Chat with AIExam 11: Casting Alloys, Wrought Alloys, and Solders
Solder metals usually rely on _____ to encourage a lower melting temperature of the solder.
(78) 
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Discuss the process of categorizing casting metals used in dentistry.
(82) VerifiedDental casting alloys (versus wrought alloys) are alloys used clinically in their as-cast form. In dentistry, casting alloys are categorized in several ways but most often on the basis of noble metal content. The nobility of an alloy is expressed as a sum of the weight percentages of the noble metals in the alloy. For example, if an alloy contains 60% gold, 10% palladium, 5% platinum, and 25% copper, the nobility would be 75% (the sum of gold, palladium, and platinum). Alloys also are described on the basis of their most common metal. For example, an alloy with 75% gold often is described as gold based, or an alloy with 60% nickel may be described as nickel based. The term based indicates which metal is the major component in the alloy and should not be confused with the term base metal. There are three major organizations worldwide. The ADA is the entity of choice in the United States.
Wrought alloys have a grain structure often described as fibrous. The fibrous structure is responsible for increased yield strength and hardness compared with the cast form of the alloys.
(80) VerifiedA
An alloy liquidus is defined as the temperature at which ____________.
(72) Which of the following statements is true about ceramics used in restorative dentistry?
(90) Which ADA class of casting alloy has the highest melting point?
(72) The ____________ is the temperature at which the entire alloy freezes on cooling.
(70) Dental alloys have a crystal structure like ice, salt, or sugar. These crystals, or _____ as they are called in metallurgy, can be seen clearly under a microscope.
(89) Why are elements such as iron, gallium, iridium and tin added to the metal bases for a ceramic-faced crown?
(67) The color of an alloy is a good predictor of its composition or other properties. Yellow alloys contain gold.
(79) What is the best solution to the problem of debonding of ceramic from a ceramic-alloy restoration after cementation in the mouth?
(76) Which of the following statements is true concerning noble and base metals?
(89) The __________ is the temperature at which an alloy melts completely.
(78) The color of oxides on metal varies from _____ on high-noble alloys and some noble alloys to _____ oxides on some base-metal alloys.
(80) A patient who is allergic to nickel might also be allergic to what other base metal?
(86) Pure metals have physical and chemical properties more appropriate to dental applications than alloy metals. Some alloys are formed into restorations by casting.
(75) 
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