Metal free ceramic/ dental education in india

1
METAL FREE CERAMICS
Biologic Considerations & Laboratory
Procedures.
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

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Introduction

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General Biologic Preparation
 Preservation of tooth structure.
 Retention and resistance form.
 Structural durability of the restoration.
 Marginal integrity.
 Preservation of the periodontium.

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Preservation of tooth structure.
 Judgment of the type of restoration to be
used.
 Design.
 Ill effects when excessively prepared
1. Thermal hypersensitivity.
2. Pulpal inflammation.
3. Necrosis.

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Retention and resistance form.
 Retention: it is the ability of the preparation
to impede the removal of the restoration
along its path of insertion.
 Resistance: it is the ability of the
preparation to prevent dislodgement of the
restoration by forces directed in a apical,
oblique, or horizontal direction.

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The Design :
The preparation has to
provide maximum
strength by establishing
flat planes at right angles
to the forces of
mastication and avoiding
sharp line angles. A
shoulder margin is also
required because it offers
superior strength as
compared to chamfer.

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Retention and resistance form.
 Estimation.
 Geometric form.
 Cement used to lute the restoration.
 Direction of the forces.

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Length of the preparation :
When a load is applied from a lingual direction, the labial
shoulder is placed under compression and only the length
of the preparation at the incisal lingual aspect provides
significant resistance to this force. short preparations cause
considerable stresses and may lead to fracture. of the
preparation

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Factors affecting Retention
 Degree of taper.
 Total surface area of the cement film.
 Area of cement under shear.
 Roughness of the tooth surface.

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Taper :
Minimal taper is recommended for maximum surface area
and support of the preparation. Excessive taper of the
preparation correlates with a reduction in breaking
strength and increase in stress concentration in the area
where support is lacking.
A 5`taper is ideal and would ensure maximum resistance
form with only one path of insertion of the crown but it is
also difficult to achieve without producing undercuts.
The safest and most practical convergence angle of all-
ceramic preparations is 10`taper, which represents an
acceptable compromise between taper and strength.

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Degree of taper
Jorgensen

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Surface area
 Greater the surface area of the ecement
film greater is the retention.
 The size of the restoration is influenced
by:
1. size of the tooth.
2. extent of coverage of the restoration.
3. additional preparations like grooves
boxes.

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Area under shear.
 The preparation must have opposing
walls.
 The opposing surfaces may be internal
such as facial and lingual walls of a
proximal box of an inlay.
 Or may be external like axial walls of full
veneer crown preparation.
 It can be also a sum of the both.

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a. Internal retention in an
inlay.
b. Slightly divergent internal
walls.
a. External retention resists
removal.
b. Approximation of the
restoration to the opposing
external axial walls.

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Surface roughness

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Resistance form
 Leverage and resistance.
 Preparation length and resistance.
 Resistance and tooth width.
 Taper and resitance.
 Rotation around a vertical axis.
 Path of insertion.

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Structural durability of the
restoration.
 Occlusal reduction and functional cusp
bevel.
 Axial reduction.
 Provision for reinforcing struts.

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Preparation for all
ceramic restorations

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Depth reduction index.

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Depth orientation grooves

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Incisal / occlusal reduction

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Facial & Lingual reduction :
The minimal acceptable facial thickness of porcelain from
an esthetic standpoint is 1.0mm, and the ideal depth of
reduction on the midfacial aspect of a typical maxillary
central incisor for an aluminous porcelain jacket crown
should be 1.3 mm. Facial depths of reduction up to
1.5mm have also been recommended for molded,
castable, and slip-cast ceramics. Lingual thickness
values of 1.5 mm are ideal but are difficult to achieve
routinely. Practically lingual thickness should be in the 1
– 1.3 mm range, and the absolute minimum should be
0.8 mm. The lingual aspect of the preparation should be
shaped to avoid uneven sections of the crowns and
sharp line angles must be avoided.

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Facial reduction

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Lingual reduction

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Proximal reduction

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Shoulder :
A well defined shoulder with adequate width
improves the fracture resistance of the crown
because it provides additional bulk at the
margins that is placed at right angles to the
direction of stresses
The more the intimate the contact between
the preparation and the ceramic crown higher
the resistance to fracture on occlusal loading.

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Shoulder / Chamfer :
When the shoulder angle of the preparation to the
longitudinal axis of the tooth is greater than 90`,
the risk if porcelain fracture increases.
The internal shoulder angle should be rounded to
reduce the stress concentration factor up to 50%
and because sharp internal line angles cannot
be easily reproduced with porcelain. Similarly ,
the internal rounded shoulder is recommended
for the In-Ceram* crown to facilitate the
adaptation of the aluminous oxide slip on the
die.

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Shoulder width :
A shoulder of uniform
thickness may round the
preparation excessively
and compromise
resistance form. For a
maxillary central incisor,
the lingual and facial
shoulder width should be
I mm with a minimum of
0.8 mm, and the
interproximal width
should be 0.5 mm
because the proximal
walls of the crown flare
out and provide sufficient
strength in the proximal
area

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Axial reduction

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Axial reduction

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Shoulder curvature (interproximally) :
The finish lines should follow a smooth
curvature that it is not too steep inter-
proximally to avoid a potential v shaped
notch that could split the labial off the
lingual aspect of the crown.www.indiandentalacademy.com

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Prepared tooth schema

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Prepared tooth schema

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Why use metal free ceramics?
There is an increase the depth of
translucency and light transmission in
the crown either deep into the crown
or across the entire crown, which
increases the life like nature of the
restoration.

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Selection of restoration:
 Strength.
 Simplicity of fabrication.
 Marginal and internal fit.
 Cost-benefit analysis.
 Skill of the operator.
 Esthetic performance.
 Potential for high volume production.

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Indications :
 Aesthetics.
 Public figures, personalities,
models, actresses and
demanding patients.

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Contra-indications:
 parafunctional activity,e.g. bruxism
 Uncorrected deflective malocclusions.
 occlusal clearance less than 0.8 mm.
 Insufficient tooth support.
 Molar teeth.

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All Ceramic Materials
Conventional
powder
Castable
cerami
cs
Pressable
ceramics
Machinable
ceramics
Infiltrated
ceramics www.indiandentalacademy.com

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Powder Slurry Ceramics :
Supplied as: Powder and liquid. The powders are available
in different shades and translucencies, and are supplied
with characterizing stains and glazes.
Fabrication: Powder and liquid mixed to a slurry which is
build up in layers on a die material to form the contours
of the restoration.
e.g. Vita Hi-Ceram (Vita Zahnfabrik)
CERABIEN (Noritake)
OPTEC H.S.P (Jeneric/Pentron)
DUCERAM L.F.C (Ducera Inc)

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Castable Ceramics :
Supplied as:
solid ceramic ingots.
Fabrication: Cores or full contour
restorations are made using a lost wax
and centrifugal casting technique.
e.g. DICOR (Dentsply).
CERAPEARL (Bioceram, Kyocera)

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Pressable Ceramics :
Supplied as: Ingots
Fabrication:
Ingots melted at higher temperatures and pressed
into a mould using a lost wax technique. These
pressed form can be made into full contour, or
can be used as a substrate for conventional
feldspathic porcelain buildup, or can be built up
by layering technique.
e.g. IPS Empress I, II (Ivoclar vivadent)
OPC (Optec Pressable Ceramic)
ALCERAM (Cerestore, Innotek dental corp)

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Infiltrated Ceramics :
These are glass infiltrated core ceramics.
This involves slipcasting technique for
making the core, and the contours of the
restoration are obtained by individual
layering and staining techniques.
e.g. In-CERAM (Vita Zahnfabrik)
Alumina infiltration
Zirconia infiltration
Spinell infiltration

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Machinable Ceramics
Supplied as: ingots in various shades.
Fabrication: Ingots are milled into desired form.
They are of two types :
1.CAD-CAM = Computer Aided Designing – Computer
Aided Milling. e.g.
CEREC (Sirona)
Ivoclar ProCAD (Ivoclar, Spring)
Dicor M.G.C (Dentsply)
Procera (Nobel Biocare)
Lava (3M ESPE)
CERCON Dentsply Ceramco
2. Copy Milling = CELAY (Mikrona Technologies)

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CASTABLE CERAMICS
 DICOR ( Dentsply)
 CERAPEARL( Kyocera)

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History :
 The DICOR castable glass ceramic is one of the
pyoceram ceramics manufactured by Corning
glass ware.
 Founded in the year 1978, after 6 years of
intensive research this ceramic system was
introduced to dentistry.
 The present system represents the cumulative
efforts of Peter.J.Adair of BIOCOR Inc., David
Grossman Ph.D of the Corning Glass ware &
Dentsply International.

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Indications :
 Anterior PJC.
 Inlays, onlays, three quarter crowns.
 Partial veneers, especially in periodontally
compromised teeth

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Contraindications :
 Clinical crown length is short.
 FPD.

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Clinical Procedure :
 The tooth structure is sufficiently removed to
allow an adequate thickness of the material for
strength and color saturation.
 For castable ceramics, the tooth reduction on all
surfaces must be no less than 1.2mm.
 Heavy chamfer (135`)`or shoulder margin.
 6`- 8`taper and all line angles rounded.
 Standard impression procedures are followed.

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 Incisal or occlusal - 1.5 mm- 2.0 mm.
 Facial or lingual - 1.0 mm – 1.5 mm.
Tooth preparation :

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Laboratory Procedures :
Die preparation.
Waxing & Spruing.
Investing & Mold conditioning.
Casting.

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Divesting.
Sprue removal.
Embedding.
Ceramming & post ceram divesting.
Finishing, coloring.

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Die Preparation :
Casts should be free of 0cclusal
artifacts,air bubbles and other
inaccuracies.
Dies must be prepared with
proper indexing. The dies
should be sectioned, trimmed
and refined with care.
Any existing undercuts must bu
blocked out to ensure wax
pattern removal without
distortion.
Die sealant should be used.
A die spacer of appropriate shade
is applied on evenly to the die
to within 1 mm of margin.

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Waxing :
 Die lubricant is applied over
the die spacer to prevent
adherence of the wax to the
die.
 All contours of the wax crown
should have a minimum
thickness of at least 1mm to
ensure adequate strength of
the crown.
 A smooth and completely
formed internal surface of the
waxed crown is necessary.
 A wild-Leitz stereomicroscope
with fibre optic light can be
used to avoid any over
extensions in the margins.

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Spruing :
 One 8 or 10 gauge wax sprue, attached to the incisal
surface of the anterior patterns, provides an adequate
gate for the ingress of the ceramic material.
 Posterior patterns are usually require 10 gauge sprues
attached to the lingual and buccal cusp tips.
 Sprue placement on molar patterns should be diagonally
opposed for more uniform flow of the fluid ceramic.
 A sprue design incorporating a perpendicular reservoir
has also produced adequate casting. Length must be
approx 3 – 4 mm.
 The pattern should be located so that its most distal
point is approx 6 – 7 mm from the open end of the
casting ring to allow adequate diffusion of the mold glass
through the investment.

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Spruing :

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Investment :
 Wax pattern must be cleansed with a debublizing agent,
any excess must be removed.
 Non-corroding casting rings that are resistant to
oxidation at high temperature must be used.
 2 layers of Kaoliner* a ring liner material (an asbestos
liner)is placed inside the ring,to permit suffficient
expansion.
 The ring liner is saturated eith water for about 10 sec
before ceating the ring on to the crucible former.
 A special phosphate bonded investment is used for
casting process.

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 This material exhibits no
setting expansion but
produces approx 1.5% thermal
expansion at high
temperatures.
 8 ml of distilled water must be
mixed with 60 gm of
investment powder for 30 sec
under vacuum with power
spatulation.
 After spatulation additional
vibration under vacuum is
carried for 20 – 30 sec.
 The mixed investment should
be carefully applied on to the
wax pattern with a camel’s hair
brush.

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Investment :
 After the wax pettern is
carefully filled and
coated, the remaining
material should be
vibrated into the ring
allowing an excess to
remain above the open
ends of the ring.
 After bench setting for 1
hr the excess material
should be trimmed even
with the top of the casting
flask.

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Mold conditioning :
 A two stage mold conditioning is employed.
 The invested pattern is placed in a cold furnace,
the temperature is raised to 249`C, and
maintained for 30 min (heat soak), 10 min of
additional time for each ring should be added if
more than three rings are placed at a time.
 The temperature is raised to 899`C, and
maintained for 2 hrs (heat soak), similarly 10 min
added for each ring.

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Casting :
A 4 gm ceramic ingot is loaded in the
ceramic crucible.
The amount of ceramic material required to
make a good casting can be determined
when multiplied by a conversion factor of
2.6, the weight of the wax pattern, sprues
and button should not exceed 4gm .
Two patterns can be cast into one flask.

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Ceramic ingot Ceramic crucible:

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Casting Machine :
 The Dentsply DICOR
casting machine
features a platinum
electric resistance-
type muffle mounted
on a electrically
driven straight
centrifugal casting
arm.
 The machine is fitted
with a special
receptacle to hold the
Dicor crucible.

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Casting Procedure :
 An ideal temperature of 1100`C is maintained for
10 min to stabilize the muffle.
 The crucible containing the ceramic ingot is
inserted through the rear muffle door.
 The crucible is properly positioned in the muffle
for melting the glass by the help if a special tool.
 The rear door is closed, the melting temperature
is adjusted to 1360`C, and the melt switch is
turned on.
 After reaching the determined temperature, this
will be maintained for 6 min.

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Casting Procedure :
 The rear muffle door is opened .
 The casting ring is removed from the burnout furnace
and placed in the cradle with the crucible and gate facing
the muffle.
 The front muffle door is opened and the muffle assembly
is slid forward towards the casting ring until it is seated.
 The casting machine cover is shut and the casting switch
is turned on. The casting arm spins automatically for 4 ½
min and then stops. By the end of the spin cycle the
casting will cool down
 The casting ring is removed form the machine and
allowed to dool for 45 min before divesting

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After casting

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Divesting :
• After cooling, the investment is removed from arround
the edges of the casting ring to a depth of approx 6 –8
mm. The investment mass can be forced out of the
retaining ring by pushing with the fingers.
 The bulk of the investment material can be broken away
from the casting with finger pressure.
 The remaining casting should be removed with an air
abrasive tool using 25 micron aluminum oxide at 40 p.s.I.
 The margin areas should be protected by covering with
the finger to prevent chipping.

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Sprue removal :
 The cast crown is cut off at the junction of
sprue and button using a suitable single or
double side diamond disc.
 The sprue is cut near the glass button to
avoid chipping.
 The remaining button must be dicsarde
and cannot be reused because the glass
is altered during melting cycle.
 The casting at this stage is non-crystalline.

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Embedding :

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Embedding :
 The casting is embedded in the ceramic embedment
material, so that the ceramming process can take place.
 During this ceramming procedure the glass is concerted
into a 55% crystalline form.
 The glass casting is embedded in a mixture of 18 ml
distilled water and 50gm of embedment powder. Hand
mixing is sufficient.
 The inside of the crown is carefully filled with the
embedment mix and then it is placed on a tray with a
concave receptacle in which additional material is
placed.
 Additional embedment is used to cover and protect the
glass crown. The material should be allowed to set for 45
– 60 min.

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Ceramming :
 This process is accomplished by a precisely controlled
ceramming furnace.
 The furnace temperature is gradually increased to
1075`C for 3 ½ hrs, this temperature should be
maintained for 6 hrs. the furnace is cooled to 200`C and
the embedment tray is removed.
 The ceramming process involves a two-stage heat
treatment. The first heat treatment is carried at the
temperature for maximum nucleation of crystals, so
maximum no: of crystals are formed. The temperature is
held for some time for the crystal growth to take place, to
attain the maximum size.

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DICOR Ceramming Furnace :

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Ceramming tray Pyrometric cone

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Postceram divesting :
 The tray is allowed to cool to room
temperature.
 The embedment is broken.
 The crown is cleaned by air-blasting with
25 micron aluminum oxide at 40 p.s.I at a
distance of approx 6inches.
 The margins should be protected from
chipping during air-blasting.

74Wax pattern – Glass form - crystalline form - finished crown
Various phases undergone

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Crown finishing :
 Crystalline glass crown is inspected for internal
nodules or irregularities, which may interfere
with seating of the casting on the die. These
irregularities csn be removed with extrafine
diamond points.
 The crows is seated on to the die and examined
for marginal overextensions. If any, must be
removed with fine white point or rubber wheel
rotating at low speed.
 The remaining sprue is removed with a double
sided diamond disc rotating at slow speed.

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Crown finishing :
 The fine opaque white skin covering the crown must be
removed. The sprue is finished and the skin is lightly
removed with a fine rubber abrasive wheel.
 After removal of the skin the crown is air blasted with 25
microns aluminum oxide at 40 psi.
 The primary and secondary occlusal anatomy can be
defined with small round and inverted cone T.C burs.
 Corrections can be done with an add-on material. The
casting is dried in front of the open muffle at 593`C and
introduced into muffle under vacuum to a temperature of
968`C for 1 min and can be shaped and adjusted to
desired contours.

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Characterization & Glazing :

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Characterization & Glazing :
 After the ceramming process the casring is achromatic,
the desired hue is decided by the shading porcelains.
 The blending of enamel and body colors must occur
while they are wet.
 The first and the second shading porcelains should be
fired at a slightly lower temperature to prevent over
glazing and glassy appearance of the crown.
 Castable ceramics can be fired repeatedly in a
conventional glazing oven without affecting the physical
properties or marginal integrity of the material

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Cementation :
 The color value is modified by a
series od dentsply shaded
cements.these cements are color
coordinated with the die spacers
that are earlier used.
 If a natural colored tooth
preparation exists, a translucent
glass ionomer cement is indicated.
In those cases the tooth structure
or a metal core is present, the use
of properly colored cement can be
of good esthetic value.
 During cementation process,
controlled, positive finger pressure
should be used to seat the crown
onto the prepared tooth. Excess
cement is completely removed
after the setting is complete.

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POWDER SLURRY
CERAMICS
Vita Hi-Ceram (Vita Zahnfabrik)
CERABIEN (Noritake)
OPTEC H.S.P (Jeneric/Pentron)
DUCERAM L.F.C (Ducera Inc)

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Lab Procedures :
 Preparing the refractory die.
 Hard core porcelain framework.
 Crown buildup.

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Refractory Die :
Apply Vita interspace varnish on to the die in 2 or 3
coatings. www.indiandentalacademy.com

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Duplication

86
In the Vita Vacumat
200 : prog 5.5, end
temp 1,000`C, pre-
drying time 10 min,
heating time 10 min,
hold time 3 min. In the
Vita Vacumat 100 :
prog 5, end temp
1000`C, pre-drying time
10 min, heating time 10
min, hold time 3 min.www.indiandentalacademy.com

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Constructing the hard core
porcelain
The Hi-Ceram hard core
porcelain has to be applied
and fired in three layers
altogether : 1. The wash
firing.; 2. Half of the require
thickness with protuberance
for later checking on the
thickness of the porcelain.;
Full build-up as a smaller
version of the crown it is to
become. Minimum thicknes
0.5mm.

88
 The thickness of hard
core porcelain
framework should not
be less than 0.5 mm.
 For additional
stability, a collar in Hi-
Ceram hard core
porcelain can be
added palatally or
lingually.

89
 The refractory die
should be blasted
away using glass
beads at a pressure
of 1- 2 bar.

90
The build up of the crown :
 The crown should be
built up to its desired
shape using Vitadur-
N dentin porcelain,
although to
compensate firing
shrinkage it must be
built longer incisally.
The cervix of the hard
core framework can
be coated before
hand using Vitadur-N
opacous porcelain.

91
A little Vitadur-N
opacous dentin
can also be
applied palatally,
so that even in
cases where
there is a deeper
than normal bite
by the occluding
teeth, any shining
through of the Hi-
Ceram hard core
porcelain will be
completely
avoided. www.indiandentalacademy.com

92
To create the
necessary space for
the enamel
porcelain, the dentin
should have a
crescent carved
away incisally and
for the smooth
transition between
the dentin and
enamel, then also
be smoothened
using a flattened
brush.

93
 For individual
shading and
characterization,
there are 5
Vitadur-N
opacous dentin, 6
dentin effect, 2
enamel effect
and 7 COLOR
porcelains
available.

94
 The shape of the
crown is now built
up in Vitadur-N
enamel porcelain.
It should be
somewhat over
dimensioned to
compensate firing
shrinkage.

95
 The crown is fired as
follows: either by
placing it onto a
fibrous pad firing
support (in which
case raise the
temperature by 10`C),
or by wrapping a
normal crown stand in
the fibrous pad
material and then
placing the crown
loosely onto it:

96
 The fired Hi-Ceram crown should be ground
all over in the normal way, using a diamond or
a green silicon carbide bur. For corrections,
clean without using any cleansing agent but
with a clean brush under running water, or a
steam jet blaster.
Then reapply the
appropriate
porcelain and fire
as for the main
vacuum firing,
except with the
temperature
reduced by 10`C.

97
 The cervical
porcelain should
be mixed with Vita
modeling liquid,
applied onto the
cervical margin,
condensed and
then bottled.
Excess cervical
porcelains should
then be removed
using either a
clean finger or a
dry brush. www.indiandentalacademy.com

98
Glaze firing :
 Applying the
Vitachrom ”L” glaze
No. 725 allows the
temperature for the
glaze firing to be
lowered, thereby
guarantying that
the cervical
margins retain its
accurate fit.

99
MACHINABLE CERAMICS

100
Classification:
CAD CAM
CERAMICS
COPY
MILLED

101
CAD – CAM Ceramics
 CEREC CEREC SCAN
 CEREC 2 CEREC InLAB
 CEREC 3
 IVOCLAR PROCAD (IVOCLAR, SPRING)
 DICOR M.G.C (DENTSPLY)
 PROCERA (NOBEL BIOCARE)
 LAVA (3M ESPE)

102
Introduction:

103
Types of CAD – CAM Devices:
 DIRECT:
Fully integrated CAD – CAM devices for
chair side restorative approach. CAD &
CAM stations are located at the dental
office.
 INDIRECT:
System that consists of several modules
with at least, distinctive CAD & CAM
stations.

104
Direct CAD - CAM
CEREC, CEREC 2, CEREC 3

105
INTRODUCTION CEREC VIDEO
CEREC

106
C
E
R
E
C
S
Y
S
T
E
Mwww.indiandentalacademy.com

107
Equipment
a computer integrated imaging and milling
system, with the restorations designed on
the computer screen

108
Ingots used
 Dicor MGC*(Machinable Glass Ceramic)(Dentsply):
This is a mica based machinable glass ceramic
containing 70% vol of crystalline phase. The
unique “House of Cards” microstructure found in
Dicor MGC is due to the inter locking of the
small platelet shaped mica-crystals with an
average size of 1 – 2 microns. This particular
structure leads to multiple crack deflections and
ensures greater strength than leucite containing
ceramics.

109
Vita Mark II (Vident):
These contain sanidine (KALSi3O8) as a
major crystalline phase within a glassy
matrix.

110
ProCad (Ivoclar):
ProCAD is reinforced with tiny leucite particles,
and has been referred to as: "Empress on a stick".

111
 Vita IN-Ceram Blanks (Vita Zhanfabrik):
These are third generation blanks from Vita.
 The Spinell MgAl2O4.
 The Alumina Al2O3.
 The Zirconia ZrO2.

112
The Spinell Blanks:
 The fine chemical and
mechanical properties
of the highly pure
synthetic spinell are
used with the aim to
obtain an esthetically
appealing, translucent
ceramic structures.

113
Alumina Blanks:
 These uses the advantages of the
synthetic corundum that is prepared from
bauxite prepared in electric melting
furnace.

114
Zirconia Blanks:
 This combines the fracture toughness of
the meta-stable tetragonal zirconium oxide
which is also referred to as “ceramic
steel”.

115
Clinical Procedure:
Preparation design.
Optical impression.
Computer generated restoration design.
Milling procedure.

116
Tooth Preparation Design:
 Tooth preparation follows typical all-
ceramic guidelines.

117
Optical impression
 The surface of the prepared teeth often lacks sufficient
reflectivity or it may have facets that give an uneven
glaze to the computer screen.
 It is therefore necessary to coat the preparation with a
special powder (titanium dioxide) that has proper light
reflectivity.
 Rubber dam must be placed to prevent fogging of the
camera lens and to aid in isolation.
 Cerec is the first system that makes intra-oral scanned
impressions a reality. This is done through a small hand
held camera. The camera, which resembles a wand,
illuminates the prepared tooth and the 2 adjacent teeth
with its light source and processes the image with the 3-
D measuring camera.

118
 The operator actually feels the wand vibrate as
the camera oscillates to scan the teeth at slightly
different angles. The Cerec software then
blends these images to create its 3D map of the
topography. This optical scanning system could
well be the precursor of much expanded use of
optical scanning in dentistry. However, the
inability to scan sub gingival margin areas and
some interproximal areas must (but probably
will) be overcome before optical scanning
becomes mainstream.

119
Optical impression:

120
Design Phase:
 With the
help of the
CEREC 3
Software
we can
choose the
basis
software
for the
designing
of
inlays/onla
ys or
crowns or
veneers.

121
Shaping of the surfaces:
1. Function
2. Correlation
3. Extrapolation

122
Function:
This design programme takes
design of the antagonist.
Correlation
This design programme allows to
copy intact occlusal surfaces.
Extrapolation
This programme calculates the
dimensions of the restoration with
reference to a tooth database and
as well as with the adjacent teeth.www.indiandentalacademy.com

123
 With using
all the
programme
s the
operator
can digitally
design the
restoration
by moving
the cursor
along the
boundaries. www.indiandentalacademy.com

124
The procedure can be stopped at any
time and can override the computer and
allow the operator to correct, the digitally
generated features.
Once the restoration has been designed,
the computer develops a 3-D model on
the screen.
All the information is stored.
The design phase usually takes 2 – 8
min.

125
CEREC VIDEO

126
Milling Phase:
 After all the data has been supplied, the
computer selects the size of the ceramic
block to be used in the milling process.
 There are wide range :
 Composition.
 Shade.
 Size.

127
 These blanks are factory fabricated and
thus are more homogenous and less
porous than materials that are made in the
lab.
 These materials also produce “chameleon
effect”.
 The material is mounted on the metal stud,
which allows it to be inserted in to the
milling hub.
 Once the material is inserted. The window
is closed an the milling process is
activated.

128www.indiandentalacademy.com

129
Advantages of CEREC System:
 One or two appointments.
 Optical impression, max time required is 5 sec.
 Wear hardness similar to enamel.
 Less fracture due to single homogenous block.
 Excellent polish.
 Improved esthetics.
 Time saving.
 Good occlusal morphology in relation to
antagonist.

130
Indirect CAD - CAM
 CEREC* SCAN, CEREC* In-LAB
 PROCERA* SYSTEM
 LAVA 3M ESPE
 Cercon® Zirconia (Dentsply)

131
CEREC SCAN:
 Tooth preparation.
 Conventional impressions.
 Die preparation.
 Controlled by one of the practice pc’s.
 Can be upgrade to CEREC 3.
 Works upon CEREC 3 software.
 Intra oral scanning device is not present.

132
CEREC SCAN (inclusive of both scanning
and milling device)with lap top(imaging
device). www.indiandentalacademy.com

133
Scanning device.

134
CEREC In-LAB:

135
Controlled Scanning:
 Consists of a compact milling unit with a
in-built scanner.
 This consists of non contact scanning for
utmost precision.
 Software runs on Windows* 98.

136
Controlled Design:
 Offers a complete spectrum of design options for
crowns and bridge framework.
 All relevant parameters can be adjusted
individually …for example, the occlusal and
radial wall thickness and the cross sectional
area of the bridge connectors.
 This system gives a visual thickness if operator
falls short of the minimum material specific wall
thickness.
 Thus the operator exerts complete control over
the design process ay all times.

137
Controlled milling:
Prior to each milling jib CEREC In-Lab
automatically checks the dimensional
accuracy of the milling tools.
The integrated soft touch control monitors
the calibration of the tools throughout the
milling process and compensates for any
wear-related inaccuracies.

138
Parallel milling with two tools:

139
High speed milling of copings and
bridge frame work.

140
Processing times:
Process step Coping Bridge
framework
Scanning
(automatic)
Approx. 10 min Approx. 20min
Design Approx. 2 min Approx. 6 min
Milling
(automatic)
Approx. 15 min Approx. 50 min

141
Procera* All-Ceram

142
Fabrication Procedures:
Tooth preparation.
Die preparation.
Scanning.
Data transfer.
Central milling.
Application of conventional porcelains.

143
Tooth preparation:
 Since the
scanner's tip is
rounded, the
finish line should
be a chamfer
placed sub-
gingivally at 0.5
mm to 0.7mm. A
rounded shoulder
may be also an
appropriate
design. www.indiandentalacademy.com

144
 A relatively
level
topography
should be
accomplishe
d during
preparation
of the
occlusal
surface of
posterior
dentition.

145
The occlusal surface of a
posterior tooth is
shaped, eliminating
undercuts and sharp
edges. Steep slopes
and sharp groves are
avoided to enable the
scanner to recognize all
of the information
through the tip.

146
For anterior dentition,
preparation of the
lingual surface
requires shaping
with diamond bur
to eliminate
debris.

147
 Fine finish lines on
the prepared tooth
enable the scanner
to precisely register
all aspects of the die
models, which
directly affects the
marginal fit of the
definitive
restoration.

148
Preparation
depths should be
between 1.0 mm
and 1.5 mm,
while the
occlusal
reduction should
be at least 2.0
mm.

149
Lab Procedures:
 The cast is made in the conventional
way, the die is ditched to make the
margin easier to identify during
scanning.
 The die is then taken to the
PROCERA* design station for
scanning and designing.

150
 A technician using the special
Procera design station scans the die
and designs the coping to be
fabricated. This station consists of a
computer, a modem and the Procera
scanner. Once positioned on the
scanner, a probe lightly touches the
die as it is rotated. A 3D map is
produced from this "tactile scan" that
consists of approximately 50,000 data
points from around the die.

151
 The technician then marks the margin
or finish line and selects an
emergence profile for the coping,
using the computer and its’ Procera
design software. This information is
then modemed to the manufacturing
facility in Fairlawn, New Jersey. In
about 4 days the Procera coping
is returned to the laboratory for further
veneering.

152
 The production starts with milling an
enlarged die to compensate for the
sintering shrinkage.
 An enlarged high-alumina coping is
milled that shrinks to the desired
shape after sintering.
 The coping is returned to the
laboratory, and body and incisal
porcelains are added in the
conventional manner.

153
Lava from 3M ESPE

154
Equipment
 Lava™ Scanner
 Lava™ Milling Unit
 Lava Therm furnace (sintering
unit).

155
Preparation
Anterior Crown
• 1.5 – 2.0 mm incisal reduction
• 1.0 – 1.5 mm lingual reduction
• 1.0 – 1.5 mm lingual reduction
• Round the internal line angles
Posterior Crown
• 1.5 – 2.0 mm
occlusal/incisal reduction •
1.0 – 2.0 mm axial reductionwww.indiandentalacademy.com

156
The optimal preparation is a shoulder or chamfered
preparation with a circumferential step or chamfer
which must be applied at an angle of >5°
(horizontal). The angle of the preparation (vertical)
should be 4° or larger. The inside angle of the
shoulder preparation must be given a rounded
contour.

157
Laboratory Preparation
 A light colored type IV or V die stone
(white, beige, buff, or green) without
plastic additives is recommended. A light,
dull (non-reflective) surface works best for
the scanning procedure.
Model bases should be removable from
the plaster that is used to attach the model
to the articulator. The model bases should
be flat, have minimal thickness and size, in
order to ensure optical accessibility.

158
A common split-cast system is
recommended. Attention should be paid
to ensure that the base of the model is
smooth and flat, without split-cast guides,
metal plates or magnets.
Overlapping areas should be blocked out
with light colored wax after consultation
with a dentist, as should defects. All
segments of the saw-cut model must be
removable from the base with double,
triple, or block pin die system to prevent
rotation or movement of the die(s) and
tissue (pontic) areas.

159
 Vertical walls and sharp line angles
are difficult for the scanning process
to decipher. Avoid preparations with
these situations (see Ideal Die
Preparation). Copings or frameworks
for implant abutment posts should
also be pinned, removable, and in die
stone or acceptable resin die
material. Margins should be ditched
according to Ideal Die Preparation
example.

160
 1. Dies should be ditched directly below the margin
– DO NOT mark the margins, or use die spacer, or
hardener on the die preparation area.
This will create a reflective surface on the die that
will compromise the scanned data of the die
surface. (Note proper angulation of prep area).

161
Undercuts, occlusal holes, surface defects
should be blocked or based-out with a resin
block-out material, or a light colored wax.
Nodules, stone-tags should be flicked, or
scraped off.

162
Severely prepped teeth with missing
proximal, buccal, lingual walls should be
built-up to adequate or desired clinical prep
design with a resin block-out material or
light colored wax. The model is now ready
to be scanned.

163
MATERIAL USED
Lava™ Frame Zirconia

164
Lava™ Scanner
Consists of a non-contact optical scan system,
a PC with a monitor, and the Lava CAD
Windows™ based software, which displays the
model as a three-dimensional object.www.indiandentalacademy.com

165
Lava™ Milling Unit
This computer-controlled precision milling unit
can mill out 21 copings or bridge frameworks
without supervision or manual intervention.www.indiandentalacademy.com

166
Lava™ Therm Furnace
Bridges and crown frameworks
undergo sintering and attain their
exact dimensions, density, and final
strength www.indiandentalacademy.com

167
3M ESPE Lava Cementation
 Cementation of Lava All Ceramic
restorations can be accomplished with
proven, conventional techniques using any
of the following cements:
3M ESPE RelyX Unicem Self-Adhesive
Universal Resin Cement
3M ESPE RelyX Luting Cement
3M ESPE Ketac-Cem Glass Ionomer
Cement

168
Cercon® Zirconia
Dentsply Ceramco

169
 Material: Yttria-stabilized zirconia.
 Recommended Use: Anterior or
posterior single crowns and multi-unit
bridges.
 Lab Processing: Computer Aided
Manufacturing (CAM) of pre-sintered
zirconia. www.indiandentalacademy.com

170
 Properties: Flexural Strength>900MPa,
Fracture Toughness=9.0MPa.m0.5,
VHN~1200, CTE~10.5 m/m/oC, at 500oC.
 Esthetics: Inherently translucent, metal-
free restorative solutions for the entire
mouth.
 Veneering: Optimally matched to
Cercon® Ceram S veneering porcelain.
 Placement: Conventional cementation or
adhesive bonding

171
 Cercon units and frameworks are
fabricated using a CAM
(computer aided manufacture)
process. The restoration is first
designed in wax on the model.
The waxed restoration is then
placed in the Cercon Brain for
scanning where a confocal laser
takes precise measurements of
the pattern.

172
 The data is then enlarged by the
Cercon Brain by approximately
50% to allow for shrinkage that
will take place during the final
sintering. The block is then milled
to replicate the expanded pattern
and is placed in specialized
sintering furnace where final
sintering takes place.

173
Technique
1. Framework waxup
2. Waxup is scanned and milled in the
Cercon Brain
3. Milled pattern ready for sintering
4. Pattern is sintered using Cercon Heat
5. Sintered pattern is seated and prepared
for ceramic layering
6. Completed Cercon Bridge

174
Framework waxup

175
Waxup is scanned and milled in the
Cercon Brain

176
Milled pattern ready for sintering

177
Pattern is sintered using Cercon
Heat

178
Sintered pattern is seated and
prepared for ceramic layering

179
Completed Cercon Bridge

180
COPY MILLED
RESTORATIONS
CELAY* System
Mikrona Technologies
Switzerland.

181
Material used

182
Procedure:
 Preparation:
shoulder with
rounded
axio-cervical
line angle.

183
Resin coping:
A prototype composite
resin coping is modeled
on the die.

184
 The resin coping modeled with
CELAY – TECH is transferred on to
the scanning / milling platform.

185
Scanning of the prototype resin with
simultaneous of the copy milled
crown substructure.

186
The finished
sintered
substructure
after firing
onto the die.

187
GLASS INFILTRATED
CERAMICS
 In-Ceram* Alumina
 In-Ceram* Spinell
 In-Ceram* Zirconiawww.indiandentalacademy.com

188
Introduction:
 This system use a slip casting (a procedure by
which a fine particle ceramic, dispersed in an
aqueous liquid medium (low viscosity slurry) is
applied on to a porous mold, which rapidly
extracts the liquid causing the formation of a
close packed but a weak ceramic particle
structure.) procedure. Then the slip-casting is
sinter fired.
 The combination of these procedures gives the
material its outstanding properties.

189
Classification:
Reinforcing
crystals
Clinical System Charestrestics
Alumina In-Ceram
Alumina (Vita)
High alumina
coping infused
with a low fusing
glass
Zirconia In-Ceram
Zirconia (Vita)
High Zirconia
coping infused
with a low fusing
glass
Magnesium
oxide spinell
In-Ceram
Spinell (Vita)
High Spinell
coping infused
with a low fusing
glass

190
Clinical procedure

191
Armamentarium:

192
 Divide the unprepared labial surface if
the tooth crown into three equal thirds.www.indiandentalacademy.com

193
 Prepare two depth orientation grooves
on the labial surface of the tooth with a
dual-guided groove cutter.www.indiandentalacademy.com

194
 Prepare palatal depth orientation
grooves. www.indiandentalacademy.com

195
 Prepare two incisal depth orientation
grooves. www.indiandentalacademy.com

196
 Condition after milling of all depth
orientation grooves.www.indiandentalacademy.com

197
 Reduction of the hard tooth substance
parallel to the incisal third of the labial
surface between the second and the third
milled groove.www.indiandentalacademy.com

198
 Reduction in the area of the labial surface
between the first and the second milled
groove and thus almost parallel to the path
of insertion. www.indiandentalacademy.com

199
 Correct preparation of the tooth in two
planes.

200
 Incorrect preparation; in one plane,
therefore insufficient reduction of
substance. Due to that insufficient wall
thickness of crown, crown mat fracture.www.indiandentalacademy.com

201
 Incorrect preparation of the tooth
surface lead to the risk of damaging of
the pulp. www.indiandentalacademy.com

202
 Application area of the proximal cutter.

203
 Use of the step cutter with depth stops:
this cutting tool is to optimize the
position and quality of the prepared
step.

204
 Palatal side is prepared with a foot ball
diamond. www.indiandentalacademy.com

205
 Smoothening of the sharp angles using
a bud shaped diamond.www.indiandentalacademy.com

206
 Defined marginal
reduction of 0.6 – 1.2
mm.
 Incisal or occlusal depth
1.5 – 2 mm.
 Shoulder with rounded
axio-cervical line angle /
chamfer is indicated in
reduced tooth
substance.

207
Laboratory Working
Procedure
In-Ceram*

208
Model Fabrication
Blocking Out
Applying the interspace varnish
Waxing up the prop
Duplicationwww.indiandentalacademy.com

209
Deflasking
Stirring VITA INCERAM special plaster
Deflasking
Trimming the plaster model
Separating the special plaster model

210
Sectioning the bridge units
Preparation margins
Preparing the slip
Pouring the slip into a plastic mixing cup
Applying the slip

211
Applying VITA In Ceram Stabilizer
1st sintering firing
2nd sintering firing
Checking on the master model
Material testing

212
Application of glass
Glass infiltration firing of
bridges in VITA INCERAMAT
Remove excess glass
Glass control firing
Completion

213
Model Fabrication
 A working model with removable dies
from a high-quality, dimensionally stable
model stone is prepared.www.indiandentalacademy.com

214
 A master model that has not been
sectioned is fabricated, for positioning,
transferring and checking the crowns
and bridges. www.indiandentalacademy.com

215
Preparation for Duplication

216
 Check the sawed die carefully for
undercuts and block out them.
Blocking Out:

217
Applying the interspace
varnish:
 The varnish must be applied to the
plaster dies in 2 – 3 coats approx. 45
microns. www.indiandentalacademy.com

218
Applying the interspace varnish:
 Epoxy or galvanized dies require 4
coats approx. 60 microns.
 ! Wait for at least 5 min after each
application of the varnish. After
applying the last coat wait for 20 min
to ensure complete drying.
 ! Do not extend the interspace varnish
over the shoulder.

219
Waxing up the prop:
For the fabrication of bridgework, a prop
must be waxed up palatally in the area of
the pontic. www.indiandentalacademy.com

220
 The prop facilitates the application of
the slip material and allows increased
absorption of liquid and quicker
extraction during the application of the
slip.
 ! The waxed up prop must not have any
under cuts.
Waxing up the prop:

221
Duplication:

222
 Duplicate with an addition polymerizing
silicone in a ratio of 1 : 1 using the dual
impression technique or……www.indiandentalacademy.com

223
 Duplicate using the pouring method
with the help of a duplicating mold.www.indiandentalacademy.com

224
Deflasking:
 After deflasking allow the impression to
harden for approx. 30 min(according to
manufacturer). www.indiandentalacademy.com

225
 Spray a wetting agent on to the
impression and allow the agent to dry.www.indiandentalacademy.com

226
Stirring the
VITA In-Ceram*
Special Plaster

227
Mixing:
 VITA In-Ceram special plaster 20g : 4.6
ml distilled water.www.indiandentalacademy.com

228
Mixing:
 Pour 4.6 ml of distilled water into the
mixing beaker, then min the content of
the sachet of VITA In-Ceram special
plaster by hand. Then mix under
vacuum for 20 sec.
 ! Make sure the mixing unit is clean and
dry. The processing time can be
lengthened by adding chilled distilled
water. www.indiandentalacademy.com

229
Pouring:
 Pour the plaster in to the mould slowly in
small increments without the formation of air
bubbles. www.indiandentalacademy.com

230
Preparation for the
application of the
SLIP

231
Deflasking:
 After filling the special plaster into the
special plaster mold, deflask after 2 hrs.www.indiandentalacademy.com

232
Grinding the special die:
 After deflasking the base must be ground flat.
During this, the models must be kept dry.
 ! Any absorption of water of water on the hardened
special die has a negative effect on the expansion
behavior.

233
Separating the bridge model:
 Partly section the special plaster model
from beneath using a separating disc.www.indiandentalacademy.com

234
Attaching the bridge model:
 Glue the special plaster bridge model onto a
VITA In-Ceram firing tray using cyanoacrylate
adhesive. www.indiandentalacademy.com

235
Sectioning the bridge unit:
 After approx.10 min, section the plaster model
between the abutment teeth with a sharp saw
blade, in order to prevent damage to the
bridge substructure due to the shrinkage in
the plaster during sintering firing.

236
Margin preparation:
 Mark the margins with a super polymer
color cartridge.www.indiandentalacademy.com

237
Manufacturing the
SLIP:

238
 Weigh out exactly 38 g of VITA In-
Ceram alumina powder.www.indiandentalacademy.com

239
 Pour the contents of 1 ampoule of ZITA In-
Ceram alumina mixing liquid and 1 drop of
VITA In-Ceram Alumina additive into a glass
beaker and mix briefly in the VITASONIC.www.indiandentalacademy.com

240
 Place the glass beaker on a vibrator
and spatulate the 38 g of VITA In-
Ceram Alumina powder slowly into the
liquid in several small portions.www.indiandentalacademy.com

241
 After the entire powder is added, place the
glass beaker in the VITASONIC for 7 min.
 ! After mixing, the slip must be homogenous.

242
 The mixture must be evacuated for 1 min.
(e.g. with a vacuum investment unit).

243
Pour the slip from the glass beaker into
the enclosed plastic mixing cup.

244
Applying the SLIP

245
 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

246
 ! Proceed rapidly when building up the
remaining slip.
 ! Do not interrupt this process, so that drying
out the layers is that have already been built
up is prevented (onion-skin effect).www.indiandentalacademy.com

247
 Since fine reworking is always required after
sintering, the slip should be applied more
richly prior to sintering firing.www.indiandentalacademy.com

248
 Carefully expose the preparation margin
with a scalpel until the marking can be seen.

249
 Final shaping of the substructure is only
carried out after sintering.

250
Sintering firing:

251
 After firing allow the substructures to cool
down to 400`C in the closed firing
temperature, and then to the room
temperature with the furnace opened.www.indiandentalacademy.com

252
Sintered substructure:
 Since the plaster model has contracted
during firing, the sintered substructure can
be easily removed from it.

253
Checking the fit of the coping on
the working model:
 Before continuing the work on the
working model, remove the interspace
varnish.
 In order to check the accuracy of the
fit, carefully place the sintered
substructure on the working model
again.

254
 Do not exert pressure
when placing.

255
 Due to dust formation when grinding
sintered dental ceramic products, always
wear a face mask. Work behind a shield
and use a suction unit.www.indiandentalacademy.com

256
 Due to dust formation when grinding sintered
dental ceramic products, always wear a face
mask. Work behind a shield and use a
suction unit.

257
 Adjust contours and functioning by grinding
slightly(fine diamond, low speeds, minimum
pressure). www.indiandentalacademy.com

258
 Be cautious in the marginal area, use very
fine grained diamond or rubber disc at low
speed with minimum pressure.
 Contours and functioning must be controlled
now, if required adjusted, because no further
adjustments can be performed after the glass
infiltration firing.

259
Completed substructure:

260
Defect repair

261
 The VITA-In-Ceram Optimizer is a mixture
of Aluminum oxide powder and wax and is
used to fill up small defects in ground or
slip-coated or sintered In-Ceram crown and
bridge substructures.www.indiandentalacademy.com

262
 Separating agent is added onto the die and
blow completely dry.
 Take up Vita In-Ceram Alumina Optimizer
with an electric wax knife and apply to the
crown margin. www.indiandentalacademy.com

263
 Remove the excess with a paper
napkin and the hot wax knife.
 Remove the substructure from the
die.
 Place the substructure on the model
again and check the optimizer that
has been applied.

264
Sintering:
 Fix the substructure on a platinum rod or
place it on a fibrous pad firing support co
that the so that the optimizer will not come
into contact with it.www.indiandentalacademy.com

265
 Firing chart.
Use ceramic furnaces in which no alloys are fired.
Check the fit on the working model.www.indiandentalacademy.com

266
Material testing:
 To check the sintered substructures for
possible micro-cracks using the Vita In-
Ceram testing liquid.www.indiandentalacademy.com

267
 The crown on the left is ok.
 The crown on the right must be
manufactured once again.

268
Application of the glass powder:
 Mix Vita In-Ceram Alumina glass
powder with distilled water to obtain a
thin consistency.
 Apply 1 – 2 rich coats with a thickness
of 1 – 2 mm only on the outer surface
of the sintered substructure using a
brush.
 The margin of the crown must not be
coated. www.indiandentalacademy.com

270
 ! During the glass infiltration of
bridge substructures on platinum
foil, the basal surface of the
pontic must not be covered with
glass powder. This can cause air
in the sintered pontic to escape,
otherwise complete glass
infiltration will not take place.

272
Glass infiltration firing in
INCERAMAT:
 Place the crown copings on platinum
pins in the firing tray, so that the crown
margins do not come in to contact with
the platinum pin in order to prevent the
glass from penetrating into the interior
of the crown.

274
 Place the coated crown copings onto a
piece of platinum foil (Pt = 95%, Au =
%5) in order to carry out the glass
infiltration firing and preheat shortly.www.indiandentalacademy.com

275
Firing chart:

276
Glass infiltration firing in the
VACUMAT:
 The glass infiltration of crown copings can
also be carried out in the dental ceramic
furnace under vacuum.www.indiandentalacademy.com

277
Firing chart:

278
Glass infiltration firing of bridge
substructures in INCERAMAT:
 Place the coated bridge substructure for the
glass infiltration firing on a piece of platinum
foil of 0.1 mm thick.www.indiandentalacademy.com

279
Firing chart :

280
 ! In the case of incomplete infiltration – if
there are chalk-like areas – the
infiltration process should be repeated.www.indiandentalacademy.com

281
 Remove the excess glass with a coarse
grained diamond instrument or heatless
abrasive almost down to the
substructure.

282
 Sandblast residual material with 50 microns
aluminum oxide at a maximum pressure of
approx. 3.0 bar.

283
Glass control firing:
 Place the substructure on a fibrous pad
supporting on a Vita firing support W .www.indiandentalacademy.com

284
 Firing chart:

285
Finishing:
 After the glass control firing sandblast the
crown with 50 microns aluminum oxide at a
maximum pressure of 3 bar.www.indiandentalacademy.com

286
Finished substructures:

287
Possible Errors:
Inadequate fit:
 Insufficiently or incorrectly blocked out.
 Interspace varnish applied to shoulder.
 Dies were not repositioned correctly after the
application of interspace varnish.
 Recovery time of silicone not followed.
 Distorted impressions.
 Mixing ratios not followed

288
 Setting time not followed.
 Improper firing temperatures.
 Preparation margin not exposed exactly
after the application of the slip.
 Improperly sandblasted glass.
 Marginal areas were sandblasted using
excessive pressure.

289
Fractured bridges:
 Prop was not waxed up correctly.
 Prop has undercuts.
 Special plaster model was not sawed.
 Insufficient exposure of prop after
application of slip, slip coated
substructures feature micro-cracks.

290
Sintering problems:
Loose flakes in the crown after sintering firing:
 Die was not wetted sufficiently during the
application of the first.
 Slip coat (rapid drying-up, consequence:
onion skin effect)
Glazing, greenish discolorations in the crown:
 Furnace temperature too high.

291
Veneering With
VITADUR*ALPHA
LAYERING TECHNIQUE

292
VITA In-Ceram Alumina crown
and bridge substructures:

293
 VITA In-Ceram Alumina crown and
bridge substructures ready for
veneering.www.indiandentalacademy.com

294
Opaque dentin:
 Apply the opaque dentin in the required
shade, beginning at the cervical area, to
cover the entire surface of the substructure.www.indiandentalacademy.com

295
Completed opaque dentin.

296
Dentin:
 Dentin is applied and built up to the
final shape of the crown. At this stage
the occlusion, laterotrusion and
protrusion should be checked in the
articulator.

297
To make enough space for the enamel, it is
necessary to reduce the volume of the
dentin accordingly.www.indiandentalacademy.com

298
 Applying enamel in several small portions to
complete the shape of the crown or the
occlusal surface. The crown should be
modeled slightly larger than the actual tooth
size to compensate for firing shrinkage.www.indiandentalacademy.com

299
In the case of bridges separate the teeth
down to the substructure before the first
firing. www.indiandentalacademy.com

300
 The finished build up ready for the first

301
 Firing chart:

302 Bridge after first firingwww.indiandentalacademy.com

303
Correction layering:
 Build up the inter-dental areas and the
basal surface of the pontic with Opaque
dentin. www.indiandentalacademy.com

304
 Complete the contour corrections with
Dentin in the body of the tooth and enamel
in the incisal area.www.indiandentalacademy.com

305
 Firing chart:

306
 Crown and bridge after correction firing.

307
Finishing:
 Trim the bridge or crown. Polish to obtain
an even, homogenous surface for the glaze

308
 To guarantee perfect articulation check the
occlusion, protrusion and laterotrusion
once more in the articulator.www.indiandentalacademy.com

309
 Glaze and stains applied.www.indiandentalacademy.com

311
Firing Chart:

312
 The finished restoration on the model.
Afterwards the interior surfaces of the
finished restoration must be sandblasted
once again with 50 microns aluminum oxide
at a maximum pressure of 3 bar.www.indiandentalacademy.com

313
Finished restoration:

314
VITA Individual Layering
Technique:

315
Opaque dentin / luminaries:
 Apply the individually shaded opaque
dentine and luminaries to the entire labial
surface.
 Enhancing the shade of the crown using
the Vitadur Alpha Luminaries.

317
 Washing or mixing in Luminaries, e.g. LM 5
in the cervical areas, LM 1 in the middle
third and LM 3 in the incisal area. Applied in
the gingival or incisal area, these dental
ceramics enhance the distribution of light in
the restoration. www.indiandentalacademy.com

318
Applying the DENTINE:
 The dentin is applied in the required shade
. The mamelons can be lightened mesially
and distally with a lighter dentine.www.indiandentalacademy.com

319
Incisal Mirror build-up:
 The incisal area is built up to the desired
height with T4 (translucent).www.indiandentalacademy.com

320
Applying Intensive:
 Intensives can be applied to add individual
shading and characterizations.

321
First intermediate firing:

322
 Crown after the first firing.www.indiandentalacademy.com

323
Mainly light shaded Translucent and Cervical
porcelains are applied for correction.
Correction:

325
Correction firing:

326
Finishing:
 After the correction firing, trim and
polish the crown as usual.www.indiandentalacademy.com

327
Glazing:
 Cover the entire surface of the crown
with the glaze material.www.indiandentalacademy.com

328
Glaze Firing:

329
Finished restoration:
 Before insertion, the inner surface of the
finished restoration should be sandblasted
once more with 50 micron aluminum oxide at
a maximum pressure of approx. 3 bar.www.indiandentalacademy.com

330
INJECTION MOLDED /
PRESSABLE CERAMICS
IPS EMPRESS* I, II
CERESTORE* (ALCERAM)
Summary

331
Material:
 This is a glass ceramic material that is
made up of a glass phase and a leucite
phase. The growth of the leucite crystals
starts at the grain edges of a ground
starting glass. These leucite crystals grow
in a multi-step fabrication process up to a
size of few microns.

332
Material: ………
 This semi-finished product in powder form
is then pressed to ingots and fired.
 The compressive strain resulting from the
leucite crystal structure in a silicate glass
matrix provides increased stability.
 This material is based on a system of…..
SiO2 – Al2O3 – K2O and complies with ISO
6872 ‘Dental Ceramic’.

333
Layering ceramic:
 This is a sintered glass ceramic which is
coated upon the lithium disilicate glass
ceramic framework. This is supplied in
powder form. They have been developed
in various versions called ‘Dentin’, ‘Incisal’,
‘Impulse, Transpa’, Effect.
 Their crystalline phase consists of apatite
(flourapatite).

334
Clinical procedure:

335
Shade selection:
 Tooth cleaning is necessary before
shade selection. Do not over dry thewww.indiandentalacademy.com

336
Tooth preparation:
 A chamfer /
shoulder
preparation (10
– 30`) with
rounded inner
angles.the
width of the
circular margin
should be
approx.1 mm.www.indiandentalacademy.com

337
 Reduce the axial
walls of the tooth on
the incisal third of the
crown by approx. 1.5
mm.
 The incisal or
occlusal reduction
should be approx.
1.5 – 2 mm.
 Anterior crowns, the
labial or palatal
reduction should be
approx. 1 – 1.5 mm.

338
Die shade selection:
 The shade of the prepared die is determined using
the Die material shade guide. With the appropriate
shade we can fabricate esthetically appealing, true-
to-nature restorations. To achieve optimum results,
the dentin should be moist when the shade is
determined. www.indiandentalacademy.com

339
Impression making:
 An addition curing silicone or any other
suitable impression material can be used.

340
Processing procedure
1.Fabricating the model.
2.Applying the spacer.
3.Connectors.
4.Contouring.
5.Spruing.
6.Investing. www.indiandentalacademy.com

341
7.Furnace calibration.
8.Pressing.
9.Divesting.
10.Control dieing.
11.Foundation firing.
12.Layering, staining, glazing.
13.Etching and cementation.

342
Fabricating the model:
 Fabricate a type IV stone model with
detachable segments according to the
impression.www.indiandentalacademy.com

343
Applying the spacer:
 It is advisable to apply a sealer to
harden the surface and to protect the
die. This sealer must not cause any
changes in the dimensions of the die.

344
 For single crowns, apply two layers of
spacer up to maximum 1 micron
thickness. www.indiandentalacademy.com

345
 Bridge restorations also require two layers of
spacer. Apply an additional layer of spacer
to the intercoronal surfaces of the abutments
(the area facing the pontic). This measure
helps prevent undesired friction.www.indiandentalacademy.com

346
IPS Bridge Connectors:
 These are prefabricated anatomically
shaped plastic connectors in six different
shapes.
 Used to contour three unit bridges and
ensure adequate size of the connector
between the pontic and bridge abutment.
 IPS connectors C1 – C6 are designed to
achieve the correct connector dimensions.

347
Areas of application:

348
Areas of application:

349
Procedure:
 Select the connector recommended for the
region for which the fabricated bridge is
intended and remove it from the harness.
 Once the bridge abutment has been
modeled with wax, attach the selected
connector to the connecter area between
the pontic and the bridge abutment.
 After that, complete modeling the full wax-up
and secure it with a silicone key.

350
 The modeled bridge is now reduced in a
targeted fashion. In other words, the area
that will be built up using layering material
after the press cycle has to be carefully
reduced so that the framework thickness
measures at least 0.8 mm.
 The plastic connector ensures that the
minimum connector thickness between the
pontic and bridge abutment is automatically
observed during the reduction process.

351
 If the labio-lingual portion of the
connector reduced, the portion of the
incisal to the cervical has to be enlarged.

352
 The connector area should measure at
least 16 mm2. 4x4 mm.www.indiandentalacademy.com

353
Framework : layering material
thickness:
 In order to achieve the best possible
surface stability by creating ample
working parameters and to design
adequate frameworks.
 The framework must be thicker than
the layering material

354
 Correct : the framework design supports the cusps.
The wall thickness of the framework is at least 0.8
mm. Only this design ensures adequate stability.
•Incorrect : the relationship between the framework and the
total space available is not proportional.

355
Framework-pontic design:

356
Contour:
 Framework design depending upon the
space available
 Full Wax-up:
Fabricate a full wax-up of the restoration.
Use the IPS connectors to ensure the
adequate size of the connector area
between the pontic and the bridge
abutment.

357
Wax-up with connector in place:

358
Wax–up from buccal:

359
Wax-up from palatal:

360
Version A:adequate space
available:
 After full wax up, the buccal and the
lingual portion of the modeled
framework is reduced in a targeted
fashion.
 Subsequently reduce the the wax-up
by the space required for the layering
material applied after pressing.

361
The labial view

362
The palatal view

363
Final wax framework for
layering:

364
Version B: Only limited space
available(reduced layering
technique)
 If only limited space is available, only the
buccal and incisal portion of the waxed-up
framework are reduced in a targeted
fashion.
 The palatal – lingual portion is waxed-up to
its full contour(anatomical shape).
 Minimum thickness between the pontic and
the bridge abutment is
maintained(connector).www.indiandentalacademy.com

365
Reduced buccal-incisal portion:

366
Palatal-lingual portion in its full
contour (anatomical shape):

367
Areas to be built up with
layering material:

368
Spruing of the framework
pattern:
 Single crowns:
For single crowns depending on the size
and volume of the wax pattern, attach an
axial sprue in the direction of flow of the
ceramic material.
Use round profile 2.5 – 3 mm / 8 gauge:
length 3 mm – max 8 mm.

369
 Bridges:
For 3 unit bridges, attach an 8 gauge round
profile axial wax sprue directly into the
abutment teeth at an angle of 45 – 60àpprox.
The attachment points of the sprue to the object and the sprue
former must be rounded and smooth. Avoid sharp edges.

370
 Wax pattern-sprue attachment:
-- Pattern angled at 45 60`.
-- The distance between the paper ring and the
patter must be at least 10 mm.
-- All sprue attachments are flared and smooth.www.indiandentalacademy.com

371
Correct spruing:

372
Incorrect spruing:

373
Incorrect spruing:

374
Correct spruing:

375
Correct spruing:

376
Incorrect spruing:

377
Correct spruing:

378
Incorrect spruing:

379
Incorrect spruing:

380
Correct spruing:

381
Incorrect spruing:

382
Incorrect spruing:

383
Correct spruing:

384
Incorrect spruing:

385
Incorrect spruing:

386
Ideal spruing:

387
Investing:
 Investment is carried out with the IPS
Empress 2 special investment material.
 Weigh the ring base (seal the opening
of the ring base with wax ).
 Position the objects to be pressed on
the ring base and attach them with wax,
weigh again.
 The difference between the two values
is the weight of the wax used.

388
 Large investment ring :
Up to 1.3g wax weight requires one large
ingot.
 Small investment ring:
Up to max 0.5 g wax weight requires one
small ingot.

389
 Remove the protective tape from the new 2-
in-1 IPS Empress paper ring, form a cylinder
exactly along the marked line and press the
two end together.www.indiandentalacademy.com

390
 Set the paper ring on the base of the
investment ring and check it for correct fit.
Use the ring stabilizer to stabilize the paper
ring. www.indiandentalacademy.com

391
 Mix the special investment material
under vacuum according to the
instructions.

392
 Fill the paper ring slightly below the
stabilizing ring.www.indiandentalacademy.com

393
 Remove the stabilizing ring and slowly
place the ring gauge on the investment
with a hinged movement.www.indiandentalacademy.com

394
 After the setting time, remove the ring gauge
and the ring base with a turning movement.
Remove the paper ring. Remove the rough
spots on the bottom surface of the
investment ring with a plaster knife.www.indiandentalacademy.com

395
 Check for 90`angle.www.indiandentalacademy.com

396
Preheating:
 If several investment rings are preheated
simultaneously, mark them, either with wax
on the ring base before investing or with a
fireproof pen after investing.www.indiandentalacademy.com

397
 The ingot support and the aluminum oxide
plunger is placed in the cold furnace.www.indiandentalacademy.com

398
 The ingot support and the aluminum
oxide plunger are placed in the cold
furnace, while the speed investment
ring is only placed in the furnace once
the final temperature has been reached.
 When placing the investment ring into
the furnace, make sure that the furnace
temperature does not drop down.
 But the special investment ring is placed
in the clod furnace with the aluminum
oxide plunger and the ingot support.

399
 Do not preheat the Empress investing with
other investment and casting objects (e.g.
soldering models, metal casting rings, etc).
 Clean and calibrate the preheat furnace.www.indiandentalacademy.com

400
Pressing:

401
Press parameters for EP-500:

402
Pressing in the EP-600:
 Programme selection
for the IPS empress 2
layering technique by
pressing F3.
 And select the ring
size.

403
Placing the ingots:
 Large investment ring:
Single restorations: maximum 1 large ingot or 1
small ingot.
Bridges: maximum 1 large ingot.
 Small investment ring:
Maximum 1 small ingot per pressing cycle.
Do not use 2 small ingots.

404
 Remove the ring from the preheating furnace
immediately after the completion of the
preheating cycle. Place the corresponding
cold ingots for the layering technique in the
investment ring. www.indiandentalacademy.com

405
 Placement of a large ingot (several
crowns or bridge)www.indiandentalacademy.com

406
 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.www.indiandentalacademy.com

407
 The press cycle runs automatically. A beep
sound indicates the end of the press cycle.www.indiandentalacademy.com

408
 Remove the investment ring from the
furnace immediately after the program is
completed and close the furnace.
 Place the investment ring on a wide-
meshed grid (IPS Empress cooling rack)
and allow it to cool to room temperature.
 The grid ensures quick and even cooling of
the investment ring and prevents undesired
heat accumulation.

409
Divesting:
 After approx. 60 minutes, after cooling, the
investment ring may shoe cracks. These
cracks are developed during cooling as a
result of the different CTE’s of the various
materials (the ingot, pressed material,
investment material).
 But do not compromise the result of the
pressing cycle.

410
 Mark the length of the plunger on the
cooled investment ring.www.indiandentalacademy.com

411
 Separate the investment ring using a
separating disc. This predetermined
breaking point enables reliable separation of
the ingot and the ceramic material.www.indiandentalacademy.com

412
 Break the investment ring at the
predetermined breaking point using a
plaster knife.www.indiandentalacademy.com

413
 Rough divestment is carried carried out with
polishing jet medium at 60 psi pressure.www.indiandentalacademy.com

414
 For fine divestment, only 2 bar (30 psi)
pressure is applied.www.indiandentalacademy.com

415
 Remove the reaction layer from the
pressed framework using the invex liquid.
 Immerse the object in invex liquid for
max. 30 min, and thoruoghly rinse the
framework with water and blast it with
aluminum oxide powder of 100 microns
size at 15 psi pressure.
 If the reaction later is not completely
removed, bubbles may form, which
subsequently lead to bonding problems
and crack in the layering ceramic.

416
 When
divesting
the object,
blast from
the direction
indicated in
the
schematic
diagram.

417
 Press result after pressing at too low
temperature.www.indiandentalacademy.com

418
 If the temperature of the furnace has
been set correctly, the pressed objects
exhibit only a thin reaction layer that can
be easily removed.www.indiandentalacademy.com

419
 If the object is pressed at too high
temperature a substantial reaction layer is
forms that is difficult to remove. If the
reaction layer is not completely removed,
the bond to the layering material is impaired.www.indiandentalacademy.com

420
Removing and finishing:
 Excessive grinding results in local
overheating of the ceramic framework and
may lead to micro-crack formation.
 Therefore keep grinding to minimum.
 Avoid inhalation of grinding dust.

421
 Use a fine diamond disk to cut the sprues. Guide
the diamond disk through a wet sponge during
cutting to ensure permanent wetting of the area to
be ground. In this way, overheating of the ceramic
framework is avoided. Use ceramic burs to process
the attachment points of the sprues.

422
 Make sure that the material
thickness is of at least 0.8 mm
throughout, and never prepare the
framework less than 0.8 mm.
 Avoid excessive heating of the
pressed material.
 Never use rotary instruments to
clean the framework. Only blast
with aluminum oxide powder (100
microns at 15 psi).

423
Fitting the framework to the die:
 Remove the spacer prior to fitting the
pressed framework on the die.
 Fine irregularities are carefully removed
with a fine diamond.
 Margins can be adjusted using diamonds
or fine emery disks.
 Always work with cooling.

424
Control die:
 According to the shade selection, the
IPS die material kit is used to enhance
the shading of the restorations.www.indiandentalacademy.com

425
 Coat the inner surface of the ceramic
framework with the IPS Empress die
material isolating liquid.www.indiandentalacademy.com

426
 Apply the corresponding die material to
the inner surface of the restoration,
using the die material condenser.www.indiandentalacademy.com

427
 Insert a die holder in to the die material.
 Die material is cured with a light
polymerization device.www.indiandentalacademy.com

428
Foundation firing:
 Carefully blast the framework with special
jet medium aluminum oxide powder (100
microns at 15 psi) prior to foundation firing.
 Clean with steam and dry with oil-free air.
Avoid contamination.

429
 The foundation
material(the
desired dentin)
is applied
thinly on the
entire
framework.

430
Firing chart for foundation firing:

431
 Framework after firing.

432
Layering diagram:

433 Dentin layeringwww.indiandentalacademy.com

434
 And completed with incisal layering.www.indiandentalacademy.com

435
 Similar procedure
is used for single
crowns.
 Occlusal view of
the completed
layering.

436
Firing chart for layering material:

437
 The temperature for firing this crown
has been set too low. The crown shows
clear signs of insufficient firing.www.indiandentalacademy.com

438
 If the restoration exhibits a shining, true-
to-nature appearance, it has been fired
with all the firing parameters set
correctly. www.indiandentalacademy.com

439
 The firing temperature was set too high,
the restoration exhibits too much of
shining.

440
Staining & characterization:
 Before starting the staining procedure,
make sure the restoration is free of dirt and
grease. A roughened surface is favorable.www.indiandentalacademy.com

441
 Apply the stains as thinly as possible,
avoid pooling and too thick layers.www.indiandentalacademy.com

442
Firing chart for stains:

443
Glazing:
 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.www.indiandentalacademy.com

444
Glaze firing chart:

445
Corrective firing:
 This is a low sintering add-on material with
medium incisal opacity for any necessary
corrections. This material can be used alone
or mixed with dentin or incisal powders in the
ratio of 50:50. www.indiandentalacademy.com

446
Finished FPD:
palatal view

447
Finished FPD:
buccal view

448
Finished
crown:
buccal/occlusal view

449
Etching:
Etching the internal surface is necessary for all
IPS Empress restorations, since this procedure
increases the shear bond strength between the
ceramic material and the composite cement. The
fracture resistance is also increased.
Etch the internal surfaces of the restoration for 20
sec using the ceramic etching gel.

450
Cementation:
 Generally adhesive cementation is
recommended for metal free ceramic
restorations.
 Conventional GI Cement can also be
used, if clinical conditions are
unsuitable for adhesive bonding and if
there is sufficient retention is available.
 The adhesive bonding must be used
for the cementation of restorations
made of the IPS Empress staining
technique. www.indiandentalacademy.com

451
CERESTORE / ALCERAM*
“Shrink Free Ceramic”
COORS BIO-MEDICAL

452
Tooth preparation:
 Labial, lingual and interproximal reduction of
1.25 mm to 1.5 mm: incisal and occlusal
reduction of 1.5 mm to 2 mm.
 The preferred margin design is a 90`full
shoulder with a rounded gingival axial line
angle with a width. of 1mm to 1.5 mm.
 Feather edge and beveled preparations are
contraindicated.
 Conventional impressions are accepted.

453
Laboratory technique:
 The non shrink property of the material
encourages a direct approach rather than
indirect casting.
 There is no solidification shrinkage, nor
the need for control investment expansion.
 Coping are formed by transfer molding the
ceramic directly on to the non shrinking
heat stable epoxy master die.

454
Epoxy die material.

455
Epoxy die kit:

456
Investing the epoxy master die
:

458
Investing with dental plaster in flask:

461
Completed flasking:

462
Wax boil out:

474
Microprocessor controlled
furnace:

475
Finished coping:

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Metal free ceramic/ dental education in india

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Metal free ceramic/ dental education in india