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2. thermoplastic molding material. thermoplastic molding material. solid at room temperature. solid at room temperature. 2

3. - Baseplate wax: sheets, establish initial arch form in construction of CD. - Bite wax: record the occlusal surfaces of teeth. - Boxing wax: sheet wax used as a border of an impression to provide base of the cast to be made. - Inlay wax: applied to dies to form direct or indirect patterns for the lost-wax tech. - Sticky wax: adheres to dry clean surfaces. 3

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6. BASE Wax: BASE Wax: that is almost always paraffin (not smooth, not glossy, flake when trimmed) (1) Hydrocarbon of paraffin or esters (2) High or low MW MODIFIER Waxes: MODIFIER Waxes: contribute properties such as increased hardness, stickiness, or brittleness (1) Hydrocarbon or ester types; (2) High or low MW COLORANT: COLORANT: 1% Fillers: some waxes contain it to control expansion and shrinkage of the wax product. Fillers: some waxes contain it to control expansion and shrinkage of the wax product. 6

7. Natural (mineral, vegetable, or animal origin and/or synthetic waxes (more homogeneous & pure) Natural waxes are complex combinations of organic compounds of high molecular weight: Hydrocarbons,e.g. saturated alkanes, & microcrystalline wax series, carnauba wax, candelilla wax. Esters, e.g.myricylpalmitate. Some waxes also contain free alcohol and acid. (Esters are formed from union of higher fatty acids with higher aliphatic alcohol with elimination of water) Alcohol+Fatty Acid  Ester+Water 7

8. Natural waxesSynthetic waxesAdditives Minerals: Paraffin Microcrystalline Barns Dahl Ozokerite Ceresin Montan Acrawax C Aerosol,OT Castorwax Flexowax C Epolene N-10 Albacer Aldo 33 Durawax 1032 Fats  Stearic acid  Glyceryltristearate  Oils  Turpentine  Color Plants :Carnauba Ouricury Candelilla Japan wax Coca butter Natural Resins  Rosin  Copal  Dammar  Sandarac  Mastin, Shellac  Kauri I nsect : Beeswax Animal: Spermaceti Synthetic Resins  Elvax  Polyethylene Polystyrene 8

9. Gum dammar: smoothness, resistant to flaking, toughness. (resin) Ceresin the hardness and water resistance of wax. Improves carving properties. Carnuba the hardness and water resistance, melting range, gives glossiness, flow at mouth temp. Beeswax the stickiness, improves flow properties at mouth temperature. (esters) Rosin the brittleness. (resin) Microcrystalline waxes stress release on cooling. 9

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11. Occurs because of the Multiple wax mixtures The liquidus line (representing the temperature at which complete melting has occurred) The solidus line (below which the composition is entirely solid) the solid + liquid range in between is quite broad (almost 40°C). To allow manipulation To develop wax flow, the temperature only needs to be heated to a point within the solid+liquid range or up to the point of the liquidus line but not much higher. Excessive heating would cause decomposition. 11

12. 12 COMPOSITION (%) TEMPERATURE (C) ParaffinCarnuba 40 30 20 60 50 70 80 90 255075100 LIQUID LIQUID + SOLID SOLID Melting Onset (Solidus) Melting Completion (Liquidus)

13. 13 Name:Origin:Composition:Melting (  C) Density (20  C) PARAFFINMineralHydrocarbon mixture50-570.90 CERESINMineralComplex hydrocarbons61-780.91-0.92 BEESWAXAnimalEster mixture62-650.95-0.96 CANDELILLAPlantC 21 hydrocarbons68-700.95-0.99 CARNAUBAPlantHydrocarbon, Ester, Fatty Acid 82-860.99-0.999 GUM DAMMAR PlantAromatic resinca 1201.040- 1.120 ROSINPlantAromatic resin acid100-1501.08

14. Methods: 1. Flame heated instruments 2. warmth of hand?? 3. dry heat as wax pot 4. Water bath, but not for inlay wax?? Flow : after the highest melting point is reached. Temperature  1/ viscosity Flow temperature must be > mouth temp if needed in solid state Over heating should be avoided? the base or modifier waxes can be decomposed. 14

15. In solids its analogous to creep In liquids its analogous to viscosity Waxes are usually non-flowable at room temperature Temperature  1/ viscosity It is critical for inlay wax to have flow less than 1% 15

16. It is low Wax should be softened evenly by rotation above the flame until it evenly softens or flows Tempered in a water bath alternately with the flame heating to allow the core to soften before dripping If a soft core of a bulk of wax is to be made, roll the wax when it is in softened status – (unable to hold shape by itself) 16

17. Used with cast metal techniques Wax patterns need to be burned to the point where no excess residue may interfere with metal casting Heat melt and/or decompose wax by the process of oxidation which completely transform it into water vapor and carbon dioxide so that no residue is left. 17

18. 18 Created by the bees wax addition in the mixture Increased if material is warmed by hand Solid waxes become tacky to other material if heated Adhesives may be applied on casts before wax application Wax dipping in bees wax increase stickiness of refractory casts Old wax adheres to new one if surface is dry

19. 19 Wax should be dimensionally stable once it has solidified (less than 1%). Invest the pattern immediately after removal from the die. Deformations: Plastic deformation Under force is by ductility. Ductility allows it to be carved or burnished Residual stress recovery Elastic Recovery

20. Residual stress reduction Heat material evenly Follow manufacturer instructions Invest within 30 min of carving Whenever wax additions are cooled. The exterior surface tends to cool first. The molten interior slowly solidifies and contracts. This encourages distortion or flow. Add in small increments, layering Store at low temperatures 20

21. 21 Very high ceramics (1-15 ppm/°C) metals (10-30 ppm/°C) waxes (30-600 ppm/°C) inlay wax (250-300 ppm/°C) ( wax pattern made in the mouth will shrink appreciably) Residual thermal stresses may change dimensions Paraffin > beeswax >carnuba  Do not heat above melting point during work

22. 22 250 ppm/  C Paraffin Carnuba Beeswax 0253040453550 0 1.2 1.0 0.8 0.6 0.4 0.2 TEMPERATURE (C) EXPANSION (%) KERR HARD WAX

23. Wax is hydrophobic To increase its wetting a surfactant could be sprayed over wax to increase flow of investment material 23

24. Coloring is not standardized Dark colors provide good color contrast for processing wax Opaque and Tooth-colored waxes provide good material for esthetic case presentations and patient education 24

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28. Uses metal castings of Inlays Attachments Crowns Pontics Partial dentures Denture base material 28

29. Forms sticks pallets, tins - Blue or green Consistencies - Hard, medium, soft, regular Application - indirect and direct technique 29 Removable Die with Waxed Inlay

30. Composition Paraffin + Carnuba + Ceresin +Beeswax + Colorants Properties - low thermal dimensional change - flow temp higher than mouth - must have clean excess residue 30

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32. Application  Used for metal framework  complete and partial dentures Forms Sheets and preformed shapes Properties  low thermal dimensional change  must have clean excess residue 32

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35. Form sheets Types I, II & III Application - wax registration of ridge form - Carved into tissue forms and Support teeth - Bite registration Properties - melting range higher than mouth temperature - Customised to climate 35

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37. Uses For edentulous impressions Corrects undercuts Closes bubbles Properties flow at mouth temperature E.g. Bite wax, mizzy 37

38. Uses To articulate models correctly Forms horse shoe shape May be supported by metal foil for stability 38

39. Forms 1 inch sheets Uses used to form base of the cast pouring May be used to modify borders of trays Properties Tacky at room temp 39 Transfer to impression EdentulousCastOrthodonticModelWorkingCast

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41. Forms Ropes manipulated at room temp Applications Add to the tray - customize for pt mouth - Comfort from sharp edges - Control imp material in mouth - Cover ortho bands and wires - to register the bite - Block out undercuts 41

42. Forms Pencil shape orange or yellow Properties hard and brittle – can reorient if broken Adhere temporarily the metal, gypsum, resin – for fabrication or repair 42

43. 43 Thank you