This document provides an overview of dental ceramics, including their composition, classification, structure, manufacturing process, and bonding to metal. It discusses the main components of dental ceramics such as feldspar, quartz, alumina, and kaolin. It classifies ceramics according to their microstructure, firing temperature, use, and composition. Key steps in the manufacturing process include fritting, porcelain condensation, sintering, and firing. The bonding of porcelain to metal involves mechanical, compressive, and chemical bonding. Methods to strengthen ceramics include minimizing stress concentrators, developing residual compressive stresses, and ion exchange.
This document discusses residual ridge resorption, which is the ongoing breakdown of the jawbone after tooth loss. It defines residual ridge resorption and classifies the types and stages. Factors that influence the rate and amount of resorption include anatomy, mechanics, metabolism, prevention through nutrition and implant placement. Surgical techniques like ridge augmentation and metal dentures can treat severe resorption. The conclusion emphasizes educating patients on treatment options based on their individual prognosis.
This document discusses considerations for fixed prosthodontics in patients with compromised periodontal health. Key points include:
- Periodontal health plays an important role in the longevity of restorations, and defective prostheses can contribute to periodontal disease progression. Successful treatment requires cooperation between periodontists and prosthodontists.
- Periodontal issues must be resolved before restorative treatment to avoid tensions on the periodontium from tooth movement. Supragingival margins and open embrasures are preferred for periodontal health.
- Temporary splinting can help determine the prognosis of a permanent restoration in periodontally compromised patients. Occlusion should not interfere with plaque control.
The document discusses various materials used in maxillofacial prosthetics. It describes ideal materials as being biocompatible, flexible, colorable, chemically stable, easy to process, and strong. Room temperature vulcanizing materials and modeling materials like clay, plaster, and wax are introduced. The fabrication phase uses extraoral materials like acrylics, vinyl polymers, and elastomers like polyurethane and silicone, which are considered most desirable due to their strength. High temperature vulcanizing silicone provides good strength and detail but requires specialized equipment for processing.
This document discusses maxillofacial materials and prosthetics. It begins with definitions of maxillofacial prosthetics and then discusses the history and characteristics of materials. The key materials discussed include acrylic resins, acrylic resin copolymers, vinyl polymers/copolymers, polyurethane elastomers, and silicone elastomers. The document provides details on the composition, advantages, and disadvantages of each material class. It also discusses classification of materials, coloration, retention, limitations, and recent advances in maxillofacial prosthetics materials.
Finishing and polishing of cast metal framework/prosthodontic coursesIndian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
There have been several changes since inception in the field of dental ceramics. Need for newer materials with improved aesthetics, flexural strength and optical properties made it necessary for introduction of advanced technology in fabrication of dental ceramics.
The document discusses different types of luting cements used to cement indirect dental restorations. It describes the ideal requirements of luting cements and provides classifications based on ingredients and application. Specific cements are discussed in detail, including their composition, setting reactions, indications, advantages and disadvantages. The key cements covered are zinc phosphate, polycarboxylate, zinc oxide eugenol, and glass ionomer.
Dental ceramics /certified fixed orthodontic courses by Indian dental academy Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
This document discusses residual ridge resorption, which is the ongoing breakdown of the jawbone after tooth loss. It defines residual ridge resorption and classifies the types and stages. Factors that influence the rate and amount of resorption include anatomy, mechanics, metabolism, prevention through nutrition and implant placement. Surgical techniques like ridge augmentation and metal dentures can treat severe resorption. The conclusion emphasizes educating patients on treatment options based on their individual prognosis.
This document discusses considerations for fixed prosthodontics in patients with compromised periodontal health. Key points include:
- Periodontal health plays an important role in the longevity of restorations, and defective prostheses can contribute to periodontal disease progression. Successful treatment requires cooperation between periodontists and prosthodontists.
- Periodontal issues must be resolved before restorative treatment to avoid tensions on the periodontium from tooth movement. Supragingival margins and open embrasures are preferred for periodontal health.
- Temporary splinting can help determine the prognosis of a permanent restoration in periodontally compromised patients. Occlusion should not interfere with plaque control.
The document discusses various materials used in maxillofacial prosthetics. It describes ideal materials as being biocompatible, flexible, colorable, chemically stable, easy to process, and strong. Room temperature vulcanizing materials and modeling materials like clay, plaster, and wax are introduced. The fabrication phase uses extraoral materials like acrylics, vinyl polymers, and elastomers like polyurethane and silicone, which are considered most desirable due to their strength. High temperature vulcanizing silicone provides good strength and detail but requires specialized equipment for processing.
This document discusses maxillofacial materials and prosthetics. It begins with definitions of maxillofacial prosthetics and then discusses the history and characteristics of materials. The key materials discussed include acrylic resins, acrylic resin copolymers, vinyl polymers/copolymers, polyurethane elastomers, and silicone elastomers. The document provides details on the composition, advantages, and disadvantages of each material class. It also discusses classification of materials, coloration, retention, limitations, and recent advances in maxillofacial prosthetics materials.
Finishing and polishing of cast metal framework/prosthodontic coursesIndian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
There have been several changes since inception in the field of dental ceramics. Need for newer materials with improved aesthetics, flexural strength and optical properties made it necessary for introduction of advanced technology in fabrication of dental ceramics.
The document discusses different types of luting cements used to cement indirect dental restorations. It describes the ideal requirements of luting cements and provides classifications based on ingredients and application. Specific cements are discussed in detail, including their composition, setting reactions, indications, advantages and disadvantages. The key cements covered are zinc phosphate, polycarboxylate, zinc oxide eugenol, and glass ionomer.
Dental ceramics /certified fixed orthodontic courses by Indian dental academy Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
This document discusses various methods used to analyze occlusal contacts, including articulating paper, film, spray, and T-Scan system. Articulating paper is most common but has limitations like being affected by saliva and producing pseudo markings. Articulating film provides more precise markings. T-Scan system can record contact sequence and distribution over time. Virtual dental patient and 3D modeling also allow quantitative assessment of occlusion over time. Choice of indicator depends on need for qualitative vs. quantitative data and environment. Proper indicator use and understanding limitations is important for accurate analysis of occlusal contacts.
Journal club presentation on tooth supported overdentures NAMITHA ANAND
This document presents a case report of a full mouth rehabilitation with an immediate maxillary denture and a mandibular tooth-supported magnet-retained overdenture. Specifically:
- A 43-year old female patient presented with missing teeth in the upper back region and multiple missing teeth in the lower arch.
- For rehabilitation, the maxillary teeth were extracted and an immediate denture placed. In the mandible, several teeth were prepared to receive magnetic attachments or copings.
- At the insertion appointment, the remaining maxillary teeth were extracted and the denture was relined. In the mandible, magnets were incorporated into the overdenture to attach it to the prepared teeth.
Arrangement of teeth in class 2 relationRohan Vadsola
This document discusses the arrangement of teeth for patients with a Class 2 malocclusion. Key points include:
- Teeth are arranged with a pronounced horizontal overlap in the front and canines positioned more posterior and lingually compared to a normal bite.
- Posterior teeth on the lower jaw may be trimmed or a premolar removed due to reduced space. Teeth with shallow inclines are selected to reduce stress.
- The upper premolars are tilted lingually and lower premolars buccally to provide stable contact between the arches.
- An atypical posterior tooth arrangement is described that provides natural positioning, a lingual contact concept of occlusion, and lever balance favorable for the compromised
An occlusal splint is a removable dental appliance that covers the biting surfaces of the teeth in one dental arch. There are several types of occlusal splints classified based on their design and intended use. The main types include permissive splints, non-permissive splints, and anterior repositioning splints. Occlusal splints are used to treat temporomandibular joint disorders by relaxing the jaw muscles, supporting the jaw in an optimal position, and reducing forces on the teeth and jaw joints.
The temporomandibular joint (TMJ) is a bilateral joint that connects the mandible to the temporal bone. It has several unique characteristics, including being the only joint with a rigid endpoint of closure. The TMJ has bony, fibrous, and muscular components that allow for hinge, protrusive, and lateral movements. Prosthodontic treatments must consider the anatomy and biomechanics of the TMJ.
The document discusses articulators, which are mechanical instruments that represent the temporomandibular joints and jaws. Articulators have evolved over time from simple plaster models to more advanced instruments. They serve several purposes, including holding dental casts to simulate jaw movements for diagnosing occlusion and fabricating dental restorations. The document outlines the classification of articulators according to different systems, requirements of articulators, and their uses in prosthodontic treatment.
This document discusses various techniques for making impressions for complete dentures. It covers topics like border molding, anatomical considerations for different ridge types, and specialized techniques for resorbed or flabby ridges. For resorbed mandibular ridges, techniques discussed include the conventional, functional, elastomeric, admix, cocktail, and modified functional impression techniques. For flabby ridges, the mucodisplacive and mucostatic impression principles are covered, as well as the one part impression and controlled lateral pressure techniques. The document provides details on selecting the appropriate impression material and technique based on a patient's clinical situation.
There are different types of soft liners used in dentistry including acrylic and silicone materials that can be cold-cured or heat-cured. Cold-cured acrylic liners are temporary while heat-cured acrylic and silicone liners are more permanent. Acrylic liners are more resilient initially but can harden over time while silicone liners remain softly permanently but are more prone to water sorption and bond degradation. Proper manipulation and curing of the soft liners is required to achieve a good fit when relining dentures.
A veneer is a thin restoration placed over tooth surfaces to improve aesthetics or protect damage. Veneers have a translucent quality giving a natural look. Tooth preparation is minimal, reducing enamel by 0.3-0.5mm with a close finish line. Impressions are taken and a try-in ensures proper fit before cementing. Follow-up appointments evaluate tissue response and margins while maintaining good oral hygiene protects the veneers. Bonding uses a micromechanical bond with hydrophilic resins to cement the veneers securely in place.
Attachments in removable partial prosthesishamide norouzi
An attachment is a connector used in removable and fixed prosthodontics that consists of two parts: a female part attached to a tooth, implant, or ridge that acts as a retainer, and a male part attached to the prosthesis. Attachments are classified based on their location, fabrication method, retention mechanism, and degree of movement allowed. Key factors to consider when selecting an attachment include the condition of the abutment teeth and ridge, space available, and the patient's dexterity. Common attachment types include intracoronal, extracoronal, stud, bar, and telescopic attachments.
The document describes the key laboratory procedures for fabricating a removable partial denture (RPD) in 8 steps:
1) Duplicating the stone cast and creating an investment cast
2) Waxing the RPD framework using preformed patterns or wrought wire
3) Spruing the waxed framework
4) Investing and burning out the sprued pattern
5) Casting the framework in metal using centrifugal force
6) Removing the casting from the investment
7) Finishing and polishing the framework, including electropolishing
8) Trying in the framework on the patient
It also explains that a work authorization delineates responsibilities and ensures quality control by providing instructions
This document discusses different types of dental ceramics, including their composition, fabrication methods, advantages, and disadvantages. It categorizes currently available all-ceramic dental materials based on their fabrication method into: conventional ceramics, castable ceramics, pressable ceramics, infiltrated ceramics, and machinable ceramics. For each category, specific materials are described along with details about their chemistry, production process, properties and clinical applications.
This document discusses all-ceramic dental restorations, specifically zirconia. It provides an overview of zirconia, including that it is a crystalline dioxide of zirconium that is superior to other ceramics due to its high strength and esthetics. Applications of zirconia include crowns, bridges, implant fixtures, abutments and prostheses. The document concludes that zirconia combined with porcelain veneers is well-suited for replacing anterior teeth and full-contour zirconia can replace posterior teeth, and resin cement provides excellent adhesion.
Cements and Adhesives For All Ceramic RestorationsAndres Cardona
This document discusses dental cements and adhesives for all-ceramic restorations. It provides an overview of different types of cements including:
- Resin-based cements which have become popular due to their ability to bond to tooth structures and restorations. They can be conventional, requiring a separate bonding agent, or self-adhesive.
- Zinc phosphate and glass ionomer cements which have disadvantages like solubility, lack of adhesion, and low mechanical strength that make them less suitable for all-ceramic restorations.
- The document focuses on resin-based cements and their role in the clinical success of all-ceramic treatments due to bonding mechanisms and ability to
This document provides an overview of CAD/CAM technology in prosthodontics. It discusses the history of CAD/CAM, including early pioneers like Duret, Moermann, and Andersson. The general principles of CAD/CAM systems are explained, including the three main components: scanners to digitize teeth, design software, and processing devices like 3-5 axis milling machines. Common techniques like subtractive milling and additive 3D printing are also summarized. Overall, the document serves as an introduction to CAD/CAM systems and how they have revolutionized dental prosthesis fabrication.
The document provides an overview of a lecture on the optical properties of ceramics. It discusses how light interacts with objects through reflection, absorption, and transmission. It defines transparency, translucency, and opacity. Specific optical phenomena in ceramics like scattering, opalescence, and fluorescence are also examined. The lecture then explores color parameters in ceramics and how their optical properties can be manipulated through composition and processing.
This document provides information on wax patterns for dental restorations. It discusses the types and properties of dental waxes used for wax patterns, including composition, flow properties and ideal requirements. It also describes techniques for fabricating wax patterns, including additive and subtractive methods, developing axial contours and occlusal morphology, and finishing margins. The goal of the wax pattern is to define the final shape and size of the dental restoration that will be produced using the lost wax casting technique.
Evolution of all ceramics&recent advances (2)/ dental coursesIndian dental academy
This document provides an overview of the evolution and recent advances in all-ceramic dental materials. It discusses early ceramic materials like denture teeth and porcelain jacket crowns, as well as more recent developments like alumina core porcelain, In-Ceram, castable ceramics like Di-Cor and Cerestore, and machinable ceramics created using CAD/CAM systems. The document also covers methods used to strengthen ceramics and details production processes for various all-ceramic systems.
Prosthetic Management of Acquired Maxillary DefectsAamir Godil
This document discusses maxillofacial defects and obturators. It begins by describing different types of maxillofacial defects, including those of the maxilla, mandible, palate, and other areas. It then focuses on defects of the maxilla, covering anatomical considerations and classifications of acquired maxillary defects. The document outlines different classes of maxillectomy defects based on the relationship to remaining teeth. Finally, it discusses obturators, including background, classifications, types including surgical, interim and definitive obturators, and fabrication procedures. The overall document provides an overview of maxillofacial defects and classifications of obturators used to treat defects following surgery.
The document discusses dental ceramics and provides information on their history, composition, classification, and applications. Key points include:
- Ceramics are inorganic compounds consisting of oxygen and metallic/semimetallic elements used to make dental prosthetics.
- Their composition typically includes feldspar, silica, kaolin, and alumina, with glass modifiers and opacifiers added.
- Ceramics can be classified based on firing method/temperature, type of material, and microstructure.
- Common ceramic systems include metal-ceramic and all-ceramic, with the former using a metal substructure and the latter being made entirely of ceramic.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This document discusses various methods used to analyze occlusal contacts, including articulating paper, film, spray, and T-Scan system. Articulating paper is most common but has limitations like being affected by saliva and producing pseudo markings. Articulating film provides more precise markings. T-Scan system can record contact sequence and distribution over time. Virtual dental patient and 3D modeling also allow quantitative assessment of occlusion over time. Choice of indicator depends on need for qualitative vs. quantitative data and environment. Proper indicator use and understanding limitations is important for accurate analysis of occlusal contacts.
Journal club presentation on tooth supported overdentures NAMITHA ANAND
This document presents a case report of a full mouth rehabilitation with an immediate maxillary denture and a mandibular tooth-supported magnet-retained overdenture. Specifically:
- A 43-year old female patient presented with missing teeth in the upper back region and multiple missing teeth in the lower arch.
- For rehabilitation, the maxillary teeth were extracted and an immediate denture placed. In the mandible, several teeth were prepared to receive magnetic attachments or copings.
- At the insertion appointment, the remaining maxillary teeth were extracted and the denture was relined. In the mandible, magnets were incorporated into the overdenture to attach it to the prepared teeth.
Arrangement of teeth in class 2 relationRohan Vadsola
This document discusses the arrangement of teeth for patients with a Class 2 malocclusion. Key points include:
- Teeth are arranged with a pronounced horizontal overlap in the front and canines positioned more posterior and lingually compared to a normal bite.
- Posterior teeth on the lower jaw may be trimmed or a premolar removed due to reduced space. Teeth with shallow inclines are selected to reduce stress.
- The upper premolars are tilted lingually and lower premolars buccally to provide stable contact between the arches.
- An atypical posterior tooth arrangement is described that provides natural positioning, a lingual contact concept of occlusion, and lever balance favorable for the compromised
An occlusal splint is a removable dental appliance that covers the biting surfaces of the teeth in one dental arch. There are several types of occlusal splints classified based on their design and intended use. The main types include permissive splints, non-permissive splints, and anterior repositioning splints. Occlusal splints are used to treat temporomandibular joint disorders by relaxing the jaw muscles, supporting the jaw in an optimal position, and reducing forces on the teeth and jaw joints.
The temporomandibular joint (TMJ) is a bilateral joint that connects the mandible to the temporal bone. It has several unique characteristics, including being the only joint with a rigid endpoint of closure. The TMJ has bony, fibrous, and muscular components that allow for hinge, protrusive, and lateral movements. Prosthodontic treatments must consider the anatomy and biomechanics of the TMJ.
The document discusses articulators, which are mechanical instruments that represent the temporomandibular joints and jaws. Articulators have evolved over time from simple plaster models to more advanced instruments. They serve several purposes, including holding dental casts to simulate jaw movements for diagnosing occlusion and fabricating dental restorations. The document outlines the classification of articulators according to different systems, requirements of articulators, and their uses in prosthodontic treatment.
This document discusses various techniques for making impressions for complete dentures. It covers topics like border molding, anatomical considerations for different ridge types, and specialized techniques for resorbed or flabby ridges. For resorbed mandibular ridges, techniques discussed include the conventional, functional, elastomeric, admix, cocktail, and modified functional impression techniques. For flabby ridges, the mucodisplacive and mucostatic impression principles are covered, as well as the one part impression and controlled lateral pressure techniques. The document provides details on selecting the appropriate impression material and technique based on a patient's clinical situation.
There are different types of soft liners used in dentistry including acrylic and silicone materials that can be cold-cured or heat-cured. Cold-cured acrylic liners are temporary while heat-cured acrylic and silicone liners are more permanent. Acrylic liners are more resilient initially but can harden over time while silicone liners remain softly permanently but are more prone to water sorption and bond degradation. Proper manipulation and curing of the soft liners is required to achieve a good fit when relining dentures.
A veneer is a thin restoration placed over tooth surfaces to improve aesthetics or protect damage. Veneers have a translucent quality giving a natural look. Tooth preparation is minimal, reducing enamel by 0.3-0.5mm with a close finish line. Impressions are taken and a try-in ensures proper fit before cementing. Follow-up appointments evaluate tissue response and margins while maintaining good oral hygiene protects the veneers. Bonding uses a micromechanical bond with hydrophilic resins to cement the veneers securely in place.
Attachments in removable partial prosthesishamide norouzi
An attachment is a connector used in removable and fixed prosthodontics that consists of two parts: a female part attached to a tooth, implant, or ridge that acts as a retainer, and a male part attached to the prosthesis. Attachments are classified based on their location, fabrication method, retention mechanism, and degree of movement allowed. Key factors to consider when selecting an attachment include the condition of the abutment teeth and ridge, space available, and the patient's dexterity. Common attachment types include intracoronal, extracoronal, stud, bar, and telescopic attachments.
The document describes the key laboratory procedures for fabricating a removable partial denture (RPD) in 8 steps:
1) Duplicating the stone cast and creating an investment cast
2) Waxing the RPD framework using preformed patterns or wrought wire
3) Spruing the waxed framework
4) Investing and burning out the sprued pattern
5) Casting the framework in metal using centrifugal force
6) Removing the casting from the investment
7) Finishing and polishing the framework, including electropolishing
8) Trying in the framework on the patient
It also explains that a work authorization delineates responsibilities and ensures quality control by providing instructions
This document discusses different types of dental ceramics, including their composition, fabrication methods, advantages, and disadvantages. It categorizes currently available all-ceramic dental materials based on their fabrication method into: conventional ceramics, castable ceramics, pressable ceramics, infiltrated ceramics, and machinable ceramics. For each category, specific materials are described along with details about their chemistry, production process, properties and clinical applications.
This document discusses all-ceramic dental restorations, specifically zirconia. It provides an overview of zirconia, including that it is a crystalline dioxide of zirconium that is superior to other ceramics due to its high strength and esthetics. Applications of zirconia include crowns, bridges, implant fixtures, abutments and prostheses. The document concludes that zirconia combined with porcelain veneers is well-suited for replacing anterior teeth and full-contour zirconia can replace posterior teeth, and resin cement provides excellent adhesion.
Cements and Adhesives For All Ceramic RestorationsAndres Cardona
This document discusses dental cements and adhesives for all-ceramic restorations. It provides an overview of different types of cements including:
- Resin-based cements which have become popular due to their ability to bond to tooth structures and restorations. They can be conventional, requiring a separate bonding agent, or self-adhesive.
- Zinc phosphate and glass ionomer cements which have disadvantages like solubility, lack of adhesion, and low mechanical strength that make them less suitable for all-ceramic restorations.
- The document focuses on resin-based cements and their role in the clinical success of all-ceramic treatments due to bonding mechanisms and ability to
This document provides an overview of CAD/CAM technology in prosthodontics. It discusses the history of CAD/CAM, including early pioneers like Duret, Moermann, and Andersson. The general principles of CAD/CAM systems are explained, including the three main components: scanners to digitize teeth, design software, and processing devices like 3-5 axis milling machines. Common techniques like subtractive milling and additive 3D printing are also summarized. Overall, the document serves as an introduction to CAD/CAM systems and how they have revolutionized dental prosthesis fabrication.
The document provides an overview of a lecture on the optical properties of ceramics. It discusses how light interacts with objects through reflection, absorption, and transmission. It defines transparency, translucency, and opacity. Specific optical phenomena in ceramics like scattering, opalescence, and fluorescence are also examined. The lecture then explores color parameters in ceramics and how their optical properties can be manipulated through composition and processing.
This document provides information on wax patterns for dental restorations. It discusses the types and properties of dental waxes used for wax patterns, including composition, flow properties and ideal requirements. It also describes techniques for fabricating wax patterns, including additive and subtractive methods, developing axial contours and occlusal morphology, and finishing margins. The goal of the wax pattern is to define the final shape and size of the dental restoration that will be produced using the lost wax casting technique.
Evolution of all ceramics&recent advances (2)/ dental coursesIndian dental academy
This document provides an overview of the evolution and recent advances in all-ceramic dental materials. It discusses early ceramic materials like denture teeth and porcelain jacket crowns, as well as more recent developments like alumina core porcelain, In-Ceram, castable ceramics like Di-Cor and Cerestore, and machinable ceramics created using CAD/CAM systems. The document also covers methods used to strengthen ceramics and details production processes for various all-ceramic systems.
Prosthetic Management of Acquired Maxillary DefectsAamir Godil
This document discusses maxillofacial defects and obturators. It begins by describing different types of maxillofacial defects, including those of the maxilla, mandible, palate, and other areas. It then focuses on defects of the maxilla, covering anatomical considerations and classifications of acquired maxillary defects. The document outlines different classes of maxillectomy defects based on the relationship to remaining teeth. Finally, it discusses obturators, including background, classifications, types including surgical, interim and definitive obturators, and fabrication procedures. The overall document provides an overview of maxillofacial defects and classifications of obturators used to treat defects following surgery.
The document discusses dental ceramics and provides information on their history, composition, classification, and applications. Key points include:
- Ceramics are inorganic compounds consisting of oxygen and metallic/semimetallic elements used to make dental prosthetics.
- Their composition typically includes feldspar, silica, kaolin, and alumina, with glass modifiers and opacifiers added.
- Ceramics can be classified based on firing method/temperature, type of material, and microstructure.
- Common ceramic systems include metal-ceramic and all-ceramic, with the former using a metal substructure and the latter being made entirely of ceramic.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The j o i n i n g welding process used to engineeringSolomon257815
This document discusses various techniques for joining ceramics to metals, including microjoining, brazing, diffusion bonding, and electrostatic bonding. It describes the properties of ceramics and metals, challenges in joining due to differences in properties, and specific techniques used such as metallization, active metal brazing using titanium, and using interlayers to accommodate thermal expansion mismatches. Glass-metal and glass-ceramic seals are also summarized, covering bonding mechanisms, joint design, and forming the seals.
This document provides an overview of ceramics, including:
- Definitions of ceramics as inorganic, non-metallic materials formed from powders and strengthened through firing.
- Classifications based on fabrication method, crystalline phase, use, firing temperature, composition, microstructure, and properties.
- A brief history of ceramics development and uses in dentistry and other applications.
- Descriptions of microstructure, common crystalline phases, and how structure influences properties.
Glass is made by melting raw materials like sand, soda ash, and limestone in a furnace at high temperatures. It is then formed into shapes and annealed by slow cooling. Glass has various properties like being transparent, brittle, and a good insulator. Common types of glass used in construction include float glass, sheet glass, wired glass, reflective glass, insulating glass, and safety glass like laminated and toughened glass. Glass bricks are also used. Tinted glass comes in various colors and is used to control heat and glare.
The document provides information on ceramics used in dentistry. It begins with an introduction to ceramics, discussing their history and composition. Ceramics are classified according to their sintering temperature and type. Methods for strengthening brittle ceramics include ion exchange, thermal tempering, and adding dispersion phases. Metal ceramic restorations and all-ceramic restorations are also summarized. Different types of ceramics used in dentistry are described briefly, including conventional powder ceramics, infiltrated ceramics, and castable ceramics.
This document discusses dental ceramics, including their classification, composition, and uses. It addresses:
1) The different types of dental ceramics classified by use, processing method, and fusion temperature including metal ceramics, ceramic denture teeth, and porcelain for jackets, crowns, veneers and inlays.
2) The composition and function of ingredients in high fusing porcelains including feldspar, quartz, and kaolin.
3) Methods for strengthening porcelain, such as chemical strengthening, dispersion strengthening, and thermal tempering.
4) Applications of all-ceramic systems including pressed ceramics, machinable ceramics, and
This document discusses different types of ceramic materials and their applications. It describes glasses, glass-ceramics, clay products, refractories, and abrasives. Glasses are used for containers and lenses. Glass-ceramics have high strength and temperature capabilities and are used for ovenware and electronics. Clay products include bricks, tiles, and pottery. Refractories withstand high temperatures and include fireclay, silica, and basic bricks. Abrasives like silicon carbide are used for grinding and require hardness.
Metal ceramics /certified fixed orthodontic courses by Indian dental academy Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
The document discusses recent advances in all-ceramic dental materials. It describes the evolution of ceramics from early dentures to modern machinable ceramics and lists various classification systems. Key points include methods to strengthen porcelain like thermal tempering and transformation toughening, as well as minimizing stress through design. Specific ceramic systems are outlined, like aluminous core porcelain developed by McLean and Hughes in 1965 and In-Ceram, which uses a slip-casting technique to form green ceramic shapes.
This document provides an introduction and overview of ceramics. It discusses the historical development of ceramics, classifications of ceramics according to fabrication method, crystalline phase, composition, microstructure and other properties. Specific ceramic materials used in dentistry like porcelain, glass ceramics, zirconia, and resin ceramics are also covered. The document examines the structure and properties of different ceramics and their applications in dental and non-dental fields.
This document provides an overview of dental ceramics. It discusses the historical perspective of dental ceramics dating back 23,000 years. It also covers the classification, composition, properties, processing methods like condensation and firing, and advances in all-ceramic and metal-ceramic dental systems. The document contains detailed information on the composition, properties and processing of various dental ceramic materials like feldspathic porcelain, leucite-reinforced porcelain, and glass ceramics. It compares conventional powder-slurry ceramics with newer CAD/CAM and machinable ceramic materials.
Dental ceramics/ rotary endodontic courses by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training
center with best faculty and flexible training programs for dental
professionals who wish to advance in their dental practice,Offers certified
courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry,
Prosthetic Dentistry, Periodontics and General Dentistry.
Glass blocks are hollow glass units with a partial vacuum that decreases heat transmission. They come in common sizes of 6, 8, or 12 inches square and 4 inches thick. A concern is that glass blocks expand more than brick walls, requiring expansion joints. Laminated glass is a type of safety glass that holds together when shattered due to an interlayer like PVB bonding the glass layers. Toughened or tempered glass is processed to be stronger than normal glass and shatter into small fragments rather than large shards when broken.
The document summarizes key information about three materials: aluminum oxide, silicon carbide, and diamond. It discusses their crystal structures, properties like hardness and thermal conductivity, common processing methods, and applications. Aluminum oxide is used as an abrasive and refractory material. Silicon carbide is very hard and used for abrasives, armor, and power electronics. Diamond is the hardest known material and used in drilling, cutting, and jewelry due to its optical properties.
Glass and ceramics are both made from sand but have different properties. Glass is made by heating sand and cooling it rapidly, resulting in an amorphous solid structure. The most common type of glass is soda-lime glass, made by heating sand, limestone, and sodium carbonate. Adding boron oxide forms borosilicate glass, which is more heat resistant. Lead crystal glass contains lead and is used for fine glassware. Ceramics are made from clay like kaolin, which hardens permanently when heated. Ceramics are very hard, brittle, chemically inert, and resist compression, making them suitable for uses like pottery, tiles, and electrical insulators.
Glass is a non-crystalline solid made primarily from silica sand, soda ash, and limestone. The most common type of glass is soda-lime glass, composed of around 75% silica. Glass was first developed around 6000 years ago and its properties are still not fully understood. It can be produced in different colors by adding various metal oxides as impurities. Ceramics are materials made from clay and other minerals like quartz, feldspar, and alumina. Traditional ceramics include pottery, bricks, and tiles, while new ceramics have superior mechanical properties. Glasses have a non-crystalline structure and silica-based window glass is the clearest example
The document discusses the biocompatibility of dental materials. It defines biocompatibility as materials being harmonious with life and not having toxic or injurious effects on biologic functions. Any material used in the body for any period of time as part of a medical treatment is considered a biomaterial. Standards and regulations from organizations like the FDA and ISO have been introduced to ensure the biocompatibility and safety of dental materials. A variety of tests are used to evaluate the biocompatibility of new materials, including primary tests, secondary tests, and usage tests. Chronic exposure to beryllium can cause berylliosis, a serious lung disease, so protective masks and gloves should be worn when working with b
The document discusses connectors in fixed partial dentures. Connectors are defined as the portion of a fixed dental prosthesis that unites the retainers and pontics. Connectors must be sufficiently strong, elliptical in cross-section, and placed as lingually and incisally as possible in anterior teeth and in the occlusal third for posterior teeth. Rigid connectors include cast, soldered, and loop connectors while non-rigid connectors allow limited movement and include dovetail, split, and cross-pin connectors. Soldering techniques such as torch, oven, laser, and infrared soldering are described for joining connectors along with considerations for solder composition and properties.
This document discusses principles of tooth preparation for prosthodontic treatment. It defines tooth preparation as mechanical treatment of hard dental tissues to restore a tooth to its original form. The key principles discussed are preservation of tooth structure, achieving retention and resistance form, and maintaining structural durability and marginal integrity of restorations. Factors that influence retention and resistance form, such as taper, surface area, and path of insertion are also examined.
The document discusses the biocompatibility of dental materials. It defines biocompatibility as materials being harmonious with life and not having toxic or injurious effects on biologic functions. Any material used in the body for any period of time to treat, augment or replace tissue or organs is considered a biomaterial. Standards for evaluating biocompatibility include primary, secondary and usage tests. Ensuring biocompatibility of dental materials is important for preventing adverse reactions like allergic responses.
Teeth selection for complete dentures involves considering several factors to ensure function and aesthetics. Size is based on facial measurements and residual ridge contours. Form depends on facial profile, sex, age and personality. Color should harmonize with complexion. Anterior teeth material is typically porcelain or acrylic. Posterior teeth shade matches anterior teeth and form depends on occlusion type. Anatomic teeth are more aesthetic but non-anatomic teeth are more comfortable in resorbed ridges. Proper teeth selection improves denture function and patient confidence.
The document discusses abrasives and polishing agents used in dentistry. It describes the benefits of finishing and polishing dental restorations, including promoting oral hygiene, enhancing oral function, and improving esthetics. It also defines abrasion and different types of abrasives, including natural and manufactured abrasives. The document outlines different techniques for finishing and polishing, including using abrasive grits, bonded abrasives, coated abrasive disks and strips, as well as non-abrasive polishing methods. Recent advancements in polishing techniques are also mentioned.
This document discusses various techniques for making impressions for removable partial dentures with distal extensions, including:
1. McLean's technique and Hindel's technique, which are physiologic impression methods that involve making an initial impression under finger pressure and a secondary impression.
2. The functional relining technique, which involves adding new material to the inner side of an existing denture base to improve fit after bone resorption.
3. The fluid wax technique, which uses a wax that flows at mouth temperature to record tissue contours over time as the impression is seated.
4. The selective pressure technique, which uses different impression materials and visual determination of complete seating to record areas under and not under pressure.
The document provides guidance on taking a case history for a completely edentulous patient. It outlines the importance of collecting personal data like name, age, sex, address, occupation, chief complaint, medical history, dental history, and psychosocial status. A thorough case history helps the dentist arrive at a probable diagnosis and treatment plan that considers the patient's general health, lifestyle factors, and expectations.
This document provides guidelines for writing a thesis or dissertation. It discusses defining research and the difference between a thesis and dissertation. Key parts of a thesis are described such as the introduction, literature review, materials and methods, results, discussion, and conclusion sections. The document emphasizes following university guidelines and formatting standards. It also provides advice on choosing a topic, conducting research, acknowledging help, and submitting the final thesis. Overall, the document serves as a comprehensive guide outlining the essential components and process for writing a successful thesis or dissertation.
This document discusses gingival retraction and impression making techniques. It describes gingival retraction as deflecting or displacing the gingiva from the tooth to record the margins. Various gingival retraction methods are covered, including mechanical retraction cords, electrosurgery, and newer cordless techniques using materials like Expasyl and Magic Foam. Key steps for making good impressions are also outlined, such as selecting the proper tray and impression material and evaluating the resulting impression. The conclusion emphasizes choosing a gingival retraction method suited to the clinical situation while prioritizing tissue health and patient comfort.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Kat...rightmanforbloodline
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
TEST BANK For Basic and Clinical Pharmacology, 14th Edition by Bertram G. Katzung, Verified Chapters 1 - 66, Complete Newest Version.
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
TEST BANK For An Introduction to Brain and Behavior, 7th Edition by Bryan Kol...rightmanforbloodline
TEST BANK For An Introduction to Brain and Behavior, 7th Edition by Bryan Kolb, Ian Q. Whishaw, Verified Chapters 1 - 16, Complete Newest Versio
TEST BANK For An Introduction to Brain and Behavior, 7th Edition by Bryan Kolb, Ian Q. Whishaw, Verified Chapters 1 - 16, Complete Newest Version
TEST BANK For An Introduction to Brain and Behavior, 7th Edition by Bryan Kolb, Ian Q. Whishaw, Verified Chapters 1 - 16, Complete Newest Version
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Cell Therapy Expansion and Challenges in Autoimmune DiseaseHealth Advances
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
3. CONTENTS
• INTRODUCTION-BASIC TERMINOLOGIES
• HISTORICAL PERSPECTIVE
• COMPOSITION AND CLASSIFICATION
• STRUCTURE
• PORCELAIN CONDENSATION
• SINTERING
• BONDING PORCELAIN TO METAL
• METHODS OF STRENGTHENING CERAMICS
• FINISHING AND POLISHING OF PORCELAINS
16 August 2022 3
4. • ALLOYS FOR METAL CERAMIC RESTORATIONS
• FACTORS AFFECTING COLOR
• PROPERTIES
• RECENT ADVANCES IN CERAMICS
• SUMMARY AND CONCLUSION
• BIBLIOGRAPHY
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18. Composition of dental ceramics
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Feldspar (60 -80 %)
is a naturally occurring mineral and composed of
two alkali aluminum silicates such as potassium
aluminum silicate (K2O-Al2O3-6SiO2); also called
as potash feldspar or ortho clase and soda
aluminum silicate (Na2O-Al2O3- 6SiO2); also
called as soda feldspar or albite .
It is the lowest melting compound and melts
first on firing.
Most of the currently available porcelains
contain potash feldspar as it imparts translucency
to the fired restoration.
19. 16 August 2022
QUARTZ:or silica –12-25%
• It is a high fusing material forms the
framework around which the other
ingredients flow. Acts as REFRACTORY
MATERIAL. IT prevents the slumping of
the crown during the liquid phase.
20. • ALUMINA: Many European tooth
manufacturers use alumina in place of silica to
strengthen the teeth, especially around the
pins.
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21. 16 August 2022
KAOLIN:0-4%
• Kaolin is a type of clay material which is usually
obtained from igneous rock containing alumina.
Kaolin acts as a binder and increases the moldability
of the unfired porcelain.
• It also imparts opacity to the porcelain restoration so
dental porcelains are formulated with limited quantity
of kaolin.
22. 16 August 2022
FLUXES:
• Potassium, lithium, sodium and calcium oxide and
boric acid are used as fluxes by interrupting the
integrity of the SiO4 network, and lower the
softening temperature of a glass by reducing the
amount of cross linking between silica and oxygen
The O: Si ratio in a glass is of greatest importance and
increasing this ratio will cause reduced viscosity,
lowered fusion temperature and increased thermal
expansion.
23. 16 August 2022
COLORING AGENTS:
The coloring pigments added to porcelain are known
as color frit.
These are prepared by fritting metallic oxides into
the basic glass used in porcelain. Some of the
common colors used are:
• Pink : Tin chromium or chroma alumina
• Yellow : Indium or praesmodyium
• Blue : Cobalt salt
• Green : Chromium oxide
• Grey : Iron oxide or platinum
24. 16 August 2022
OPACIFYING AGENT :
• translucency …..metal oxide ….refractive index .
…..melting point
FLUORESCENCE :
• The natural teeth possess a yellow white fluorescence,
Eg.the uranium salt, sodium di urinate.
This salt produces a strong greenish-yellow color.
Radiation hazards of including uranium.
So lanthanide oxide is used
26. CERAMIC MANUFACTURING--
Fritting:
• The term frit is used to describe the final glass
product.
• The raw mineral powders are mixed together in
a refractory crucible and heated to a
temperature well above their ultimate maturing
temperature.
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27. • The oxides melt together to form a molten
glass, gases are allowed to escape and
the melt is then quenched in water.
•
• The red hot glass striking the cold water
immediately breaks up into fragments and
this is termed as ‘frit’.
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29. Ceramics can be classified by their Microstructure
(i.e., amount and type of crystalline phase and glass
composition).
They can also be classified by the Processing
technique (power-liquid, pressed or machined).
CLASSIFICATION
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30. MICROSTRUCTURAL CLASSIFICATION
At the microstructural level, There can be infinite
variability of the microstructures of materials, but they can be
broken down into four basic compositional categories, with a
few subgroups:
composition category 1 – glass-based systems (mainly
silica),
composition category 2 – glass-based systems (mainly
silica) with fillers, usually crystalline (typically leucite or, more
recently, lithium disilicate),
composition category 3 – crystalline- based systems with
glass fillers (mainly alumina) and
composition category 4 – polycrystalline solids (alumina
and zirconia).
16 August 2022
31. CLASSIFICATION
II.ACCORDING TO FIRING TEMPERATURE:
• High fusing : 1300 degree centigrade
• Medium fusing : 1101-1300 degree “
centigrade
• Low fusing : 850-1100 deg.centi
• Ultra low fusing :< 850 degree centigrade
16 August 2022
35. STRUCTURE
Dental porcelains
contain a crystal phase
and glass phase based
on the silica structure.
This structure is
characterized by the Si-
O tetrahedron in which
a Si 4+ cation is
positioned at the center
of a tetrahedron with O-
anions at each four
corners
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38. PORCELAIN CONDENSATION
Porcelain is supplied as a fine powder that is
designed to be mixed with DISTILLED water or
another vehicle and condensed to desired form.
16 August 2022
50. SINTERING OF PORCELAIN
The purpose of firing is simply to fuse the particles
together, a process called sintering.
The condensed porcelain mass is placed …..
Preheating for 5 min …. rapid production of steam
16 August 2022
54. • The fewer the firing cycles to which the
restoration is exposed, the higher will be the
strength and better the esthetics.
• Minimum of three firings are needed for
fabrication of ceramometal restoration:
• Porcelain shrinks 30-40 % during firing-
oversize the buildup.
16 August 2022
56. Porcelain for PFM are fired under vacuum thus as the
furnace door closes the pressure is lowered to 0.1
atmosphere and the temp is raise until firing tempo
is reached .
The vacuum is then released and the furnace pressure
returns to 1 atm- Dense pore free porcelain.
16 August 2022
57. GLAZING
• After porcelain is cleaned required stains
are applied and porcelain returned to
furnace for final glaze firing.
• When the glazing temp is reaches a thin
glassy film( glaze) is formed by viscous
flow on the porcelain surface.
• Glazed porcelain is stronger than unglazed.
• Glaze is effective in reducing crack
propagation.
• If glaze is removed by grinding transverse
strength is reduced to half.
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59. Two types of glazes :
• Over glaze
• Self glaze.
• Porcelains may be characterized with stains and
glazes to provide a more life like appearance.
• One method of ensuring that the stains remain
permanently is by incorporating the stains internally
16 August 2022
60. COOLING:
• Must be carried out gradually and uniformly.
• Too rapid – surface cracking and loss of strength
• Too slow- might induce formation of additional
leucite. Increased the overall coefficient of thermal
expansion cracking, crazing.
• Less is the no of firing higher is the strength and
better the esthetics. Too many firing cycles – lifeless
over translucent porcelain.
16 August 2022
61. BONDING PORCELAIN TO
METAL
The primary requirement for ……
• The nature of bond can be divided into three main
components:
• Mechanical
• Compressive
• Chemical
16 August 2022
62. Mechanical:
• It is dependent upon good wetting of the metal or
metal oxide surface by porcelain. It is improved
by a textured surface.
• A rough surface may enhance the bond resistance
against induced shear stresses, especially for base
metal alloys. E.g.: air abrasion.
Advantages:
• Enhances wettability
• Additive bond strength
• Increased surface area
16 August 2022
63. COMPRESSIVE BONDING
• Ceramo-metal systems are deliberately
designed with a very small degree of
mismatch in order to leave the porcelain
in a state of compression.
16 August 2022
64. • When dental porcelain is fired onto metal with a
definite oxide (indium, tin or zinc oxide) layer, the
oxygen surface of the molten glass diffuses within
the oxygen surface on the metal to reduce then no.
of bridging oxygen and thus improves the
screening of cations at the interface
16 August 2022
CHEMICAL BONDING:
65. Procedure of oxide forming : -- --Preheating
The metal is degassed by heating at 1000
degrees in vacuum for around 10 min and then
slowly air cooled in normal atmosphere. This
procedure will:
Degas the casting.
Induce age hardening of the alloy.
Base metal atoms will diffuse onto the
surface to form an oxide film.
: 16 August 2022
71. • Develop residual compressive stresses
• Minimize the number of firing cycles
• Minimize tensile stress through optimal
design of ceramic prosthesis
16 August 2022
72. Ion Exchange—small alkali ions to large
ions produce compressive force leading to
strengthening
16 August 2022
74. • Dispersion strengthening
--This is reinforcement with a dispersed phase of
a different material that is capable of hindering
a crack from propagating through the material
16 August 2022
76. ABRASIVENESS OF DENTAL CERAMICS
• Abrasive wear mechanisms for ceramics and tooth
enamel are predominantly due to micro fracture
which results from gouging, asperities, impact, and
contact stresses that cause cracks or localized
fracture.
• Steps to minimize wear:
Ensure cuspid guided disclusion
Eliminate occlusal prematurities
Use metal in functional bruxing areas
If occlusion in ceramic, use ultralow fusing ceramics
Polish functional ceramic surfaces
Repolish ceramic surfaces periodically
Readjust occlusion periodically if needed.
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77. • 1. Contour with flexible diamond disks,
diamond burs, heatless stones or green
stones (Silicone carbide)
• 2. Finish with white stones or abrasive
impregnated rubber disks, cups or points.
• 3. Polish with fine impregnated rubber
cups, and points or diamond paste applied
with a brush
• 4. Apply an over glaze layer.
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78. ALLOYS USED FOR METAL-CERAMIC
RESTORATIONS
1.HIGH NOBLE:
Gold-platinum-palladium
Gold palladium-silver
Gold-palladium
3.PREDOMINANTLY BASE
Nickel-chromium
Nickel-chromium-beryllium
Cobalt-chromium
2.NOBLE:
Palladium-silver
High palladium
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80. FACTORS AFFECTING THE COLOR
OF CERAMICS:
The three dimensions of color:
• Hue: dominant color of an object,
wavelength
• Chroma: saturation
• Value: lightness or darkness
….independent of hue
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81. • Metamerism: objects that appear to be color matched
under one type of light appear different under
another light source
• Fluorescence: the property of an object to emit light
of different wavelength than the one incident upon
it
• In the dental operatory or laboratory color matching
is usually performed by the use of shade guide.
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84. • Dentin is more opaque than enamel and will
reflect light.. pale yellow in color
• Enamel……crystalline……. different refractory
indices at the incisal region ….bluish white
(thick) at cervical margin-yellow (thin. reflects
color of underlying dentin)
• …..Translucence……DEPTH
• “
16 August 2022
85. PROPERTIES
VARIOUS Restorative materials at our disposal:
1.Metals- have high tensile strength, toughness,
hardness, resistance to abrasion, fracture resistance,
elasticity, ductility, fatigue resistance poor
aesthetics
2.Polymers-inferior in most of these properties---
BRITTLE FRACTURE
3.Composites-BRITTLE FRACTURE -superb aesthetics
4.Ceramics-No ductility, high compressive strength,
low shear and tensile strengths excellent aesthetics
16 August 2022
86. MECHANICAL PROPERTIES
• COMPRESSIVE STRENGTH:
-- Maximal stress required to fracture a
structure under compression.
Enamel :37,800 psi
Dentin : 44,200 psi
Porcelain : 25,000 psi
• TENSILE STRENGTH:
• Maximal stress required to fracture a structure
under tension.
Porcelain: 5,000 psi
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87. HARDNESS (KHN):
Enamel: 343 (KHN)
Dentin: 068 “
Porcelain: 460 “
FLEXURAL STRENGTH (BENDING STRENGTH OR
MODULOUS OF RUPTURE):
-- Force per unit area at the point of fracture of a test
specimen subjected to flexural loading.
• Feldspathic porcelain : 141 MPa
• Aluminous porcelain : 139 MPa
• IPS Empress2 : 400 MPa
• Gold alloy : 350-600 MPa
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88. • FRACTURE TOUGHNESS: total energy per unit
volume to fracture the alloy
--Feldspathic porcelain: 0.9-1.5 MPa.m1/2
---Aluminous porcelain: 2-2.9
---Yttria stabilized zirconia: 9
----Gold alloy: 20
----- Enamel: 0.7
------IPS Empress2: 3.3
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89. THERMAL PROPERTIES
THERMAL COEFFICIENT OF EXPANSION:(
mm/mm.K)*10-6
------Change in unit length per unit rise in
temperature
Tooth : 11.4
Low fusing ceramic: 12.2-15.8
IPS Empress 2: 10.6
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90. • THERMAL CONDUCTIVITY (cal.cm/cm2.sec.C):
Ability of a body to transfer energy
• Enamel: 0.0022
• Dentin: 0.0015
•Porcelain: 0.0030
THERMAL DIFFUSIVITY (cm2/sec):
Enamel: 0.0042
Dentin: 0.0026
Porcelain: 0.64
• “
16 August 2022
91. • MODULOUS OF ELASTICITY-- elastic deformation
before they rupture
Porcelain: 69GPa
Type IV gold alloy: 99.3 GPa
Composite: 16.6Gpa
• Because of their moderately high m of elasticity and
relatively low tensile strength porcelains can undergo
very little elastic deformation (0.1%) before they
rupture i.e., they are not flexible
16 August 2022
93. 1.METAL CERAMIC CROWNS BASED ON BURNISHED
FOIL COPINGS: THE CAPTEK SYSTEM
• Malleable Captek metal strips are burnished on a
refractory die to fabricate the metal coping of a metal
ceramic crown without the use of a melting and casting
process.
• The finished metal coping may be described as a
composite material consisting of a gold matrix reinforced
with small particles of a Pt-Pd-Au alloy.
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95. 16 August 2022
The units are then veneered with two thin layers of
opaque porcelain and other veneering porcelains.
The Captek coping has a thickness of 0.25 mm which
is half of the traditional cast metals thus providing
additional space for vennering porcelain.
96. 2.CASTABLE GLASS CERAMICS : DICOR
Dicor is a castable glass (55% tetraflurosilicic mica crystals) that
is formed into an inlay, facial veneer or full crown
restoration by a lost wax casting process……..
, it is covered by a protective embedment material and subjected
to heat treatment that causes mica to grow within the glass
matrix. This process is called CERAMMING.
Then it is fit on dies, ground as necessary and coated with
veneering porcelain.
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99. • ADV:
Ease of fabrication
Improved esthetics-chameleon effect
Minimal shrinkage
Good marginal fit
High flexural strength
Low thermal expansion
Minimal abrasiveness of enamel
• DISADV:
Limited use in low stress areas (Low tensile
strength)
Inability to be colored internally
16 August 2022
100. 3.PRESSABLE GLASS CERAMICS (IPS EMPRESS):
Provided as core ingots that are heated and pressed until
the ingot flows into a mold.
It contains a higher proportion of leucite crystals that increase
resistance to crack propagation.
The hot pressing process occurs over a 45 min period at high
temperature to produce the ceramic substructure.
The crown form can be either stained and glazed or built up
using a conventional layering technique.
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103. ADV:
Lack of metal
Translucent ceramic core
High flexural strength
Excellent fit
Excellent esthetics
DISADV:
-- Potential to fracture in
posterior areas
-- Need to use resin cement
16 August 2022
104. 4.INFILTRATED CERAMICS (INCERAM):
– Available as two component system:
– Powder: alumina/spinell/zirconia
• - Low viscosity glass
A slurry of the powder is slip cast on a refractory die and heated in
a furnace at 1120 degree centigrade for 10 hrs and then it is
infiltrated with the low viscosity glass at 1100 degree centigrade for
4 hrs to eliminate porosity and to strengthen the slip cast core.
• ADV:
– Lack of metal substructure
– High flexural strength
– Excellent fit
• DISADV:
Opacity
Special die material and high temperature oven is required
Have abrasive properties
16 August 2022
108. 5.CAD –CAM CERAMICS
(PROCERA, CEREC, CELAY, DICOR MGC):
It stands for Computer aided design/Computer aided
manufacturing.
It is supplied as ceramic ingots available in various
shades. These are placed in a machinable apparatus to
produce the desired contours.
This machined restoration is checked for fit on the
tooth.
Occlusal adjustment is done followed by polishing,
etching and bonding the restoration to the prepared
tooth.
16 August 2022
120. SUMMARY & CONCLUSION
Considerable advances in the field of dental ceramics has
brought forth novel processing technologies which have enhanced
the properties and clinical acceptability of these materials.
Yet, these have yet again highlighted our inability to
comprehend its greatest deficiencies, i.e., inadequate tensile
strength and brittleness.
It is this challenge to the upcoming prosthodontists that
ceramics beckons, and to which we all should rise.
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121. BIBLIOGRAPHY
• Restorative dental materials – Robert G.Craig, John
M. Powers,8th Edition.
• Phillips’science of dental materials – Kenneth
J.Anusavice,11th Edition.
• Notes on Dental materials – E.C.Combe,6th Edition.
• Ralph W.Philips- Skinner’s Science of Dental
Materials.
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122. • Dental Materials Properties and Manipulation – Robert
G.Craig,O’Brien,Powers.
• Clinical Handling of Dental Materials-
Smith,Wright,Brown.
• Clinical aspects of Dental Materials – Philips – 8th Edition.
• Theory and Practice for Ceramo Metal Restorations –
Masahiro Kuwata
• The Science and Art of Dental Ceramics,Vol II : Bridge
Design and Laboratory Proceedures In Dental Ceramics –
John W.Mclean
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123. •Evaluation and comparison of shear bond strength of
three porcelain repair systems with various surface
treatments in response to thermal stress – an in vitro
study - Dr. Meenakshi T.
•Kelly J.R.et al .Ceramics in Dentistry: Historical roots
and Current Perspective.J Prosthet Dent 1996;75:18-32.
•Duret F,Jean-louis Blouin,Duret Bernard. CAD-CAM in
Dentistry.JADA 1988;117:715-720.
•Sulaiman F,Chai J, Jameson LM, A Comparison of the
Marginal Fit of In-Ceram,Ips Empress,and Procera
Crowns. Int J Prosthodont 1997;10:478-484.
•Chai J et al, Probability of Fracture of All-Ceramic
Crowns. Int J Prosthodont 2000;13:420-424.
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