PPT_FOR_COSMETIC_RESTORATION.pptx for prosthetic and orthotic students

Cosmetic restoration

1. MATERIALS USED IN SILICONE PROSTHESIS ANIL KUMAR PROSTHETIST & ORTHOTIST KSCH NEWDELHI

2. A successful prosthetic extremity replacement require three majors Creative ability Technical knowledge Correct selection of material

3. Objectives of silicone prosthesis Restoration of aesthetic and cosmetic appearance Restoration of function Protection of tissues Healing effect Psychological therapy

4. Ideal material for cosmetic restoration Flexibility Colour and translucency Chemical and environmental stability Ease of processing Strength Ease of duplication Weight

5. CRITERIA FOR COSMETIC RESTORATION MATERIAL Processing characteristics Intrinsic and extrinsic coloration possible Low solubility parameter Sufficient working time Low curing temperature Performance characteristics Tensile strength Tear resistance Surface hardness

6. Impression phase 1. Alginate 2.Room temperature vulcanizing material 3. Plaster of Paris Modeling phase 1. Modeling clay 2. Plaster 4. waxes Fabrication phase Silicones(HTV, RTV) Acrylic resin

7. Alginate Impression material Types Mixing time Working time Setting time I- Fast set 45 sec 1.25 mins 1-2 mins II- Normal set 60 sec 2 mins 2-4.5 mins MANIPULATION Prepare a proper mixture of water & powder. The measured powder is sifted into the premeasured water. Water added first to ensure complete wetting of powder particles. Clean equipment is important. Avoid incorporating air into the mix. Figure –of-eight motion is best, with the mix being swiped or stropped against the sides of the bowl with intermittent rotations (180˚) of the spatula to press out air bubbles. All of the powder must be dissolved.

8. Modeling 1. Modeling clay 2. Plaster 4. waxes

9. Modeling materials Ideal Properties Malleable • Sufficient strength • Should be possible to accept texture into this material which will be imparted to the finished mold .

10. Plaster Type I - Plaster used as an impression material Type II - Plaster used as a model material Type III - Stone used as a mounting material and a model material Type IV - Stone used as a die material

11. Waxes Waxes are thermoplastic materials which are solids at room temperature but melt without decomposition to form mobile liquids

12. MODELLING WAX A type of pattern wax Pink Color Available in sheet form

13. Waxes

14. Fabrication phase Silicones(HTV, RTV) Acrylic resin

15. Fabrication material

16. CLASSIFICATION OF SILICONE Based on mechanism R oom temperature (RTV) High temperature (HTV) According to application Implant grade . Medical grade (External use)

17. HTV SILICONES Silastic S-6508 Silastic 370,372,373 Silastic 4-4514 Silastic 4-4515 MDX 4-4159 SE- 4524 U Q7-4635 Q7-4650 Q7-4735

18. ADVANTAGES OF HTV OVER RTV Less chances of air bubble entrapment, since hand mixing of catalyst & pigments. 2. Increased tear strength. 3. Increased flexibility.

19. Advantages of this material Most importantly it has a high tear strength. Unusually thin edges can be designed in a prosthesis without the risk of damage during wear & removal.

20. Coloration Distribution of pigment equivalent to its human skin and whose overall colours appears to change precisely as does that of a human skin under all type The base shade selected should be slightly lighter than the lightest skin tones of the patient because the prosthesis will be darken by the either intrinsic and extrinsic coloration . Color match of the prosthesis depends on the skill, color activity of the individual and light source. light sources such as common or halogen light bulbs must be avoided .

21. Primary colors : Red, yellow, blue—are those that cannot be formed by mixing of other colors; they occur naturally. Secondary colors : Secondary colors are formed by mixing primary colors ( i.e , red + yellow = orange; yellow + blue = green; blue + red = violet ).

22. Primary color Secondary color Complementary color Red Red + yellow = orange Red -green Yellow Yellow + blue = green Yellow-violet Blue Blue + red = violet Blue -orange

23. Spectrophotometers used to measure patient skin color spectrophotometer Kaolin Powder Calcined White G-102 used to create opacity with silicone products Dry Pigments

24. Common colors for laminar glazes are : Red bluish glaze . Golden tan glaze Dark brown glaze Opaque Yellow White color Dark blue or purple Opaque, Pink to red helix color

25. Intrinsic coloration Red bluish glaze is painted into the first layer of mould Red bluish glaze is painted into the first layer of mould

26. Extrinsic Coloration Apply the extrinsic pigments in small amounts and on the surface of the prosthesis.

27. Adhesives Adhesives are expected to retain prostheses during ordinary & extreme facial expressions, build-up of sebaceous secretions & water & change of weather conditions. Most facial prostheses are retained with medical grade adhesive . Selection depends : Not harmful or toxic to living tissue. Ease of applicability. Removal on daily basis.

28. Classification of Adhesive Rubber-based liquid adhesives (natural & latex) Silicone Cyanoacrylates

29. Silicone adhesives ( Holister ) Are a form of RTV silicone dissolved in solvent. Once applied, the solvent evaporates & a tacky surface forms that form bond with another surface. Despite their low adhesive strength, they have good resistance to moisture & weathering with low water sorption.

30. Limitation in maxillofacial material No single maxillofacial material is ideal for every patient. Continued effect of sunlight and vascular dilatation & contraction on the natural tissues cannot be duplicated in the prosthesis . Variations of skin tone when the patient is exposed to different light sources ( fluorescent, & natural light) cannot be duplicated in the prosthesis. The prosthesis cannot duplicate the full facial movement of the non defective side.

31. Thank you