Die and die materials/ cosmetic dentistry training

SEMINAR
ON
DIE AND DIE MATERIALS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

INTRODUCTION
In Dentistry, replicas of the hard and soft
tissues are used for diagnosis and
treatment of oral disease, these replicas
are called “study models” or “casts” or
“dies”. The working cast and dies work
simultaneously to achieve a long lasting
serviceable restoration.

STUDY MODELS
They are used for observation of patient’s
oral structures e.g. orthodontic study
models.

CAST
Definitions
• It is a working model.
• It is a reproduction of the
shape and features made
from an impression of
the surface e. g. the casts
of the remaining ridges in
the edentulous patients
are used to make
dentures for the patient.

DIE
• According to the definition given in
Phillips is a “reproduction of a
prepared
tooth made from a gypsum product,
epoxy resin, a metal or a refractory
material”.
or
• The positive reproduction of the form
of a prepared tooth in a suitable hard
substance.
• Extremely accurate replicas of a
single tooth and are generally used to
make crown and inlays.www.indiandentalacademy.com

IDEAL REQUIREMENTS
OF A DIE MATERIAL
• It should be accurate.
• Dimensionally stable.
• Good strength
• Abrasion resistance.
• Ability to reproduce fine details.
• Ease of use.
• Compatibility with impression material.

TYPES OF DIE MATERIALS
• The type IV and type V gypsum
• Epoxy resin die material
• The eletroformed dies.
• Metal sprayed dies.
• Amalgam dies.
• Silico phosphate dies
• Ceramic dies
• The flexible dies.

TYPE IV AND TYPE V GYPSUM DIE
• Chemically both are alpha-calcium
sulphate hemihydrate derived from
densite.
• Type IV contains extra salts to reduce its
setting expansion compared to type V.
Advantages:
• Accurate and inexpensive
• Offers excellent working time
• Good abrasion resistance
• Requires minimal equipment
• Easy to manipulate
• Compatible with all impression materials.

Disadvantages:
Poor resistance to abrasion.
Uses:
• Making individual dies for full gold
crowns and porcelain fused to metal.
• Constructing cast metal denture
framework.

EPOXY RESINS OR POLYMERS
FILLED WITH POLYMERS
• They are used to overcome the low strength
and abrasion resistance of die stone.
• They are either self cure acrylic materials or
polymeric materials (epoxy resins, polyesters
and epimines) with fillers(metallic or
ceramic).
Advantages:
• More Abrasion resistance &Not as brittle as
die stones.
• Reproduction of details better than gypsum.
• Setting time can be accelerated by increasing
amount of catalyst or amount of hydrolysed
anhydrides.

Disadvantages:
• Shrinkage on polymerisation
dies are undersized
• Compressive strength less than gypsum
dies
• Long setting time
• Incompatible with some impression
materials like polysulphide and
hydrocolloids
• Unsuitable for precision fixed partial
procedures
• Hardener is toxic and allergenic, should
not come in contact with skin during
manipulation.

ELECTROPLATED AND
METAL PLATED DIES
• This is used to overcome the poor
abrasion resistance of gypsum
• It involves the deposition of coat of silver
or copper or gold on the impression.
Procedure: Areas coated with powdered
silver or graphite → placed in an
electrolytic solution (copper sulphate or
silver cyanide) → anode (pure silver or
copper) → ions move from anode to
cathode.

Compatibility of Tray Materials:
• Silver will be built upon the surface of the any
metal tray so that it is good practice to use acrylic
and polystyrene trays.
• Never us aluminum trays or rings for impression
taking as exposed aluminum will contaminate the
electrolyte.
The Current Density
• 60mA for a quadrant impression to 150mA for a full
arch and higher current densities of upto 250mA
for a full dentition (for silver).
• 5 to 50 mamp/cm2
of cathode surface is applied for
approximately 10 hours.

Commercially
available plating unit
Final impression after
cleaning and dryingwww.indiandentalacademy.com

Final impression is
metalized with fine silver
powder
Cathode wire is insertedwww.indiandentalacademy.com

Electrolytic solution is placed in
preparation with eye dropper to
p[prevent air bubbles.
Impression is connected to
electrical source and
submerged, kept at a
distance of 15cm from
anodewww.indiandentalacademy.com

Impression after completion of
silver plating
Separation of dies using the
piercing saw

Completed silver plated dies and
casts mounted on articulatorwww.indiandentalacademy.com

APPARATUS FOR SILVER
PLATING IMPRESSIONS
a  is impression submerged in electrolyte solution
b  a silver bar, source of the silver ions
c  power supply www.indiandentalacademy.com

Advantages:
• Excellent clinical results
• Most abrasion resistant
• High strength
Disadvantages:
• Limited to non aqueous impression
materials
• Expensive
• Impression material and electrodeposits
can contribute to die inaccuracy
• Time consuming and special equipment is
required
• Health hazardwww.indiandentalacademy.com

METAL SPRAYED DIES
A bismuth-tin alloy, which melts at 138ºC,
can be sprayed directly onto an impression
to form a metal shell, which can then be
filled with dental stone.
Advantage: A metal coated die can be
obtained rapidly from elastomeric
impression material.
Disadvantage:
Alloy is rather soft.
Care is needed to prevent abrasion of die.

AMALGAM DIE
The copper band modeling plastic
impression is used. It is wrapped in the
wax or tape and embedded in a plaster to
condense the amalgam effectively.
Advantages:
Produces a hard die
Reproduces fine detail and sharp margins
Disadvantages:
Requires skill to condense amalgam
Time consuming
Technique sensitive
High thermal conductivitywww.indiandentalacademy.com

CEMENT DIES
• Siloco phosphate or polyacrylic acid
bonded cement is used as a die material.
Advantages:
Harder than die stone
Disadvantage:
Shrinkage on setting
Brittleness and tendency to crack due to
dehydration

CERAMIC DIE MATERIAL
Two ceramic die materials are available
• a material for the production of dies on
which porcelain restorations are to be
fabricated without the use of platinum
foil matrix. To form the dies heating to
over 1000ºC is necessary.
• The ceramic material powder and liquid,
and mixed to putty like consistency after
1 hour, the material is removed from
impression and fired at 600ºC for 8
minutes to produce a hard stone die.

FLEXIBLE DIE MATERIALS
Similar to heavy bodied silicone or
polyether impression material.
Uses: To fabricate provisional restorations,
indirect composite inlays or on lays chair
side
Advantages: More rapid setting
Ease of removal of provisional or inlay
Precaution: Select a compatible
combination of impression and die material
that provide good surface detail. E.g.
Impregum-F die material with Extrude
Light impression material.www.indiandentalacademy.com

SELECTION CRITERIA FOR
WORKING CAST AND DIE
• The choice of die material is made before
the impression procedure.
• It should be easily sectionable and easy
to trim with routinely available equipment.
• Compatible with the separating agent.
• Available in a colour that contrasts with
the wax.
• Easily wettable by the wax must be
compatible with the impression material

• A die should replicate the tooth preparation
in the most minute details as well as the
unprepared areas of the tooth.
• The die should have a fixed location in three
dimensions in the working model.
• The die are removable and return precisely to
their original position.
• a die should have a root like extension that
serves as handle.
• Working cast may be inverted with no
movement of the die.

PREPARATION OF IMPRESSION
FOR DIE MAKING
• Saliva or blood residue impression should be
rinsed off as it leads to improper setting of
gypsum products → soft chalky & inaccurate
surface.

• Rubber impression materials should be
completely dry.
• The surface of hydrocolloid impression
material must not be dehydrated instead
• It should still glisten and soaked in 3%
potassium sulfate solution for 15 minutes.
this improves surface details, accelerates
setting, hardens the stone surface, reduces
formation of the hemihydrate's on the
surface of the stone and produces a
superior die.

CONSTRUCTION OF THE DIE
AND THE WORKING MODEL
Two Techniques:
• Multiple pour intact cast technique/ solid cast
with individual dies or working cast with
separate dies.

• The removable die cast technique or technique
utilizing one pour cast or working cast with a
removable die.

WORKING CAST WITH SEPARATE DIE
Objectives of the die from the first pour:
• For final readaptation of the wax pattern
• Detail adjustments
• Surface treatment
• Sprucing of the wax pattern
Objectives of the second cast:
• Mounted on the articulator with the
opposing model
• Used to check for wax pattern contacts,
contours and occluding morphology.
• The preparation replicas are inseparable
from the second cast.www.indiandentalacademy.com

Advantages:
• Ease of fabrication of wax pattern
• Complete immobilization of the prepared
tooth replica
• No vertical and horizontal shifting
• No special equipment is required
• Accurate fabrication
Disadvantages:
• Manipulation of wax pattern from the
working model to the die can induce
stresses.
• Dimensional inaccuracies in multiple pours.
• Limitation-can only be used with elastomeric
impression materials.www.indiandentalacademy.com

PROCEDURE OF MAKING
INDIVIDUAL DIES

WORKING CAST WITH THE
REMOVABLE DIE SYSTEM
Die is a part of working articulated cast.
Advantages:
• Less chances of wax pattern distortion
• Eliminates discrepancies between separate
die and working cast
• Eliminates discrepancies of relief agent
• Die can be removed for Margination and
finishing
• No limitation with impression materials
• Saves time and effort

Disadvantages:
• Risk of error due to improper seating of die
in working cast.
• Chances of introducing additional variables
in cast fabrication.
• Necessity of additional tools and
equipments.

TECHNIQUES FOR ORIENTING THE
DEVICES IN THE WORKING CASTS
Pre Pour Technique:
In this technique the
device is oriented in the
impression before it is
poured ().
One method of
positioning pins before
initial pour of stone
(Rudd & Morrow)

Post Pour Technique:
• The device is attached to the underside of a cast
that has already been poured. It is also called as
dry pinning.

Basis of different die systems
• Dowel pin
• Retention devices
• Orientation aids.

TYPES OF DOWELS
A. Flat sided single Dowel
B. Single curve Dowel
C. Double strait dowel
with a common head
D. Two separate parallel
Dowels
E. Key plastic outer tray

Single
Dowel
pin and
twin
dowel
pin

Self positioning dowel pin attached to impression by wire
tagging. Suffers from defect of firm locationwww.indiandentalacademy.com

A & B: Conventional Dowel Pins, large and
small; C: J pin; D & E: Short & Long index
pin for pindex system

DIFFERENT REMOVABLE
DIE SYSTEMS
• Brass Dowel pin
• Plastic pin
• J pin
• Logix model system
• Curve Dowel pin
• Pindex system
(Whaledent)
• TDI system
• Di-lok system
• Typadon tray system
• The accutrak system
• DVA model system
• Zeiser (Girrbach)
system
• Strip cast technique
• Magnet pin setter
technique
• Monotrac
system(VSP)www.indiandentalacademy.com

• According to the study on the accuracy of the
first 4 removable die system (d) the logix
model system was more difficult to use as the
dies fit very tightly in the master cast and
require more effort to remove and replace.
• (b) The plastipin exhibited the least amount of
horizontal shift.
• (a) The brass Dowel
pin exhibited the
greatest shift in
both directions.
• (c) J pin

MAGNETIC PIN SETTER
1. Lower plastic table
2. Rectangular block;
3. Metallic upper
table
4. Magnetic
assemblies
5. It hold the metal
rods and dowel pins
According to the study by Caren B. Troendle et al
(1981) gave this technique especially for multiple
adjacent abutments.

Plastic table in lowered position,
impression placed securely into matrix
putty covered with plastic wrap
By moving magnets horizontally
or rods vertically double pins
can be ideally positioned

Putty acts as a index
Dowel pins

Finer dies contain ideally positioned
dowel pins
Poured impression is carefully
raised to its elevated position
and retained in by the
rectangular block www.indiandentalacademy.com

Dowel pins placed over the
impression with dowel pins
Paper clips are added to provide
retention for the second pour of stone

Bankers pins placed in impression
Additional mortite placed
over the pins
DOWEL PIN POSITIONING TECHNIQUE FOR
FIXED PARTIAL DENTURE WORKING CAST
Robinson and Block (1981) reported that this method
reduces the least account of inaccuracy in an
horizontal direction and the second lowest vertical
deviation of 4 types of removable dies.

Dowel pins placed into stone
contact flat head of bankers pins
Bankers pins and mortite have been
removed and gypsum separator has
been applied
Pouring of die stone, taking care not
to cover the heads of the pins

ADVANTAGES
Simple and accurate technique
Saves the time and effort of working with cubersom
bobby pins, paper clips, anaesthetic needle and sticky
wax
No pins are pushed into the impression material that
might cause distortion.
It allows the dental lab technician to place the Dowel
pins free hand after the impression has been poured.
It does away with management problems associated
with pre-positioning the Dowel and stabilizing it with
sticky wax.
Excellent vision
The heavy body and sticky characteristics of Mortite
ensures that the banker pins will not be dislodged
during vibration of stone and the Dowel pins can be
precisely located. www.indiandentalacademy.com

Pins placed in impression at
angles to conform with easy
withdrawal of dowel pin
First coat of pour of stone
vibrated out of mold to leave a
thin coating
This has been advocated (Reed 1968) that the dowel pins should be
located prior to pouring the cast

Locating dowel pins in stone
cast during initial set
Impression boxed in with wax
and stone based pour over pins
which can be deleted by wax balls

CURVE DOWEL PIN SYSTEM
PRE POUR TECHNIQUE
A: curved pin
B: Positioning bar
C: Straight pins
D: First pour of die stone
2 mm deep depressions
are made on either side of
the dowels that will carry
the unprepared teethwww.indiandentalacademy.com

Petrolatum applied
Boxing the cast, the tips
of the dowel sticking
through
The die is removed by
pressing on the exposed tip

POST POUR TECHNIQUE
Trimmed working cast
Holes are drilled into the underside of the
cast

The cast is keyed with a
large acrylic bur
The head of the curve
dowel is seated into the
hole with the
cyanoacrylate cement
Cemented curved dowels.
Broken lines indicate where
the segments will be
separated by saw cuts

TWO DOWEL COMMERCIAL
PIN SYSTEMS
• The pindex system (whaledent)
• The TDI system
• The core of both techniques is using
cemented dowel pin.
Parts of Pindex
machine
Pouring
Thickness of
the cast

Trimming of
palate area
Marking of thin
holes with
pencil
Marks placed
under the
illuminated dot
Thumbs used
to stabilize the
cast

Shorter pins
are placed first
Grey sleeves
blocked with wax
Utility wax placed at
the end of long pins
After boxing the
base is pouredwww.indiandentalacademy.com

The base form is
filled with micro
stone
Stone is vibrated
around the bases of
the pinswww.indiandentalacademy.com

Removable dies from
perforated tray systems
• The typadon tray system.
• The dy-lok system.
• For both, the gypsum cast is poured as before
removed from the impression and trimmed to
conform to the shape of the tray.
• A single pour can also be done.
• Also called keyed matrix system as it allows the
opportunity to fabricate a fixed prosthesis
without sectioning the abutment dies apart and
thus accurately maintain the relationship
between abutments.

Single pour
technique
When set it is
removed
The tray is
removed
Sectioning ¾
through the stone
Separated and
trimmed dies
Mounted cast
and traywww.indiandentalacademy.com

ADVANTAGES
• No worry about dowel pins coming loose
• Or improper saw cuts passing through the
dowel pins.
The typadon tray system

The accutrak tray system
• Modification of a plastic tray with internal
grooves and notches.
• Two pour technique is used. sectioning is
done from the base of the cast to avoid the
damage to the inter proximal finish lines.

REFRACTORY DIE TECHNIQUE
Modivet system A vinyl polysiloxane
impression material is mixed
Pouring Base plate is removed

Yellow stone base is removed
Heat resistant pinning system
The die of the prepared tooth

After pouring in the in
a refractory
investment and
repinned.
Application of
separating media
Yellow stone base is poured
Prepared die

ANOTHER METHOD
A strip of putty is
wrapped
Duplicating paste
is allowed to set
for at least 30 min
Removal of tray
from the cast
Master die
removed

Pouring of refractory
material
Duplicated refractory die

MONOTRAC SYSTEM

QUADRANT ARCH

BASED ON PRECISION DRILL AND
SPECIAL BASEPLATES
• DVA model system
• Zeiser model system
• Removal die
• Cast pouring
unimpeded
• Compensates
for extension of
casts
• Single pour

•Special equipment
needed
•Quite technique
sensitor
Excellent if
carefully done
Care needed when
seating pins

ZEISER MODEL SYSTEM

Strip cast technique
• Offer more control, resulting in fewer difficulties
of those dies which are extremely close to one
another.
• Advantages:
• Provides landmarks for placement of dowel pins
in the center of the die.
• Provides concave die base to index the die on the
cast .
• Speedy separation of the die.
• Eliminates use of saws or rotatory instruments

Tanquist 1982 producing accurate removable dies
from elastic full arch impressions

DIE PREPARATION
• Die trimming or physiologic contouring.
• Die hardening materials.

Recent developments
• The calay system.
• The cerec system.

Summary and conclusion
Every system has its own pros and cons therefore
it mainly depends on the individual's skill to get
maximum advantage. Even then the pindex system
has been most widely accepted. More recently it
may be replaced with some other systems like
Monotrac system which saves time and improves
the efficiency

REFERENCES
• Shillurburg H.T., Hobbs, Whitselt L.D.: Fundamental of fixed
prosthodontics. Chicago, Quintessence Publishing Co., 1997.
• Craig R.G., Powers J.M.: Restorative dental materials, ed. 11,
Mosby, Harcourt, India, 2002.
• Annusavice: Philips Science of Dental Materials, ed. 11,
Elsevier, 2004.
• Thayer K.E. Fixed prosthodontics. Chicago, Year Book Medical
Publishers Inc. 1984.
• Dykeuna, Goodare, Philips, Johnson’s Modern Practice in
fixed prosthodontics. Ed. 4, W.B. Saunders Co.
• Rudd K.D., Morrow R.M., Rhoads J.E. Dental laboratory
procedures. Fixed partial dentures. Ed. 2, Vol 2, St Louis,
Toronto, Princeton, The C.V, Mosby Company, 1986.
• Roseinstiel, Land, Fujimoto. Contemporary fixed
prosthodontics, ed. 3, Mosby, Inc. 2001.
• Sturdevant C.M., Roberson T.M., Heymann H.O., Sturdevant
J.R. The art and science of operative dentistry. Ed. 3, Mosby
Year Book Inc. 1997.
• Craig, Flowers, Neatha. Dental materials properties and
manipulation, ed. 7, Mosby Publishers. 2000.www.indiandentalacademy.com

• Glodwin M., Bagby M. Clinicla aspects of dental materials.
Lippincott Williams & Welkins 1999.
• Tanquist R.A. Die trimming: A guide to physiologic contour. J.
Prosthet. Dent. 48: 485, 1982.
• Robinson F.B., Block B. Dowel pin positioning technique for
fixed partial denture working casts, J. Prosthet. Dent. 46: 215,
1981.
• Troendle K.B., Twendle R.G., cavozos E. Positioning dowel pins
for removable dies. J. Prosthet. Dent. 46: 575, 1981.
• Beck, D.B. Precision technique for trimming dies using a
magnificent device. J. Prosthet Dent. 43(5): 590-591, 1980.
• Hyens M. Hembree J.H. Relative accuracy of four removable
die systems. J. Prosthet. Dent. 48: 163, 1982.
• Fan P.L., Powers J.M., reid B.G. Surface mechanical properties
of stone, resin and metal dies. J. Am. Dent. Assoc. 103: 408
1981.
• Mclean JW,The science and art of dental ceramics ,vol
II.Bridge designs and laboratory procedures in ental
ceramics.1st
ed.Quintessence Books 1980.
• Smith D, Nayyer A, Koth DL.Fabrication of removable stone
dies using cemented dowel pins.Gehl DH. J Prosthet Dent
1979;41(5):579-81. www.indiandentalacademy.com

• Crispin BJ , Watson JF , Bauer JG ,Frawley KR. Silver plated
dies. Part I : Palatability of impression materials. J Prosthet
Dent 1984;51(5):631-36.
• Fukui H, Lacy AM, Jendersen MD,:Effectivenes of hardening
films on die stone. J Prosthet Dent 1980 ; 44(1):57-63.
• Crispin BJ , Watson JF , Bauer JG ,Frawley KR,: Silver
plated dies. Part II : Marginal accuracy of cast restorations. J
Prosthet Dent 1984;51(6):768-73.
• Bailey JH, Donovan TE, Preston JD,:The dimensional
accuracy of improved dental stone, silver plated and epoxy
resin die materials. J Prosthet Dent 1988;59(3):307-10.
• Nomura GT, Reisbick MH & Preston JD:An investigation of
epoxy resin dies. J Prosthet Dent 1980; 44(1): 45-49.
• Schwartz HB, Lenpold RJ, Thompson VP:Linear dimensional
accuracy of epoxy resins and stone dies 1981; 45(6): 621-
625
• Derrien G & Strutz G,:Comparison of transverse strength &
dimensional variation between die stone,die epoxy resin &
die polyurethane resin.J Prosthet Dent 1995; 74: 569-74.www.indiandentalacademy.com

• Chaffee NR, Bailey JH & Sherrad DJ:Dimensional accuracy
of improved dental stone and epoxy resin die materials Part I
: Single die Prosthet Dent 1997; 77: 131-35.
• Chaffee NR, Bailey JH & Sherrad DJ:Dimensional accuracy
of improved dental stone and epoxy resin die materials Part
II : Complete arch form. J Prosthet Dent 1997; 77: 235-238.
• Duke P,Moore K, Hang SP& Andre CJ,:Study of physical
properties of type IV Gypsum, resin containing & epoxy die
materials J Prosthet Dent 2000 ; 83 : 46- 73.

Thank you
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Die and die materials/ cosmetic dentistry training

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