Porcelain and its applicationsnew/certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

 CONTENTS:
1. introduction
2. indications
3. contra indications
4. fabrication of porcelain
5. conventional method
6. internal characterization
7. glazing and surface characterization
8. different systems and their method of porcelain
build up
9. recent advances in porcelain
10. conclusion
11. references

Denture teeth
&
Dentures -Duchateau 1774
Ceramic paintings and Vases

1887 – CH. Land (platinum foil technique)
1962 PFM – Weinstein
1965 McLean and Hughes aluminium core porcelain
1957 Vines and Sommelman – Vaccum firing
1940 with advent of acrylics PJC lost popularity.

 1887 – CH. Land gave porcelain jacket crown
 1965 - McLean and hughes -aluminous core
porcelain
 1980 - In ceram-slip casting, castable ceramics
 Latest 1990’s - machinable ceramics(CADCAM)
Evolution of all ceramic restorations :

 Ceramics in dentistry is a recent phenomenon, the desire for a
durable and esthetic material is ancient.
 Although metals have many characteristics that make them
useful in dentistry they do not look like natural teeth.
 In contrast a superb esthetics, translucency, light
transmission and biocompatibility result can be achieved with
ALL CERAMICS’s.

The fracture resistance of all-ceramic crown is based on
adequate support by the preparation, proper patient selection,
strength of crown material and type of luting cement.
Indications include….
 All anterior teeth where esthetics is of prime factor.

 Conservation of tooth structure and maintenance of
periodontal health.
 Lower incisors where space is available.
 Limited use on the premolar teeth where the occlusion
allows some protection for the buccal shearing cusps.

 In cases of parafunctional activity of the mandible,e.g.
bruxism. Or any deflective malocclusions remaining
uncorrected.
 Where occlusal clearance after tooth preparation is less
than 0.8 mm, e.g. very thin teeth, deep incisal over jets with
lingual wear facets.
 Insufficient tooth support or where the preparation design
causes sudden changes of thickness in the porcelain.

 Porcelain modeling liquid
 Paper napkin
 Glass slab or palette
 Tissues or gauze squares
 Two cups of distilled water
 Glass spatula
 Serrated instrument
 Porcelain tweezers or hemostat
 Ceramist's sable brushes (no. 2,4, and 6) and whipping brush
 Razor blade or modeling knife
 Cyanoacrylate resin
 Colored pencil or felt marker
 Articulating tape
 Ceramic-bound stones
 Flexible thin diamond disk (about 20 mm in diameter)

 Step-by-step Procedure. After the metal substructure has
been oxidized, it must be inspected carefully. An uninterrupted
oxide layer should cover the entire surface to be veneered

 When selecting the opaque bottle, shake it to mix the powder
thoroughly. Then place it on the bench to allow the smaller
pigment particles to settle.
 Dispense a small amount of powder on a glass slab or palette.
Add some modeling liquid and mix it with the spatula. Metal
instruments should not be used
 Moisten the substructure with some of the liquid and pick up a
small bead of opaque With the tip. of the brush or spatula.
Apply it to the coping, which should be held with the porcelain
tweezers.

 Use light vibration to spread the material thinly and evenly.
Excess moisture that comes to the surface can be blotted off
with a clean tissue.
 Apply a second bead on top of the first and spread it in a
similar manner. To minimize the entrapment of air when the two
masses met,

 Once the veneering surface is covered, add more material to a
dry base. Wetting the initial application before adding more
porcelain may be necessary.
 When the entire veneering surface has been covered, remove
any excess material from other surfaces with the side of a
slightly moistened brush

 After removing any excess porcelain, carefully inspect the
inside of the restoration for porcelain particles

 Before firing, inspect the opaque application to see that it
satisfies the following criteria
1. The entire veneering surface is “evenly covered with a smooth
layer that masks the color of the metal”
2. There is “no excess” anywhere on the veneering surface
3. There is no “opaque on any external surface” adjacent to the
veneer
4. There is no “opaque on the internal aspect” of the
substructure.

 If these criteria have been met, the coping is transferred to a
sagger tray and placed near the open muffle of the porcelain
furnace for several minutes. This allows moisture to evaporate.

 After the first firing, remove the work from the muffle and set
it aside to cool to room temperature
 When the veneer is removed from the furnace, it will appear
yellow; however, when it has cooled, the more representative
“matte - white” color is apparent. Fixed opaque should have an
eggshell appearance

 . After firing. check that the opaque application meets the
following criteria:
1. Relatively “smooth even layer” masking the color of the
framework
2. Eggshell appearance
3. “No excess” any external or internal surface of the
restoration (which would prevent it from seating fully on the
die)

 The use of several porcelains in one restoration is common. Body
porcelains with increased opacity may be used where less
translucency is required (e.g., gingival area of the pontic, incisal
mamelons) to mimic existing anatomic features of adjacent
natural teeth.

 Dispense the neck, body, incisal and other powders on a glass
slab or palette.
 Mix the powders with the recommended liquid or distilled water.
The moisture content for these powders should be the same as
for opaque porcelain
 Wet the previously fired opaque layer with a small amount of
the liquid and place bead of neck powder on the cervical portion
of the veneering surface

 A tissue is held close for removal of excess surface moisture.
During the entire buildup procedure the facial surface should
not be blotted with tissue because the smaller pigment particles
might be removed.

 After placing the neck powered and sculpting it build the veneer
to anatomic contour with body porcelain.
 Use the adjacent and opposing teeth as a guide. Where contact
is anticipated between the wet buildup and stone cast, the cast
can be coated with a small amount of Cyanoacrylate resin,
immediately blown into a thin layer.
 This will seal the surface and prevent the absorption of
moisture from the buildup

 To compensate for the firing shrinkage that results when the
particles fuse, slightly overbuild the porcelain.
 A typical metal – ceramic anterior crown will shrink 0.6mm at
the incisal edge and 0.5mm midfacially
 When the body buildup is completed, assess it for proper
mesiodistal, faciolingual and incisogingival contour.
 make a cut back for more translucent incisal powder.

 Apply the incisal powder in the same manner and overbuild the
restoration as described for body porcelain
 Mark the opposing teeth on the stone cast with a, red or green
felt tip marker. These markings will not be absorbed if the cast
first has been coated with Cyanoacrylate resin

 Only red or green dyes burn off without leaving a residue,
should be used for these markings. Blue or black pigments
usually contain metal oxides or carbon, which after firing can
discolor the porcelain
 Moisten the proximal contact areas immediately before
removing the completed buildup from the cast
 The internal aspect of the coping should be re-inspected

 . Place the restoration on a sagger tray close to the open muffle
at the drying
 temperature recommended by the manufacturer. A drying time
of 6 to 10 minutes is usually sufficient
 If restoration is fired prematurely the residual moisture in the
buildup may generate steam, and the accompanying Vapour
pressure will cause the buildup to explode.
 When the bake is completed, the work should cool to room
temperature before further handling

 cooling rates may lead to residual stresses that will eventually
result in porcelain fracture during function
 Be especially critical when evaluating the first bake. If the
surface is fissured, grind the porcelain before adding any more.
 The shape of the restoration should conform to the standards
set by dental anatomy and the predetermined occlusal scheme
for the patient

 Remove all excess material with ceramic bound stones.
 A flexible diamond disk is imperative for proper shaping of the
embrasure spaces.
 To extend its life, the disk should be kept moist
 When the restoration has been contoured and all necessary
areas reduced, certain portions will probably require a second
application of porcelain
 Before second corrective bake, clean the restoration
ultrasonically to remove any grinding debris

 Place the second body and incisal layers correctly on the slightly
moistened low bisque bake
 However, multiple firing will lead to devitrification of the
porcelain, with a loss of translucency and a decrease in the
restoration’s fracture resistance

 Internal or intrinsic characterization or staining may be
accomplished by incorporating colored pigments in the opaque,
body, or incisal porcelain powders.
 These pigments are ceramic in nature and have physical
properties similar to the porcelain powders
 If the internal characterization is not achieved properly then
the porcelain must be stripped from the substructure

 The appearance of the finished restoration depends on its color,
shade, and characterizing dental porcelain to mimic the
appearance of natural teeth
 The appearance of restorations can be influenced considerably
through the selected use of optical illusion.
 The human eye is capable of discerning difference in height and
width, but its depth perception is far less developed:.
 The perceived size of a tooth depends on the reflection of its
line angles and the relative position and spacing of these
reflections

 The surface texture of a metal ceramic rest should resemble
that of the adjacent teeth, including selected characterizing
irregularities that exist on those teeth. Several rules of light
reflection must be remembered when attempting to accomplish
this
 1. A flat surface will reflect primarily parallel bundles
 2. A convex surface will result in divergence fleeted light,
whereas a concave surface will create a convergent light bundle
 3. Sharp transitions (e.g., geometric line angles) will result in line
reflections, but smooth, gentle flowing curved surfaces will
create a reflection pattern with greater surface area.

 Care must also be taken not to "overcharacterised” which would
draw attention to the restoration and reveal that it is artificial.

 Metal ceramic restorations are glazed to create a shiny surface
similar to that of natural teeth. The glazing cycle can be
performed concurrently with any necessary surface
characterization
 In autoglazing the contoured bisque is raised to its fusion
temperature and maintained for a time before cooling. A
pyroplastic surface flow occurs, and a vitreous layer or surface
glaze is formed.

 Apply the glaze material in the usual
manner using a brush. Make sure not to
apply the glaze material either too thick or
too thin layers.

 By contrast in overglazing a separate mix of powder liquid is
applied to the surface of a shaped restoration, and the
restoration is subsequently fired. The firing procedure is similar
to that for autoglazing,

 Surface stains are highly pigmented glazes which can be mixed
with glycerin and water
 When it turns white and chalky, any excess that may have been
accidentally applied to the metal surface is removed, .and the
restoration is fired

 Before starting the staining procedure,
make sure the restoration is free of dirt
and grease. A roughened surface is
favorable. www.indiandentalacademy.com

 Apply the stains as thinly as possible,
avoid pooling and too thick layers.

 Many patients object to the grayness at the margin associated
with metal-ceramic restorations. However, hiding the margin
subgingivally may not be possible. If esthetics is of prime
importance, a collarless metal-ceramic crown should be
considered.

 The collarless crown's most obvious advantage is the esthetic
improvement it offers compared to the conventional metal-
ceramic restoration
 Plaque removal also is easier when gingival tissues are in contact
with vacuum-fired glazed porcelain than when they are
contacting highly polished gold.
 . Therefore, porcelain would appear to be the material of choice
for restorations that will be in contact with gingival tissues

 Due to careless handling, fracture of the unsupported margin is
sometimes a problem during try-in or cementation
 In addition, the collarless metal-ceramic restoration is more
time consuming and therefore more costly to make

 A porcelain labial margin is indicated when a conventional metal-
ceramic restoration will not create the desired esthetic result
 It is contraindication when an extremely smooth,1 mm-wide
shoulder cannot be prepared in the area of the ceramic veneer.
 the limitations of the operator and technical auxiliaries should
be carefully and objectively assessed before the dentist and
patient submit themselves to a fixed prosthesis consisting
multiple collarless retainers

 Platinum foil matrix Technique:
 Step-by-step procedure
 1.Wax the metal substructure and cast it in the conventional
manner.
 2.To prevent the foil from becoming distorted on removal, block
out undercuts apical to the margin. Modeling compound is
suitable for the shoulder of this step.

 3.Burnish a small piece of platinum foil onto the facial portion of
the die where the porcelain margin is to be placed, and extend it
a few millimeters onto the axial wall of the preparation.
 4. After burnishing, trim it so there is a 2-to3-mn “skirt” lying
cervical to the margin

 Remove the casting from the die, together with the foil, and
position the assembly between the electrodes of an orthodontic
spot welder.
 The foil can now be welded to the framework, which should be
done as close as possible to the edge of the metal. Four or five
welds are usually adequate to attach the foil to the
substructure.
 The restoration is then fabricated in a conventional manner,

 7. When the coronal portion has been shaped to a satisfactory
contour, burnish the foil and fill in the ditched portion with
cervical porcelain.
 8. When the desired contour has been obtained after firing,
time the platinum skirt.
 9. Leave the platinum that covers the shoulder portion of the
preparation and seat the crown on the original die for final
cervical contouring

 10. When satisfied with characterization, staining, and glazing,
remove the foil and cement the restoration after verifying the
fit one more time.

 Because this technique is less time consuming and easier to
perform then the platinum foil technique, it is more widely used.
 The substructure is fabricated in the same manner, but the die
is coated with a layer of Cyanoacrylate resin, and the porcelain
is condensed directly onto it Separation is achieved with a
porcelain release agent

 The principal difficulty associated with the Cyanoacrylate
technique occurs during the staining and glazing firing.
 because the porcelain is not supported as in the platinum foil
technique , the margin tends to round off slightly; therefore
,special shoulder powders are needed.

 Step-by-step procedure:
 1.Apply Cyanoacrylate resin to the labial margin area of the die.
This acts as a sealant of the porous stone. Compressed air
should be used to minimize the thickness of the film.
 2. Apply porcelain release agent to the shoulder of the prepared
die.
 3.Seat the opaqued casting on the die.

 4. Mix shoulder porcelain and apply it directly to die and the
opaque porcelain.
 5. After the first firing of the shoulder porcelain ,reseat the
crown on the die.
 At this time, the restoration should examined for margin
discrepancies.

 6. Reduplicate the die, reseat the crown, and apply a thinner mix
of shoulder powder to the margin
 7. When the firing is completed, use a water-soluble marking
agent to detect premature contacts.
 The marking agent is applied to the shoulder, and the
restoration is then gently tried on the die.
 The markings will be visible on the porcelain and the inner
aspect of the casting.

 8. Adjust any areas of contact of the restoration and proceed
with the conventional buildup of body and incisal porcelains,
followed by glazing of the final restoration.

 Step-by step procedure:
 1. After coating the substructure with opaque porcelain,
lubricate the die with a porcelain release agent.
 2. Apply the porcelain- wax mixture to the cervical shoulder .
use an electric waxing instrument to flow it into the proper
areas.
 3. with a conventional wax-carving instrument, shape the
material and blend it into the opaque

 4.A second application will be needed. Using the electric waxing
instrument, keep the mixture liquid long enough so that capillary
action can draw it into the marginal discrepancies
 The restoration is completed in the conventional manner.

 The high strength ceramic core was first introduced to
dentistry by Mclean and Hughes in 1965. they advocated using
aluminous porcelain, which is composed of aluminum oxide
(alumina) crystals dispersed in a glassy matrix
 The technique devised by Mclean used an opaque inner core
containing 50% by weight alumina for high strength

 High strength core frameworks for all ceramic restorations can
be produced with a slip casting procedure such as the In-cream.
 Slip casting is a traditional technique in the ceramic industry
and is used to make sanitary ware
 The starting media in slip-casting is a slip that is an aqueous
suspension of fine alumina in water with dispersing agents.
 The slip is applied on to a porous refractory die, which absorbs
the water from the slip and leads to the condensation of the slip
on the die. The piece is then fired at high temperature(11500 C).

 Weigh out exactly 38 g of VITA In-Ceram
alumina powder.

 Start to apply the slip in the area of the
pontic.
 Build up to half of the height of the pontic.
 Then coat the abutment dies fully and
connect them to the pontic.www.indiandentalacademy.com

 ! Proceed rapidly when building up the
remaining slip.
 ! Do not interrupt this process, so that
drying out of layers that have already been
built up is prevented (onion-skin effect).www.indiandentalacademy.com

 Carefully expose the preparation margin with
a scalpel until the marking can be seen.

1965 Mc lean and Hughes
40 t0 50 wt% of Al2O3
Flexural strength 131 Mpa
Platinum foil technique
ALUMINOUS CORE PORCELAIN
Finished CoresMaster
model with
dies
Platinum foil
adapted to die
(Hi-Ceram)

Unsintered CrownsDentin Ceramic
additions
Finished Crowns on
dies
Post-Cementation

Al2O3 slip Glass infiltration
Vita Inceramat3
Giordono 1995 : Al2O3 Core glass infiltrated Ceramic > Strength than Hi-
Ceram, Di-Cor & Feldspathic Porcelain
Vaccumat 4000 Premium

Duplication
In-Ceram
refractory dies
In-Ceram
application
Al2O3 slip
vita inceramat
Working model
Glass
infiltration 4hrsShrinkage of www.indiandentalacademy.com

Application of body
and incisal porcelain
Postoperative veiw
of In-Ceram
crowns
Finished In-
Ceram copings
(Air abraded)
Finished crowns
Preoperative veiw
Probster et al : Strength of In-Ceram > IPS Empress < PFM

 Fabrication Procedure :
 1. Duplicate the working die with an elastomeric impression
material and pour it with the special refractory die material
 2. Mix the appropriate shade of alumina slip with ultrasonic
agitation, place the mixture under a vacuum,
 brush apply it to the-plaster die and shape it with a blade,
trimming back to the margins carefully

 3. The slip is fired in a special furnace initially through a
prolonged drying cycle to 120°. C (248° F) that dries the die
material, which shrinks away from the core.
 Then the alumina is fired at 1120° C (2048° F) the resulting core
is porous and weak at this stage but can be carefully
transferred to the master die after the die spacer is removed.
 The relatively low sintering shrinkage (about 0.3%) is
compensated for by an expansion of the refractory material.

 4. Paint a thick coat of the appropriate shade of glass mixture
on to the surface of the core and fire at 1100°C (2012°F) As the
glass melts.
 5. Remove excess glass from the core by grinding and airborne
particle abrasion.
 Body and incisal porcelain is applied to the core in manner
similar to that for metal ceramic crowns.
 6. After moistening the core, mix the powder with modeling
liquid and apply increments with a brush.

 7. Remove moisture with a paper tissue held against lingual
surface. The capillary action will condense the porcelain
particles slight vibration brings further moisture to the surface
before the next increment is added. To prevent voids from
forming between increments always add to a moist surface.
 8. When the crown has the correct shape cut it back to allow
room for incisal porcelain

 9. Apply incisal porcelain, overbuilding the incisal edge by 1 to
1.5 mm to allow for firing shrinkage.
 10. Lightly condense the buildup with a large whipping brush.
Absorb excess moisture with a tissue.
 11. Remove the crown from the working cast and add material
inter approximately to allow for shrinkage.
 12. Dry the crown and fire it.

 Leucite based:
 Hot pressed ceramics are becoming increasingly popular in
dentistry. The restorations are waxed, invested, and pressed in
 Most hot pressed materials contain leucite as major crystalline
phase, dispersed in a glassy matrix

 Empress 2 ingots

 The ingot support and the aluminum oxide
plunger is placed in the cold furnace.

 After selecting the exact press parameters,
Place the investment ring with the ingot, in
the press furnace and start the process by
closing the head.

 The press cycle runs automatically. A beep
sound indicates the end of the press cycle.

 Mark the length of the plunger on the
cooled investment ring.

 Separate the investment ring using a
separating disc. This predetermined
breaking point enables reliable separation
of the ingot and the ceramic material.

 Break the investment ring at the
predetermined breaking point using a
plaster knife.

 For fine divestment, only 2 bar (30 psi)
pressure is applied.

LEUCITE REINFORCED IPS EMPRESS
Pre cerammed Ingots
Processing :

Wax pattern
Ceramic ingot
& Al plunger
Investing
Pressing under vaccum
11500C
Sprue removal
Burn out 8500 C
26 min hold

 The crystal size varies from 3 to 10 nm and the leucite content
varies from about 50% by volume depending on the material
 Ceramic ingots are pressed at high temperature from 9000 C to
11650 C [16500 F to 21300 F] depending on the material into a
refractor mold made by the lost-wax technique.

 Two finishing techniques can be used: a characterization
technique (surface stain only) and a layering technique, involving
the application of a veneering porcelain
 the currently available leucite-containing materials for pressing
are IPS Empress, optimal Pressable ceramic and two lower
fusing materials, Cerpress and Finesse.

 Lithium Silicate based.
 IPS Empress 2 is recently introduced hot-pressed ceramic.
 The major crysta1line phase of the core material is a lithium
disilicate. The material is pressed at 9200 C (1690 F) and
layered with a glass containing some dispersed apatite crystals.
 application for anterior three unit fixed partial dentures.

 1. Wax the restoration to final contour, sprue, and.
 2. Heat the investment to 8000 C to burn out the wax pattern.
 3. Insert a ceramic ingot of the approximate shade and alumina
plunger in the special pressing furnace.
 4. After heating to 11500 C, the softened ceramic is slowly
pressed into the mold under vacuum

 5. After pressing recover the restoration from the investment
by airborne particle abrasion, remove the Sprue , and refit it to
the die.
 Esthetics can be enhanced by applying an enamel layer of
matching porcelain or by adding surface characterization. The
procedure for an FPD is similar.

 The evolution of CAD /CAM systems for the production of
machined inlays, onlays, veeners crowns led to the development
of a new generation of ceramics that are machinable.

CEREC SYSTEMS PROCERA SYSTEM
CELAY SYSTEM

CEREC SYSTEMS
Materials involved :
Vita mart II, Dicor MGC and Pro Cad
Sanidine
KAlSi3O8
Mica crystals
70%
Leucite containing
ceramic
CERamic REConstruction,
Optical scanning

The compact, mobile unit consists of three components: a small
camera, a computer screen and a three – axis – of – rotation milling
machine.

The cad/cam cerec system has evolved from the: cerec-1,which
fabricated only marginally fitting single and dual surface ceramic inlays.
Cerec-2,which showed advances in computing, upgraded
software and expanded form of grinding technique.

Cerec-3 that can design well-fitting inlays, onlays, crowns,
veneers etc., in a single visit.

3D cerec
Scanning and designing
3 dimensional viewing Millingwww.indiandentalacademy.com

 referred to as “ceramic steel”.

Parallel milling with two tools:

High speed milling of copings and bridge frame work.

 Cerec system. The cerec system has been marketed for several
years with the improved cerec 2 system introduced in the mid-
1990s.

 Fabrication procedure:
 1.Tooth preparation follows typical all ceramic guidelines.
 2.Coat the preparation with opaque powder
 3. Image the preparation with the optical scanner, aligning the
camera with the path of
insertion of the restoration When the best view is obtained, it
is stored in the computer.
 4. Identify and mark the margins and contours on the computer
screen. computer software assists with this step

 5. Insert the appropriate shade of ceramic block in the milling
machine. The fabrication time for a crown is about 20 minutes .
Additional characterization is achieved with stains.
 6. Try the restoration back in the mouth, etch, and, lute it to
place as described.

 The Celay system uses a “copy milling” technique to manufacture
ceramic inlays or onlays.
 This material is similar to Vita Mark ll. ceramic, used with the
Cerec 2 system. Alternatively, blanks of the InCeram Alumina or
InCeram Spinell materials can be used. Marginal accuracy seems
to be good, a little better than the Cerec 2 system.

CELAY SYSTEM
Uses copy milling technique
Resin pattern fabricated directly on master die and pattern is used for
milling porcelain restorations
Jacot et al 1998 : in ceram blanks in celay system.
Inlay pattern mounted
(copy side)
Copy milling pattern out
of ceramic material
(milling side)

 The Procera AllCeram system involves an industrial CAD/ CAM
processes.
 The die is mechanically scanned by the technician, and the data
are sent to a work station where an enlarged die is milled using a
computer-controlled milling machine.
 This enlargement is necessary to compensate for the sintering
shrinkage

PROCERA SYSTEM
Dies are enlarged to compensate for sintering shrinkage.
Scanning
Milling machine
Shape on computer
screen
Contact scanner

Processing method
Procera restorations

 Step by step procedure :
 1. Tooth preparation follows all ceramic guidelines.
 2. The cast is made in the conventional way but the die is
ditched to make the margin easier to identify during scanning
 3. The die is mapped using a contact scanner
 4. The shape of the prepared tooth is transferred to the
computer screen

 5. The design of the restoration is transferred to the
manufacturer via computer line
 6. The production process starts with milling an enlarged die to
compensate for the sintering shrinkage
 7. An enlarged high-alumina coping is milled that shrinks to the
desired shape after sintering
 8. The coping is returned to the laboratory and body and incisal
porcelains are applied in the conventional manner

 In the captek system the coping is produced from two metal-
impregnated wax sheets that are adapted to a die and fried.
The first sheet forms a porous gold platinum palladium layer
that is impregnated with 97% gold.
 Advantages of the system include excellent esthetics and
marginal adaptation.

 Fabrication Procedure
 1. Duplicate the working die in the special refractory material.
 2. Cut a piece of the gold platinum palladium impregnated wax
sheet
 3. Adapt the foil to the die. Then it is fired to 107C (1965 F)
forming a porous metal coping.
 4. Adapt the second gold impregnated wax and refire, Capillary
action draws the gold into the porous gold platinum palladium
structure to form the finished coping

 Build up the opaque body and incisal porcelains in manner similar
to that for a conventional metal ceramic crown.
 Glaze the completed restoration and polish the metal foil at the
margin. The procedure has been adapted for FPD’s.

 Electroformed :
 The Helioform HF 600 system uses an electroforming technique
to produce a thin Pure gold coping.
 .

(HELIO FORM HF 600 SYSTEM)
Equipment Polyurethane dies
Completed restorations
ELECTRO FORMED

 Step by step procedure
 1. Duplicate the working die with the poly urethane material
 2. Drill the polyurethane and glue the electrode into the die
 3. Apply an even coat of the silver spacer to the preparation and
allow it to dry
 4. Insert the dies into the plating equipment. A magnetic stirrer
ensures circulation of the cyanide free gold sulfite solution

 5. Turn on the electrical current, and gold will be deposited on
the die at an appropriate rate of 0.02mm per hour.
 6. Remove the plated copings by heating the dies and remove
the silver spacer with nitric acid or air abrasion.
 7. Trim flash from the margin with an abrasive silicone wheel
and seat the coping on the die
 8. Air-abrade the surface and apply the special bonding paste
before porcelain application

 Porcelain labial veneers can be fabricated using a refractory die
technique as well as on a platinum matrix

Ceramic veneer F P D
Ceramic inlay metal reinforced F P D
Ceramic veneer / Composite substructure F P D

 Step-by-step Procedure :
 1. Modify the working die by blocking" out tooth undercuts with
modeling plastic
 2. Adapt the platinum foil (0.025 mm). Careful adaptation is
essential for good fit, especially at the proximal incisal margin,
where the tinner's joint is made.

 3. Remove, clean, and degas the foil. Airborne particle abrasion
can be used for this step. Porcelain labial veneers can also be
made with hot pressed ceramics and the machinable systems.
 4. Build up and fire the veneers. This is generally done in two or
three layers, particularly if the veneer is required to mask
tetracycline staining and a more opaque initial layer is applied.

 5. Contour and glaze the facings..
 6. Remove the foil before try-in

 1. Pour an elastomeric impression of the prepared teeth in Type
IV or V stone;
then repour it or duplicate it in ceramic refractory,
 2. Trim the refractory cast as far as possible to minimize the
quantity of ammonia released during decontamination.
 3. Mark the margins lightly with a special pencil
 . Decontaminate the cast by firing according to the
manufacturer's instructions

 5. Allow the cast to. cool and then soak it in soaking liquid or
distilled water for 5 minutes. This will seal the die and prevent
moisture from being drawn out of the porcelain buildup:
 6. Apply an initial layer of porcelain to the die and fire

 7. Build up the restorations onto moist dies; for inlays, leave
short of the margins.
 8. Make a relieving cut through the central fossa and fire the
porcelain
 9. Fill in the central fossa area and build up to the margins and
 10 Contour and refine occlusion and proximal contacts. Glaze
according to the.
 11. Remove the investment. Transfer the restorations to the
master dies on the mounted cast

 The performance of all ceramics restoration has been enhanced
by the use of resin bonding. This technique was first devised for
the porcelain laminate veneer technique and has been applied to
other ceramic restorations.
 The technique uses hydrofluoric acid or a less toxic substitute
to etch the ceramic and a silane coupling agent to bond a resin
Luting agent to the ceramic.
 The Luting agent is bonded to enamel later etching with
phosphoric acid as with resin retained FPDs and bonded to
dentine with a dentine bonding agent

All ceramic Resin bonded fixed partial dentures
Introduced 1986-1988 Ibsen et al and Garber et al
Matthias kern 2005 :Cantilever all-ceramic resin bonded FPD

 1. Support the restoration in soft wax with the fitting surface
uppermost.
 2. Apply a 1-mm coat of the etching gel to the fitting surface
only.
 3. The etching time will depend on the ceramic material.
Feldspathic porcelain is typically etched for 5 minutes.
 4. Very carefully rinse away the gel under running water.
 5. Continue to rinse until all the gel color has been removed.

 6. Dry the ceramic with oil-free air
 7. Apply the silane according to the manufacturer's
recommendations. and care must be taken to clean the fitting
face thoroughly with alcohol before cementation,

1993 Luthy et al – Post made of TZP-ZrO2
High flexural strength 1400 Mpa
1994 Sandhaus – Zirconia post with composite core
1995 Akagawa et al - Castable ceramic attached to zirconia post
1997 Ivoclar – introduced Ceramic core directly pressed onto Zirconia post
Direct method
Indirect method

RECENT APPLICATIONS OF CERAMICS IN
SURGERY
Recently, the world of surgery is amazed with a sensation :
Atraumatic scalpels made of ceramics.
The cutting edge cannot be made thinner than 0.7 microns when
metal is used.
Ceramics made up of zirconium dioxide nano-powder with
admixtures of aluminum and yttrium in water, can serve to form such
a material which can be used to produce the cutting edge thickness
of 0.1 - 0.2 microns.
The post operative wound heals up 2 -3 times quicker if the ceramic
scalpel is used, as the blades had dissected the tissue without
traumatizing it.
(Mendeleev University of Chemical Technology, Moscow,
14/03/2003)

Ceramics in Orthodontics
 Most recent application of ceramics in orthodontics is
in fabrication of orthodontic brackets.
 The development and demand for these items has been
driven solely by esthetics.
 Polycrystalline alumina is the material of choice in this
application.
Advantages::
 A profitable alternative to metal brackets.
 Bonds and debonds like metal.
 Excellent control of tooth movement.
 Less friction for better treatment times.
 Lowest profile in an all-ceramic bracket.
 Maximum patient comfort.

Implants and ceramics: Entering the New
Millennium.
 The demand for optimal single tooth implant esthetics
has lead to perhaps the most exciting development in
implant abutment design, the ceramic abutment.
 Three different designs are currently available:
CerAdapt.
CeraOne.
CeraBase.
(The Intl Journal of Oral & Maxillofacial Implants 2000; vol
15; Pg 76-94)

 Improved materials and the bonded ceramic
technique have renewed interest in all ceramic
restorations.
 The highest strength materials may be suitable
for high stress applications including FPDs
 However they are relatively new and still lack the
support of long-term clinical experience and
research

Each system has its own merits, but may
also have shortcomings.
Combinations of materials and techniques are
beginning to emerge which aim to exploit the
best features of each.
Glass-ceramic and glass-infiltrated alumina
blocks for CAD-CAM restoration production
are examples of these and it is anticipated
that this trend is likely to continue….

 AN EVALUATION OF MECHANICAL PROPERTIES
OF “HYDROTHERMAL” DENTAL GLASS AFTER
WATER IMMERSION AND SURFACE POLISHING
 OBJ: to investigate claims that duceram low-
fusing ceramic a “hydrothermal” dental
veneer will increase strength after hydrolytic
testing and surface polishing
 RESULTS: results obtained do not support
claims for surface flaw and/ or defect healing
through the formation of an SiOH layer at the
surface of duceram specimens overtime

 A TWO YEAR CLINICAL EVALUATION OF
LITHIA- DISILICATE- BASED ALL CERAMIC
CROWNS AND FIXED PARTIAL DENTURES
 Obj: This was to evaluate the clinical
performance of crowns and F.P.D’s made with
Empress 2 over a 2yr period.
 Results: no crown fractures were observed
during the 2yr follow up, how ever 50%
catastrophic failures of F.P.D’s occur. 25%
failures occur with in 1yr clinical period. and
other 25% occur with in the 2nd yr
 Significance: single unit empress2 all ceramic
crowns exhibited a satisfactory clinical
performance over a 2yr period

 Kennth.J.Anusavice. Science of dental materials;
10th edition, Kennth.J.Anusavice.
 Tylmans theory and practice of fixed
prosthodontics.
 Fundamentals of fixed prosthodontics: third edition,
Prof Herbert T Shillinburg.
 Restorative dental materials, 10th edition; Craig CG.
 Applied dental materials; 8th edition, John F McCabe
and Angus W G Walls.
 Stephen F Rosenstiel; Contemporary Fixed
Prosthodontics
 Herbert T Shillinburg; Fundamentals of Tooth
Preparations

Porcelain and its applicationsnew/certified fixed orthodontic courses by Indian dental academy

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