
 To avoidTo avoid
any creatingany creating
bubbles, fillbubbles, fill
the mold bythe mold by
pouring inpouring in
the mixturethe mixture
in a finein a fine
stream.stream.
WorkingWorking
time approxtime approx
2 ½ min.2 ½ min.
Setting timeSetting time
– 20 – 30– 20 – 30
min.min.

128
 Remove theRemove the
die from thedie from the
solidifiedsolidified
cast ofcast of
paste, andpaste, and
clean off theclean off the
varnishvarnish
using theusing the
varnishvarnish
thinner.thinner.

129
 Mix theMix the
refractory Hi-refractory Hi-
Ceram dieCeram die
material togethermaterial together
with the diewith the die
material liquid:material liquid:
for this, thefor this, the
liquid should beliquid should be
drawn into thedrawn into the
dosing syringedosing syringe
to the 3 ml mark,to the 3 ml mark,
for one 15 gmfor one 15 gm
sachet ofsachet of
powder. *Stirpowder. *Stir
the two materialsthe two materials
for at least 1for at least 1
min.min.

130
 On a vibratorOn a vibrator
without anywithout any
bubbles fill thebubbles fill the
mold that is tomold that is to
be duplicated.be duplicated.
While it is stillWhile it is still
soft, set asoft, set a
porcelainporcelain
retaining pinretaining pin
into the dieinto the die
material, so asmaterial, so as
to later be ableto later be able
to safely fix theto safely fix the
die onto adie onto a
porcelain firingporcelain firing
tray.tray. www.indiandentalacademy.com

131
 The setting timeThe setting time
for Hi-Ceramfor Hi-Ceram
die materialdie material
varies betweenvaries between
1 ½ - 2 hrs,1 ½ - 2 hrs,
depending ondepending on
the roomthe room
temperature.temperature.
After no moreAfter no more
than 6 hrs thethan 6 hrs the
die is removeddie is removed
from the mold.from the mold.

132
 The die should be set onThe die should be set on
a porcelain tray for thea porcelain tray for the
refractory material torefractory material to
harden. Pre dry the dieharden. Pre dry the die
in the VITA Vacumatin the VITA Vacumat
200 /100 : with the200 /100 : with the
furnace on standby(orfurnace on standby(or
prog A), lower the firingprog A), lower the firing
tray by manual controltray by manual control
key and the place thekey and the place the
die onto it. Only whendie onto it. Only when
the die material hasthe die material has
turned light green theturned light green the
following prog isfollowing prog is
initiated ……….initiated ………. www.indiandentalacademy.com

133
 In theIn the VitaVita
Vacumat 200Vacumat 200 ::
prog 5.5, endprog 5.5, end
temp 1,000`C,temp 1,000`C,
pre-drying timepre-drying time
10 min, heating10 min, heating
time 10 min, holdtime 10 min, hold
time 3 min. In thetime 3 min. In the
Vita VacumatVita Vacumat
100100 : prog 5, end: prog 5, end
temp 1000`C, pre-temp 1000`C, pre-
drying time 10drying time 10
min, heating timemin, heating time
10 min, hold time10 min, hold time
3 min.3 min.

134
Constructing the hard core
porcelain

135
 The Hi-Ceram hardThe Hi-Ceram hard
core porcelain has tocore porcelain has to
be applied and firedbe applied and fired
in three layersin three layers
altogether : 1. Thealtogether : 1. The
wash firing.; 2. Halfwash firing.; 2. Half
of the requiredof the required
thickness withthickness with
protuberances forprotuberances for
later checking on thelater checking on the
thickness of thethickness of the
porcelain.; 3. Fullporcelain.; 3. Full
build-up as a smallerbuild-up as a smaller
version of the crownversion of the crown
it is to become.it is to become.
Minimum thickness-Minimum thickness-
0.5mm.0.5mm.

136
 Prior toPrior to
each neweach new
applicationapplication
of Hi-Ceramof Hi-Ceram
hard corehard core
porcelain,porcelain,
the diethe die
should firstshould first
be allowedbe allowed
to cool andto cool and
then left tothen left to
soak insoak in
water untilwater until
no moreno more
bubbles arebubbles are
beingbeing
emitted.emitted.

137
 Excess waterExcess water
should beshould be
soaked up. Next,soaked up. Next,
Hi-Ceram hardHi-Ceram hard
core porcelaincore porcelain
powder is mixedpowder is mixed
together withtogether with
Vita modelingVita modeling
liquid “P” to aliquid “P” to a
thin, creamythin, creamy
consistency.consistency.
This is thenThis is then
applied as a thinapplied as a thin
wash onto thewash onto the
die.die.

138
 Pre dry thePre dry the
die on thedie on the
loweredlowered
firing trayfiring tray
of theof the
furnacefurnace
until it hasuntil it has
againagain
turned lightturned light
green, andgreen, and
then fire asthen fire as
follows,follows,
using ausing a
standbystandby
temperaturetemperature
of 600`C :of 600`C :

139
 In the Vita vacumat 200:In the Vita vacumat 200:
programme 6.6, end temperature 1170`C,programme 6.6, end temperature 1170`C,
pre-drying time 6 min, heating time 10 min,pre-drying time 6 min, heating time 10 min,
hold time 0 min, vacuum firing time 10hold time 0 min, vacuum firing time 10
min.min.
programme 6, end temperature 1170`C, pre-programme 6, end temperature 1170`C, pre-
drying time 6 min, heating time 10 min,drying time 6 min, heating time 10 min,
min.min. www.indiandentalacademy.com

140
 Soak the die in waterSoak the die in water
again, and then applyagain, and then apply
the hard core porcelainthe hard core porcelain
for second firing. Tofor second firing. To
make sure of having themake sure of having the
correct thickness of Hi-correct thickness of Hi-
Ceram hard coreCeram hard core
porcelain,porcelain,
protuberances or pointsprotuberances or points
can be constructed forcan be constructed for
control purposes. Thecontrol purposes. The
firing instructions arefiring instructions are
the same as for the 1the same as for the 1stst
hard core porcelainhard core porcelain
firing.firing. www.indiandentalacademy.com

141
 The fully built up hard core porcelain in itsThe fully built up hard core porcelain in its
final form before the third firing.final form before the third firing.
For this, fire fire as follows, using a standby temperature of 600`C

142
Programme 6.7, end temperature 1170`C, pre-Programme 6.7, end temperature 1170`C, pre-
drying tome 6 min, heating up tome 6 min,drying tome 6 min, heating up tome 6 min,
min.min.
Programme 6, end temperature 1170`C, pre-Programme 6, end temperature 1170`C, pre-
drying time 6min, heating up tome 10 min,drying time 6min, heating up tome 10 min,
min.min. www.indiandentalacademy.com

143
 The thickness of hard core porcelainThe thickness of hard core porcelain
framework should not be less than 0.5 mm.framework should not be less than 0.5 mm.
 For additional stability, a collar in Hi-For additional stability, a collar in Hi-
Ceram hard core porcelain can be addedCeram hard core porcelain can be added
palatally or lingually.palatally or lingually.

144
 Just as with VitaJust as with Vita
VMK metal-ceramicVMK metal-ceramic
porcelain, Hi-Ceramporcelain, Hi-Ceram
hard core porcelainshard core porcelains
can also be shadedcan also be shaded
individually using theindividually using the
Hi-Ceram COLORHi-Ceram COLOR
hard-core porcelains,hard-core porcelains,
e.g. ti reinforce thee.g. ti reinforce the
shade from within inshade from within in
cases where thecases where the
thickness of the dentinthickness of the dentin
porcelain is thinnerporcelain is thinner
than normal.than normal.

145
 TheThe
refractoryrefractory
die shoulddie should
be blastedbe blasted
away usingaway using
glass beadsglass beads
at aat a
pressure ofpressure of
1- 2 bar.1- 2 bar.

146
 The finished Hi-The finished Hi-
frame work onframe work on
the stone die.the stone die.
Any areas ofAny areas of
interface orinterface or
feathered edgesfeathered edges
should beshould be
carefully groundcarefully ground
down ordown or
removed using aremoved using a
fine-grainedfine-grained
diamond.diamond.

147
 As the Hi-Ceram hard core framework has notAs the Hi-Ceram hard core framework has not
been constructed on the model, any areas that arebeen constructed on the model, any areas that are
now found to have been built up too high or toonow found to have been built up too high or too
thick can be corrected using a fie grainedthick can be corrected using a fie grained
diamond.diamond.

148
The build up of the
crown :

149
 The crown shouldThe crown should
be built up to itsbe built up to its
desired shape usingdesired shape using
Vitadur-N dentinVitadur-N dentin
porcelain, althoughporcelain, although
to compensate firingto compensate firing
shrinkage it must beshrinkage it must be
built longerbuilt longer
incisally. The cervixincisally. The cervix
of the hard coreof the hard core
framework can beframework can be
coated before handcoated before hand
using Vitadur-Nusing Vitadur-N
opacous porcelain.opacous porcelain.

150
 A little Vitadur-NA little Vitadur-N
opacous dentin canopacous dentin can
also be appliedalso be applied
palatally, so thatpalatally, so that
even in caseseven in cases
where there is awhere there is a
deeper than normaldeeper than normal
bite by thebite by the
occluding teeth,occluding teeth,
any shiningany shining
through of the Hi-through of the Hi-
porcelain will beporcelain will be
completelycompletely
avoided.avoided. www.indiandentalacademy.com

151
 To create theTo create the
necessary spacenecessary space
for the enamelfor the enamel
porcelain, theporcelain, the
dentin should havedentin should have
a crescent carveda crescent carved
away incisally andaway incisally and
for the smoothfor the smooth
transition betweentransition between
the dentin andthe dentin and
enamel, then alsoenamel, then also
be smoothenedbe smoothened
using a flattenedusing a flattened
brush.brush.

152
 For individualFor individual
shading andshading and
characterizatiocharacterizatio
n, there are 5n, there are 5
Vitadur-NVitadur-N
opacousopacous
dentin, 6dentin, 6
dentin effect,dentin effect,
2 enamel2 enamel
effect and 7effect and 7
COLORCOLOR
porcelainsporcelains
available.available. www.indiandentalacademy.com

153
 The shape of theThe shape of the
crown is nowcrown is now
built up inbuilt up in
Vitadur-NVitadur-N
enamelenamel
porcelain. Itporcelain. It
should beshould be
somewhat oversomewhat over
dimensioned todimensioned to
compensatecompensate
firing shrinkage.firing shrinkage.

154
 The crown is firedThe crown is fired
as follows: either byas follows: either by
placing it onto aplacing it onto a
fibrous pad firingfibrous pad firing
support (in whichsupport (in which
case raise thecase raise the
temperature bytemperature by
10`C), or by10`C), or by
wrapping a normalwrapping a normal
crown stand in thecrown stand in the
fibrous pad materialfibrous pad material
and then placing theand then placing the
crown loosely ontocrown loosely onto
it:it:

155
drying time 6 min, heating up time 6 min,drying time 6 min, heating up time 6 min,
hold time 1 min, vacuum firing time 6 min.hold time 1 min, vacuum firing time 6 min.
 In the Vita vacumat :In the Vita vacumat :
hold time 1 min, vacuum firing time 6 min.hold time 1 min, vacuum firing time 6 min.

156
 The fired Hi-Ceram crown should be groundThe fired Hi-Ceram crown should be ground
all over in the normal way, using a diamondall over in the normal way, using a diamond
or a green silicon carbide bur. Foror a green silicon carbide bur. For
corrections, clean without using anycorrections, clean without using any
cleansing agent but with a clean brush undercleansing agent but with a clean brush under
running water, or a steam jet blaster.running water, or a steam jet blaster.
Then reapply the
appropriate
porcelain and fire
as for the main
vacuum firing,
except with the
temperature
reduced by 10`C.

157
 Before each firing, it is also possible toBefore each firing, it is also possible to
improve the accuracy of fit and esthetics ofimprove the accuracy of fit and esthetics of
the cervical margin: the stone die shouldthe cervical margin: the stone die should
first be insulated using one drop thin bodiedfirst be insulated using one drop thin bodied
super glue. This sealing of the surface willsuper glue. This sealing of the surface will
prevent the die from soaking up anyprevent the die from soaking up any
moisture from the porcelain. Next, tomoisture from the porcelain. Next, to
prevent to prevent the modeled porcelainprevent to prevent the modeled porcelain
from sticking to the die, the chamfer shouldfrom sticking to the die, the chamfer should
be thinly coated with Hi-Ceram die releasebe thinly coated with Hi-Ceram die release
before applying the cervical porcelain.before applying the cervical porcelain.

158
 The cervicalThe cervical
porcelain should beporcelain should be
mixed with Vitamixed with Vita
modeling liquid,modeling liquid,
applied onto theapplied onto the
cervical margin,cervical margin,
condensed and thencondensed and then
bottled. Excessbottled. Excess
cervical porcelainscervical porcelains
should then beshould then be
removed usingremoved using
either a clean fingereither a clean finger
or a dry brush.or a dry brush.

159
 Without beingWithout being
tilted, the crowntilted, the crown
should beshould be
removed andremoved and
fired as ……fired as ……

160
Cervical porcelain firing in the Vita vacumat 200Cervical porcelain firing in the Vita vacumat 200
programme 6.8, end temperature 940`C, pre-programme 6.8, end temperature 940`C, pre-
drying time 6 min, heating up time 6 min, holddrying time 6 min, heating up time 6 min, hold
time 1 min, vacuum firing time 6 min.time 1 min, vacuum firing time 6 min.
Cervical porcelain firing in the Vita vacumat 100Cervical porcelain firing in the Vita vacumat 100
programme 6, end temperature 940`C, pre-programme 6, end temperature 940`C, pre-
drying time 6 min, heating up time 6 min, holddrying time 6 min, heating up time 6 min, hold
time 1 min, vacuum firing time 6 min.time 1 min, vacuum firing time 6 min.

161
Glaze firing :
 Applying theApplying the
Vitachrom ”L”Vitachrom ”L”
glaze No. 725glaze No. 725
allows theallows the
temperature fortemperature for
the glaze firingthe glaze firing
to be lowered,to be lowered,
therebythereby
guarantyingguarantying
that the cervicalthat the cervical
margins retainmargins retain
its accurate fit.its accurate fit.www.indiandentalacademy.com

162
 Glaze firing in the Vita vacumat 200:Glaze firing in the Vita vacumat 200:
hold time 1 min.hold time 1 min.
 Glaze firing in the Vita vacumat 100:Glaze firing in the Vita vacumat 100:
hold time 1 min.hold time 1 min.

163
Finished Vita Hi-ceram crowns

164
Optec HSP

165
Introduction:
Optec HSP(Jeneric / Pentron) is a Leucite-Optec HSP(Jeneric / Pentron) is a Leucite-
reinforced feldspathic porcelain that isreinforced feldspathic porcelain that is
condensed and sintered like aluminouscondensed and sintered like aluminous
porcelain and traditional porcelain. Hasporcelain and traditional porcelain. Has
greater strength than traditional feldspathicgreater strength than traditional feldspathic
porcelains due to increased amount ofporcelains due to increased amount of
leucite. The manufacturer disperses theleucite. The manufacturer disperses the
leucite crystals in a glassy matrix byleucite crystals in a glassy matrix by
controlling their nucleation crystal growthcontrolling their nucleation crystal growth
during the initial production of theduring the initial production of the
porcelain powder.porcelain powder.www.indiandentalacademy.com

166
 Because of its increased strength, Optec HSP*Because of its increased strength, Optec HSP*
does not require a core when used to fabricate alldoes not require a core when used to fabricate all
ceramic restorations, as is necessary withceramic restorations, as is necessary with
aluminous PJC’s. the body and incisal porcelainsaluminous PJC’s. the body and incisal porcelains
are pigmented to provide the desired shade andare pigmented to provide the desired shade and
translucency. The leucite and glass componentstranslucency. The leucite and glass components
are fused together during the baking processare fused together during the baking process
(1020`C). The buildup and contouring of the(1020`C). The buildup and contouring of the
crown is done on a special semi-permeable diecrown is done on a special semi-permeable die
material. It has a moderately opaque corematerial. It has a moderately opaque core
compared with a metal or an aluminous porcelaincompared with a metal or an aluminous porcelain
core, it is more translucent than alumina-corecore, it is more translucent than alumina-core
crowns and glass infiltrated alumina core crowns.crowns and glass infiltrated alumina core crowns.

167
Advantages:
 Lack of metal or opaque substructure.Lack of metal or opaque substructure.
 Good translucency.Good translucency.
 Moderate flexural strength.Moderate flexural strength.
 No special laboratory equipments needed.No special laboratory equipments needed.

168
Disadvantages:
 Potential marginal inaccuracy caused byPotential marginal inaccuracy caused by
porcelain sintering shrinkage.porcelain sintering shrinkage.
 Potential to fracture in posterior teeth.Potential to fracture in posterior teeth.
Leucite reinforced porcelain that is condensedLeucite reinforced porcelain that is condensed
and sintered shrinks when fired because ofand sintered shrinks when fired because of
the volumetric decrease caused by sintering,the volumetric decrease caused by sintering,
and the fit of the crowns made from thisand the fit of the crowns made from this
ceramic is not as good as that of PFMceramic is not as good as that of PFM
crowns with metal margins.crowns with metal margins.

169
Duceram LFC:

170
Introduction:
 The development of very low fusingThe development of very low fusing
ceramics(fusing temperature 660`C) meantceramics(fusing temperature 660`C) meant
that a simple and accurate technique forthat a simple and accurate technique for
building up and firing all-ceramicbuilding up and firing all-ceramic
restorations.restorations.

171
Method of Fabrication:
Tooth preparation.Tooth preparation.
Die preparation.Die preparation.
Ceramic core.Ceramic core.
Ceramic buildup.Ceramic buildup.

172
Tooth preparation:
Preparation for a CJC with a peripheral shoulder.www.indiandentalacademy.com

173
Ceramic coping preparation :
 Refractory die.Refractory die.
 Initial ceramic connector layer.Initial ceramic connector layer.
 Ceramic core buildup.Ceramic core buildup.

174
A fine layer of initial ceramic over the refractory die the
refractory die (Ducera-lay) is fired at 980`C. This connector
layer should be bright and even
Ceramic
connector:

175
Ceramic Core:
Lamination in
Duceram
ceramic
directly on the
refractory die
to produce a
ceramic
coping of 0.3
mm thickness

176
Lamination
in Duceram
ceramic
directly on
the refractory
die to
produce a
ceramic
coping of 0.3
mm thickness

177
Lamination
in Duceram
ceramic
directly on
the
refractory
die to
produce a
ceramic
coping of
0.3 mm
thickness

178
The coping is
fired at 940`C.
Various shades
can be
introduced at
this stage.

179
After firing the coping is gently sandblasted
off the refractory material using 50 micron
aluminum oxide powder.www.indiandentalacademy.com

180
Prepared coping

181
Ceramic Buildup:
The coping is replaced on the plaster cast.The coping is replaced on the plaster cast.
Lamination can the be completed using aLamination can the be completed using a
low-fusing ceramic, which will be fired atlow-fusing ceramic, which will be fired at
660`C in a vacuum.660`C in a vacuum.www.indiandentalacademy.com

182
Completed Duceram-LFC Crown:
Facial view ^

183
Completed Duceram-LFC Crown:
Lingual view (Courtesy : Marc Cristou)www.indiandentalacademy.com

184
Properties:
 Flexural strength – 110 Mpa.Flexural strength – 110 Mpa.
 Hardness is close to that of natural toothHardness is close to that of natural tooth
due to absence of leucite.mdue to absence of leucite.m
 Opalescence of the natural tooth can beOpalescence of the natural tooth can be
reproduced.reproduced.
 Fluorescence of LFC is very close to that ofFluorescence of LFC is very close to that of
natural tooth.natural tooth.

185
Fluorescence:
 ComparisonComparison
ofof
fluorescencefluorescence
of naturalof natural
teeth(green),teeth(green),
DuceramDuceram
LFC(blue),LFC(blue),

186
Fluorescence:
LFC (circle left); traditional ceramic material (circleLFC (circle left); traditional ceramic material (circle
right); natural tooth (middle).right); natural tooth (middle).

187
Advantages:
 Excellent marginal adaptation.Excellent marginal adaptation.
 Use of plaster master cast.Use of plaster master cast.
 No special equipment required.No special equipment required.
 Allows for modification by repeated firings.Allows for modification by repeated firings.
 Abrasion rate close to that of natural tooth.Abrasion rate close to that of natural tooth.
 Good visual qualities, including bestGood visual qualities, including best
reproduction of opalescence of natural teeth.reproduction of opalescence of natural teeth.

188
Indications:
 Laminate veneers.Laminate veneers.
 Jacket crowns.Jacket crowns.
 Inlays.Inlays.
 Onlays.Onlays.
 If high transparency ceramic is required.If high transparency ceramic is required.

189
Contraindications:
 Masking grossly discolored tooth.Masking grossly discolored tooth.
 When aiming for high fracture resistance.When aiming for high fracture resistance.
 All other common contraindications.All other common contraindications.

190
MACHINABLE CERAMICS
Summary www.indiandentalacademy.com

191
Classification:
a ceramic restoration
fabricated by use of a
computer aided design -
computer aided milling
a process of milling a
structure using a device that
traces the surface of a metal,
ceramic or a polymer
pattern and transfers the
traced spatial positions to a
cutting station.
C A D -C A M C e r a m ic s C o p y -M il l e d C e r a m ic s
M ac h in able C er a m ic s

192
CAD – CAM Ceramics
CERECCEREC CEREC SCANCEREC SCAN
CEREC 2CEREC 2 CEREC InLABCEREC InLAB
CEREC 3CEREC 3 PROCERAPROCERA

193
Introduction:
The introduction of Computer-Aided-Designing &The introduction of Computer-Aided-Designing &
Computer-Aided-Milling(CAD-CAM) systems toComputer-Aided-Milling(CAD-CAM) systems to
prosthetic dentistry represents a majorprosthetic dentistry represents a major
technological breakthrough. It is now possible totechnological breakthrough. It is now possible to
design and fabricate ceramic restorations at adesign and fabricate ceramic restorations at a
single appointment, as opposed to the traditionalsingle appointment, as opposed to the traditional
method of making impressions, fabricating ofmethod of making impressions, fabricating of
provisional prosthesis, and using a lab forprovisional prosthesis, and using a lab for
development of the restoration. These restorationsdevelopment of the restoration. These restorations
save dentists and patients time, provide an estheticsave dentists and patients time, provide an esthetic
restoration, and have the potential for wearrestoration, and have the potential for wear
resistance.resistance. www.indiandentalacademy.com

194
History:
Optical scanning and computer generation ofOptical scanning and computer generation of
restorations were attempted as early as 1971restorations were attempted as early as 1971
(Altschuler, 1971/1973) but the continued(Altschuler, 1971/1973) but the continued
improvement in technology, a number ofimprovement in technology, a number of
systems are currently being investigated atsystems are currently being investigated at
this time………this time………
Duret & PrestonDuret & Preston 19811981
Brendestini et alBrendestini et al 19851985
RekowRekow 19871987
WilliamsWilliams 19871987
Duret et alDuret et al 19881988www.indiandentalacademy.com

195
Objectives:
 To eliminate traditional impression methods.To eliminate traditional impression methods.
 To design, the future restoration inTo design, the future restoration in
accordance with the preparation, the functionaccordance with the preparation, the function
and natural anatomy,e.g. with the use ofand natural anatomy,e.g. with the use of
computer.computer.
 To produce the restoration chair side.To produce the restoration chair side.
 To improve the restoration qualities,To improve the restoration qualities,
mechanical resistance, marginal fit, surfacemechanical resistance, marginal fit, surface
quality and esthetics.quality and esthetics.www.indiandentalacademy.com

196
Types of CAD – CAM Devices:
 DIRECT:DIRECT:
Fully integrated CAD – CAM devices forFully integrated CAD – CAM devices for
chair side restorative approach. CAD &chair side restorative approach. CAD &
CAM stations are located at the dentalCAM stations are located at the dental
office.office.
 INDIRECT:INDIRECT:
System that consists of several modules withSystem that consists of several modules with
at least, distinctive CAD & CAM stations.at least, distinctive CAD & CAM stations.

197
Indirect Method:
 The optical impression is taken in the dentalThe optical impression is taken in the dental
office, where CAD is done; data areoffice, where CAD is done; data are
transmitted to CAM station for restorationtransmitted to CAM station for restoration
fabrication.fabrication.
 The optical impression is taken in the dentalThe optical impression is taken in the dental
office; collected information is thenoffice; collected information is then
transmitted to a central station, where CADtransmitted to a central station, where CAD
& CAM modules operate.& CAM modules operate.

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