Die materials used in prosthodontics

1. MATERIALS USED IN DIE
FABRICATION
PRESENTED BY
DR ARUN KUMAR C S

2. INTRODUCTION
• Replica of Hard and soft tissue.
• Study model
• Cast
• Die

3. Die:
It is the positive reproduction of the form of the
prepared tooth in any suitable substance.
GPT 9
A reproduction of a prepared tooth made from a
gypsum product, epoxy resin, a metal or a refractory
material.
Anusavice (11th edi)
The die is a model of the individual prepared tooth on
which the margins of the wax patterns are finished.
Schillingburg

4. BASIC REQUIREMENTS OF DIE MATERIALS
1. Reproduce an impression .
2. Dimensionally stable .
3. Setting expansion, contraction, and dimensional
variations must be minimum.
4. Strong and durable .
Robert G.Craig -Restorative dental materials- 7th edition

5. 5. Resistance to shearing forces and abrasion .
6. Compatibility with impression materials.
7. Economical
8. Easy to use
Robert G.Craig -Restorative dental materials- 7th edition

6. Non Metallic Die Material
• Gypsum Products
• Silicophosphate Cement
• Refractory Die Materials
Metallic Die Material
• Electroformed Dies
• Amalgam
• Metal Sprayed Dies
Polymeric Die Material
• Flexible Die Materials
• Epoxy Resins
Robert G.Craig -Restorative dental materials- 7th edition

7. COMPATIBILITY WITH IMPRESSION MATERIALS
Dental stone •Impression compound
•Alginate
•Zinc oxide euginol
•Agar-agar
•Rubber base material
Electro plated (copper) •Rubber base material
Electro plated ( silver) •Polysulphide
•Polyether
•Addition silicone
Polymer epoxy •Rubber base material
Resin •Polyether
•Addition silicone
•Polysulphide

8. GYPSUM PRODUCTS
Kenneth J.Anusavice -Philip’s science of dental materials- 11th edition.
Gypsum products are available in five forms (ADA Type I-
V)
Type I- Impression plaster.
Type II- Model plaster.
Type III- Dental stone.
Type IV- Dental stone with high strength.
Type V- Dental stone with high strength and high
expansion.

9. CaSO4 • 2H2O CaSO4 •½H2O +1½H2O
(Gypsum) (calcium sulphate a hemihydrate)
Gypsum is ground and subjected to temperature of 110o
to 120oC to drive off the water of crystallisation
GYPSUM PRODUCT
Calcination
reaction
In autoclave
Boil with 30% CaCl2 or MgCl2
Or
0.5 - 1% sodium succinate
Kenneth J.Anusavice -Philip’s science of dental materials- 11th edition.

10. Formula CaSO4-(1/2)H2O
Powder Shape: Uniform
Density Dense ( compared to type II)
Production Steps Heat to 100C in 30%CaCl2
solution or MgCl2.
( 100 C water or
autoclave 0.5% sodium
succinate)

11. α- hemihydrate Main composition
Potassium sulfate 2-3 % accelerator
Sodium citrate Retarder
Coloring agent 2%

12. Stone, High Strength (Type IV) (ADA No: 35)
Anusavice Phillips Science Of Dental Materials 10th Edition

13. PROPERTIES
Water: powder ratio 0.20 to 0.22 %
Setting time Initial
Final
7min
9 min
Setting expansion 0.5 to 0.7%
Compressive strength 5000 Psi
Dry hardness 92RHN
Dimensional changes 0.06%
Tensile strength 8 Mpa

14. Die Stone, High Strength, High Expansion (Type V)
ADA No: 35

15. PROPERTIES
Setting Expansion 0.10% - 0.30%.
W/P ratio 0.18 – 0.22
Setting time 12±4min
compressive strength 7000psi.
Mixing time 30sec to 1min
Working time 3 min
Temperature alters the setting time Above 50˚c retards settin
At 100˚c no reaction

16. • High-strength Type V dental stone may produce a
harder cast
• Higher degree of brittleness V.
• Type IV resin gypsum product (Resin Rock)
PROPERTIES
Schwedhelm ER, Lepe X. Fracture strength of type IV and type V die stone as a function of time. J Prosthet Dent. 1997 Dec;78(6):554-9
Fracture

17. Reproduction of detail
Gypsum dies do not reproduce surface detail as well
as electroplated or epoxy dies.
Hardness and abrasion resistance
3 times than epoxy die .
conventional type IV gypsum exhibited the highest
surface hardness
Duke P, Moore BK, Haug SP, Andres CJ. Study of the physical properties of type IV gypsum, resin-containing, and epoxy die materials. J Prosthet Dent.
2000 Apr;83(4):466-73.

18. Dimensional stability
• Liner expansion on setting V.
• Growth of the CaSO4 2H2O (dehydrate) crystals and
their impingement on one another.
• High strength stone has a setting expansion of
about 0.01% to 0.08%.
• Little change IV
Kenneth J.Anusavice -Philip’s science of dental materials- 11th edition

19. Disinfection:
• By immersing the cast in disinfectant solution like
sodium hypochlorite,glutaraldehyde.
• Incorporating disinfectant in the stone itself
• There is a significant increase in linear dimension and
significant decrease in wet compressive strength but
both the solution produced loss of surface details.
Abdullah MA. Surface detail, compressive strength, and dimensional accuracy of gypsum casts after repeated immersion in
hypochlorite solution. J Prosthet Dent. 2006 Jun;95(6):462-8

20. Advantages
• Compatible with all impression materials.
• Ability to reproduce fine detail and sharp
margins.
• Dimensionally accurate IV .
• Economic.
• Easy to use.

21. Disadvantages
• Susceptibility to abrasion .

22. METHODS TO INCREASE ABRASIVE RESISTANCE
Substitution by colloidal silica .
• Colloidal silica: Inc resistance to surface abrasion.
• Gum Arabic
• Resin Rock
• Impregnating acrylic resin into stone die.
(compressive strength-7,000 psi)
Low viscosity resins i.e. cynoacrylate .
Hahremannezhad HH, Mohamed SE, Stewart GP, Weinberg R. Effects of cyanoacrylates on die stone. J Prosthet Dent. 1983 May;49(5):639-46

23. ELECTROPLATED DIES
• Metal dies can be made by Cu / Ag plating
• Electroplating.
• Early 1930 s
Robert G.Craig -Restorative dental materials- 7th edition

24. PROPERTIES:-
• Detailed reproduction up to 30µm.
• Have moderately high strength, adequate hardness &
excellent abrasion resistance.
- An electrolyte solution
- A source of direct current.
- An anode – pure copper
- pure silver
METALIZING

25. COPPER PLATING
• Copper plated dies – Compound or addition silicone
rubber impressions.
• 1930’s
• Surface of the impression material is treated so that
it conducts electrically. This process is referred to as
metallizing.
Composition:
• Copper sulfate
• Sulfuric acid
• Phenolsulfonic acid
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31

26. • Surface coated with fine particles of copper or
graphite.
• The coated impression is made the cathode .
• Copper plate is anode.
• Immersed in an electrolytic solution of copper
sulphate together with alcohol or phenol.
• A current - 15 mA for 10 hours.
Notes on dental materials E.C COMBE 6TH edition

27. • Cause slow dissolution of the anode .
• Electro tuned die surface is then filled with dental
stone.
• Greater surface hardness and resistance to
abrasion than that of gypsum.

28. SILVER PLATING
• Indicated for polysulphide , polyether, and silicon
rubber impression materials.
Composition:
• Silver cyanide
• Potassium cyanide
• Potassium carbonate
• Distilled water .
Notes on dental materials E.C COMBE 6TH edition

29. • Similar to that of copper plating .
• 5 mA is sufficient.
• Coated with silver or graphite powder is made the
cathode.
• Anode is silver plate.
• The electrolyte is an alkaline solution of silver
cyanide with potassium cyanide and potassium
carborate in distilled water .

30. • Not significantly accurate than stone dies
• Continued polymerization lead to dimensional change .
• Silver cyanide solution toxic hydrocyanic acid
• Friable metal deposit if current set  too high.
• Silicone difficult , because of low surface energy.
• Polyether imbibes water.
• Polysulfide silver plated but difficult to copper plate.
PROPERTIES

31. Advantages
• No expansion or contraction occur with
electroformed dies.
• Higher strength, hardness and abrasion resistance.
• Finishing and polishing of metal restoration .
• Crown margin accuracy.
Crispin BJ, Watson JF, Frawley KR. Silver-plated dies. Part II: Marginal accuracy of cast restorations. J Prosthet Dent. 1984 Jun;51(6):768-73

32. Disadvantages
• Time consuming.
• Special equipment .
• Not compatible with all impression materials.
• Expensive.
• Precaution needed.
Stevens L, Spratley MH. Accuracy of stone, epoxy and silver plate-acrylic models. Dent Mater. 1987 Apr;3(2):52-5
Stevens L, Spratley MH. Accuracy of stone, epoxy and silver plate-acrylic models. Dent Mater. 1987 Apr;3(2):52-5

33. METAL SPRAYED DIES
• Bismuth alloy with fusing point of 136ºF
is melted at 145ºF.
• Die is poured & solidify at 30 pounds of pressure.
• Advantages :
• Rapidly from elastomeric impression materials.
• Disadvantages :
• Alloy is soft, care is needed to prevent abrasion of
the die.
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31

34. AMALGAM DIES
• Material of choice previously ,largely
replaced by electroplated dies.
• Resistant to Abrasion.
Procedure
Made by packing amalgam into impression made of
impression compound.
Advantages
• Superior strength
• Resistance to abrasion and reproduce fine details and
sharp margins.
Notes on dental materials E.C COMBE 6TH edition

35. Disadvantage.
• Impression compound.
• Dimensional accuracy may vary .
• Time duration is high.
• It has high thermal conductivity

36. SILICO PHOSPHATE CEMENT
Similar to the filling and cementing
material.
Composition
The powder is a mixture of silicate powder
and zinc oxide liquid contains phosphoric acid.
Notes on dental materials E.C COMBE 6TH edition

37. Advantages:
• Strength and surface hardness are superior to
stone.
Disadvantages:
• Contracts during setting
• Dimensionally inaccurate.
• Loss of water on standing .
• Presence of surface voids can occur.
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31

38. EPOXY RESIN
• Used with polyether, polysulphide
or silicone
• Hardner polyamine causes polymerization.
• Toxic .
Composition
• Epoxy resins, polyester and Epiamines or polymeric
materials with fillers (either metallic or ceramic
fillers).
Stephen f. Rosenstiel, Contemporary Fixed Prosthodontics- 3rd edition

39. PROPERTIES
• Working time – 15 min.
• Setting time – 1 to 12 hours depending on the
product.
• Knoop hardness number is 25 KHN ±15 less than
that of high strength stone (77 KHN).
• Compressive strength after 7 days is 16,000 psi.
• Abrasion resistance is superior .
Stephen f. Rosenstiel, Contemporary Fixed Prosthodontics- 3rd edition

40. • Shrinkage during polymerization - 0.03% and 0.3% .
• Viscous when poured , porosity can occur.
• Agar and alginate materials .
• Compatible with polyether, polysulphide or silicon
impression materials.
Paquette JM, Taniguchi T, White SN. Dimensional accuracy of an epoxy resin die material using two setting methods. J Prosthet Dent. 2000
Mar;83(3):301-5

41. • Better detail reproduction, abrasion resistance, and
transverse strength than the gypsum materials.
• Retarding the setting reaction improves its accuracy .
• Detail duplication of epoxy resin dies is comparable to
that of die stone.
• Hardness values of epoxy resin are less than those of
die stone.
Philip Duke, B.K eith Moore, Steven P. Haug and Carle J. Andres Study of the physical properties of type 4 gypsum, resin-containing, and
epoxy die material J Prosthet Dent 2000;83:466-73

42. Advantages
• Abrasion resistance.
• Less brittle than die stones.
• Can be carved at room temperature.
Disadvantages
• Cannot be used with agar and alginate impression
material.
• Shrinkage on polymerization.
• Less dimensional stability.
• Expensive.

43. FLEXIBLE DIE MATERIALS:-
- Similar to heavy bodied silicone or polyether impression
material.
Use:-
- To make provisional restoration.
- Indirect composite resin inlays or onlays chairside
Advantage:-
- More rapid setting – 10min.
- Ease of removal of provisional
restoration.

44. Irreversible hydrocolloid impression
Fill with the fast setting, medium
viscosity polyvinyl impression material
Polyvinyl cast into the pre
operative mold
POLYVINYL DIE

45. The polyvinyl cast is flexed to
remove tooth colored resin from
the undercuts.
Interim restoration on the prepared
tooth
Douglass Smith, Arun Nayyar, David L. Koth - Fabrication of removable dies using cemented dowel pins J Prosthet
Dent: 1992:68:372-4

46. • Polyurethane is the most accurate,
strongest and cleanest die material
than die stone and epoxy
• silicone impression materials
• Base and hardener
Properties
• No noticeable shrinkage or expansion
• More accurate than epoxy
• Water resistant
• superior mechanical properties (94.82 MPa).
Derrien G, Sturtz G. Comparison of transverse strength and dimensional variations between die stone, die epoxy resin, and die
polyurethane resin. J Prosthet Dent. 1995 Dec;74(6):569-74
POLYURETHANE

47. Uses
• Long span bridges, inlay, onlay preparations
• excellent for scanning
• fabricating CAD/CAM models
• shoulder and partial crown preparations

48. CERAMIC DIE MATERIALS
• Recent advance in die materials.
• Porcelain inlays , onlays and veneers.
Manipulation:
• Supplied as powder and liquid system.
• Mixed into paste and vibrated into the impression
and allowed to set for an hour.
• After which the material is removed and fired at
600ºc for 8 mts to produce a strong die
Toreskog SV, Phillips RA, Schnell RI,.Properties of die materials: A comparative study ,J Prosthe Dent ,Vol 16, iss 1, Jan–Feb 1966, Pg 119-
31

49. CAD CAM
• CEREC
• The E4D (D4D TECH)
• DCS PRECIDENT SYSTEM
• iTero
• LAVA

50. CAD CAM
CEREC SYSTEM

51. Preparation covered with opaque powder
( Titanium dioxide )

52. Image as
viewed on monitor
Cavity outlines are identified for
formation of future restoration

53. Cerec milling unit

54. DCS PRECIDENT SYSTEM
• Designed for metal
copings for PFM .
• Conventional wax up
required.
• Touch probe
• Acceptable marginal
accuracy.

55. • Concludes that manual adjustment significantly
improves the marginal accuracy of CAD/CAM
system-fabricated titanium copings.
• The highest marginal accuracy was achieved with
the DCS system, using a longer refinement time.
Witkowski S, Komine F, Gerds T. Marginal accuracy of titanium copings fabricated by casting and CAD/CAM techniques. J Prosthet Dent. 2006
Jul;96(1):47-52

56. iTero
• The iTero system uses a
camera that takes
several views (stills),
and uses a strobe effect
as well as a small probe
that touches the tooth
to give an optimal focal
length.
• NO use of powder

57. LAVA
• Chairside Oral Scanner (LAVA COS, 3M ESPE) takes a
completely different approach using a continuous
video stream of the teeth.

58. • Crowns from intraoral scans revealed significantly
better marginal fit than crowns from silicone
impressions.
• Marginal discrepancies in both groups were within
the limits of clinical acceptability.
• Crowns from intraoral scans tended to show better
interproximal contact area quality.
• Crowns from both groups performed equally well
with regard to occlusion
Syrek A, Reich G, Ranftl D, Klein C, Cerny B, Brodesser J. Clinical evaluation of all-ceramic crowns fabricated from intraoral digital impressions
based on the principle of active wavefront sampling. J Dent. 2010 Jul;38(7):553-9. doi: 10.1016/j.jdent.2010.03.015

59. ADVANTAGE
• Saves time and one visit for in-office systems
• Opportunity to view occlusion
• Accurate restorations created .
• Accurate, wear- and chip-resistant physical
CAD/CAM derived model.
• No casting/soldering errors.
• Cross-infection control.
Agrawal P, Thompson G, Cho SH, Ziebert GJ. Evaluation of die trim morphology made by CAD-CAM technology. J Prosthet Dent.
2017 Sep;118(3):406-412. doi: 10.1016/j.prosdent.2016.10.027

60. DIE HARDENER
• Materials applied on the surface to increase the
surface hardness
Die hardener:
1.Cynoacrylate resins
2.Acrylic resin lacquer

61. DIE SPACER
• Applied on the die to provide space for the luting
cements.
Die spacer:
1.Resins.
2.Paints.
3.Nail polish.
4.Thermoplastic resins.
Optimal thickness:20-40 micron

62. • Application of die spacer Exerts a favorable
influence on the SBS of composite-bonded
restoration.
• Best marginal adaptation when the die Spacer
covered all of the preparation down to 0.5 mm
short of the marginal finish line
Cho SH, Chang WG, Lim BS, Lee YK. Effect of die spacer thickness on shear bond strength of porcelain laminate veneers. J Prosthet
Dent. 2006 Mar;95(3):201-8

63. DIE SEPARATOR
• Prevent wax adhering on to the stone
• Prevent wax distort on removing.
Die separator:
1.Oils.
2.Liquid soap.
3.Detergents.

64. CONCLUSION
Good impression and die fabrication with proper
selection of the die material and its manipulation
paramount to achieve accuracy in the final
restoration.

65. REFERENCES
• Kenneth J.Anusavice -Philip’s science of dental materials- 11th
edition.
• Robert G.Craig -Restorative dental materials- 11th edition.
• William J.O’Brien -Dental materials and their selection- 3rd
edition.
• Stephen f. Rosenstiel, Contemporary Fixed Prosthodontics- 3rd
edition.
• Herbet T. Shillingburg - Fundamentals of fixed prosthodontics
third edition.
• Notes on dental materials E.C COMBE 6TH edition

66. • Abdullah MA. Surface detail, compressive strength, and dimensional accuracy
of gypsum casts after repeated immersion in hypochlorite solution.J Prosthet
Dent. 2006 Jun;95(6):462-8
• Hahremannezhad HH, Mohamed SE, Stewart GP, Weinberg R. Effects of
cyanoacrylates on die stone. J Prosthet Dent. 1983 May;49(5):639-46
• Duke P, Moore BK, Haug SP, Andres CJ. Study of the physical properties of type
IV gypsum, resin-containing, and epoxy die materials. J Prosthet Dent. 2000
Apr;83(4):466-73.
• Schwedhelm ER, Lepe X. Fracture strength of type IV and type V die stone as a
function of time. J Prosthet Dent. 1997 Dec;78(6):554-9
• Stevens L, Spratley MH. Accuracy of stone, epoxy and silver plate-acrylic
models. Dent Mater. 1987 Apr;3(2):52-5

67. • Paquette JM, Taniguchi T, White SN. Dimensional accuracy of an epoxy
resin die material using two setting methods. J Prosthet Dent. 2000
Mar;83(3):301-5
• Philip Duke, B.K eith Moore, Steven P. Haug and Carle J. Andres Study of
the physical properties of type 4 gypsum, resin-containing, and epoxy
die material J Prosthet Dent 2000;83:466-73
• Douglass Smith, Arun Nayyar, David L. Koth - Fabrication of removable
dies using cemented dowel pins J Prosthet Dent: 1992:68:372-4
• Derrien G, Sturtz G. Comparison of transverse strength and dimensional
variations between die stone, die epoxy resin, and die polyurethane
resin. J Prosthet Dent. 1995 Dec;74(6):569-74
• Cho SH, Chang WG, Lim BS, Lee YK. Effect of die spacer thickness on
shear bond strength of porcelain laminate veneers. J Prosthet Dent.
2006 Mar;95(3):201-8

68. • Agrawal P, Thompson G, Cho SH, Ziebert GJ. Evaluation of die trim morphology
made by CAD-CAM technology .J Prosthet Dent. 2017 Sep;118(3):406-412. doi:
10.1016/j.prosdent.2016.10.027
• Crispin BJ, Watson JF, Frawley KR. Silver-plated dies. Part II: Marginal
accuracy of cast restorations. J Prosthet Dent. 1984 Jun;51(6):768-73
• Witkowski S, Komine F, Gerds T. Marginal accuracy of titanium copings
fabricated by casting and CAD/CAM techniques. J Prosthet Dent. 2006
Jul;96(1):47-52
• Syrek A, Reich G, Ranftl D, Klein C, Cerny B, Brodesser J. Clinical
evaluation of all-ceramic crowns fabricated from intraoral digital
impressions based on the principle of active wavefront sampling. J Dent.
2010 Jul;38(7):553-9. doi: 10.1016/j.jdent.2010.03.015

69. THANK YOU