This document discusses different types of all-ceramic dental restorations. It describes 6 main classifications: 1) Condensed ceramics like feldspathic porcelain and leucite-reinforced cores 2) Castable glass ceramics like Dicor 3) Machinable glass ceramics like Dicor MGC 4) Pressable glass ceramics like IPS Empress and IPS Empress 2 5) Slip-cast glass infiltrated ceramics like In-Ceram Alumina, Spinell, and Zirconia 6) Milled ceramic restorations/cores made from blocks using CAD-CAM or copy milling. For each classification, the document provides details on composition,

1. ALL-CERAMIC
RESTORATIONS
Dr MEENU MERRY C PAUL
Professor-Prosthodontics
Malabar Dental College

2. CLASSIFICATION OF ALL-CERAMICS
1. Condensed - sintered
 Traditional feldspathic PJC
(used on small anterior restoration..maxi lateral incisor)
 PJC with aluminous core (Hi-Ceram)
…..not for posterior teeth
…..Alumina has high fracture toughness
….better esthetics than metal-ceramic
 Leucite-reinforced core
....greater leucite high flexural strength(104 MPa)
high compressive strength
high TE coefficient
….More esthetic than aluminous porcelain
 Magnesia-based core…flexural strength (131 MPa)

3. 2. Castable Glass Ceramics (Dicor)
3. Machinable Glass Ceramics (Dicor MGC)
4. Pressable Glass Ceramics
 IPS Empress (leucite-reinforced)
 IPS Empress 2 (lithia disilicate reinforced)
5. Slip cast-Glass Infiltrated Ceramics
 Glass infiltrated aluminous core(In-Ceram
Alumina)
 Glass infiltrated spinell core(In-Ceram Spinell)
 Glass infiltrated zirconia core(In-Ceram Zirconia)
6. Milled Ceramic Restoration/Cores
(Blocks/blanks of various ceramics are machined to form the
restoration…eg: Alumina, Zirconia, Lithia disilicate)
 CAD-CAM restoration
 Copy milled restoration

4. GLASS-CERAMIC is formed into the desired shape as a glass,then subjected to
heat treatment to induce partial vitrification(loss of glassy structure by
crystallization of glass)
Glass ceramics…are partially crystallized glass and show properties of both
crystalline and amorphous (glassy) materials.
CASTABLE GLASS CERAMICS-Dicor

5. DICOR
The first commercially available castable glass-ceramic material for dental use
Developed by The Corning Glass Works (Corning N.Y.) and marketed by Dentsply
(U.S.A)
DICOR…. 55 vol % tetrasilicic fluormica crystals
….initially cast as a glass by a lost-wax technique and subsequently heat-treated
resulting in a controlled crystallization to produce a glass - ceramic material.
Dicor….55 vol% tetrasilicic fluormica crystals
Dicor MGC..70 vol% tetrasilicic fluormica platelets
(2μm diameter)
….a higher quality product
…has been crystallized by manufacturer
& provided as CAD-CAM blanks/ingots
…mechanical properties similar to DICOR,
but has less translucency

6. DICOR
USES…. Inlay, facial veneer, full crown(low stress)
MODE OF SUPPLY
…..originally supplied as glass ingots that were melted &
cast into refractory mold
…..A precrystallized form called Dicor MGC is available as
machinable blanks for CAD-CAM
EQUIPMENT
 DICOR Casting Machine
 DICOR Ceramming Furnace with Ceramming Trays

7. Casting
•Similar to “lost-wax technique”
•The only porcelain restoration made by
centrifugal casting technique
•Wax pattern…investing
•Wax burnout..nuggets of dicor melted(1350°C),
cast into mold
•Glass casting carefully removed
FABRICATION OF DICOR
 Casting
 Ceramming

8. Ceramming
• Glass casting is then covered by a protective
“embedment” material & subjected to
a heat treatment that causes
crystals of crystalline material(mica) to grow
within the glass matrix.
• This crystal nucleation&crystal growth…CERAMMING
• After ceramming,the glass is fitted on die….
• …..Coated with veneering material

9. Chameleon effect of DICOR
This means Dicor glass – ceramics change color according to their surroundings, which enhances
its esthetic properties.Part of color of restoration is picked up from adjacent teeth as well as from
luting cements
The transparent crystals scatter the incoming light. The light and also its color, is disbursed as if
the light is bouncing off a large number of small mirrors that reflect the light and spread it over the
entire glass-ceramic.

10. PRESSABLE GLASS CERAMICS
(HOT PRESSED)
(INJECTION MOLDED)
…heat pressing relies on the application of external pressure to sinter & shape the
ceramic at high temp

11. IPS Empress
leucite (K Al Si2 O6) reinforced-35 vol%
Wax pattern…invested…mold formed
Molten Feldspathic glass is forced into the mold
at 1150-1180°C under pressure(in a pressing furnace)
It is allowed to cool under controlled conditions which allows reinforcing leucite crystals
to form
Veneered with LEUCITE CRYSTALS in a glass matrix

12. IPS Empress 2
Lithium disilicate (Li2 Si2 O5) reinforced-70 vol%
Heat Pressed at 890-920°C
Veneering ceramic contains APATITE CRYSTALS..
(Coefficient of expn…9.7ppm/°C)
This veneering ceramic should not be used with
IPS Empress - whose coefficient of expn is high
....15.0ppm/°C

13. ADVANTAGES OF Pressable Ceramics
IPS Empress….good esthetics
IPS Empress 2….high strength…but high opacity
No metal..good esthetics
Moderately high flexural strength
Excellent fit
DISADVANTAGES
Fracture tendency in posterior areas
Resin cement needed to bond crown
micromechanically to tooth structure
IPS Empress 2….. high opacity
Equipment costly

14. In Ceram Spinell..porous spinell core made from
magnesium-alumina powder(MgO – Al2 O3)
….most translucent of the 3 In Cerams
…..for antr single unit crowns,inlays,onlays&veneers
In Ceram Alumina
…Al2 O3
….used for anterior& posterior crowns,antr 3 unit FPD
In Ceram Zirconia
.. Al2 O3 - ZrO2
….not for anterior prosthesis(high opacity)
…..used for posterior FPD&crowns
(high strength&fracture toughness)
GLASS INFILTRATED
CERAMICS
(SLIP-CAST CERAMICS)

15. In Ceram crown fabrication process(3 steps)
1. Slip Casting- condensation of an aqueous porcelain slip on a refractory die(make an intensely
dense core & sinter)
A slurry of one of these(alumina powder/magnesium-alumina powder/zirconia) is slip cast on a
porous refractory die& heated in a furnace to produce a partially sintered coping.
2. Glass Infiltration- A unique process by which molten glass is drawn into pores by capillary
action at high temp.
Sintered core is infiltrated with molten glass at 1100°C for 4 hours (to eliminate porosity,to
increase density & to strengthen the slip cast core)
3. Veneering of Core- infiltrated core is veneered with feldspathic porcelain& fired

16. Lack of metal….esthetics
Relatively high flexural strength& toughness
Ability to be successfully cemented with any cement
In Ceram Zirconia….high strength(but high opacity)
In Ceram Spinell…. High esthetics …low flexural strength

17. MACHINABLE CERAMICS
CAD-CAM Ceramics
COPY MILLING

18. CAD-CAM procedure
 Scanning - Scanner/Digitizer
 Designing
 Milling
Ceramic blanks are needed
Scanners/Digitizer
Contact probes
Scanners-Intra oral hand-held ,Lab scanners
Computer Aided Design……..
Computer Assisted Machining
(Computer Aided Manufacturer)

20. BENEFITS
One Visit
Tooth coloured restorations
Optical impressions(no cost for impression materials)
No temporaries(no cost for temporary crown)
Complete control from preparation until seating of restoration

21. CAD-CAM….. Scans the preparation
Copy milling….. Scans the pattern
COPY MILLING
….A pattern is produced in the lab on a
traditional stone die
….Then replica of that handmade pattern is made in ceramic using a copy
milling machine

22. ADVANTAGES of CAD-CAM
Negligible porosity in CAD-CAM core ceramics
….so greater strength
Reduced chair side time
Patient comfort, good acceptance
No temporary crowns needed
Highly esthetic
No impression procedure needed
Single appointment (with CEREC system)
A core ceramic can be selected
for strength & fracture resistance
for low abrasiveness/
for translucency

23. DISADVANTAGES of CAD-CAM
 Costly Equipment
 Lack of computer-controlled processing
support for occlusal adjustment
Scanning the preparation is technique
sensitive

24. References
Phillip’s Science of dental materials
Craig’s Restorative dental materials