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Questions and Answers
What is the purpose of investment expansion in the casting process?
What is the purpose of investment expansion in the casting process?
Which factor influences the setting expansion of gypsum in the casting process?
Which factor influences the setting expansion of gypsum in the casting process?
What type of casting alloy is suitable for crowns and fixed dental prostheses?
What type of casting alloy is suitable for crowns and fixed dental prostheses?
What is the recommended material for the sprue in the casting process?
What is the recommended material for the sprue in the casting process?
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What is the purpose of the crucible former in the casting process?
What is the purpose of the crucible former in the casting process?
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What is the function of the liner in the casting ring?
What is the function of the liner in the casting ring?
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What is the first step in the investing process?
What is the first step in the investing process?
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What is the purpose of wax elimination in the casting process?
What is the purpose of wax elimination in the casting process?
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What is the recommended temperature for placing the ring in the furnace during wax elimination?
What is the recommended temperature for placing the ring in the furnace during wax elimination?
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What is the purpose of quenching the ring into cold water after wax elimination?
What is the purpose of quenching the ring into cold water after wax elimination?
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What is the function of the sprue in the casting process?
What is the function of the sprue in the casting process?
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What is the primary consideration for selecting a casting alloy?
What is the primary consideration for selecting a casting alloy?
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What is the first step in the Lost Wax Technique?
What is the first step in the Lost Wax Technique?
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What is the purpose of the sprue in the Lost Wax Technique?
What is the purpose of the sprue in the Lost Wax Technique?
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What is the shrinkage percentage for nickel-chromium alloys used for dental restorations?
What is the shrinkage percentage for nickel-chromium alloys used for dental restorations?
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Why must the mold be larger than the original wax pattern in the Lost Wax Technique?
Why must the mold be larger than the original wax pattern in the Lost Wax Technique?
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Which type of investment material is stable above 650°C and suitable for metal ceramic alloys?
Which type of investment material is stable above 650°C and suitable for metal ceramic alloys?
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What is the binder for Phosphate bonded investment material?
What is the binder for Phosphate bonded investment material?
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Which investment material satisfies most requirements but is not suitable for casting metal ceramic alloys due to the high heat requirement?
Which investment material satisfies most requirements but is not suitable for casting metal ceramic alloys due to the high heat requirement?
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What is the common outcome of using Silica bonded investment material?
What is the common outcome of using Silica bonded investment material?
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What is the main limitation of Silica bonded investment material?
What is the main limitation of Silica bonded investment material?
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What are the three important requirements for investment material?
What are the three important requirements for investment material?
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What is the purpose of the investment material in the Lost Wax Technique?
What is the purpose of the investment material in the Lost Wax Technique?
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What is the primary purpose of the sprue in the Lost Wax Technique?
What is the primary purpose of the sprue in the Lost Wax Technique?
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Study Notes
Investment Expansion in Casting Process
- The purpose of investment expansion is to compensate for the shrinkage of the alloy during solidification.
Factors Influencing Setting Expansion of Gypsum
- The setting expansion of gypsum is influenced by the type of gypsum and the time allowed for its setting.
Casting Alloys for Crowns and Fixed Dental Prostheses
- Nickel-chromium alloy is suitable for crowns and fixed dental prostheses.
Recommended Material for Sprue
- The recommended material for the sprue is wax or plastic.
Purpose of Crucible Former
- The crucible former is used to hold the casting alloy in the correct shape.
Function of Liner in Casting Ring
- The liner is used to facilitate the removal of the investment material from the casting ring.
Investing Process
- The first step in the investing process is to coat the wax pattern with a refractory material.
Purpose of Wax Elimination
- Wax elimination is done to create a cavity for the casting alloy.
Temperature for Wax Elimination
- The recommended temperature for placing the ring in the furnace during wax elimination is 538°C.
Purpose of Quenching
- Quenching the ring into cold water after wax elimination is done to prevent distortion and cracking of the investment material.
Function of Sprue
- The sprue is used to direct the flow of molten alloy into the casting ring.
Primary Consideration for Selecting a Casting Alloy
- The primary consideration for selecting a casting alloy is its biocompatibility.
Lost Wax Technique
- The first step in the Lost Wax Technique is to create a wax pattern.
- The purpose of the sprue in the Lost Wax Technique is to direct the flow of molten alloy into the casting ring.
Shrinkage Percentage for Nickel-Chromium Alloys
- The shrinkage percentage for nickel-chromium alloys used for dental restorations is 2.1-2.3%.
Mold Size in Lost Wax Technique
- The mold must be larger than the original wax pattern to accommodate the shrinkage of the alloy.
Investment Material for Metal Ceramic Alloys
- Phosphate-bonded investment material is stable above 650°C and suitable for metal ceramic alloys.
Binder for Phosphate Bonded Investment Material
- The binder for Phosphate bonded investment material is phosphoric acid.
Silica Bonded Investment Material
- Silica bonded investment material is not suitable for casting metal ceramic alloys due to the high heat requirement.
- The common outcome of using Silica bonded investment material is a rough surface finish.
- The main limitation of Silica bonded investment material is its thermal instability.
Requirements for Investment Material
- The three important requirements for investment material are thermal stability, strength, and refractoriness.
Purpose of Investment Material
- The purpose of the investment material in the Lost Wax Technique is to hold the shape of the casting and provide a smooth surface finish.
Primary Purpose of Sprue
- The primary purpose of the sprue in the Lost Wax Technique is to direct the flow of molten alloy into the casting ring.
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Description
Test your knowledge of the lost wax technique and materials used in investment casting with this quiz. Explore topics such as the process of converting wax patterns to cast metal, the use of heat-resistant investment materials, and shrinkage compensation in molten alloys for dental restorations.
