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ALL CERAMIC RESTORATION


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All ceramic restorations:-

-All ceramic inlays

-all ceramic onlays-porcelain laminate veneers

-all ceramic crowns

Fabrication process:1-sintered

2-heat pressed

3-cast

4-slip cast5-computer generated

6-metal reinforced


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1-Sintering steps:

-mixing slurry powder +liquid -condensation

-vacuum firing -staining and glazing.

Examples

I Aluminous porcelain jacket crowns

-Either1- Use platinum foil (0.5)

-We choose platinum because it is a noble metal doesnt form oxide so no fusion

will occur.

-The foil will cover the stone

-.N.B.porcelain can't be applied on stone die.

-Then build the porcelain core (40-50% alumina) over the foil.-the final contour (restoration) either formed by:

1-porcelain layering technique.

We add porcelain layers using feldespathic porcelain

2-surface characterization, build the core to its maximum contour from the

beginningadd colors to the surface.

-In all-ceramic we dont need opaque coz the color is matched.

2-Refractory die (vitadur-N and Hi-ceramic)

special material smoother than stone die to apply porcelain directly.


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II optec HSP (High Strength Porcelain)

-refractory die (with matching thermal

expansion)-firing at 1038C

III foil crown>>1st system (vita)

>>pt foil(0.09-0.159mm burnished on die)

>>feldspathic porcelain

IV Mirage


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2-Heat-PressedSteps:

-wax pattern

-investment

-burnout at 850C-pressed at 1150C

Injection molding (ingots are softened not melted)

-surface staining or layer technique.

Examples:

I IPS empress 1(ivoclar po rcelain s ystem )-leucite based-inlays,onlays,veneers,crowns

II IPS emp ress 2-Lithium silicate based

-crowns,FPDs


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3-Slip-casting

-Slip: suspension of fine particles in a liquid

-Liquid=alumina powder, water, additive

Steps:

1-duplicate the stone die after coating it with spacer.2-use special die plaster as duplicating material this plaster

-Porousso can absorb water.

-Shrink upon heating.

3-after duplication coat the special die with the slip.4-upn drying water will be absorbed by the porous plaster from

slip (condensation), so layer of slip will be participated.

5-Sintering 10 hours at 1120C (shrinkage of the die)so it will

be separated from the slip shell.

6-Mix of glass powder and water applied on coplings.

7-infiltration 4-6 hours at 1100C (glass infiltration)molten glass

is drawn into the porous by capillary action to reinforce and

strengthens the shell.

8-excess glass removed-finish with air abrasion.


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Examples:

I in-ceram spinell

-Magnesium spinell (MgAl2O4)

I I in-ceram zir conia

-Zirconide (ZrO2)More strong

N.B.-empress and in Ceram are the most usable techniques

-Shoulder finish line is used because it provides both marginal fit

and resist breakage.

-Shoulder with bevel finish line should be avoided because forceswill be directed to the bevel causing fracture.


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4-Cast Glass-ceramics-Gass-ceramics

Steps:

1-Wax pattern

2-Investment

3-Burnout

4-melt the porcelain then cast the glass ceramic with motor driven casting machine (like

metal)

5-glassceramics surface staining or layer technique

*This technique not used any more.

Examples:

I Dicor

-Tetra silicate fluomica

I I Dicor plus

-Dicor core and aluminous porcelain

III Dicor MGC (Mica Glass Ceram ic)

-Higher percent crystallinity-Cerec process


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5-Computer-generated systemsI CAD-CAM

I I CEREC Process

-Laser imaging camera (optical impression) scanning the preparation after coating itwith opaque powder.

-Operator programs the design of inlays/onlays

-Computer directs the milling machine

-Dicor MGC, Vita MarkII

I I I celay process

-Direct resin pattern (tooth-die)fabricated on the prepared tooth or on master die.-Copy milling

I V Procera All-Ceram system-Industrial CAD/CAM process

-Die scanning, contact scanner by touching the dieenlarge it a little so it

will compensate for porcelain shrinkage later during firing.

-Milling machine


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6-METAL REINFORCED SYSTEMS-Thin metal coping on which the ceramic is fired

-It is metal ceramic as opposed to all-ceramic

-provide best marginal accuracy.

I Captek SystemSteps:

1-duplicate working die in the special refractory material.

2 -2 metal impregnated wax sheetsadapted to a die and firedformin

gold-platinum-palladium coping layer

3--Porcelain application in a manner similar to that for a conventional metal

ceramic crown

I I ElectroformedSteps:

1-the working die with the polyurethane material.

2-coat the die silver spacerdry

3-insert the die into the plating equipment.

4-Pure gold coping (controlled thickness)

5 -Noble metal paste primer

6-Porcelain application


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I ndications of al l-ceramics1-High esthetic requirements

2-Favorable distribution of occlusal load (due to the weakness of therestoration).

3-Considerable proximal caries

4-Incisal edge reasonable intact (no attrition)

5-used with endodontic teeth if used with cement mask the metallic color.

Contraindications1-Conservative restoration can be used2-High caries index

3-Insufficient tooth structure

4-thin teeth facial-lingual

5-Unfavorable distribution of occlusal load (patient with Para functional habit)6-endodontic teeth with post and core because: Translu cency o f porcelain

cannot m ask out cast metal or p refabr icated post s ystem.


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Advantages:

1-superior esthetic.2-excellent transulecency(similar to that of natural

tooth)

3-good tissue response.

Disadvantages

1-low strength

2-abrasive

3-marginal accuracy

4technique difficulties


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In-Ceram Impress

Incisally 1.5mm 2mm

All around 1.2-1.5 1mm

Step by step procedure 1-Incisal (occlusal reduction)

The completed reduction of the incisal edge should provide 1.5 to

2 mm of clearance.

2-Facial reduction

orientation grooves placed :one in the middle of the facial wall

,one in the mesiofacial, and one in the distofacial line angles.

1-1.5mm reduction is performed with a cervical component

parallel to the proposed path of withdrawal and an incisalcomponent to the original contour of the tooth.

3-Lingual reduction

1-1.5mm clearance in all mandibular excursive movements has

been obtained4-Shoule finish line is on all surfacesshould be 1-1.2 mm wide.

If the margins are subgingivally the finish line should be deep chamfer.

5-Finishing

amount of reduction


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*Hight of clinical crown for all ceramic crowns5mm before tooth preparation.

For porcelain fused to metal 3.5 mm


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**Problem with fixed bridge all ceramicweak at

connectorthe connector should be at least 4

mmtoo bulkyimpinge on IDPtissue irritation

(contraindication from periodontal view)

***FPD span length:

Anterior to canine not more than 11mm

Distal to canine not more than 9mm

BESTOFLUCK

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