DENTAL CERAMIC AND ITS ADVANCEMENTS.pptx

DENTAL CERAMIC AND ITS
ADVANCEMENTS
PERCEPTOR- DR. CAPT ANSHUL ARORA
PRESENTER- DR. ZADENO KITHAN

CONTENTS
• INTRODUCTION
 HISTORY
 DEFINITION
 CLASSIFICATION
 COMPOSITION
 INDICATIONS
 CONTRAINDICATIONS
 DISADVANTAGES
 PROPERTIES
 PROCESSING OF DENTAL CERAMIC
 METHODS OF STRENGTHENING
CERAMICS
• METAL CERAMIC SYSTEM
• ALL CERAMIC SYSTEM
• RECENT ADVANCES IN DENTAL
CERAMICS
• CONCLUSION

INTRODUCTION
 Ceramic materials have rapidly become the material of choice for indirect restorations.
 Advances in digital dentistry led to a rapid switch from porcelain fused to metal restorations to
all-ceramic restorations.
 Variations in composition, microstructure and processing affect mechanical properties and use
of these materials. Therefore, having a better understanding of their differences is important
for proper clinical selection.

HISTORY
The word “ceramic” is derived from the Greek word “ker a mikόV” (Keramos). This is term is
also related to a Sanskrit word which means “burned earth” because the basic component was
clay.
Chronology of events in the evolution of dental ceramics
1774
1789
1830
Porcelain teeth were used instead of ivory teeth
Porcelain teeth were introduced to dentistry
Early dental porcelain was developed
1903 Porcelain jacket crowns were introduced
1952 Glass ceramics were invented

1984
1980–
1987
1984
1983
1965 Dental aluminous core ceramic was developed
Porcelain laminate crown was introduced
Castable all-ceramic material (Dicor) was
introduced
First CAD-CAM unit (CEREC) was developed
CAD-CAM technology was first developed
Early
1990s
Pressable glass ceramics—IPS Empress was
released in the market

DEFINITION
 Compounds of one or more metals with non metallic element, usually oxygen formed of
chemical and biochemically stable substances that are strong, hard, brittle and inert non
conductors of thermal and electrical energy.
GPT 9th ed.
 Dental ceramics are nonmetallic, inorganic structures, primarily containing compounds of
oxygen with one or more metallic or semimetallic elements (aluminum, calcium, lithium,
magnesium, phosphorus, potassium, silicon, sodium, titanium, and zirconium).
PHILLIPS SCIENCE OF DENTAL MATERIALS (11TH ED.)

Ceramic is a more generalized term for any product
made from a nonmetallic inorganic material processed
by firing at high temperatures
Porcelain is a restrictive term used for the mixture of
kaolin, quartz, and feldspar which, when fired at high
temperatures, gives a glassy, translucent finish and is
less porous than ordinary ceramic

CLASSIFICATION
• Feldspathic porcelain
• leucite reinforced porcelain
• Aluminous porcelain
• Alumina
• Glass infiltrated alumina
• Glass infiltrated spinel
• Glass infiltrated zirconia
• Glass ceramic
• High (1315°C– 1370°C)
• Medium (1090°C–1260°C)
• low (870°C–1065°C) &
• Ultra-low (<850°C) fusing
COMPOSITION
FUSION
TEMPERATURE

• Sintering
• Casting
• machining
• Denture teeth
• Metal ceramic restorations
• Veneers
• Inlays/Onlays
• Crowns and anterior bridges
METHOD OF
FABRICATION
USE

o Core porcelain: is the basis of porcelain jacket
crown, must have good mechanical properties.
o Dentin or Body porcelain: more translucent than
core porcelain, largely governs the shape and color
of restoration.
o Enamel porcelain: is used in areas requiring
maximum translucency, for example- at the
incisal edge
APPLICATION

DENTAL CERAMIC AND ITS ADVANCEMENTS.pptx

COMPOSITION
FELDSPAR
 Naturally occurring mixtures of soda and potash aluminosilicates.
 Soda -tends to lower the fusion temperature,
 Potash -increases the viscosity of the molten glass
 Glass phase formation- during firing, it fuses and forms a glassy
phase, forms a translucent glassy matrix.
 Retains shape when fused at high temperature
 Leucite formation- Undergoes incongruent melting between
1150- 1530˚C to form leucite (crystalline mineral)

QUARTZ
– Refractory skeleton
– Strengthens and hardens porcelain
during the firing cycle
Kaolin (Al2O3.2SiO2.2H2O)
– Binder
– Gives opacity therefore generally omitted
Al2O3
– Strength and opacity
– Alters softening temperature
– Increases viscosity

BASIC OXIDES
 SILICA
- The principal glass forming oxide
- Present in most dental ceramics up to 60%
 ALUMINA
-Hardest and strongest of the oxides used in ceramic
- Helps in building strong chemical links between silica and the fluxes

Introduction-Alumina is one of the most commonly used and researched structural ceramic because of its
excellent properties. However, its intrinsic brittleness is the fatal drawback, which hinders it from wider
applications. How to improve its fracture toughness as well as the bending strength is always challenging
for material researchers.
Materials and methods -Alumina matrix composites were fabricated by hot-pressing, in which some
additives, including zirconia, alumina platelets, and MXene, were incorporated. The influence of
the introduced additives on their microstructure and mechanical properties was investigated.
Conclusion: Incorporation of zirconia was beneficial to the mechanical properties due to the phase-
transformation strengthening and toughening mechanism. Aumina platelets resulted in high fracture
toughness because of the self-toughening of elongated grains. The synergistic effect of alumina
platelets and MXene enormously improved the fracture toughness.
Fabrication of high-strength and high-toughness alumina
ceramics by introducing additives properly.

 LITHIUM OXIDE (LI2O)
- The lightest, smallest, and most reactive of the oxides.
- Acts as a powerful auxiliary alkaline flux with thermal expansion–lowering
effects.
• MAGNESIUM OXIDE (MGO)
- Acts like a flux at lower temperatures.
-As as a matting agent and to increase opacity.

 ZINC OXIDE (ZNO)
- In smaller amounts,helps in achieving glossy and brilliant surfaces.
- In larger amounts, it causes opacity.
STRONTIUM OXIDE (SRO)
Has matting and crystallizing properties

CALCIUM
OXIDE
(CAO)
BORIC
OXIDE
(B2O3)
POTASH
(K2O) AND
SODA
(NA2O)

 Addition of concentrated color frits/flux to the porcelain is not enough to impart
lifelike tooth since the porcelain is too translucent.
 Dentin colors require greater opacity compared to enamel shades; hence specific
opacifiers need to be added
Zirconia/zi
rconium
dioxide
(ZrO2)
Tin oxide
(SnO2),
Titanium
oxide
(TiO2)

PIGMENTS
Naturally occurring porcelains have a greenish hue. To overcome this color and to give the
dental ceramics lifelike enamel and dentin colors, various pigments are added

• Aesthetic alternative for discolored teeth.
• Badly or grossly carious teeth.
• Traumatic fracture of incisal angles or buccal cusps of teeth.
• Congenital abnormalities.
• Veneers.
• Inlays or onlays.
• Abutment retainers.
• Denture as tooth material.
• Splinting of mobile teeth with metal backing.
• Occlusal corrections and improvement of alignment or function.

• Individuals with parafunctional habits like bruxism.
• Short clinical crown
• Immature teeth
• Unfavourable occlusion
• Supra gingival preparations( when used alongside adhesive cements)

o Brittle
o High shrinkage of conventional porcelains
o Technique sensitive
o Specialized training required
o Costly equipment
o More tooth reduction
o Attrition of opposing tooth
o Difficult to repair
o Expensive

Biocompati
bility
Esthetics Durability
Ability to be
formed into
precise
shapes
– Colour and Translucency – Long term colour stability – Wear resistant – No Solubility

 The process of packing the particles together and of removing the liquid binder is known as
condensation.
-The main driving force involved in condensing dental porcelain is surface tension.
Methods of condensation
• WET BRUSH
APPLICATION METHOD
• VIBRATION
• SPATULATION
• WHIPPING
• MECHANICAL
• ULTRASONIC VIBRATION

 A process of heating closely packed particles to achieve interparticle bonding
and sufficient diffusion to decrease the surface area or increase the density of
the structure.
TYPES OF FIRING
Air fired
– Slow maturation period
to allow air to escape.
Held at 30-50 degree less
than maximum firing
temperature
• Vacuum fired
– Dense, pore-free
mass
– Shorter firing time
• Diffusible gas firing
procedure
– Helium, hydrogen
or steam

Purpose: To evaluate the effect of extended firing on bond strength in densely sintered ceramics
of the zirconium reinforced lithium silicate, lithium disilicate, and feldspathic ceramic.
Materials and methods: Three types of ceramics were evaluated: zirconium reinforced lithium
silicate, lithium disilicate, feldspathic ceramic. A total of 6 ceramic blocks, two for each
material were used in the study. Each block was cut into four square sections. A total of 24
ceramic surfaces were randomly distributed into 6 groups (n = 4 surfaces per group) divided
according to the variables: heat treatment: conventional firing or extended firing; test time:
immediate (24 hours after cementation) or longevity (after 1000 cycles of thermocycling). The
bond strength tests were performed in a semi-universal test machine for microshear bond
strength.
Conclusion: Extended firing did not influence the micro-shear bond strength of zirconium
reinforced lithium silicate, lithium disilicate, feldspathic ceramic.

 The aim of glazing is to seal the minute irregularities
and pores present on the surface of the fired porcelain
1) SELF GLAZE OR AUTO GLAZE (HIGH
TEMPERATURE )
2) ADD ON GLAZE-
 Higher glass modifiers
 Lower temperature
 Less durable
Unglazed ceramic has a rough surface
that may result in (depending on the
location) wear of the opposing/
adjacent teeth, plaque accumulation
and gingival inflammation, and
staining of the crown
Clinical significance

 Ceramics with their inherent brittleness and low tensile strength and with the irregularities in
their structure are inherently weak.
 The surface defects in ceramics are the specific areas for concentration of tensile stresses in the
oral cavity. Such cracks and surface irregularities/discontinuities are called stress raisers.
A.Development of residual
compressive stresses within the
surface of the material
B.Interruption of crack
propagation through the material

A. DEVELOPMENT OF RESIDUAL COMPRESSIVE STRESSES
WITHIN THE SURFACE OF THE MATERIAL
1. Development of residual compressive stresses:
-The most common method
-Introduction of residual compressive stresses within the veneering ceramic.
2. Reduced number of firing cycles:
-Multiple firings increase the thermal expansion coefficient. When this expansion coefficient
exceeds that of metal, the mismatch between the porcelain and the metal will result in stresses
during cooling that induce crack formation and propagation.

3. Optimal design of prostheses
- line angles should be well rounded for all-ceramic restorations
Tensile stresses in a ceramic- fixed partial denture can be reduced in two ways:
(a) the height of the connector can be increased to a maximum of 4 mm and
(b) (b) the radius of curvature of the gingival embrasure portion of the interproximal connector
is broadened
4. Ion exchange:
When sodium-containing glass is immersed in a molten potassium salt, the K+ ions present in
the bath exchange places with the Na+ ions present on the surface of the glass and remain in
place even after cooling

4. Thermal tempering:
The rapid cooling of the surface of material while it is still in its molten state by quenching forms
a rigid surface with a still molten inner core.
As the molten core starts to solidify it starts to shrink pulling the rigid outer surface inwards.

B. INTERRUPTION OF CRACK PROPAGATION THROUGH THE
MATERIAL
1. Dispersion strengthening
- Ceramics can be reinforced with a dispersed phase of a different metal.
- Most of the newer generation of high strength ceramics is reinforced with tougher crystalline
particles, which block crack propagation, thereby increasing fracture resistance.
2. Transformation toughening:
-A change in the crystal structure under stress, which absorbs the energy required for
propagation of the crack

• Metal ceramic systems combine the strength and
accuracy of cast metal with the esthetics of porcelain.

A veneering ceramic is fired onto the metal substructure
to produce an esthetically acceptable restoration.
The ceramic veneer is done in a minimum of two layers,
the first being the opaque layer, which masks the dark
metal and provides the metal–ceramic bond.

• Gold-platinum-palladium
• Gold palladium
• Gold palladium silver
• Palladium silver
• High palladium
• Nickel-chromium
• Cobalt-chromium
• Other systems
NOBLE METAL
ALLOYS
BASE METAL
ALLOYS

1. The alloy must have a high melting temperature. The melting range must be substantially higher
(greater than 100°C) than the firing temperature of the veneering porcelain.
2. The veneering porcelain must have a low fusing temperature so that no creep, sag, or distortion of the
framework takes place during sintering.
3. The porcelain must wet the alloy readily when applied as a slurry to prevent voids forming at the
metal-ceramic interface. In general, the contact angle should be 60 degrees or less
4. A strong bond between the ceramic and metal is essential and is achieved by chemical reaction of the
opaque porcelain with metal oxides on the surface of metal and by mechanical interlocking made
possible by roughening of the metal coping.

5.CTEs of the porcelain and metal must be compatible so that the
veneering porcelain never undergoes tensile stresses, which would lead
to cracking.
6. Adequate stiffness and strength of the metal framework are especially
important for FDPs and posterior crowns
7.High resistance to deformation at high temperature is essential.
8. Adequate design of the restoration is critical. The preparation should
provide for adequate thickness of the metal coping, as well as enough
space for an adequate thickness of the porcelain to yield an esthetic
restoration.

 High strength values due to
metal reinforcement. More
fracture resistant.
 Improved fit on individual crowns
provided by cast metal collar.
 Less tooth structure removal
compared to all ceramic restorations.
• Difficult to obtain good esthetics due to
increased opacity of metal substructure.
• More difficult to create depth of
translucency because of dense
opaque porcelain
• Preparation for metal ceramic requires
significant tooth reduction to provide
sufficient space for the materials when
compared to all metal restoration.
• Patients may be allergic to the metal

Objectives: The objective of this systematic review was to assess the 5-year survival rates and
incidences of complications of all-ceramic fixed dental prostheses (FDPs) and to compare them with
• The 5-year survival of metal–ceramic FDPs was significantly (P<0.0001) higher with
94.4% [95 confidence interval (CI): 91.1–96.5%] than the survival of all-ceramic FDPs,
being 88.6%
• The frequencies of material fractures (framework and veneering material) were
significantly (P<0.0001) higher for all-ceramic FDPs (6.5% and 13.6%) compared with
those of metal–ceramic FDPs (1.6% and 2.9%).
• Other technical complications like loss of retention and biological complications like
caries and loss of pulp vitality were similar for the two types of reconstructions over the
5-year observation period.

 Discolored teeth
 Grossly decayed carious
teeth
 Congenital anomalies
 Splinting mobile teeth
 Occlusal corrections
 Alignment corrections
• Active caries or untreated periodontal
disease.
• In young patients with large pulp chambers
due to high risk of pulp exposure
• Teeth where enamel wear is high and there
is insufficient bulk of tooth structure to
allow room for metal and porcelain.
• Anterior teeth where esthetics is
of prime importance
• Short and thin crowns

 The bond strength between porcelain and metal is an important requirement for good long-term
performance of metal-ceramic restorations.
 In general, the bond is a result of chemisorption by diffusion between the surface oxide layer
on the alloy and the porcelain.
For metal alloys that do not oxidize easily,
this oxide layer is formed during a special firing
cycle prior to opaque porcelain application
For metal alloys that do oxidize easily,
the oxide layer is formed during wetting
of the alloy by the porcelain and
subsequent firing cycle

(A) Metal-metal oxide (adhesive);
B) metal oxide-metal oxide (cohesive);
C) ceramic-ceramic (cohesive).

1.CONVENTIONAL FELDSPATHIC PORCELAIN
Naturally occurring aluminosilicates and their synthetic forms are used in dentistry. They are
known as feldspathic porcelain as they contain varying amounts of sodium and potassium
feldspars.

Silica, alumina, alkali, and alkaline earth carbonates along with feldspar are ground and mixed together
carefully and heated to about 1200°C in a large crucible to form a glassy phase with an amorphous
structure and a crystalline phase consisting of the tetragonal leucite
The mix of glass and leucite is then rapidly quenched in water, which causes the mass to shatter
into small fragments
Ball milled to obtain the desirable particle size
distribution

2.VENEERING CERAMICS
Porcelain may be veneered over metal or an aluminous core (glass ceramics and zirconia core )
opaque
Body
(dentin)
Enamel
Opaque porcelain is a thick viscous liquid that is applied in layers of 100 mm over
the metal coping to mask the metal’s color
contain high color saturation
Exhibit higher translucency

TYPES OF VENEERING CERAMICS
 1. Low-fusing ceramics: Feldspar-based and nepheline syenite-based ceramics
 2. Ultra-low–fusing ceramics: Porcelains and glasses
 3. Stains
 4. Glazes: Add-on glazes and self glaze

3. ALUMINA REINFORCED CERAMICS
1)BONDED ALUMINA CROWN WITH CERVICAL
PLATINUM FOIL RE-INFORCEMENT
2)ALUMINA TUBE PONTIC: Bridge pontic using high
profile alumina tubes as an anchorage area.
3)PLATINUM BONDED ALUMINA BRIDGE:
Reduction in fracture through retainer crown in the
bonded alumina bridge.

4.SWAGED GOLD ALLOY FOIL-CERAMIC
CROWNS
1. The thinner foil alloy coping allows a greater thickness of
ceramic, thereby, improving the esthetics
2. The gold color of the alloy improves the esthetics of the
restoration.
ADVANTAGES

5. BONDED PLATINUM FOIL CERAMIC
CROWNS
 A platinum foil coping is adapted on to the die.
 To improve the bonding of the ceramic to the platinum foil
coping, an electrodeposition technique is used.
 A thin layer of tin is electrodeposited on to the foil and then
oxidized in a furnace.

 McLean and Hughes (1965) were the first to introduce alumina (Al2O3) as a
reinforcing phase in dental porcelain. This led to the development of new
ceramic systems that used ceramic substructures without the presence of metal.
 Compared to ceramics for metal veneering, the all-ceramic materials have a
greater amount of crystalline phase (35–99 vol%)

CONVENTIONAL
POWDER SLURRY
CERAMICS
* Hi ceram – Alumina
reinforced porcelain
* Optec HSP – Leucite
reinforced porcelain
• COMPUTER -
AIDED
DESIGN/COMPUT
ER-AIDED
MILLING
(CAD/CAM)
* Cerec CAD/CAM with
aluminium oxide
coping
* Procera

Castable
ceramics
* Dicor
Infiltrated
ceramics
* In-Ceram
Pressable ceramics
* IPS empress
* Optec pressable
ceramic
Machinable
ceramics
* Cerec vitablocks
* Celay blocks
* Dicor MGC

 Stronger materials that involve better fabricating techniques.
 Can be etched and bonded to the underlying tooth structure with
newer dentin adhesives.
 Greater tooth reduction than what was previously used for PJC’s is carried out

CERAMICS BASED ON THEIR
MICROSTRUCTURAL PHASE
 Amorphous glass ceramics are made from materials that contain mainly silica, with
varying amounts of alumina.
 First used for manufacture of porcelain teeth.
 Since their mechanical properties are low (fl exural strength—50 to 60 MPa), they are
used only as veneering material over metal or ceramic substructure.
1.GLASS-BASED SYSTEMS(AMORPHOUS GLASS)

2. GLASS-BASED SYSTEMS WITH A SECOND CRYSTALLINE PHASE
Similar to that of conventional feldspathic porcelain; the difference being
the varying types of crystals that have been added to or grown in the glass
matrix. The crystalline phase can either be:
A. Leucite (formed by increasing the K2O content of the aluminosilicate
glass)
B. Lithium disilicate (adding lithium oxide to the aluminosilicate glass)
C. Fluorapatite

• Depending on the amount of leucite present, the ceramic can be
categorized as moderate or high leucite-containing ceramic
• Processed by heat pressing method
A. LEUCITE -CONTAINING
FELDSPATHIC GLASS
Leucite-containing feldspathic glass with fluorapatite—IPS
d.SIGN.

B. LITHIUM DISILICATE GLASS
CERAMICS
• A true glass ceramic introduced by Ivoclar Vivadent as Empress II (at present
as e.max® pressable and machinable ceramics)
• Much higher flexural strength than feldspathic ceramic (about three times
greater).
• Greater translucency due to the relatively low refractive index of the lithium
disilicate crystals.
Pressable lithium disilicate ceramic material—e.max®
Pressable System (Ivoclar Vivadent)

C. FLOURAPATITE –
CONTAINING
ALUMINOSILICATE GLASS
Fluorapatite, a fluoride containing calcium
phosphate [Ca5(PO4) 3F], contributes to the CTE
and optical properties of the porcelain, hence can be
used as a veneering material, so it matches the
lithium disilicate pressable or machinable core
ceramic material

3. POLYCRYSTALLINE SOLIDS
• This class of material is the solid core ceramic framework material over which
veneering porcelain is then layered, such as solid core alumina and zirconia
• These are solid, sintered single-phase (monophase) ceramics formed by
directly sintering crystals together without any intervening matrix to form a
dense, air-free, glass-free polycrystalline structure

 Zirconia is a polymorphic material that exists in three allotropes: monoclinic,
tetragonal, and cubic.
 Pure zirconia is monoclinic (m) at room temperature and this phase is stable up
to 1170°C. Above this temperature, it transforms into the tetragonal phase (t)
and then into the cubic phase (c) at 2370°C
1.Pure zirconia
2.Fully stabilized zirconia,
3.Partially stabilized zirconia (PSZ)
Zirconia-based
ceramics
PSZ, especially yttrium stabilized (3Y-TZP), is most commonly used
in dentistry

Fully sintered blocks are processed by hot isostatic pressing (HIP) at
temperatures between 1400°C and 1500°C.
The powder is prepressed into blocks or flexible molds
These blocks are then vacuum sealed in an airtight rubber or plastic bag and placed into
a fluid-filled chamber.
Pressure is then applied to the fluid and transmitted evenly around the zirconia.
Heat is applied to the chamber, which sinters the zirconia to full
density.
This process causes the block to achieve a final density close to 99% with high
hardness

milling a 100% dense presintered block of
zirconia directly
• Requires a rigid milling unit and takes 2–4 hours to mill a
coping because it is extremely difficult mill a dense
zirconia.
• No postmill sintering is required and there is no shrinkage at
all.
• The coping can be made to the exact dimensions
Extended milling time and frequent wear of the
milling burs
Disadvantage
1

2 Initially mill a partially sintered zirconia block,
which will be 50% dense
The blocks will be weaker and take much less time to mill, but require an
additional 6–8 hours of sintering postmilling. There is considerable
shrinkage
Lava (3M
ESPE)
Cercon
(Dentsply,
York, PA)
Vita YZ
(Vident/V
ita)
e.max®
ZirCAD

1. Optical qualities of the restoration due to its high opacity
2. Porosity incorporated during the manufacture of the infrastructure can affect
the strength of these restorations.
3. Bonding of zirconia to resin cement is questionable, owing to its surface
stability. Establishing a durable chemical or a mechanical bond with zirconia
is difficult

1.CONVENTIONAL POWDER SLURRY
CERAMICS
 Processing: Sintering
USE
veneering metal or ceramic framework or can also be used alone as anterior veneering
material. Eg- Aluminous porcelain crowns (PJCs), Optec HSP
CERAMICS BASED ON THEIR PROCESSING
TECHNIQUE

ALUMINOUS PORCELAIN CROWNS (PJCS)
Made with platinum foil backing which is
later removed
Mc Lean and Hughes (1965)
E.g. Hi-ceram, Vitadur N
Advantages:
• Better esthetics
Disadvantages:
• Inadequate strength for posterior teeth

OPTEC HSP
 Feldspathic composition glass filled with crystalline leucite
 Leucite reinforced porcelain – 50.6%wt
 Increased strength APPLICATIONS
• Inlays
• Onlays
• Anterior crowns
• Veneers
ADVANTAGES
• More translucent than alumina core crowns.
• Good flexural strength – 146Mpa.
• No special processing equipment
• Lack of metal or opaque substructure.
• Can be etched
DISADVANTAGES
• Higher chances of wearing of
opposing teeth
• Potential to fracture in posterior
teeth.
• Requires a special die material.

2.CASTABLE CERAMIC SYSTEMS
 Processing: casting through lost wax technique
 Casting at 1350˚C, heat treatment at 1075˚C for 10 hrs.
DICOR
First commercially available castable glass ceramic for dental use made by
Corning Glass Works
Contains 55 vol% of tetrasilicic fluormica crystals in a glass matrix
DICOR MGC
Glass ceramic Dicor with almost 70%
tetrasilicic fluormica crystals

ADVANATAGES
• Increased strength and toughness
• Good marginal adaptation (30-60 m)
• Ease of fabrication
• Improved esthetics – Chameleon effect
• Minimal processing shrinkage
• Low thermal expansion
• Minimal abrasiveness to tooth structure
DISADVANTAGES
• Inability to be coloured
internally
• Grinding of restoration may
leave white area
• Technique sensitive

3.PRESSABLE GLASS CERAMICS
Fabricated by a technique similar to injection molding
1. The wax patterns of the restorations are invested in refractory
material and heated to 850°C in a furnace to burn off the wax
and create the mold space.
2. It is then transferred to the pressing furnace
3. A ceramic ingot and an alumina plunger is inserted in to the
sprue .
4. The core or restoration is retrieved from the flask.
5. Compatible veneering porcelains are added to the core to build
up the final restoration.
6. It can also be directly fabricated as a crown in which case, the
crown is stained and glazed directly.

Laboratory steps in fabrication of crown using
pressable ceramic material (e.max® Pressable Ceramic
System, Ivoclar Vivadent) staining method

FIRST-GENERATION PRESSABLE CERAMICS
• contain 35–40 vol% of leucite as its crystalline phase.
• Due to the dispersion of these fine leucite crystals in the ceramic, the flexural strength
and fracture toughness are twice that of feldspathic ceramic.
• DISADVANTAGE - higher porosity (9%)
SECOND-GENERATION PRESSABLE CERAMICS
• Contain 65 vol% of lithium disilicate as their crystalline phase.
• The final microstructure of this generation of ceramics consists of highly interlocked
lithium disilicate crystals, 5 mm in length and 0.8 mm in diameter

IPS EMPRESS
Higher Leucite: 23.6% and 41.3%
Coefficient of Thermal Expansion – 15ppm/˚C
Stained and glazed or veneered

ADVANTAGES
• Heat pressing gives better marginal fit
• Good esthetics
• Moderately high flexural strength -112 MPa
DISADVANTAGES
• Potential to fracture in posterior areas
• Need for special equipment
APPLICATIONS
• Anterior crowns
• Veneers
• Inlays

OPTEC OPC (OPTIMAL PRESSABLE CERAMIC )
Advantages:
Good flexural strength
Translucent and dense
Can be etched and bonded to natural tooth.
Disadvantages:
Increased abrasiveness
Special equipment required

4. INFILTRATED CERAMICS
-Sadoun 1989
• In-Ceram Alumina
• In-Ceram Spinell
• In-Ceram Zirconia
Successor system of Hi-ceram, differing from this system by having sufficiently
lower grain size of aluminum oxide and thereby greater density.

Aluminum-oxide
(Al2O3)
Flexural strength processing uses
In-Ceram
Alumina (VITA
Zahnfabrik)
400-600 MPa Slip-cast, milled Crowns, FPDP
In-Ceram Spinell
(VITA
Zahnfabrik)
325-400 MPa Milled Crowns
In-Ceram
Zirconia
(VITA
Zahnfabrik)
700-900 MPa millled
Densely sintered
Crowns,
posterior FPDP
Veneers,
crowns,
anterior FPDP

APPLICATONS
- Single anterior and posterior
crowns.
- Anterior 3 - unit bridges.
- Implant supported bridges
(recently).
Advantages
• Lack of metal substructure.
• It has extremely high flexural
strength - 450Mpa strongest
all ceramic dental restorations
presently available.
• Excellent fit, as little shrinkage
occurs due to sufficient time at
optimum temperature, which
causes bonding between
particles at small areas.

DISADVANTAGES
Opacity of the material and hence can be used
only as a core.
a)Special die material and high temperature oven is
required.
b)Wear of opposing occluding enamel or dentin occurs
if the In ceram restoration is a part of heavy incisal
guidance or canine rise

Processing of infiltrated ceramics: slip casting
The core is made from fine grained particles that are mixed with water to from a
suspension referred to as a ‘slip’, is painted on a gypsum die (absorbent
refractory die).
The die draws water from the slurry under capillary pressure thereby depositing a
layer of solid alumina on the surface, which is subsequently sintered/baked at
1120oc for 10hrs to produce an opaque porous core. This process is called ‘slip
casting’

1. All-ceramic restorations exhibited superior light transmission when compared to PFM
restorations with facial or circumferential porcelain margins.
2. IPS Empress and In-Ceram Spinell all-ceramic restorations demonstrated equally good light
transmission properties.
3. IPS Empress best resembled the adjacent tooth.
4. In-Ceram Spinell presented better reflection and refraction characteristics, as well as color
matching properties, versus a PFM restoration with a 2-mm short coping and 360-degree
porcelain margin.

5.MACHINABLE CERAMICS
Processing: CAD-CAM or Copy- milling
Types:
• FELDSPATHIC PORCELAINS
• GLASS CERAMICS (Dicor
MGC light and Dicor MGC dark;
Dentsply).

• This is a machinable glass ceramic composed of fluorosilicate mica
crystals in a glass matrix.
• It has greater flexural strength than cast dicor .
• They have shown to be softer than conventional feldspathic
porcelain
• Produces less abrasive wear of the opposing tooth structure than
cerec mark I but causes more wear than cerec markII
Dicor MGC-

6. CAD-CAM CERAMICS
 (CAD-CAM) technology was first introduced in dentistry by Duret in 1988.
 Fully sintered ceramic materials available for use with CAD-CAM include feldspar-
based, leucite-based, lithium-disilicate–based, and zirconia-based ceramics
Restorations made from preprocessed
blocks of ceramics, milled by computerized
design and machine, tend to have superior
mechanical properties and density due to
standardized manufacturing process as
compared to powder/ liquid or pressed
restorations

3 parts:
– Camera or Scanner to take picture of the
preparation
– Computer to design the prosthesis
– Milling machine
Sirona CEREC blocks (glass/crystal), Empress CAD and Authentic (both
glass/leucite), IPS e.max block (lithium disilicate)
Available as monochromatic
and polychromatic blocks Lithium disilicate
molar crown milled by
CAD/CAM technique

Purpose
The purpose of this in vitro study was to determine and compare mechanical properties (flexural
strength, flexural modulus, modulus of resilience) and compare the margin edge quality of recently
introduced polymer-based CAD/CAM materials with some of their commercially available composite
resin and ceramic counterparts.
Material and methods
The materials studied were Lava Ultimate Restorative (LVU; 3M ESPE), Enamic (ENA; Vita Zahnfabrik),
Cerasmart (CES; GC Dental Products), IPS Empress CAD (EMP; Ivoclar Vivadent AG), Vitablocs Mark II
(VM2; Vita Zahnfabrik), and Paradigm MZ100 Block (MZ1; 3M ESPE).
Conclusions
The new-generation polymer-based materials tested in this study exhibited significantly higher
flexural strength and modulus of resilience, along with lower flexural modulus values compared
with the tested ceramic or hybrid materials. Crowns milled from the new resin-based blocks seemed to
exhibit visibly smoother margins compared with the ceramic materials studied.

CEREC 1 (SIEMENS LTD.)
– Came into use in
1985
– Advantages:
• Ease of use
• Single appointment
• Wide range of shapes could be milled
– Disadvantages:
• Large marginal gaps
• Inability to cut concave areas
• Difficulty of extending veneers into areas of
missing tooth

CEREC 2 SYSTEM
• Came into use in 1994.
• Benefits of Cerec 2 system:-
• Benefits for the patients:-
-Esthetic and cosmetic restoration
-Best material properties in dental ceramics.
-Biocompatible.
-Cost-effective.
-Quick turn around time (1 day laboratory time)
Perfect occlusion.
-High marginal integrity.
-No metal in mouth.

• 2) Benefits for the dentist:-
- Economic production in the laboratory.
- Increased precision.
- Better interproximal integrity.
- No polishing needed.
- Contacts optimized in the Laboratory.

CEREC 3 SYSTEM
Cerec 3 (Sirona Corp.)
– Came into use in 2000, 2001
– 3D scanning (Sirocam)
– Better computing power
• Windows 2000

ADVANTAGES
• Negligible porosity
• No impression
• Single appointment
• No lab charges
• Reduced assistant time
DISADVANTAGES
• Expensive equipment
• Lack of occlusal adjustment
• Specialized training
APPLICATIONS
Inlays, onlays,
V
eneers Crowns and
bridges

PROCERA
Procera All-Ceram
– Nobel Biocare, Sweden 1993
– 99.9% pure alumina
– 15-20% shrinkage
– Method:
• Die scanned by Procera scanner and information sent to lab
• Enlarged die fabricated by CAD-CAM process
• Powder dry-pressed
• Sintered (1600-1700˚C)
• Veneered - feldspathic porcelain

ADVANTAGES
• High Flexural strength
• High hardness
• Good marginal fit
• More translucent than infiltrated ceramics
DISADVANTAGES
• Special equipments and
computer software
APPLICATIONS
• Anterior and posterior crowns
• Inlays and onlays

The aim of this study was to quantitatively measure tooth and ceramic wear over a 2-year
period using a novel superimposition technique. Three ceramic systems—experimental hot-
pressed ceramic (EC), Procera AllCeram (PA), and metalceramic—were used
The quantitative evaluation showed more wear
in Procera AllCeram at the occlusal contact
areas, whereas the experimental and metal-
ceramic systems showed less wear.
The metal-caramic and experimental systems showed
less change, indicating improved wear resistance
compared with Procera AllCeram. In addition, enamel
opposing metal-ceramic and experimental crowns
showed less wear compared to enamel opposed by
Procera AllCeram crowns

RECENT ADVANCES IN DENTAL
CERAMICS

MONOLITHIC ZIRCONIA
RESTORATION
• Developed to overcome problems related to chipping of porcelain layers applied
over zirconia
• The microstructure of Y-TZPs for monolithic prostheses has been tailored to
improve their translucency in comparison with conventional Y-TZP.
• The better translucency of the new zirconia materials has been achieved by
means of microstructural modifications like-
Decrease in alumina content
Increase in density,
Decrease in grain size,
Addition of cubic zirconia and
Decrease in the amount of impurities
and structural defects.

Fifty patients were recruited and underwent restoration with a Lava Plus
monolithic zirconia crown (Lava™ Frame Zirconia, 3M Espe, Germany)
on premolars or molars. Patients were monitored over a 5-year follow-up
(2014-19), recording any biological and/or mechanical complications
-The survival rate was 98% after 5 years. Only 6% of the crowns
presented some type of complication (two debonding and one root
fracture). No fracture or fissures were detected.
-The monolithic zirconia crowns suffered less wear than the enamel
of antagonist teeth.

Polymer infiltrated ceramic networks
(PICNs)
• The material is considered a resin-ceramic composite material, composed
of two interconnected networks: a dominant ceramic and a polymer.
• Developed based on the glass infiltrated ceramic technology (In-Ceram
System, Vita, Bad Sachingen, Germany), which was originally released by
Vita in the 90’s.
ADVANTAGE- An elastic modulus that is
approximately 50% lower compared to
feldspathic ceramics and hence closer to that of
dentin, they are easier to mill and adjust, and
can be more easily repaired by composite resins
DISADVANTAGE- Due to the inferior optical
properties, PICNs are more suitable in the molar
than in the anterior region Vita enamic

SHRINK-FREE
CERAMICS
CERESTORE SYSTEM
• The application of an all ceramic crown employing a
unique shrink-free alumina substrate with specially
formlulated porcelain veneers (cerestore system) offers a
viable alternative to both the metal ceramic crown and
traditional PJC.
• The development of the advanced alumina ceramic
substrate allows the construction of highly durable all
ceramic restorations with exceptional fit.

METHOD
• The shrink free- ceramic can be formed directly on the master die,
producing extreme accuracy of fit .
• A master die made from a special epoxy resin die material, which is heat
stable and undergoes permanent controlled expansions during curing.
• The ceramic substrate supplied as dense pellet of the compacted shrink free
formulation is heated until it is flowable (160oC) and then transferred by
pressure into a suitable mold directly on the master die. After it sets, the green
substrate is removed from die and sintered/controlled firing is carried out
resulting in zero shrinkage of the ceramic

 Hahn (1995, 1997) proposed a new ceramic material that is a
hybrid between organic and inorganic components.
Polyvinyl siloxane 50 vol%
– Ti 30%
Inert filler (Al2O3) 15%
Titanium boride 5%
 Mixture can be handled like composite and cured .
 Firing - 1150ºC for 6 hrs in N2 atmosphere
HYBRID
CERAMICS

CEROMERS
• Ceromer is an acronym for
“ceramic optimized polymer”.
• This restorative material is biocompatible,
metal free which exhibits the strength and
potential wear resistance of metal supported
restorations and can be effectively adjusted
and polished chair-side

ADVANTAGES:
– Good wear resistance
– Good strength
– Easily contoured
DISADVANTAGES:
– Needs complete isolation
– Cannot be used in very high
stress regions
– Preferably supra-gingival
margins
APPLICATIONS
– Posterior bridge
– Implant restorations
– Fillings
– Repair of ceramics

Although Ceramics had a great past in dentistry and are the most esthetic
materials to restore missing tooth structures, it is evident that clinical research is
slower in catching up with the fast advancements occurring in the field of
ceramic technology.
when selected judiciously and used correctly, all-ceramic restorations can have
excellent esthetic, biological, and mechanical/physical properties. The end result
can be both attractive to patients and rewarding to the clinician

 Philips. Science of dental materials. Kenneth J. Anusvice. XIIth Edition.
 Robert G. Craig. Restorative dental materials.Xth Edition. Mosby Publication.
 Ronald E. Goldstein. Esthetics in dentistry. IInd Edition.
 Barry G. Dale, Kenneth W. Ascheim - Esthetic dentistry, IInd Edition
 Vimal K Sikri- Textbook of Operative Dentistry, 4th edition.
 Recent advancements in materials for all ceramic restoration, Jason A. Griggs
 Materials used in dentistry : S Mahalaxmi

• Silva LHD, Lima E, Miranda RBP, Favero SS, Lohbauer U, Cesar PF. Dental ceramics: a review of
new materials and processing methods. Braz Oral Res. 2017 Aug 28;31(suppl 1):e58.
• Wang W, Chen J, Sun X, Sun G, Liang Y, Bi J. Influence of Additives on Microstructure and
Mechanical Properties of Alumina Ceramics. Materials (Basel). 2022 Apr 18;15(8):2956
• Costa SO, Lima SNL, Nassif MV, Millan Cardenas AF, Tavarez RRJ, Lima DM, Bandeca MC.
Evaluation of the Bond Strength of Densely Sintered Ceramics Subjected to Extended Firing. Clin
Cosmet Investig Dent. 2021 Sep 1;13:371-377
• Sailer I, Pjetursson BE, Zwahlen M, Hämmerle CH. A systematic review of the survival and
complication rates of all-ceramic and metal-ceramic reconstructions after an observation period of
at least 3 years. Part II: Fixed dental prostheses. Clin Oral Implants Res. 2007 Jun;18 Suppl 3:86-
96.
• Raptis NV, Michalakis KX, Hirayama H. Optical behavior of current ceramic systems. Int J
Periodontics Restorative Dent. 2006 Feb;26(1):31-41.
• Awada A, Nathanson D. Mechanical properties of resin-ceramic CAD/CAM restorative materials.
J Prosthet Dent. 2015 Oct;114(4):587-93.
• Solá-Ruiz MF, Baixauli-López M, Roig-Vanaclocha A, Amengual-Lorenzo J, Agustín-Panadero R.
Prospective study of monolithic zirconia crowns: clinical behavior and survival rate at a 5-year
follow-up. J Prosthodont Res. 2021 Aug 21;65(3):284-290. doi: 10.2186/jpr.JPR_D_20_00034.
Epub 2020 Oct 14. PMID: 33041280.

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