Dental Waxes
Dental Waxes Definitions:
Dental wax: A low mol. weight ester of fatty acids derived from natural and synthetic components such as petroleum derivatives that soften to a plastic state at a relatively low temperature.
Inlay wax: A specialized dental wax that can be applied to dies to form direct or indirect patterns for the lost wax technique used for casting metals or hot pressing of ceramics.
Classification of Dental Waxes
Inlay Casting Wax (ADA – 4) [Spotter]
Inlay Casting Wax Types
- Type 1 Medium
- Type 2 – Soft
Inlay Casting Wax Composition
- Paraffin wax
- Gumdummar
- Carnauba wax
- Coloring agent.
Inlay Casting Wax Uses:
- Restorations such as inlays crowns and bridges.
Base plate wax (ADA – 24) [Spotter]
Base plate wax Types:
- Type 1 – Soft
- Type 2 – Medium
- Type 3 – Hard
Base plate wax Composition:
- Cerasin – 80%
- Beeswax – 12%
- Rest carnauba, natural or synthetic, micro crystallin.
Base plate wax Uses:
- Occlusal rims
- Produce the desired contour of the denture after the teeth are set in position.
- Patterns for orthodontic appliances.
Types of Inlay Wax (ADA 4)
- Type 1 – Medium wax
- Type 2 – Soft wax
Base plate wax Preparation:
- Direct wax technique
- Indirect wax technique
Components Of Dental Waxes
Dental Burs
Dental Bus Definition: Miniature milling cutters used in dentistry.
Dental Bus Types: Carbon steel burs and tungsten carbide burs
Dental Bus Rake Angle: The face of the bur tooth is at an angle to the radial line from the center to the cutting edge. This angle is the rake angle.
Wrought Base Metal Alloys
Stainless steel: When chromium (12-30 of) is added to steel (Fe-based alloy </2% carbon), it is called stainless steel alloy.
Resistant to tarnish and corrosion due to chromium.
Austenitic stainless steel – orthodontic vire
- Also called 18-8 stainless steel
- Used most commonly by the orthodontist in the form of bands and wire
- Also used as an implant
Cast And Die Dental Material
Cast And Die Dental Material Types:
1. Gypsum:
- Dental stone, high strength – type 4
- Dental stone, high strength high expansion – type V
- Dental stone + Lignosulphonates.
2. Metals:
- Electroformed / Electroplated.
- Sprayed metals.
- Amalgam.
3. Polymers:
- Metal-filled resins or inorganic-filled resins.
- Epoxy resins.
4. Types of cement:
- Silicon phosphate or poly acrylic acid bonded types of cement.
5. Ceramic:
- For direct taking of porcelain crown on preparation.
Cast And Die Dental Material Welding: The term welding is used if two pieces of similar metal are terminal together without the addition of another metal that the metal pieces are heated to a high enough temperature so they join together by melting and flowing.
Cast And Die Dental Material Brazing: During brazing, the metal parts are joined together by melting a filler metal between them at a temperature below the solidus temperature of the metal being found above 450°C.
Cast And Die Dental Material Soldering: During soldering, metal parts are joined together by melting a filler metal between being joined and below 450° C.
Cast And Die Dental Material Fluxes: Compound applied to metal surfaces that dissolve on prevents the formation of oxides and other undesirable substances that may reduce the quality on strength of a soldered on brazed area commonly used – boric/borate compound, fluoride (KF).
Cast And Die Dental Material Antiflux: A substance such as graphite that prevents the flow of molten solders on areas coated by the substance.
Tarnish And Corrosion
Tarnish-Surface discoloration on metal.
Corrosion- Actual deterioration of a metal by a reaction with the environment.
Metal with higher electrode potential – Gold + 1.50 (cathode)
Metal with lowest electrode potential – zinc -0.76 (anode)
Miscellaneous Mixing
Major mixing: Commonly given
- Alginate
- Zinc oxide eugenol paste
- Zinc phosphate cement
- Dental amalgam
Minor mixing:
- Mixing of plaster of Paris
- Mixing of stone plaster
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