The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
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dental ceramics silicate ceramics and oxidceramics/ oral surgery courses
1. Dental ceramicsDental ceramics
Silicate ceramics and oxidceramicsSilicate ceramics and oxidceramics
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
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6. Images from KaVo Everest CAD/CAM system
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7. Why use
ceramics
Biocompatibility
Aesthetics
Durability
The biocompatability issue is essential to prevent adverse
reactions within the patients
The use of dentally coloured glasses can provide
replacement structures that can be made to imitate tooth
structure in both colour, translucency and response to
different lighting sources.
Improvements in fracture toughness, wear resistance,
machinability, solubility and flexural strength
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8. Ceramics used in dentistry
Fillings
Veneering metal frameworks
All ceramic restorations
Denture teeth
Implants
Orthodontic brackets
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10. Glass matrix + Crystals
An overcooled
liquid
Not crystalline, but
still ordered structure
Silica tetrahedron
network
Glass modifiers
built in network
Most important crystals:
Leucit
Fluormica
Aluminium
Spinell
Zirconia
They determin the
physicalphysical, chemicalchemical and opticaloptical
properties of the ceramics
(their composition varies in each type of ceramic)
Basic structure of dental ceramics
Two different phases built by metallic (Al,Ca, Mg, K etc) and non-metallic (Si, O,
B, F etc.) elements:
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11. First ceramic material in dentistry
Feldspathic Porcelain:
derived from the natural mineral feldspar
75%feldspar,22-25% quartz, 0-3% kaolin
Feldspar:
Provides for transparency and influences the flow characteristics of the
ceramics.
Quartz (silicon oxide):
Provides for adequate strength and also for transparency.
Kaolin:
Provides for the necessary opaque properties.
Fritting:-cleaning and mixing raw materials, heating, melting, sudden
cooling and grinding to fine powder
Sintering:powder mixing with liquid, firing, powder particles stick
together
Shrinkage:appr. 30 vol%
Structure: leucite crystals in silica glass matrix
Disadvantage:brittle,hard,rigidwww.indiandentalacademy.com
12. Image from Bego Virtual Academy
Veneering metal frameworks
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19. Veneering ceramics
Used for the porcelain-fused-to-metal technique
Based on modified feldspathic porcelain
Binding oxides for metal-ceramic bond
Leucite content:thermal expansion coeff.
Fusing temperature 200-250 C lower than metal framework (low fusing
ceramics)
Synthetic ceramics (metal –ceramics)
No natural raw materials
Made of high purity chemicals
Tempering:guided heating process, to
form certain type, size, amount and
dispersion of crystals (micro-leucite
crystals
Standard physical, chemical and optical
properties
Standard quality
Low or ultra-low fusing temperature
Hydrothermal ceramics
• tempering and fusing in high pressure
steam
• Hydroxil ions built in glassy matrix
• Compact and homogenous structure
• Better fracture toughness and lower
hardness
• Leucite content allows veneering
frameworks
• Ultra-low fusing temp. Can be achieved
• Pure glass can be used for dental
purposes (one and only among dental
ceramics)www.indiandentalacademy.com
20. The bonding of ceramic
materials to alloys
follows four principles:
Shrinking the ceramic onto the metal frame -
coefficient of thermal expansion
Chemical bond The bond is formed by means of
oxygen bridges between the silicon atoms of the
ceramic and the metal oxides of the alloy.
Mechanical retention is created through finishing and
blasting of the frames-surface enlargement also takes
place.
Bonding through adhesion takes place via
intermolecular forces (VAN DER WAAL forces)www.indiandentalacademy.com
22. driving forces for developments:
Public perception that metal-free restorations are more
aesthetic
Disadvantages of the metal ceramic systems include
radiopacity, some questions centring around metal
biocompatibility and lack of natural aesthetics
Difference in reliability between metal-ceramic systems
and all-ceramic systems
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23. All ceramic restorations
Laboratory processing
Silicate ceramics
o Sintering
o Casting
o Pressing
o CAD/CAM
Oxidceramics
o infiltration and /or CAD/CAM technology
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24. SinteringSintering is a method for making objects from powder, by heating the
material (below its melting point) until its particles adhere to each other
The base-material for heating ceramic on:The base-material for heating ceramic on:
- platinum foilplatinum foil (removable heat-resistant cap
from the gypsum cast)
- Heat resistant investment material madeHeat resistant investment material made
castcast
- Hydrothermal glass/ Duceram LFCHydrothermal glass/ Duceram LFC
SinteringSintering
under vacuumvacuum to prevent
porositieswww.indiandentalacademy.com
25. Casting (Dicor)
CastingCasting is a process by which a
material is introduced into a mold
while it is liquid, allowed to solidify in
the shape inside the mould, and then
removed producing a fabricated
object
Cast using lost-wax investment method
followed by heat-treatment to
precipitate a crystalline phase
Pressing (Empress)
PressedPressed ceramic technology produces
consistently precise crowns by
eliminating shrinkage, porosity and
the inconsistency of brush build-upswww.indiandentalacademy.com
26. Glass Ceramic
first a glassy matrix is produced
precursors of crystals are in glassy matrix, crystals
produced by tempering (heating),
“bonded” to the remaining tooth structure using a dental
BisGMA based composite resin
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27. Glass infiltration
Oxidceramics
Glass infiltrated Alumina system
In-ceram Alumina
In-Ceram Spinell
In –Ceram Zirconia
Slip-cast slurry in porous mould-sintered
— infiltration by low viscosity glass —
veneered with more translucent
feldspathic frit
Slip-cast slurry: A fine particle ceramic dispersed in an
aqueous liquid medium is poured into a porous mould
which rapidly extracts the liquid causing the formation
of a close-packed but weak ceramic particle structure.www.indiandentalacademy.com
28. Polycrystal Oxid ceramics
High strength underlying core to support veneering
porcelain which gives the final shape and aesthetic
attributes required for the restoration.
Yttrium stabilized Zirconium -dioxide ceramics:
ZrO2 95%+ 5% Yttrium
More to come: lecture on CAD/CAM systems
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29. Thank You forThank You for
Your attentionYour attention
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