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Questions and Answers
What is the primary advantage of gold alloys compared to nickel-titanium alloys?
Which disadvantage is specifically associated with gold alloys?
What is a significant feature of the austenitic form of 18/8 stainless steel?
Which component is added to gold alloys primarily to counteract copper's color?
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What property does zinc provide to gold alloys?
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What impact does heating gold alloys to temperatures between 400-900 degrees have?
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Which disadvantage of gold alloys relates to the process of soldering?
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What is a common disadvantage of using gold alloys in dental applications?
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What does the yield strength represent in a material?
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Which characteristic allows orthodontic wires to return to their original shape after being bent?
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What is the relationship between yield strength and modulus of elasticity described as?
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What is the maximum stress that a material can withstand before failure in tension called?
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Which characteristic of orthodontic wires contributes to low friction during movement?
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What determines the maximum amount of elastic activation before permanent deformation occurs?
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How is the stored energy in orthodontic wires generally characterized?
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What does the term 'formability' refer to in the context of orthodontic wires?
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Which type of metal is primarily used for conventional metal brackets?
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What is a key advantage of cast brackets over stamped brackets?
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What are the two primary disadvantages of stainless steel brackets?
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Which of the following is a characteristic of stainless steel used for orthodontic brackets?
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Which type of non-metallic bracket is made from polycarbonate and initially utilized for orthodontic applications?
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What reaction can occur if nickel is leached from orthodontic appliances?
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Which of the following metals is NOT mentioned as a component of brackets?
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What is a disadvantage of non-metallic brackets compared to metal brackets?
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What type of stainless steel is typically used for manufacturing orthodontic brackets?
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Which of the following bracket types offers clear aesthetic appearance?
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What is the primary function of the acrylic button in the design of the palatal portion of the appliance?
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Which type of wire is used to connect the upper molars in the design of the appliance?
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What advantage does the Nance appliance provide during treatment?
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What is a notable disadvantage of the Nance appliance related to hygiene?
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In what case does the Nance appliance enhance anchorage significantly?
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What potential issue arises from the lack of an anterior stop in the Nance appliance?
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Which feature of the Nance appliance allows for easy cleaning?
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What structural link does the 0.036 SS wire form in the Nance appliance?
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What is the term for the energy storing capacity of a wire represented by the area under the elastic deformation curve?
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Which property indicates how well a wire can handle force without deforming?
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What material characteristic contributes to a wire's resistance to corrosion and its interaction with bodily tissues?
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Which type of stainless steel is commonly used in orthodontics due to its significant stiffness and resiliency?
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Which option represents the ability to join components of wire using methods like soldering?
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What effect can excessive friction at the bracket/wire interface have on orthodontic treatment?
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Which alloy is derived from the addition of chromium to iron?
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What is the significance of high formability in wire materials?
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Study Notes
Composite/Coated Wires
- 18/8 Stainless Steel Composition: Contains 18% chromium and 8% nickel, known for its austenitic form.
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Gold Alloys: Biocompatible, inert, and environmentally stable; used before the 1930s.
- Type I and II: Type I has increased gold content, while Type II has lesser gold content.
- Additives: Copper (age hardening), silver (color counteract), palladium and platinum (melting temperature increase), nickel (strength), zinc (antioxidant).
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Advantages of Gold Alloys:
- High stiffness and yield strength (approximately 1400 MPa).
- Excellent formability and environmental stability.
- Good joinability and biocompatibility.
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Disadvantages of Gold Alloys:
- Demanding soldering, lower springback compared to nickel-titanium alloys, and high modulus of elasticity requires frequent activations.
Bracket Materials
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Metal Brackets: Predominantly made of stainless steel (316 and 318 type).
- Benefits include low cost, sufficient strength for deformation resistance, corrosion resistance, and good mechanical properties.
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Non-Metal Brackets: Include plastic, porcelain, and polycarbonate options.
- Plastic Brackets: Initially made from polycarbonate; limited use for complex tooth movements.
Manufacturing Methods of Metal Brackets
- Stamped Brackets: Created by pressing sheet metal into a die; historically common until the advent of prescription straight wire appliances.
- Cast Brackets: Molten metal poured into molds; offers accuracy and durability, preferred for modern orthodontic appliances.
Characteristics of Orthodontic Wires
- Springback: Measures the elastic limit of a wire's deformation, related to yield strength and modulus of elasticity.
- Tensile Strength: Maximum stress a material can withstand in tension before failure.
- Elastic Deformation: Proportional to the stress received (Proportional Limit).
- Formability: Ability to bend wires into desired shapes without fracturing.
- Biocompatibility: Tolerance to tissue and resistance to corrosion.
Nance Appliance
- A fixed bilateral space maintainer for maxillary space retention following the loss of deciduous molars.
- Provides improved anchorage during orthodontic alignment and leveling; reduces risk of tissue inflammation.
- Challenges: Hygiene issues due to food debris accumulation; lack of anterior stops may lead to tooth shift.
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Description
This quiz focuses on the properties and applications of composite and coated wires, specifically 18/8 stainless steel, known for its high chromium and nickel content. Explore the advantages and disadvantages of materials like gold and austenitic forms, particularly in orthodontics with j.Optiflex archwires.
