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Questions and Answers
What is the absolute minimum thickness of porcelain recommended for a restoration?
Which feature is crucial for maximum restoration strength and longevity?
What should be avoided to prevent burnishing of the metal and subsequent fracture of the porcelain?
What is the recommended thickness for a noble metal coping?
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Where should occlusal contacts occur to minimize wear on opposing teeth?
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What should be recognized when lingual contacts on maxillary restorations are placed on porcelain?
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What is a logical framework design for maxillary posterior teeth?
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What could be used on the facial surface to minimize destruction of tooth structure for a facial shoulder?
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What should be waxed to ensure a uniform thickness of porcelain and correct contours?
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What can result in unsupported, fracture-prone porcelain?
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Where should the greater portion of a crown with porcelain occlusal coverage be made of?
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What is the composition of a metal-ceramic restoration (MCR)?
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What role does opaque porcelain play in a metal-ceramic restoration (MCR)?
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What is the significance of the difference in coefficients of thermal expansion between the metal and porcelain in a restoration?
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What is the melting range requirement for the alloy used in the coping of a metal-ceramic restoration?
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What is a characteristic of high noble alloys used in metal-ceramic restorations?
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Why are gold-palladium alloys preferred for metal-ceramic crowns and fixed partial dentures?
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What is a disadvantage of using alloys containing little or no gold for metal-ceramic restorations?
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What must the coping design of a metal-ceramic restoration reflect to provide structural integrity?
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Why is reducing kaolin content important in dental porcelains used for metal-ceramic restorations?
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What are properties that make gold-palladium alloys preferred for metal-ceramic restorations?
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What are some disadvantages of using alloys containing little or no gold for metal-ceramic restorations?
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Why is reducing kaolin content important in dental porcelains used for metal-ceramic restorations?
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What do metal-ceramic restorations combine?
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What is another name for a metal-ceramic crown?
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Which component of metal-ceramic restorations provides strength and accuracy?
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What is the primary benefit of metal-ceramic restorations?
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Which term was commonly used in the dental literature during the 1970s and 1980s for metal-ceramic crowns?
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What is the purpose of the porcelain in metal-ceramic restorations?
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Which material provides the esthetic component in metal-ceramic restorations?
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What is the key feature of metal-ceramic restorations that distinguishes them from other types of crowns?
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What aspect makes metal-ceramic restorations suitable for posterior teeth?
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What type of restoration is a Ceramco crown?
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What aspect of metal-ceramic restorations affects their esthetic appeal?
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What is the main function of the metal framework in metal-ceramic restorations?
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What is the recommended absolute minimum thickness of porcelain for a restoration?
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How thick should a noble metal coping be for maximum restoration strength and longevity?
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What is the ideal thickness range for porcelain in a restoration, considering both esthetics and strength?
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Where should occlusal contacts occur to minimize wear on opposing teeth in metal-ceramic restorations?
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What is the recommended width for a metal collar on the facial surface to minimize destruction of tooth structure for a facial shoulder?
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What type of contour distributes stress best on the veneering area of porcelain?
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What should be avoided in the porcelain support design to prevent burnishing of the metal and subsequent fracture of the porcelain?
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What should the outer junction of porcelain to metal be at to avoid burnishing of the metal?
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What is the potential consequence of placing occlusal contacts near the porcelain-metal junction line?
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What is the potential consequence of designing a restoration with thick areas of porcelain beyond 2.0 mm?
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What can result from inadequate vertical overlap to place occlusal contacts on metal?
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What should the final decision regarding the design and composition of the restoration be?
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What are the advantages and disadvantages of metal ceramic restoration?
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Explain the structural components of different metal alloys used in prosthodontics.
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What criteria determines the amount of veneer ceramic coverage in metal ceramic restorations?
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What are the names that the metal-ceramic crown has gone by since its introduction to dentistry?
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What do metal-ceramic restorations combine?
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What is the significance of the difference in coefficients of thermal expansion between the metal and porcelain in a restoration?
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What is the purpose of the porcelain in metal-ceramic restorations?
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What should be recognized when lingual contacts on maxillary restorations are placed on porcelain?
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What is another name for a metal-ceramic crown?
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What can result in unsupported, fracture-prone porcelain?
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What is a disadvantage of using alloys containing little or no gold for metal-ceramic restorations?
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What is the composition of a metal-ceramic restoration (MCR)?
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What are the three layers of porcelain used to cover the metal coping in a metal-ceramic restoration?
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What is the success rate reported by Näpänkangas and Raustia for metal-ceramic fixed partial dentures after 18 years of use?
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What is the recommended difference in coefficient of thermal expansion between the metal and porcelain used in a restoration?
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What is the melting range requirement for the alloy used in the coping of a metal-ceramic restoration?
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What are the main factors that the choice of an alloy for a metal-ceramic restoration will depend on?
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What is the ideal noble metal content for high noble alloys used in metal-ceramic crowns and fixed partial dentures?
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What are some problems associated with using alloys containing little or no gold for metal-ceramic restorations?
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What characteristic of dental porcelains used for metal-ceramic restorations makes them behave more like glass than a true ceramic?
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What is the melting range of the noble alloys most commonly used for metal-ceramic crowns and fixed partial dentures?
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What is the purpose of the opaque porcelain in a metal-ceramic restoration?
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What must the coping design of a metal-ceramic restoration reflect in order to provide structural integrity?
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What are the properties of gold-palladium alloys that make them preferred for metal-ceramic crowns and fixed partial dentures?
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Porcelain should be kept at a minimum thickness of ______ mm, and the desirable thickness is 1.0 to 1.5 mm.
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An example is the improperly designed pontic framework with a thick ______ extension of porcelain.
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A noble metal coping should be at least 0.3 to 0.5 mm ______.
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The porcelain-metal junction should be placed 1.0 mm from occlusal contacts at the position of maximal ______.
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To place occlusal contacts in metal, the porcelain on the facial surface extends over the cusp tip and about halfway down the palatal incline of the facial cusp on maxillary ______ and molars.
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Mandibular first premolars will often require complete porcelain coverage of the occlusal surfaces of metal-ceramic ______.
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The distal half of second premolars and molars can be unveneered to allow more occlusal contacts to be on ______ if the patient can be satisfied with a tooth colored veneer on the mesial marginal ridge, proximal contact, fossa, and cusp incline.
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A 1.0- to 2.0-mm-wide metal ______ can be used on the facial surface to minimize the destruction of tooth structure for a facial shoulder.
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A posterior crown with porcelain occlusal coverage should have a 3.0-mm metal ______ on the lingual, with metal support under the marginal ridges.
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The absolute minimum thickness of porcelain is ______ mm, and the desirable thickness is 1.0 to 1.5 mm.
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The metal must be as hard as practical, and the coping design must ensure an optimum bulk for ______.
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Porcelain should be kept at a minimum thickness of 0.7 mm, and the desirable thickness is 1.0 to 1.5 ______.
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Metal-ceramic restorations combine the strength and accuracy of cast metal with the esthetics of ______.
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The metal-ceramic crown has gone by a variety of names since its introduction to dentistry nearly five decades ago. It was called a Ceramco crown, a ______ veneer crown (PVC), a ______-fused-to-gold (PFG) crown, and a ______-fused to metal (PFM) crown, a term commonly used in the dental literature during the 1970s and 1980s.
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Metal-ceramic restorations combine the strength and accuracy of cast metal with the esthetics of ______.
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The metal-ceramic crown has gone by a variety of names since its introduction to dentistry nearly five decades ago. It was called a Ceramco crown, a ______ crown (PVC), a porcelain-fused-to-gold (PFG) crown, and a porcelain-fused to metal (PFM) crown, a term commonly used in the dental literature during the 1970s and 1980s.
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The metal-ceramic crown has gone by a variety of names since its introduction to dentistry nearly five decades ago. It was called a Ceramco crown, a porcelain veneer crown (PVC), a ______ crown, and a porcelain-fused to metal (PFM) crown, a term commonly used in the dental literature during the 1970s and 1980s.
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Metal-ceramic restorations combine the strength and accuracy of ______ metal with the esthetics of porcelain.
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The metal-ceramic crown has gone by a variety of names since its introduction to dentistry nearly five decades ago. It was called a Ceramco crown, a porcelain veneer crown (PVC), a porcelain-fused-to-gold (PFG) crown, and a ______ crown, a term commonly used in the dental literature during the 1970s and 1980s.
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Metal-ceramic restorations combine the ______ and accuracy of cast metal with the esthetics of porcelain.
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The metal-ceramic crown has gone by a variety of names since its introduction to dentistry nearly five decades ago. It was called a Ceramco crown, a ______ crown (PVC), a porcelain-fused-to-gold (PFG) crown, and a porcelain-fused to metal (PFM) crown, a term commonly used in the dental literature during the 1970s and 1980s.
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Metal-ceramic restorations combine the ______ and accuracy of cast metal with the esthetics of porcelain.
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The metal-ceramic crown has gone by a variety of names since its introduction to dentistry nearly five decades ago. It was called a ______ crown, a porcelain veneer crown (PVC), a porcelain-fused-to-gold (PFG) crown, and a porcelain-fused to metal (PFM) crown, a term commonly used in the dental literature during the 1970s and 1980s.
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The metal-ceramic crown has gone by a variety of names since its introduction to dentistry nearly five decades ago. It was called a Ceramco crown, a ______ crown (PVC), a porcelain-fused-to-gold (PFG) crown, and a porcelain-fused to metal (PFM) crown, a term commonly used in the dental literature during the 1970s and 1980s.
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The MCR is composed of a metal casting, or coping, that fits over the tooth preparation and ceramic that is fused to the ______.
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The contours in the area that has been cut away will be replaced with porcelain that will mask or hide the metal coping, produce the desired contours, and make the restoration esthetically ______.
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The porcelain and metal used for a restoration must have compatible melting temperatures and coefficients of ______ expansion.
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The coefficient of thermal expansion of porcelain can be increased to as much as 7 to 8 × 10^6 /°C by the addition of an alkali such as ______.
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The melting range of the alloy used in the coping must be 170°C to 280°C (300°F to 500°F) higher than the fusing temperature of the porcelain applied to ______.
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The porcelain used must not require that the metal be heated much beyond this ______.
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A classification system proposed by the American Dental Association is based on noble metal content. High noble alloys have a noble metal content greater than 60%, with at least 40% gold: gold, platinum, ______.
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The choice of an alloy will depend on a variety of factors: cost, rigidity, cast ability, ease of finishing and polishing, corrosion resistance, compatibility with specific porcelains, and personal ______.
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Gold-palladium alloys have proven most satisfactory for metal-ceramic crowns and fixed partial dentures. These alloys are composed of gold (44% to 55%) and palladium (35% to 45%), with small amounts of gallium, indium, and/or ______.
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The metal coping must allow the porcelain to remain in compression by supporting the incisal region, the occlusal table, and the ______ ridges.
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The coping design can have an important effect on the success or failure of the ______.
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The porcelain must remain in compression by supporting the incisal region, the occlusal table, and the ______ ridges.
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Metal-ceramic restorations are commonly used to describe restorations such as crowns, inlays, and veneers. The abbreviation MCR stands for metal-ceramic ___________.
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The metal coping in an MCR is covered with three layers of porcelain: opaque porcelain, dentin porcelain, and ________ porcelain.
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The coefficient of thermal expansion of porcelain can be increased to as much as 7 to 8 × $10^6/°C$ by the addition of an alkali such as _______ carbonate.
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The melting range of the alloy used in the coping must be 170°C to 280°C (300°F to 500°F) higher than the fusing temperature of the __________ applied to it.
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Gold-palladium alloys have proven most satisfactory for metal-ceramic crowns and fixed partial dentures. These alloys are composed of gold (44% to 55%) and palladium (35% to 45%), with small amounts of gallium, indium, and/or _________.
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A logical transition was the application of materials commonly used in the fabrication of removable partial denture frameworks to fixed prosthodontics. These alloys possess desirable properties such as low cost, increased strength and hardness, high fusion temperatures, and greater resistance to distortion during porcelain firing. However, there are inherent problems with these alloys when used as an integral part of a metal-ceramic system. The disadvantages include excessive oxide formation, difficulty in finishing and polishing, and questionable ___________.
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The metal coping must allow the porcelain to remain in compression by supporting the incisal region, the occlusal table, and the marginal _________.
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No alloy system is superior in all aspects. The choice of an alloy will depend on a variety of factors: cost, rigidity, cast ability, ease of finishing and polishing, corrosion resistance, compatibility with specific porcelains, and personal ___________.
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The porcelain and metal used for a restoration must have compatible melting temperatures and coefficients of thermal expansion. Conventional gold alloys have a high coefficient of thermal expansion (14 × $10^6/°C$), while conventional porcelain possesses a much lower value (2 to 4 × $10^6/°C$). A difference of only 1.7 × $10^6/°C$ can produce sufficient shear stress to produce failure of the ________.
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Alloys Used The properties of the porcelain cannot be considered alone. The porcelain and metal used for a restoration must have compatible melting temperatures and coefficients of thermal expansion. Conventional gold alloys have a high coefficient of thermal expansion (14 × $10^6/°C$), while conventional porcelain possesses a much lower value (2 to 4 × $10^6/°C$). A difference of only 1.7 × $10^6/°C$ can produce sufficient shear stress to produce failure of the _________.
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The metal coping in an MCR is covered with three layers of porcelain: opaque porcelain, dentin porcelain, and _________ porcelain.
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The contours in the area that has been cut away will be replaced with porcelain that will mask or hide the metal coping, produce the desired contours, and make the restoration esthetically _________.
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