1. RECENT ADVANCES IN DENTAL CERAMICS

2. CONTENTS Introduction History Glass infiltrated alumina Incerams
Procera all ceram
Pressable ceramics
Machinable ceramics
CAD CAM

3. INTRODUCTION
Though conventional ceramics provide esthetically pleasing retorations they have many drawbacks which limit their use.With more and more studies coming in the field of ceramics and with the advent of digital technology newer and better products are flooding the market these days.The “chinese clay” of olden days have become the unavoidable product in esthetic dentistry...

4. resin-bonded ceramics
* reinforced ceramic core systems
resin-bonded ceramics
metal-ceramics

5. HISTORY Since the stone age ceramics have been important for humans.
1789-de_chemant & Duchateau.
1822-baking process.
1825-commercial production by Stockton.
1903-Dr.Charles Land-first ceramic crown
1962-Patents by weinstien and wenstein.
1965-Mclean & Hughes

7. CLASSIFICATION USE ABRASIVEN ESS ANT. POST. CROWNS VENEERS P&C
COMPO SITION
PROCESSING METHOD
TRANSLU CENCY
PURE ALUMINA
P.ZIRCONIA
P.SILICA GLASS
LEUCITE.G.CER
LITHIA BASED
FIRING TEMP.
MICRO STRUCTURE
SINTERING
PARTIAL SINT
GLASS INFIL.
CAD-CAM
COPY MILLING
OPAQUE
TRANSLUCENT
TRANSPARENT
LOW FUSING
MEDIUM
HIGH FUSING
GLASS
CRYTALLINE
CRYSTAL -GLASS

8. WHY DO WE NEED ADVANCED PRODUCTS ???

9. One of the most serious drawbacks with the early dental porcelains were their lack of strength and toughness, which seriously limited their use. In order to overcome these problems, there are two possible solution.
One solution is to provide the dental porcelain with support from a stronger substructure.
The other option is to produce ceramics, which are stronger and tougher.

11. Metal free ceramic systems
All ceramic systems can provide better esthetics.
Wide range of tranlucency opacities are available
Soft tissue health
No over contouring

12. Glass infiltrated alumina
In-ceram alumina
Supplied as one of the three core ceramics.
1)in-ceram spinell
2)in-ceram alumina
3)in-ceram zirconia

13. In - ceram
A slurry of material is slip cast on porous refractory die and heated in a furnace to produce a partially sineterd coping.
This coping is infiltrated with glass at temp1100*c -4hrs

14. In-ceram alumina
Indication-anterior and posterior crowns and anterior 3-unit FPDs.
Flexuarl strength-500mPa
The final ICA core consists of 70wt% alumina and 30wt%sodiumlnathanum glass.

15. Advantages Moderately high flexural strength and fracture resistance.
A metal free structure
An ability to be used succesfully with conventional luting cements

16. Drawbacks
Marginal seal is not as good as procera-all ceram or IPS Empress.
High degree of opacity
Inability to be etched
Technique sensitive

17. In ceram spinnel
Indications-anterior single unit creowna,inlays,onlays & veneers.
It is the most translucent among the three .
It was introduced as an aletrnative to ICA

18. Improved translucency.....better esthetics.

19. onlays veneers single anteriors anterior bridges single posteriors
single anteriors
anterior bridges
single posteriors
posterior bridges  
Inlays
onlays
veneers
In-Ceram Spinell X
In-Ceram Alumina
In-Ceram Zirconia

20. In ceram zirconia Indication-posterior crowns
Not recommended in anteriors due to the high degree of opacity
But has good modulous of elasticity and fracture toghness.
Though it has better strength its use is limited to posteriors due to its greater opacity.

22. Castable and machinable ceramics
When used in posteriors ceramic crowns are succeptible to fracture.
Critical flaw...??

23. First commercially available castable ceramic- dicor,developed by corning glass works.
Dicor is a castable glass.
Indicated for onlays,facial veneers,full crown restorations.
technique......ceramming

24. Procera all ceram
Composed of densely sintered high purity Aluminium oxide core+all ceram veneering porcelain.
Contains 99% alumina.
It is one of the hardest among the ceramics.

25. Indications-anterior & posterior crowns,veneers,onlays...
Procera scanner is used.
It is developed through CAD-CAM processing.

28. CAD-CAM ceramics Computer aided designing and computer aided milling.
The internal surface of inlays or crowns is ground with diamond discs according to the scanned image of the praparation

29. ADVANTAGES No wear of the opposing tooth Strength Fracture resistance
Low translucensy

31. Lava zirconia They are zirconia based products.
First the milled prosthesis is removed from the milling unit.
The zirconia frame work is placed in the cercon furnace and fire at 1350*C for 6 hours.

32. The purest tetragonal zirconia has got the greatest fracture toughness and flexural strength.
Contra indicated in patients with bruxism.
Only minimal occlusal reduction of 2mm needed.

33. Finesse all ceramic It is a new product patended to dentsply.
Indications-crowns anterior&posterior
Veneers
Inlays
onlays

34. Finesse All-Ceramic achieve an ideal bond without the need to create a wash layer
Thus saving time and enhancing the strength of the restoration.
It is a leucite reinforced ceramic glass material.
Flexural strength- 125mPa

35. "Pressing" - lost wax injection molding
At 930°C, for 20 min
Inherently fluorescent
Ideal transparency range from (clear) to (opaceous)

36. PRESSABLE CERAMICS Introduces by MAC CULLOCH IN 1968
Here,the glass is formed into the devised shape.
Then it is subjected to partial devitrification.a presssure moulding technique is followed.

37. IPS empress-is a glass ceramic avialable as ingots,
Which can be heated and pressed until the ingots flows into a mold.
It contains higher concentration of leucite crystals that increase the resistance to crack propagation.
It can be tained ,glazed or built up by layering technique.

38. ADVANTAGES No metal component Translucent ceramic core
Moderately high flexural strength
Excellent fit
Excellent esthetics

39. Disadvantages Potential to fracture(in posterior)
Requires a resin cement to micromechanically bond to the tooth structure.

41. Y - TZP...??

42. Yttrium tetragonal zirconia polycrystal
One the latest advacements in the field of all ceramic restorations.
Phase transformation from monoclonal to tetragonal on firing.
Adding zerconia stablizes the core during this phase transformation.

43. Also the presence of water causes crack propagation and stress corrosion reactions.
But Y-TZP substructures are independent of this phenomena.
In vitro studies show a flexural strength of mPa.

44. Hydroxy apatite based ceramics
Cera pearl,developed by Kyocera co. in CA.
Here the main ceystalline phase is oxy apatite which can be tranformed to hydroxy apatite on hydration.
Commonly used in implants...for better flexural strength and bonding.

45. Shade
Dimensions of color
Hue
Chroma
Value
Metamerism & Flouresence

46. Conclusion
Advances in the field of ceramics gives hand full of newer products for the dentist.
Which will surely enhance the esthetic and strength characters.
A carefull selection of these products are essential for successful outcome.

47. Bibliography Text book of dental materials-Anusavice.
Dental technitian news letter-2009 march
Text book of ceramics fabrication-Naylor.
Recent advances in ceramics- Dr.Jennifer,ohio,USA

48. T H A N K Y O U