recent advances in dental ceramics recent advances in dental ceramics

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RECENT ADVANCES IN DENTAL CERAMICS RECENT ADVANCES IN DENTAL CERAMICS Slide 2 CONTENTS Introduction Introduction History History Glass infiltrated alumina Glass infiltrated alumina Incerams Incerams Procera all ceram Procera all ceram Pressable ceramics Pressable ceramics Machinable ceramics Machinable ceramics CAD CAM CAD CAM Slide 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... Slide 4 * reinforced ceramic core systems metal-ceramics resin-bonded ceramics Slide 5 HISTORY Since the stone age ceramics have been important for humans. Since the stone age ceramics have been important for humans. 1789-de_chemant & Duchateau. 1789-de_chemant & Duchateau. 1822-baking process. 1822-baking process. 1825-commercial production by Stockton. 1825-commercial production by Stockton. 1903-Dr.Charles Land-first ceramic crown 1903-Dr.Charles Land-first ceramic crown 1962-Patents by weinstien and wenstein. 1962-Patents by weinstien and wenstein. 1965-Mclean & Hughes 1965-Mclean & Hughes Slide 6 Slide 7 CLASSIFICATION USE COMPO SITION PROCESSING METHOD FIRING TEMP.MICRO STRUCT URE TRANSLU CENCY ABRASIVEN ESS OPAQUE TRANSLUCENT TRANSPARENT GLASS CRYTALLINE CRYSTAL -GLASS LOW FUSING MEDIUM HIGH FUSING SINTERING PARTIAL SINT GLASS INFIL. CAD-CAM COPY MILLING PURE ALUMINA P.ZIRCONIA P.SILICA GLASS LEUCITE.G.CER LITHIA BASED ANT. POST. CROWNS VENEERS P&C Slide 8 WHY DO WE NEED ADVANCED PRODUCTS ??? Slide 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 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. 1.One solution is to provide the dental porcelain with support from a stronger substructure. 2.The other option is to produce ceramics, which are stronger and tougher. Slide 10 Slide 11 Metal free ceramic systems All ceramic systems can provide better esthetics. All ceramic systems can provide better esthetics. Wide range of tranlucency opacities are available Wide range of tranlucency opacities are available Soft tissue health Soft tissue health No over contouring No over contouring Slide 12 Glass infiltrated alumina In-ceram alumina In-ceram alumina Supplied as one of the three core ceramics. Supplied as one of the three core ceramics. 1)in-ceram spinell 1)in-ceram spinell 2)in-ceram alumina 2)in-ceram alumina 3)in-ceram zirconia 3)in-ceram zirconia Slide 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. 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 This coping is infiltrated with glass at temp1100*c -4hrs Slide 14 In-ceram alumina Indication-anterior and posterior crowns and anterior 3-unit FPDs. Indication-anterior and posterior crowns and anterior 3-unit FPDs. Flexuarl strength-500mPa Flexuarl strength-500mPa The final ICA core consists of 70wt% alumina and 30wt%sodiumlnathanum glass. The final ICA core consists of 70wt% alumina and 30wt%sodiumlnathanum glass. Slide 15 Advantages Moderately high flexural strength and fracture resistance. Moderately high flexural strength and fracture resistance. A metal free structure A metal free structure An ability to be used succesfully with conventional luting cements An ability to be used succesfully with conventional luting cements Slide 16 Drawbacks Marginal seal is not as good as procera-all ceram or IPS Empress. Marginal seal is not as good as procera-all ceram or IPS Empress. High degree of opacity High degree of opacity Inability to be etched Inability to be etched Technique sensitive Technique sensitive Slide 17 In ceram spinnel Indications-anterior single unit creowna,inlays,onlays & veneers. Indications-anterior single unit creowna,inlays,onlays & veneers. It is the most translucent among the three. It is the most translucent among the three. It was introduced as an aletrnative to ICA It was introduced as an aletrnative to ICA Slide 18 Improved translucency.....better esthetics. Improved translucency.....better esthetics. Slide 19 single anterior s anterior bridges single posterio rs posterior bridges posterior bridges Inlays onlaysveneers In- Ceram Spinell X XXX In- Ceram Alumina XXX In- Ceram Zirconia XX Slide 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. Slide 21 Slide 22 Castable and machinable ceramics When used in posteriors ceramic crowns are succeptible to fracture. Critical flaw...?? Slide 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 Slide 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. Slide 25 Indications-anterior & posterior crowns,veneers,onlays... Procera scanner is used. It is developed through CAD-CAM processing. Slide 26 Slide 27 Slide 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 Slide 29 ADVANTAGES No wear of the opposing tooth No wear of the opposing tooth Strength Strength Fracture resistance Fracture resistance Low translucensy Low translucensy Slide 30 Slide 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. Slide 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. Slide 33 Finesse all ceramic It is a new product patended to dentsply. Indications-crowns anterior&posterior Veneers Veneers Inlays Inlays onlays onlays Slide 34 Finesse All-Ceramic achieve an ideal bond without the need to create a wash layer 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. Thus saving time and enhancing the strength of the restoration. It is a leucite reinforced ceramic glass material. It is a leucite reinforced ceramic glass material. Flexural strength- 125mPa Flexural strength- 125mPa Slide 35 "Pressing" - lost wax injection molding "Pressing" - lost wax injection molding At 930C, for 20 min At 930C, for 20 min Inherently fluorescent Inherently fluorescent Ideal transparency range from (clear) to (opaceous) Ideal transparency range from (clear) to (opaceous) Slide 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. Slide 37 IPS empress-is a glass ceramic avialable as ingots, IPS empress-is a glass ceramic avialable as ingots, Which can be heated and pressed until the ingots flows into a mold. 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 contains higher concentration of leucite crystals that increase the resistance to crack propagation. It can be tained,glazed or built up by layering technique. It can be tained,glazed or built up by layering technique. Slide 38 No metal component Translucent ceramic core Translucent ceramic core Moderately high flexural strength Moderately high flexural strength Excellent fit Excellent fit Excellent esthetics Excellent esthetics ADVANTAGES Slide 39 Disadvantages Potential to fracture(in posterior) Requires a resin cement to micromechanically bond to the tooth structure. Slide 40 Slide 41 Y - TZP...?? Slide 42 Yttrium tetragonal zirconia polycrystal One the latest advacements in the field of all ceramic restorations. One the latest advacements in the field of all ceramic restorations. Phase transformation from monoclonal to tetragonal on firing. Phase transformation from monoclonal to tetragonal on firing. Adding zerconia stablizes the core during this phase transformation. Adding zerconia stablizes the core during this phase transformation. Slide 43 Also the presence of water causes crack propagation and stress corrosion reactions. Also the presence of water causes crack propagation and stress corrosion reactions. But Y-TZP substructures are independent of this phenomena. But Y-TZP substructures are independent of this phenomena. In vitro studies show a flexural strength of 900- 1200mPa. In vitro studies show a flexural strength of 900- 1200mPa. Slide 44 Hydroxy apatite based ceramics Cera pearl,developed by Kyocera co. in CA. 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. Here the main ceystalline phase is oxy apatite which can be tranformed to hydroxy apatite on hydratio

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