in this lecture we will define the dental ceramic, history ,properties, types, uses, cons and pros of dental ceramic. hope you enjoy it.

1. porcelain material

2. Topics
porcelain material
- Definition.
- History.
- Properties.
- Types.
- Uses.
- Advantages & disadvantages.
- MCR troubleshooting.

3. Definition
• Dental porcelain is a dental material used by dental technicians to
create biocompatible lifelike dental restorations, such as crowns,
bridges, and veneers. Evidence suggests they are an effective material
as they are biocompatible, aesthetic, insoluble and have a hardness.
• Ceramics is inorganic, non-metallic materials, which are typically
crystalline in nature, and are compounds formed between metallic and
nonmetallic elements such as aluminum & oxygen (alumina - Al2O3),
calcium & oxygen (calcia-CaO), silicon & nitrogen (nitride- Si3N4).

4. 1. Their use in dentistry dates as far back as 1889
when Charles H. Land patented the all-porcelain
“jacket” crown. This new type of ceramic crown
was introduced in 1900s.
The procedure consisted of rebuilding the
missing tooth with a porcelain covering, or
“jacket” as Land called it.
The porcelain “jacket” crown (PJC) was used
extensively until the 1950s. It was not strong
and breakable.
2. Porcelain-fused-to-metal (PFM) crown was
developed in the late 1950s by Abraham
Weinstein.
The bond between the metal and porcelain
prevented stress cracks from forming.
The addition of a metal block-out opaque layer
diminished the esthetics of these restorations.
A History of Dental Ceramics

5. The process involved the use of the lost-wax
casting technique, which produced a casted glass
restoration. Then, this was heat-treated. The
resultant crown was shaded with an application
of a superficial color layer.
The processing difficulties and high incidence of
fracture were factors that led to the abandonment
of this system.
4. Another development in the 1950s by Corning
Glass Works led to the creation of the castable
crown system.
Although it had twice the strength of the
traditional PJC, it still could be used in the
anterior region only (due to its lower strength). Its
higher opacity was also major drawback.
W. McLean and T.H. Hughes developed this new
version of the porcelain jacket crown that had an
inner core of aluminous porcelain containing
40% to 50% alumina crystals.
3. A resurgence of an all-ceramic restoration came
in 1965 with the addition of industrial aluminous
porcelain (more than 50%) to feldspathic
porcelain manufacturing.

6. This core consisted of 99.9% alumina to which a
feldspathic ceramic was layered. The use of
CAD/CAM technology spurred a whole new
generation of ceramic substructures consisting of
zirconium dioxide.
One study found to have a superior marginal fit
provide a framework with sufficient flexural
strength, allowing them to be used for multi-unit
posterior bridges.
6. In the mid 1990s Nobel Biocare introduced the
Procer AllCeram core, which was the first
(CAD/CAM) substructure.
This process of pressing ceramic ingots became
very popular due to the esthetics and ease of use
in the laboratory. Despite the increase in strength
of, but fracture was still possible when used in
the posterior region.
The initial steps for fabrication for Empress and
OPC in which the restoration was formed in wax
then a heated leucite-reinforced ceramic ingot
was pressed into the mold using a specially
designed pressing furnace.
5. Ceramics Empress I and optimal pressable
glass (OPC) were introduced in the late 1980s
and were the first pressable ceramic materials.

7. 8. Authentic, a second-generation, low-fusing,
high-expansion, leucite glass-reinforced
ceramic material, was introduced into the
European market in 1998 by Ceramay GmbH
& Co and later that year was introduced to the
US market by Microstar.
A 5-year study revealed a 70% success rate when
used as a fixed partial denture framework.
The frame-work was layered with a veneering
ceramic specially designed for the lithium
disilicate.
7. In 1998 IPS Empress II introduced , which was
a lithium disilicate ceramic material used as a
single- and multiple-unit framework indicated for
the anterior region.

8. The flexural strength of the material was found to be more than 170% higher
than any of the currently used leucite-reinforced ceramics. The ceramic
material can be milled or waxed, and then pressed to full contour and
subsequently stained. Another option allows for cutting the crown back,
followed with layering with different specially designed apatite ceramic glass.
9. Lithium disilicate re-emerged in 2006 as a pressable ingot and partially
crystalized milling block.
The layering ceramic has the same basic components as natural tooth enamel.

9. Properties
Chemical Properties:
1. High melting point.
2. Corrosion resistance.
3. Ionic bond ( where one is a metal and the other is non-metal ).

10. Physical properties:
1. Have good compressive strength(strong bond).
2. High hardness.
3. The nature, amount, particle size and coefficient of thermal expansion of
crystalline phases influence the mechanical and optical properties of the materials.
Dental ceramics possesses very good resistance to the compressive stresses,
however, they are very poor under tensile and shear stresses.
4. This imparts brittle nature to the ceramic and tend to fracture under tensile
stresses.

11. biological properties:
-Dental ceramics exhibit excellent biocompatibility with the oral soft tissues.
thermal properties:
1. Coefficient Of thermal expansion similar to that of enamel and dentine.
2. Low thermal diffusivity.

12. Types
1. Metal-ceramic restoration (MCR):
These restorations are composed of:
Metal substructure (Coping) supporting
a ceramic veneer those are chemically
and mechanically-bonded together.

13. 2. All-Ceramic restoration:
All-Ceramic crowns are cosmetic dental
restorations used to cap or completely cover
a tooth being restored. All-Ceramic crowns are
translucent and are the most naturally looking
tooth replacement. does not contain metal
substructures.

14. Types
Oxide ceramic
All-Ceramic
Fluormica
Glass-
Ceramics
Porcelain-
Fused-to-
Metals/Ceramic
Metal Systems Metal-
Oxide
Based
Ceramics
Glass-
Infiltrated
Ceramics
Zirconia-
Based
Ceramics
Alumina
Based
Ceramics
Lithium
Disilicate
Ceramics
Leucite
Reinforced
Feldspathic
Ceramics
Glass-Ceramics

15. Uses of dental ceramics
Inlay Pinlay
Overlay
Onlay

16. Crown Bridge Veneers
PFM
All
ceramics

17. Advantages
1. Good esthetic.
2. Long lasting material.
3. Ceramic restorations have the ability to mimic the reflective quality of original
teeth, allowing all-ceramic crowns to blend with surrounding teeth.
4. Fracture resistance.
5. Tooth and implant supported.

18. Disadvantages
1. Sensitivity may occur to hot and cold.
2. Brittle material leads to porcelain chipping.
3. Bacteria can be accomplished with poor adaptation and fitting.
4. Allergic reaction may occur to MCR restorations.
5. Fixed restorations more expensive than any restorations.

19. MCR troubleshooting
Failure Reason
1)Fracture during bisque bake - Improper condensation.
- Improper moisture control.
- Poor framework design.
- Incompatible metal-porcelain combination.
2) Bubbles - Too many firings
- Air entrapment during building of restoration.
- Improper moisture control.
- Poor metal preparation.
- Poor casting technique.
3) Unsatisfactory appearance - Poor communication with technician.
- Inadequate tooth reduction.
- Opaque too thick.
- Excessive firing.
4) Clinical fracture - Poor framework design.
- Centric stops too close to metal – ceramic interface.
- Improper metal preparation.

20. MOATH BASHEER
FATMEH AL
BASHITI
AL ANOUD
KHRISAT
MAJD KAHLOUT
ORGANIZED BY:
DT.SARAH OMARI