recent advances in ceramic

1. Presented by-
Dr. Prerna chandak
1st yr PG student
CERAMICS
1 Ceramics

2. CONTENTS
Introduction
History of Ceramic
Composition of Ceramic
Properties
Classification of Ceramic
Method of strengthening Ceramic
2 Ceramics

3.  Ceramic is derived from GREEK word
“ K E R A M I K O S ” meaning Burnt
earth.
 Ceramic is therefore an earthy material,
usually of a silicate nature.
Introduction
3 Ceramics

4. According to GPT 9
Ceramic is defined as Compounds of one or more
metals with a nonmetallic element, usually oxygen
they are formed of chemical and biochemically stable
substances that are strong , hard, brittle, and inert
non-conductors of thermal and electrical energy.
4 Ceramics

5.  Dental ceramics are attractive because of their
biocompatibility, long-term colour stability, chemical
durability ,wear resistance, and ability to be formed into
precise shapes.
5 Ceramics

6. According to GPT 9
Ceramics6
 Porcelain is defined as Ceramic material formed of
infusible elements joined by lower fusing materials most
dental porcelains are glasses and are used in the
fabrication of artificial teeth for dentures, pontics and
facings, metal ceramic restorations, including fixed dental
prostheses, as well as all ceramic restorations such as
crowns, laminate veneers, inlays ,onlays, and other
restorations .

7. HISTORY
&
EVOLUTION OF CERAMICS
7 Ceramics

8. Ceramics8
In 700 B.C., the Etruscans made
artificial teeth of ivory , bone,
human teeth, and animal teeth
(possibly oxen).
One of the first sets of dentures made
for U.S. President George Washington
contained extracted teeth but later his
dentures were made of hippopotamus
ivory.

9. The first porcelain tooth material was patented in 1789 by a
French dentist de Chemant in collaboration with a French
pharmacist Duchateau.
The first ceramic crowns and inlays were made by C.H.LAND in
1886. He fused feldspathic to burnished platinum foil.
9 Ceramics
In 1962, Weinstein patented a leucite-containing porcelain frit
for use in metal-ceramic restorations.

10. The first commercial porcelain was developed by Vita
Zahnfabrik in about 1963.
 The popularity of all ceramic systems increased after the
introduction of alumina reinforced dental porcelain by
McLean and HUGHES in 1965 .
10 Ceramics

11. Composition of ceramic
11 Ceramics

12. The various ingredients used in different
formulations of ceramics are :
1.Silica (Quartz or Flint) – Filler
2.Kaolin (China clay) – Binder
3.Feldspar – Basic glass former
4.Water – Important glass modifier
12 Ceramics

13. 5.Fluxes – Glass modifiers
6.Colour pigments
7.Opacifying agents
8.Stains and colour modifiers
13 Ceramics

14. Silica is the basic structural unit of
the glass network
Silica (SiO2): crystalline quartz,
crystalline cristobalite,
crystalline tridymite, and
noncrystalline fused silica.
Silica
14 Ceramics

15. Fluxes (low-fusing glasses) are often included to reduce the
temperature required to sinter the porcelain powder
particles at sufficiently low temperatures so that the alloy to
which it is fired does not melt or sustain sag (flexural creep)
deformation.
Fluxes
15 Ceramics

16. Boric Oxide fluxes
 Boric Oxide (B2O3) although a powerful flux (glass
modifier), it can also act as a glass former and form its own
glass network, producing Boron Glasses.
16 Ceramics

17. Glass Modifiers
 Can be defined as elements that interfere with the
integrity of the SiO2 (glass) network and alter their three-
dimensional state. Their functions are:
 To decrease the softening point by reducing the amount of
cross linking between oxygen and glass forming elements.
 Decrease the viscosity (flux action increasing the flow)
17 Ceramics

18. Hydrated aluminium silicate
Its functions are:
• Acts as a binder It gives opacity to the mass and helps in
maintaining the shape of the unfired porcelain during firing.
• At high temperature, it fuses and reacts with other
ingredients to form the glassy matrix.
Kaolin ( White China Clay)
18 Ceramics

19. Feldspars
 Types of feldspar :
 Soda feldspar –
Decreases fusion
temperature
 Potash feldspar –
Increases the viscosity of
glass.
19 Ceramics

20. Role of feldspar
 Glass phase formation: During firing, the feldspar fuses
and forms a glassy phase that softens and flows slightly
allowing the porcelain powder particles to coalesce
together. The glassy phase forms a translucent glassy
matrix.
 Leucite formation: Another important property of feldspar
is its tendency to form the crystalline mineral leucite.
20 Ceramics

21. Leucite
 Is a potassium-aluminum-silicate mineral with a high
coefficient of thermal expansion ( 20-25x100C) compared
to feldspathic glasses ( 10x100C). Feldspar heated at
temperature of 11500c and 15300c it undergoes
incongruent melting.
21 Ceramics

22. Functions of Leucite
 To raise the coefficient of thermal expansion of porcelain and bring
it closer to that of the metal substrate, consequently increasing the
hardness and fusion temperature.
22 Ceramics

23. Intermediate Oxides/ Glass
former
Addition of glass modifiers to reduce the softening point also
decreases the viscosity, resulting in slump or pyroplastic flow;
hence it is necessary to produce glasses with high viscosity as
well as low firing temperature. This can be done by the
incorporation of an intermediate oxide such as alumina (Al2O3),
to increase the viscosity of glass.
23 Ceramics

24. Colouring agents
 Dental porcelains coloured by the addition of concentrated
colour frits which are prepared by fritting high
temperature resistant colouring pigments (generally
metallic oxides) into the basic glass.
24 Ceramics

25. The colour pigments used are:
 Yellowish brown – Titanium oxide
 Blue -Cobalt salts in the form of oxide
 Green - Copper oxide
 Brown- nickel oxide/iron
 Lavender- manganese oxide
25 Ceramics

26. Opacifying agents
The common metallic oxides used are –
 Cerium oxide
 Titanium oxide
 Zirconia oxide
26 Ceramics

27.  Tin oxide and Zirconium oxide (ZrO2)- most popularly used
opacifying agent (usually added with the concentrated
colour frit to the porcelain during final preparation.
27 Ceramics

28. Dental ceramic Classification
According to sintering temperature
 High fusing > 13000C Denture teeth
 Medium fusing 1101 –13000
 Low fusing 850 – 11010 C crown& bridge
 Ultra low fusing <8500C.
28 Ceramics

29. ACCORDING TO TYPE:
•Feldspathic porcelain
•Aluminous porcelain
•Glass infiltrated aluminous
•Glass infiltrated spinel
•Glass ceramics
29 Ceramics

30. ACCORDING TO USE
 Ceramic for artificial teeth
 Jacket crown, inlay and onlay ceramic
 Metal ceramic
 Anterior bridge ceramic
30 Ceramics

31. ACCORDING TO SUBSTRATE
MATERIAL
 Cast metal
 Sintered metal
 Swaged metal
 Glass ceramic
 CAD/CAM.
31 Ceramics

32. Currently available all-ceramics can
be broadly categorized according to
their method of fabrication
Conventional (powder – slurry)
ceramics
Infiltrated ceramics
Castable ceramics
Pressable ceramics
Machinable ceramics
32 Ceramics

33. Properties of porcelain
 The characteristic properties of porcelain are hardness,
compressive strength, esthetic, opacity, translucency.
 Low to moderate fracture toughness.
 Refractory nature
 Insoluble in oral environment.
 Extremely biocompatible.
 Resistance to thermal and chemical attack.
33 Ceramics

34. Flexural strength
 Ground porcelain 75.8 Mpa
 Glazed porcelain 141.1 Mpa
 Compressive strength 331 Mpa
 Tensile strength 34Mpa
 Shear strength 110 Mpa
34 Ceramics

35. Disadvantages
 The major weakness of ceramics is their inability to flex
and to fracture at a minimum deformation of 0.1%.
 Brittleness is its biggest disadvantage and a major
disadvantage to porcelain is decreased tensile strength.
 Another major drawback is the potential to cause abrasive
wear on the opposing dentition.
35 Ceramics

36. Methods of strengthening brittle materials
1.Ion exchange
2.Thermal tempering
3.Thermal compatiability
Minimise stress concentration
1. Reducing stress raisers
2. Minimise tensile stresses
Residual compressive
stresses
Interruption of crack
propagation
Addition of
dispersion phase
Change in crystalline
structure
Particle stabilized
zirconia
Toughness of
particle
Alumina
,leucite
36 Ceramics

37. Ionexchange/chemical tempering
.
Potassium ion is about 35%
larger than the Sodium ion.
Which Increases flexural
strength of feldspathic
porcelains.
37 Ceramics

38. THERMAL TEMPERING
 Rapidly cooling the surface of the object while it is hot and
in the softened (molten) state.
 As the molten core solidifies, it tends to shrink, but the
outer skin remains rigid which create residual compressive
stress.
 It is more effective to quench hot glass-phase ceramics in
silicone oil or other special liquids.
38 Ceramics

39. Thermal Compatibility
39 Ceramics
•The metal ceramic should be selected with a slight mismatch in their
thermal coefficient. So that the metal contract slightly more than
ceramic on cooling from the firing temperature to room temperature .
•This mismatch leaves the ceramic in residual compression and
provide additional strength for the prosthesis.

40. Transformation toughening
40 Ceramics
•When small tough crystals are homogenously distributed in the
glass, the ceramic structure is strengthened because cracks cannot
penetrate the fine part as easily as they can penetrate the glass.
•Various dispersed crystalline phase include alumina ,leuite,
tetrasilicic fluoromica ,lithia disilicate and magnesium alumina
spinel.

41. •When zirconia is heated between 1470-2010 oC and cooled to
room temperature its crystal being to change from tetragonal to
monoclinc phase at about 1150 oC.
During heating there is large volume expansion and high tensile
stress this causes zirconia to crack during cooling.
Additives like 3 mol% yttrium oxide can prevent this polymorhic
transformation
41 Ceramics

42. 42 Ceramics

43. METAL CERAMIC RESTORATIONS
Ceramics43
 The metal-ceramic restoration first became
available commercially during the later 1950.
 The metal-ceramic restoration consists of a metal
substructure supporting a ceramic veneer that is
mechanically and chemically bonded .

44. Ceramics44

45. Ceramics45
c
c

46. Ceramics46

47. Three factor control the durability of metal -
ceramic bonding
Ceramics47

48. Failure of metal ceramic crown
Ceramics48

49. Advantages
Ceramics49
 Better fracture resistance because of the metal
reinforcement.
 Better marginal fit because of the metal frame .

50. Disadvantages
Ceramics50
 Comparatively less esthetic (when compared to the all
porcelain crown) because of the reduced translucency as a
result of the underlying metal and the opaque .
 Margins may appear dark because of the metal.
 This sometimes shows through the gingiva causing it to
appear dark and unesthetic

51. Compared to Metal-ceramics, the advantages
of All-ceramic restorations include:
• Increased translucency
• Improved fluorescence
• Greater contribution of color from the
underlying tooth structure
• Inertness
• Biocompatibility
• Resistance to corrosion
• Low temperature / electrical
conductivity
51 Ceramics

52. Newer types of All Ceramic
Restorative Materials
• Eg. : Optec HSP
• In-Ceram
• Cerec
• Celay
• IPS Empress
• Optec Pressable Ceramic
Variations of
feldspathic porcelain
• E.g. : Dicor
• Duceram LFC
Entirely Different
compositions
52 Ceramics

53. CONVENTIONAL
POWDER/ SLURRY
CERAMICS
53 Ceramics

54. (1965 Mc lean and Hughes)
•40 t0 50 wt% of Al2O3 (interrupt crack propagation)
•Feldspar
•Quartz
•kaolin
•Flexural strength 131 Mpa
ALUMINOUS CORE PORCELAIN
(Hi-Ceram)

55. Finished Cores
Master model with
dies
Platinum foil adapted to die
Platinum foil adapted to die
Platinum foil technique ALUMINOUS PORCELAIN

56. Unsintered Crowns
Dentin Ceramic additions
Finished Crowns on
dies
Post-Cementation
ALUMINOUS PORCELAIN

57. Advantages
Fracture Resistance in the aluminous PJC improved
platinum matrix was left in the completed but diminished esthetic.
.
Disadvantage
Low coefficient of thermal expansion in the range of 8 x 10-6/0C.
Requires specially formulated and compatible enamel and dentin
porcelains for veneering.
1) Improvement in strength is insufficient to bear high stresses
Decrease the amount of light transmitted

58. Magnesia – Reinforced Porcelain
O’Brien in 1984
• High expansion ceramics
• Core material.
• Crystalline magnesia (40-60%) ‘Forsterite’.
• Magnesia crystals strengthen glass matrix by both dispersion
strengthening and crystallization within the matrix .
• Flexural strength (131 Mpa)
• Glazed strength (269 MPa)

59. ADVANTAGE:
• Increased co-efficient of thermal expansion
• Improved strength (glass infiltration of magnesia core)

60. • FELDSPATHIC PORCELAINS.
• Leucite crystals in the glass - matrix (50%).
• Condensed and sintered on a refractory die.
• Strength nucleation and growth of leucite crystals.
• Transluceny closeness of the refractive index of leucite
with that of the glass matrix
• Flexure strength is approximately 140 MPa..
LEUCITE – REINFORCED PORCELAINS
Optec HSP

61. Advantages
• High strength despite of metal(leuicte reinforcement)
• Good translusency
• Moderate flexural strength
Disadvantage
• Marginal inaccuracy(shrinkage).
• Fracture in posterior teeth.
• High abrasive effect on opposing teeth.

62. HYDRO THERMAL CERAMICS
Ryabov et al--1970
• Low fusing ceramics + hydroxyl groups(plastified layer)
• Melting , softening point, sintering temperatures were reduced
• Thermal expansion , strength-----not compromised
•Self healing effect---micro flaws
•Formulations:
•single phase porcelain
•leucite containing two phase material

63. DISADVANTAGES :
Cannot be directly sintered on metallic substructure .Inner lining of
conventional high-fusing ceramic is required on the metal substructure
because of the low coefficient of expansion.

64. DUCERAM LFC
FABRICATION:
Duceram MC -----base layer-----9300 c
Duceram LFC------6600 c-----no glaze required
Fabrication:
Refractory die----mc slurry(930)-----LFC(660)----no glaze
.
GOLDEN GATE SYSTEM: Gold alloy + ducera LFC
DUCERA GOLD: Type IV gold + ducera LFC
HYDRO THERMAL
CERAMICS

65. Advantages:
•Lower fusion temperature (680-7000 C)
•Increased coefficient of thermal expansion
•Minimal abrasion of opposing dentition( natural teeth)
•Greater toughness and durability
•Greater density
•Higher flexural strength attributed to OH- ion exchange and sealing
of surface microcracks
•Greater fracture resistance
•Surface resistant to chemical attack by fluoride containing agents.
•Highly polishable, not requiring re-glazing during adjustment

66. CASTABLE CERAMICS

67.  Castable glass-ceramic systems was developed by
Corning glass worker and introduced by Dentsply
international.
 Castable glass that is formed into an inlay, facial veneer or
full crown by lost wax process similar to that employed
for metals.
Glass ceramic (Dicor )
67 Ceramics

68. Glass casting
core/ coping
Crystal nucleation &
growth…
- veneering porcelain
Glass + covered by
protective embedment
material
Heat treatment
/ceramming
68 Ceramics

69.  Casting techniques similar to the conventional lost wax
technique used for cast-metal restorations.
 Excellent marginal fit.
 The wear on the opposing occlusion is predicted to be less
than that of conventional porcelains.
 Flexural strengths is 172 Mpa reportedly greater than it is for
conventional porcelain.
ADVANTAGES
69 Ceramics

70.  Most Translucent of all the all-ceramic materials.
 However color must be developed using several coats of
surface glaze, or Dicor must be veneered with porcelain.
 Dicor, because of its high translucency, has a chameleon-
like effect and merges with the surrounding teeth.
70 Ceramics

71. • Once stained, the surface cannot be adjusted without
compromising the esthetics.
• The colorant is a surface stain, hence any grinding on the
restoration leaves an unaesthetic opaque white area.
• Removal of the external cerammed layer has been reported to
affect the flexural strength.
• Technique sensitive.
DISADVANTAGES
71 Ceramics

72. INFILTERED CERAMICS

73. Flexural
strength
350 MPa 500 MPa 700 MPa
In-ceram
Alumina
In-ceram
Spinel
In-ceram
Zirconia
INFILTERED CERAMICS
The final In-Ceram structure consists of two 3-dimensionally
interpenetrating phases :
crystalline phase- alumina, magnesia,zirconia.
Glassy phase

74. A process used to form green ceramic shape by applying a
slurry of ceramic particles and water or a special liquid to a porous
substrate Such as a die material, there by allowing capillary action
to remove water and densify the mass of deposited particles
IN-CERAM (Vident)
( Slip casting technique )SAADOUN 1985---FRANCE

75. Composition: Alumina/ Al203 crystalline (Volume fraction) 99.56
wt% with particle size 3.8m
An Infiltration glass lanthanum aluminosilicate with small amounts
of sodium and calcium (Lanthanum-decreases the viscosity of the
glass to assist infiltration and increases its refractive index to
improve translucency).
Fabrication stages :
Slip casting
Veneering of core
INCERAM ALUMINA

76. Duplication
In-Ceram
refractory dies
In-Ceram
application
Working model
INCERAM ALUMINA

77. Al2O3 slip
10 hrs 1120 0C- vita inceramat
Shrinkage of dies Glass infiltration
4hrs 11000C

78. Application of body
and incisal porcelain
Postoperative veiw
of In-Ceram crowns
Finished In-
Ceram copings
Finished crowns
Preoperative veiw

79. VENEERING OF CORE
•Aluminous veneering porcelain (Vitadur N, Vident) of required shade is
applied by conventional powder-slurry method.
•Final firing is followed by adjustments and glazing of external surface.
•The internal surface is sandblasted (with 50 Al2O3) since the density of
In-Ceram core makes conventional methods of etching with HF acid
ineffective for bonding with a resin-cement.

80. PROPERTIES
STRENGTH :
• The densely packed crystalline particles (70% alumina) limit crack
propagation and prevent fracture.
• The flexure strength is extremely high in the 450 MPa range (the
strongest all-ceramic dental restoration presently available).

81. COLOR :
•The final color of the In-Ceram restorations is generally influenced by
the color of the alumina core, which tends to be opaque.
•The colorants used generally consist of transitional metal ions
incorporated into the glass structure itself.
•However, in the spinel variety, the core is more transparent and its
corresponding infiltration glass is slightly tinted.

82. USES:
Single anterior & posterior crowns
Anterior 3-unit FPD's
ADVANTAGE:
•Minimal firing shrinkage, hence an accurate fit.
•High flexure strengths (3 times).
•Aluminous core being opaque can be used to cover darkened teeth
or post/ core.
•Wear of opposing teeth is lesser
•Improved esthetics due to lack of metal as substructure.
•Biocompatible, diminished plaque accumulation, .

83. DISADVANTAGES:
•Requires specialized equipment.
•Poor optical properties or esthetics (opaque alumina core).
•Incapability of being etched .
•Slip casting is a complex technique and requires considerable
practice.
•Considerable reduction of tooth surface

84. Improvement in optical properties
Incorporating magnesium- alumina spinel (Mg Al2O4)
( translucency)
Fabrication: similar to In-Ceram crowns
IN-CERAM SPINELL

85. Ceramics85
Advantage
Spinel renders greater strength characteristics.
Spinel has extended uses(Inlay / Onlay, ceramic core
material and even Veneers.)
spinel exhibited better translucency than alumina

86. Disadvantage:
•Incapable to be etched by HF.
•25% reduction in flexural strength.

87. Mixture of zirconium oxide 20% aluminia 62% and 18%
infiltrated glass is a framework material improved physical
properties .
PROPERTIES:
• High flexural strength ( 1.4 times the stability 2-3 times impact
capacity compared to ln-Ceram Alumina),
• Excellent Marginal Accuracy
• Biocompatibility.
IN-CERAM ZIRCONIA

88. Ceramics88
This technique allows fabrication of all-ceramic bridges even in the
posterior molar area.
Disadvantage :
Poor esthetics due to increased opacity.

89. PRESSABLE CERAMICS

90. SHRINK FREE LEUCITE REINFORCED
cerestore IPS Empress
al – ceram optec pressable
PRESSABLE CERAMICS
INJECTION MOLD GLASS CERAMIC

91. Ceramics91
CERESTORE is a shrink-free ceramic with crystallized
magnesium alumina spinel fabricated by the injection molded
technique to form a dispersion strengthened core.
Composition (Core)
Al2O3 (Corundum) 60%
MgAl2O4 (Spinel) 22%
BaMg2Al3(Barium Osomilite) 10%

92. Properties :
•Flexural strength : 225 Mpa
•Fit : exceptional fit because of direct moulding process.
•Low thermal conductivity
•Radio density similar to enamel
•Biocompatible
CERESTORE

93. Advantages
•Dimensional stability of the core material in the molded
(unfired) and fired states.
•Esthetics.
•Biocompatible (inert) and resistant to plaque formation
(glazed surface).
•Radio density similar to that of enamel (presence of barium
osmolite phase in the fired core allows radiographic
examination of marginal fit )
CERESTORE

94. Ceramics94
•Low thermal conductivity.
•Low coefficient of thermal expansion and high modulus of
elasticity results in protection of cement seal
•Better accuracy of fit and marginal integrity.

95. • LIMITATIONS and high clinical failure rates of the Cerestore led to
the withdrawal of this product from the market. The material
underwent further improvement and developed into a product
with a 70 to 90% higher flexural strength. This was marketed under
the commercial name Al Ceram (Innotek Dental, Lakewood, Colo.).
CERESTORE

96. IPS-EMPRESS
(PRESSABLE CERAMIC)
Hot pressed ceramics
Leucite reinforced
K2O – Al2O3 – 4 SiO2
Lithium Disilicate reinforced
2SiO2 – Li2O
IPS Empress IPS Empress 2

97. Pressable glass ceramics
Injection-molded Glass-Ceramic
IPS Empress ( Ivoclar-Vivadent)
This system uses high-temperature pressing
of a pre-cerammed glass ceramic with
hydrostatic pressure in a vaccum unit.

98. Wax pattern–de-waxed by placing ring
in cold burnout oven & heated to
850deg.C./90mins
Ring is Placed in pressing furnace
Heated ceramic ingot
Pressed into mold over 45 mins under
700-11000 C.
Pressed restoration- painted/covered
with ceramic and fired/ conventional
layering technique can be used.

99. Empress hydrostatically controlled furnace
Cold burnout
oven—
8500C/90mins.
Precerammed pellets

100. Pneumatic
plunger
Maintains
hydrostatic
pressure
1,1000 C /45mins.
under vacuum

101. Pressed ceramic restorations are cleaned with a glass bead
air abrader.

102. SURFACE STAINING
TECHNIQUE
Shading porcelains in syringes
Restoration painted
& fire(850DC/2min)
using vacuum.

103. Ceramics103
Disadvantages
• Complex specialized laboratory equipment and cost.
• Inadequate flexural strength compared to the metal-ceramic
restorations.
• Poor abrasion resistance, hence not recommended in patients
with heavy bruxism or inadequate clearance.

104. Leucite
content
Conventi
onal
Porcelain
Dicor IPS
Empress
Pressable
ceramic
30-35% 50-60% 80-85%

105. Properties :
Flexural strength : 160-180 Mpa
The increase in strength has been attributed to :
The pressing step which increases the density of leucite crystals.
Subsequent heat treatments which initiate growth of additional
leucite crystals.
Esthetics : High esthetic value
Marginal adaptation : Better marginal adaptation compared to
aluminous core material.

106. Advantages
•Lack of metal or an opaque ceramic core
•Moderate flexural strength (120-180 MPa range)
•Excellent fit (low-shrinkage ceramic)
•Improved esthetics (translucent, fluorescent)
•Etchable

107. Ceramics107
•Less susceptible to fatigue and stress failure
•Less abrasive to opposing tooth
•Biocompatible material
•Unlike previous glass-ceramic systems IPS Empress does not
require ceramming to initiate the crystalline phase of leucite
crystals (They are formed throughout the various temperature
cycles).

108. Disadvantages
• Potential to fracture in posterior areas.
• Need for special laboratory equipment such as pressing oven
and die material (expensive)
• Inability to cover the color of a darkened tooth preparation or
post and core, since the crowns are relatively translucent.
• Compressive strength and flexural strength lesser than metal-
ceramic or glass-infiltrated (In-Ceram) crowns.

109. Second generation of pressable materials for all-ceramic bridges.
•lithium disilicate crystal >60vol%.
• The apatite crystals -layered-improved optical properties
(translucency, light scattering) which contribute to the unique
chameleon effect
I P S EMPRESS 2 (Ivoclar)

110. IPS
Empress
IPS Empress 2
Flexural
strength
Upto 150
MPa
> 400 Mpa
Other applications : - Core build-up system with the pre-fabricated zircon oxide
root canal posts
.

111. Ceramics111
Advantages
•High biocompatibility
•Excellent fracture resistance
•High radiopacity
•Outstanding translucency

112. Ceramics112
•The cerammed restorations have a high degree of stability during
subsequent shading or layering techniques.
•The pre-cerammed porcelain has a high degree of flexural tensile
strength (exceeding 200 MPa).
•The versatility of the process allows for the development of very
esthetic restorations ranging from inlays & onlays to full crowns and
laminate veneers (1mm).
•Posterior teeth- fracture susceptibility need to use special, expensive
lab. equipment.

113. References
1.CONTEMPORARY FIXED PROSTHODONtic -ROSENSTIEL
2.PHILLIPS SCIENCE OF DENTAL MATERIALS -ANUSAVICE
3.FUNDAMENTALS OF FIXED PROSTHODONTICS -SCHILLINGBURG
4.CONTEMPORARY ESTHETIC DENTISTRY: -BRUCE J.CRISPIN
5.ESTHETIC DENTISTRY: AN ARTISTS SCIENCE RATNADEEP PATIL
-