2 CONTENTS Introduction History Glass infiltrated alumina Incerams Procera all ceramPressable ceramicsMachinable ceramicsCAD CAM
3 INTRODUCTIONThough 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...
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 crown1962-Patents by weinstien and wenstein.1965-Mclean & Hughes
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.
19 onlays veneers single anteriors anterior bridges single posteriors single anteriorsanterior bridgessingle posteriorsposterior bridges InlaysonlaysveneersIn-Ceram SpinellXIn-Ceram AluminaIn-Ceram Zirconia
20 In ceram zirconia Indication-posterior crowns Not recommended in anteriors due to the high degree of opacityBut has good modulous of elasticity and fracture toghness.Though it has better strength its use is limited to posteriors due to its greater opacity.
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&posteriorVeneersInlaysonlays
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 minInherently fluorescentIdeal 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 strengthExcellent fitExcellent esthetics
39 Disadvantages Potential to fracture(in posterior) Requires a resin cement to micromechanically bond to the tooth structure.
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 ShadeDimensions of colorHueChromaValueMetamerism & Flouresence
46 ConclusionAdvances 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 marchText book of ceramics fabrication-Naylor.Recent advances in ceramics- Dr.Jennifer,ohio,USA