Die materials used in prosthodontics

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 Reproduce an impression . Dimensionally stable . Setting expansion, contraction, and dimensional variations must be minimum. S trong and durable . Robert G.Craig -Restorative dental materials- 7th edition

5. Resistance to shearing forces and abrasion . Compatibility with impression materials . 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 110 o to 120 o C 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 10 th 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 setting At 100˚c no reaction

16. H igh-strength Type V dental stone may produce a harder cast H igher 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 L iner expansion on setting V. G rowth 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 C ompatible with all impression materials. A bility 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 . H ahremannezhad 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. E arly 1930 s Robert G.Craig -Restorative dental materials- 7th edition

24. PROPERTIES :- D etailed 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 S urface 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. S urface coated with fine particles of copper or graphite . The coated impression is made the cathode . C opper plate is anode. I mmersed 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 . E lectro 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. S imilar to that of copper plating . 5 mA is sufficient . C oated 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. H igher strength, hardness and abrasion resistance . F inishing and polishing of metal restoration . C rown 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 : R apidly 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. R esistant to Abrasion. Procedure M ade by packing amalgam into impression made of impression compound . Advantages S uperior strength R esistance to abrasion and reproduce fine details and sharp margins. Notes on dental materials E.C COMBE 6TH edition

35. Disadvantage . I mpression compound . D imensional accuracy may vary . Time duration is high. It has high thermal conductivity

36. SILICO PHOSPHATE CEMENT S imilar 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 U sed with polyether , polysulphide or silicone H ardner polyamine causes polymerization . T oxic . 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. B etter 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 A brasion 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. P olyurethane 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 M ore accurate than epoxy W ater 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 R ecent advance in die materials . P orcelain inlays , onlays and veneers . Manipulation: Supplied as powder and liquid system. M ixed 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: Cynoacrylate resins Acrylic resin lacquer Optimal thickness: 2-3 micron

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

62. A pplication of die spacer Exerts a favorable influence on the SBS of composite-bonded restoration. B est 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 P revent wax distort on removing. Die separator: Oils. Liquid soap. Detergents.

64. CONCLUSION G ood impression and die fabrication with p roper 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 H ahremannezhad 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

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