The document discusses various die materials and systems used for indirect restorations. It defines a die as a positive reproduction of a prepared tooth used to fabricate restorations outside the mouth. Common die materials include gypsum, resins, metals and polymers, each with advantages and disadvantages. Removable die systems like dowel pins, Di-Lok and Pindex are discussed which allow repositioning of dies in the working cast for wax pattern fabrication. Proper selection of die material and system depends on factors like accuracy, strength and compatibility with impression materials.

2. INTRODUCTION
Fabrication of restorations of Fixed
Prosthodontics require indirect
techniques , in which the
fabrication of the restoration is done
outside the mouth. For this ,an
accurate duplication of prepared teeth
and maintenance of their relationship
to one another is important.

3. DEFINITION
Die may be defined as the
positive reproduction of the
form of a prepared tooth in
any suitable substance.
For the restoration to fit
accurately in the mouth ,
the die should be accurate .

4. DOWEL PIN – A metal pin used in
stone casts to remove die sections and
replace them accurately in the original
position .
DIE SPACER –An agent applied to a
die to provide space for the luting
agent in the finished casting.

6. IDEAL REQUIREMENTS
- Dimensional accuracy .
- High abrasion resistance .
- Ability to produce fine details .
- Compatibility with all impression
materials .
- Toughness to resist breakage.

7. - Colour contrast with wax ,porcelain ,
- Ease of manipulation and rapid
fabrication .
- Non injurious to touch and inhalation
- Economical .

8. CLASSIFICATION
I .ACCORDING TO THE TYPE OF
MATERIAL :
a) Gypsum Products :
Type IV Dental Stone .
Type V Dental stone ,high strength , high expansion
Type V Dental stone with ligho sulphonates .

9. b) Metal and metal coated dies :
Electroformed dies .
Metal sprayed dies .
Silver amalgam dies .
c) Resin or polymer dies :
Metal or inorganic filled resins .
Epoxy resins .

10. d) Cements :
Silicophosphates .
Polyacrylic acid bonded cement .
e) Refractory Materials :
Divestments .
Investments (for RPD frameworks ) .
f) Flexible die materials .

11. II . Based on the design :
a) Working cast with seperate
die system .
b) Working cast with
removable die system .
c)Accutrac system .

12. GYPSUM DIE MATERIALS
- Most commonly used .
-
- A D A specification No : 25 .
- Type IV & V are used .

13. Advantages
Easy to use .
Relatively inexpensive .
Easy manipulation .
Good working time .
Minimum shrinkage .
Compatible with all impression
materials .
Good colour contrast .

14. Disadvantages
Mechanical properties not ideal .
Brittle .
Less abrasion resistant .

15. Modifications
To overcome the abrasion
resistance
a) Add colloidal silica .
b) Impregnate the surface with a low
viscosity
resin such as cyanoacrylate .
RESIN ROCK * (WHIP MIX ) .

16. ELECTROPLATED DIES
It is the deposition of a coat of a metal .
Pure silver or copper is used .
ELECTROFORMING :
It is process by which a thin coating of metal
is deposited on the impression , after which
a gypsum cast is poured into the impression
.

17. PLATING CAN BE DONE :
 Individual tooth preparation .
 Full arch impression .
 Compound impression .( copper plated .)
 Polysulfide . (silver plated .)
 Silicone impression .

18.  ) Plating the impression
Electrolyte placed into
deeper parts of impression

19. C) pouring cast into
plated impression

20. Silver plated die .
Remaining silver fash
between teeth severed
with sharp scalpel .

21. ADVANTAGES :
Dimensional accuracy .
Hard & abrasion resistant .
Economical .
Does not absorb oil or water .
Imparts smooth surface to wax
pattern .
Prevents cuspal wear

22. DISADVANTAGES
 Difficult to trim .
 Silver bath – health hazard .
 Colour contrast not good .
 Not compatible with all impression materials .
 Adaptation of wax not as good as stone

23. RESINS
They are used to overcome low
strength and abrasion resistance of
stone .
Epoxy resins are commonly used .
Polyurethane may also be used .
The are most effective with rubber
based impression materials .
(Silicones & Polyether )

24. EPOXY RESIN
 Supplied as resin paste and liquid activator (amine)
Trade names:
 Epoxydent, Oxydental products
 Epoxy die material, Dentsply
 Pri-Die, Jelenko
 Diemmet

25. ADVANTAGES
 Tougher .
 Dimensionally stable .
 More abrasion resistant .
 Detail production better .
 Can be used at room temp .

26. DISADVANTAGES
 Shrinkage during polymerisation .
 Viscous ,does not flow readily .
 Setting may take upto 24 hrs .
 Expensive .
 Tight fitting prostheses .
 Not compatible with hydrocolloid & Polysulfide .

27. FLEXIBLE DIE MATERIALS
They are similar to heavy bodied silicone or
polyether impression materials .
Advantages over gypsum :
More rapid setting .
Ease of removal of interim restoration .

28. Flexible die material is
Injected into the impression .
Putty applied to force the impression
Material into the impression
Set material .
Die removed .

29.  Provisional Restoration fabricated using composite
resin
 Resin cured

30.  Model sectioned to allow proximal access for
contouring
 Restoration removed from flexible die

31. Advantage:
 Less time required
 Overcomes problems associated with making interim
restoration on arches that have significant undercuts
Disadvantage:
 Expensive
 Separator surface details poor

32. ALTERNATIVE DIE MATERIALS
A ) Silicophosphate cements :
Similar to filling & cementing
material .
Adv : Harder than die stone .
Disadv : Shrinkage on setting .
Loss of water on standing .

33. SILVER AMALGAM
Similar to restorative material .
Advantages :
Harder dies .
Reproduces fine details and sharp
margins

34. DISADVANTAGES
-Can be packed only to a rigid impression .
Takes long time to reach maximum
hardness .
High thermal conductivity .
Separating agent needed.

35. POLYMERS & FILLED
POLYMERS
Self cured acrylic resins , Polymeric
materials with fillers .
ADV :
More abrasion resistant .
Not as brittle as die stone .
DISADV :
Shrinkage on polymerisation .

36. MEATAL SPRAYED DIES
A Bismuth – Tin alloy (MP -138*c) can be
sprayed directly on to an impression to
form a metal shell which can be filled
with dental stone .
ADV :
Can be obtained rapidly from
elastomeric impression material .
DISADV :
Care should be taken to ptrevent
abrasion if the alloy is soft .

37. Advantage:
 Less time consuming than electroplating
Disadvantage:
 Alloy is soft low abrasion resistance
 Complex equipments required
 Inhalation of spray dangerous
 Compatible with elastomeric impressions only.

38. CERAMIC DIE MATERIALS
Two types of materials are available .
1) .One without using the platinum foil
matrix for porcelain restorations .
2) . A ceramic material ,supplied as a
powder & liquid

39. DIE SPACER Provides space for the
luting agent
Olden days: etching or milling to
get space

40. Various materials used as die
spacers
Finger nail paint
Lacquer
Model air craft dope

41.  Should flow uniformly and smoothly
 Color should be readily identifiable on the
die
 Thinners are available to decrease the
viscosity of die spacer.

42.  Brush strokes in one direction
 Wait for 2 mins before
 applying
Should be applied
0.5-1mm short of margin

43. Die Spacer Pens (Kerr Laboratory)
Poly fiber disposable tip.
0ptimal thickness is 20-40micrometre

44. Die hardener
Materials applied on the surface
of die to increase the surface
hardness.
Should have low viscosity
Commonly used materials as die
hardeners:
• Cyanoacrylate resins
• Acrylic resin lacquer.

45. 
 Applied to finish line area of the die to
prevent abrasion by waxing instruments
during the fabrication of wax pattern
 Applied with brush or PKT instrument no 1.
Quickly blown off and dried from above the
margin toward the cervical area.
or
Blot with tissue
Optimal thickness : 2-3 micrometre .

46. Die Separator
Easy removal of wax pattern without
damaging margins.
Applied with brush
excess to be removed with tissue paper

47. DIE SYSTEMS
Working cast with separate die
Working cast with removable die
Dowel pin system .
Di – Lock Tray system .
Pindex system .
Accutrac system .

48. WORKING CAST WITH SEPARATE
DIE
Simplest method of fabrication
Advantages:Easy to fabricate
Keeps relation between abutments fixed
better contours and emergence profile
While wax pattern fabrication.

49. Disadvantages
 Wax pattern must be transferred from die
to cast  destroy internal adaptation of
wax
 Some times difficult to seat wax pattern on
the cast
- Different impressions
- Second pour –impression damaged
- Different thickness of spacers

50. Procedure
Both working cast and sectional die can be
obtained by:
Pouring impression twice
Making two impressions

51. Preparation of
separate die
 Stone added to side
of impression in small
increments
 Tray tilted to fill the
Impression displacing
air as it moves

52.  Add stone in small increments
If large amount of stone dropped into preparation
or
if two sizable masses of stone meet
Air trapped voids
 Build to height of approx 1 inch

53. Pour stone to receive working cast
Make base
Retrieve cast

54. Trim sectional cast
 Octagonal in shape
 Sides parallel or slightly
 taper towards base
 Handle 1 inch long

55.  Pear shaped acrylic bur
  trimmed apical to finish line
 Final trimming sharp blade
 Smoothened

56. Contour be approximately like root
To facilitate good axial
contours in the restoration .

57.  Finish line highlighted
 with red pencil
 Not to use black graphite
 pencil
 Apply die spacer

58.  Fabrication of FPD
 Die of each part is left
 joined to each other by
 means of common base
 Edentulous ridge area
 cut back

59. Advantage:
 Convenient to use
 Various drawback of separate die are overcome
Disadvantage:
 Risk of introducing error in the pattern if die does not
seat accurately in the working cast

60. WORKING CAST WITH REMOVABLE
DIE

61. Requirements:
1) dies must return to their exact
original position
2) dies must remain stable even when
inverted
3) cast containing dies must be easy to
mount on an articulator

62. Methods of repositioning die in its
working cast
Systems using die pins
Systems using pre formed
plastic trays without die pins

63. Pre pour technique Post pour technique
Devices are oriented
in the impression
before it is poured
Attached to the underside
of the cast that has
already been poured

64. Conventional dowel pin systems
Dowel pin (GPT 7): a metal pin used
in
stone casts to remove die sections
and
replace them accurately in the
original position

65. Curved
straight

66. Flat sided
dowel
Rounded
single
dowel pin
Double straight dowel
with common head
(Bi pin)

67. Procedure
(pre pour technique)
Procedure
 Marking to act as
 guide in placement
 of pins
(pre pour technique)

68. D) Straight pins with
modeling clay
E) Matchsticks

69. F) Bobby pins

70.  Die stone poured into impression filling the
impressions of teeth
and covering the knurled end of the dowel
pin

71.  V- shaped orientation
grooves made
Separating media-area
adjacent to each
dowel pin

72. Small wax ball placed
on tip of each dowel
Boxing done

76. Curved dowel pin

77. Orientation grooves made

78. Di lok tray system

79. Snap apart plastic tray with internal orienting
grooves and notches to reassemble the working
cast and die.
Before using check for
space in articulator

80. Cast poured1inch ht
No stone in lingual
area
Trim to fit Di
lok tray

81. horizontal
Grooves
Fill tray ¾ with stone
Seat the cast  cervical area
of teeth be about 4mm above
the edge
Of tray

82. Disassemble the tray

83. Cut till ¾ length

85. PINDEX SYSTEM
(Coltene / Whaledent)

86. Similar to post pour dowel pin technique .
Showed the least horizontal movement .
Adv :
Allows accurate placement of the die pins .
Excellent if instrument is well maintained .
Disadv :
Special equipment is needed .

87. Accu- Trac Die Precision System
(Coltène Whaledent)

88. Used in fabrication of porcelain
laminate veneers
Removable die system that is
modification of a plastic tray with
internal grooves and notches
The technique of obtaining die is
similar to Di-lok system

89. Other systems include
DVA Model system and Zeiser model
system
These systems use a precision drill and
special base plates that are aligned and
drilled to provide die removal
Advantage: allows for expansion of
stone , which is relieved by saw cuts

90. CONCLUSION
A good impression and accurate die
are
the first steps towards the fabrication
of
an accurate restoration. Proper
selection of the die material and its
manipulation are paramount to achieve
accuracy in the die.

91. Removable die systems are preferable, as
they can be used with all impression
materials , as no second pour is required.
Proper sectioning of the cast and their
reassembly depends on the system used.
Choice of the die material and system
depends on the operator, as none fulfills all
the requirements. The advantage and
disadvantage of each must be weighed.

92. References
 Herbet T Shillingburg- Fundamentals of Fixed
Prosthodontics- 3rd edition
 Notes on Dental Materials, E. C Combe- 6th edition
 Contemporary Fixed Prosthodontics IIIrd Edition by
Rosenthal, Land & Fujimoto.
 Kenneth J,. Anusavice- PhilipsScience of Dental materials-
10th edition
 Robert G Craig- Restorative dental Materials- 11th Edition
 William J. o brien- Dental matereials and their selection-
3rd edition