This document discusses the history and classification of dental ceramics. It begins with definitions of ceramics and discusses Greek and Sanskrit origins of the word. It then categorizes dental ceramics according to their use, firing temperature, processing method, microstructure, composition, translucency, and application. The document provides a historical perspective on the development of dental ceramics from ancient times to modern CAD/CAM systems. It also covers the composition, properties, advantages, and disadvantages of various dental ceramics.
This document discusses the importance of circumferential tie and bevels in dental preparations. It defines different types of bevels such as partial, short, long, full, counter, and hollow ground bevels. It also discusses different extensions used in preparations like flares, skirts, collars, and their indications. The ideal requirements of peripheral margins and factors affecting bevel angle are explained. Bevel placement in teeth with facets and their importance in cast restorations is also summarized.
Dental Ceramics and Porcelain fused to metal isabel
This document discusses ceramics and porcelain fused to metal restorations. It describes the composition and properties of dental ceramics and porcelains, including feldspathic and aluminous porcelains. The applications and parts of porcelain fused to metal restorations are outlined. The benefits and drawbacks of metal-ceramic restorations are summarized. Requirements for the metal coping and bonding of porcelain to the coping are also summarized.
Casting Procedures & Casting Defects in DentistryJehan Dordi
This document provides information on casting procedures used in dentistry. It discusses various topics related to casting including sprue and spruing, crucible formers, investing, burnout procedures, casting machines, fluxes, heat treatment, divesting, finishing, defects, and literature reviews. The key steps in casting procedures are outlined, including tooth preparation, impression, die preparation, wax pattern fabrication, spruing, investing, burnout, casting, divesting, cleaning, and finishing the casting. Detailed information is provided on sprue types, materials, length, diameter, direction, location, and techniques for spruing patterns of different types and sizes.
The wax pattern is a precursor to the final cast restoration and must be fabricated precisely. There are two techniques for making wax patterns - direct and indirect. Various waxes are used depending on the type of restoration. For inlay patterns, the wax needs to flow easily when heated but be rigid when cool and carve precisely without distortion. The pattern is stored on the die and invested soon after fabrication. The die is prepared, relieved, and lubricated before pattern fabrication. Patterns are built up by adding wax for the coping, axial contours, emergence profile, occlusal morphology, and refined margins. Cusp-marginal ridge and cusp-fossa occlusal schemes are classified.
This document discusses the process of fabricating porcelain for dental crowns. It begins with an introduction and overview of porcelain in dentistry. It then describes in detail the conventional method for applying and building up porcelain on a metal substructure in multiple firing stages. This includes applying opaque, body and incisal layers to achieve proper contours and characterization. The document also discusses indications, contraindications and techniques for internal characterization, glazing, staining and creating collarless crowns.
This document provides information on dental casting procedures. It discusses the history of casting, steps in the casting process such as wax pattern fabrication and sprue attachment, types of investments and burnout procedures. The key points are: casting has been used since ancient times to produce jewelry and was introduced to dentistry by Taggart in 1907; the process involves fabricating a wax pattern, investing it, then burning out the wax and casting dental alloys into the mold.
This document discusses the importance of circumferential tie and bevels in dental preparations. It defines different types of bevels such as partial, short, long, full, counter, and hollow ground bevels. It also discusses different extensions used in preparations like flares, skirts, collars, and their indications. The ideal requirements of peripheral margins and factors affecting bevel angle are explained. Bevel placement in teeth with facets and their importance in cast restorations is also summarized.
Dental Ceramics and Porcelain fused to metal isabel
This document discusses ceramics and porcelain fused to metal restorations. It describes the composition and properties of dental ceramics and porcelains, including feldspathic and aluminous porcelains. The applications and parts of porcelain fused to metal restorations are outlined. The benefits and drawbacks of metal-ceramic restorations are summarized. Requirements for the metal coping and bonding of porcelain to the coping are also summarized.
Casting Procedures & Casting Defects in DentistryJehan Dordi
This document provides information on casting procedures used in dentistry. It discusses various topics related to casting including sprue and spruing, crucible formers, investing, burnout procedures, casting machines, fluxes, heat treatment, divesting, finishing, defects, and literature reviews. The key steps in casting procedures are outlined, including tooth preparation, impression, die preparation, wax pattern fabrication, spruing, investing, burnout, casting, divesting, cleaning, and finishing the casting. Detailed information is provided on sprue types, materials, length, diameter, direction, location, and techniques for spruing patterns of different types and sizes.
The wax pattern is a precursor to the final cast restoration and must be fabricated precisely. There are two techniques for making wax patterns - direct and indirect. Various waxes are used depending on the type of restoration. For inlay patterns, the wax needs to flow easily when heated but be rigid when cool and carve precisely without distortion. The pattern is stored on the die and invested soon after fabrication. The die is prepared, relieved, and lubricated before pattern fabrication. Patterns are built up by adding wax for the coping, axial contours, emergence profile, occlusal morphology, and refined margins. Cusp-marginal ridge and cusp-fossa occlusal schemes are classified.
This document discusses the process of fabricating porcelain for dental crowns. It begins with an introduction and overview of porcelain in dentistry. It then describes in detail the conventional method for applying and building up porcelain on a metal substructure in multiple firing stages. This includes applying opaque, body and incisal layers to achieve proper contours and characterization. The document also discusses indications, contraindications and techniques for internal characterization, glazing, staining and creating collarless crowns.
This document provides information on dental casting procedures. It discusses the history of casting, steps in the casting process such as wax pattern fabrication and sprue attachment, types of investments and burnout procedures. The key points are: casting has been used since ancient times to produce jewelry and was introduced to dentistry by Taggart in 1907; the process involves fabricating a wax pattern, investing it, then burning out the wax and casting dental alloys into the mold.
brief description about pressable ceramicsCONTENTS: • Introduction • Definition For Dental Ceramics • Definition For Pressable Ceramics • History • Various All Ceramic Systems • Classification • Pressable Ceramics • History • Generation Of Pressable Ceramics • Cerestore – Development Fabrication Advantage Disadvantage 2
3. IPS Empress - Materials And Composition Special Furnace Fabrication Advantage Disadvantage IPS Empress 2- INDICATION Properties Fabrication Method Advantage Disadvantage IPS Emax Press - Microstructure Composition Properties OPC 3G- Development Indication Properties 3
4. INTRODUCTION There have been significant TECHNOLOGICAL advances in the field of dental ceramics over the last 10 years which have made a corresponding increase in the number of materials available. Improvements in strength, clinical performance, and longevity have made all ceramic restorations more popular and more predictable 4
5. DEFINITION FOR DENTAL CERAMICS⁶ An inorganic compound with non metallic properties typically consisting of oxygen and one or more metallic or semi metallic elements (e.g ;Aluminium, Calcium, Lithium, Mangnesium, Potassium, Sodium, Silicon, Tin , Titanium And Zirconium)that is formulated to produce the whole or part of a ceramic based dental prosthesis 5
6. DEFINITION FOR PRESSABLE CERAMICS ⁶ • A ceramic that can be heated to a specified temperature and forced under pressure to fill a cavity in a refractory mold 6
7. HISTORY OF DENTAL CERAMICS ⁶ • 1789-first porcelain tooth material by a French dentist De Chemant • 1774- mineral paste teeth by Duchateau in England • 1808-terrometallic porcelain teeth by Italian dentist Fonzi • 1817- Planteu introduced porcelain teeth in US • 1837- Ash developed improved version of porcelain teeth 7
8. • 1903 – Dr.Charless introduced ceramic crowns in dentistry he fabricate ceramic crown using platinum foil matrix and high fusing feldspathic porcelain excellent esthetics but low flexural strength resulted in failure • 1965- dental aluminous core Porcelain by Mclean and Huges • 1984- Dicor by Adair and Grossman 8
9. 9
10. VARIOUS ALL CERAMIC SYSTEMS Aluminous core ceramics Slip cast ceramics Heat pressed ceramics Machined ceramics Machined and sintered ceramics Metal reinforced system 10
11. MICROSTRUCTURAL CLASSIFICATION⁵ Category 1: Glass-based systems (mainly silica) Category 2: Glass-based systems (mainly silica) with fillers usually crystalline (typically leucite or a different high-fusing glass) a) Low-to-moderate leucite-
This document discusses root canal sealers, including their definition, requirements, functions, and classifications. It describes various common sealers such as zinc oxide eugenol sealers like Kerr Pulp Canal Sealer, Procosol, and Grossman Sealer. It also discusses non-eugenol sealers, medicated sealers, and calcium hydroxide based sealers. The document provides details on the composition, properties, advantages, disadvantages and uses of different sealers.
This document outlines the steps in the lost wax casting procedure for dental restorations. It begins by introducing lost wax casting and describing the key steps: 1) Wax pattern removal, 2) Spruing, 3) Investing, 4) Burnout, 5) Casting. It then provides details on wax patterns, sprue formers, crucible formers, casting rings, and the investing procedure. Important considerations for each step are highlighted to produce an accurate casting.
This document discusses metal-free ceramics used in dentistry. It provides definitions of various types of ceramics like feldspathic porcelain, glass ceramics, and zirconia. The document discusses the history, classification, composition, properties and strengthening techniques of ceramics. It also compares different metal-free ceramic systems and discusses their clinical applications and cementation.
The document provides an overview of occlusion including general aspects, clinical significance, forces acting on restored teeth, occlusal considerations for restoring individual teeth, modes of recording occlusal relations, and checking castings for occlusion. It discusses supporting and non-supporting cusps, functional and non-functional occlusion, centric relation, centric occlusion, occlusal schemes, and guidance of occlusion. Qualitative and quantitative methods for analyzing occlusion are also presented including articulating paper, foils, pastes, silk strips, photocclusion, and computer-assisted dynamic analysis.
This document discusses acid etching of dental surfaces. It describes how acid etching was first proposed in 1955 to increase bond strength between composite resin and enamel. Acid etching removes enamel and creates an irregular porous surface that allows resin to penetrate through micromechanical interlocking, improving bond strength. Factors like acid type/concentration, etching duration, and fluoride levels can affect bonding. While acid etching is effective, some alternatives under investigation include crystal growth solutions, air abrasion, and lasers, but they have not achieved bond strengths as high as acid etching.
The document provides an overview of all-ceramic dental restorations. It discusses the history of ceramics in dentistry, different ceramic materials used including aluminous core ceramics, heat pressed ceramics, machinable ceramics, and zirconia ceramics. It also outlines the different all-ceramic restoration types including crowns, fixed partial dentures, inlays, onlays, and veneers. The clinical procedures for fabricating and cementing all-ceramic restorations are described including tooth preparation, impression taking, temporization, try-in, finishing, and cementation. Factors affecting the selection of all-ceramic restorations are also
This document provides information on preparing class I amalgam cavity restorations. It discusses the materials used for amalgam fillings, including their advantages and disadvantages. It describes the Black system for cavity preparation, which involves establishing an outline, resistance, retention, and convenience form. It provides details on preparing simple, compound, and complex class I cavities, including removing caries, obtaining the proper depth and angles, and finishing cavity walls. Enameloplasty and cusp capping techniques are also covered. The goal is to conserve tooth structure while ensuring the restoration is retained and can withstand occlusal forces.
The document outlines the steps for tooth preparation for a restoration, including checking the reduction with a matrix, cutting grooves 1mm deep in three planes, reducing the incisal edge by 2-3mm, cutting interproximally to produce a 1mm chamfer and prepare the axial walls at 10 degree inclination and 20 degree convergence, checking even labial reduction of 1.0-1.2mm including a labial chamfer, preparing palatally with 1mm depth grooves, placing retraction cords, taking impressions, and removing the impression.
The document discusses tooth preparation for dental amalgam restorations. It defines tooth preparation and its goals. It describes the general factors to consider like diagnosis, occlusion, esthetics, and patient/material factors. It outlines the specific tooth preparation steps for Class I and Class II amalgam restorations, including extending the outline, preparing the proximal walls and boxes, finishing line angles and margins. Primary resistance and retention forms are achieved through features like box shape, 90 degree cavosurface angles, rounding internal angles, and minimal tooth reduction.
This document provides guidelines for preparing class II inlay restorations. It describes initial procedures like evaluating occlusion and administering anesthesia. It discusses preparing the occlusal outline, proximal box, bevels, and flares. Modifications for specific tooth shapes and situations are covered. Preparation variations like slices and flares are explained. Special considerations for abutment teeth and root surface lesions are also summarized. The document provides a thorough overview of class II inlay preparation techniques.
This document discusses different types of connectors used in fixed partial dentures (FPDs). It defines connectors and lists their requirements. Rigid connectors include cast, soldered, welded, and loop connectors. Non-rigid connectors involve dovetail, split pontic, cross pin, and wing connectors. Design considerations for connectors include hygiene, biomechanics, aesthetics, and strength. Common rigid connector fabrication methods and their pros and cons are outlined. Indications for different connector types depend on factors like abutment alignment and span length.
laboratory procedures in make of complete dentureddert
Upload By : Ahmed Ali Abbas
Babylon University College of Dentistry
download this file from Website on google is
theoptimalsmile.wix.com/dentistry
تحميل بقلم: أحمد علي عباس
جامعة بابل كلية طب الأسنان
تحميل هذا الملف من موقع على جوجل
theoptimalsmile.wix.com/dentistry
Ceramics have many applications in dentistry due to their esthetic qualities, strength, and biocompatibility. Ceramics are used in crowns, bridges, veneers, dentures, and more. There are several types of ceramics including metal-ceramics, which combine a ceramic material fused to a metal framework for strength, and all-ceramic options made of materials like alumina and zirconia. Ceramic materials are fabricated through processes like sintering, heat pressing, slip-casting, and CAD/CAM milling. Ceramics provide natural-looking and long-lasting restorations but also have limitations like brittleness which new materials continue to address
Wax patterns fabrication for fixed partial denturesShebin Abraham
This document provides information on the principles and techniques for fabricating wax patterns for crowns and fixed dental prostheses using the lost wax technique. It discusses the prerequisites for wax patterns including correcting defects on dies, providing cement space, and marking margins. Details are given on materials used for wax patterns and different waxing techniques. The sequence of wax pattern fabrication is outlined including coping formation, evaluation, shaping proximal, axial, and occlusal surfaces, and finishing margins. Occlusal schemes and developing cusp-fossa and cusp-marginal ridge relationships during waxing are also described. The goal is to produce highly accurate wax patterns to result in well-fitting cast restorations.
This document provides instructions for constructing a special tray for making final impressions for complete dentures. It describes how to outline and fabricate rigid trays made of light-cured resin for the maxillary and mandibular arches using a preliminary cast. The trays are trimmed to be 2mm short of the vestibule with clearance for frenal attachments. Handles are added to the trays for positioning in the mouth during the impression. Wax spacers are then used on the casts under the trays to provide a uniform 3mm space for impression material.
The document discusses the history and generations of dentin bonding agents. It describes the challenges of bonding to dentin due to its composition and structure. Early bonding agents bonded weakly to the smear layer rather than dentin. Current bonding agents condition and prime the dentin surface to allow resin infiltration and strong bonding. They are classified based on their treatment of the smear layer and number of clinical steps.
Double seal in endodontics and conservative dentistrydrepsitaghosh
Introduction:
The ultimate goal of root canal therapy is to conquer the complex root canal system by perfect obturation. The primary objectives of operative endodontics are total debridement of the pulpal space, development of a fluid–tight seal at the apical foramen and total obturation of the root canal. Earlier, root canals have been reported to be filled with Amalgam, Asbestos, Balsam, Bamboo, Cement, Copper, Gold Foil, Iron, Lead, OxyChloride of Zinc, Paraffin, Pastes, Plaster of Paris, Resin, Rubber, Silverpoints, Tin foil etc., Among all these materials tried, none of them met the requirements of an ideal obturating material.
Even after a three dimensional obturation of the system, coronal restoration may fail to provide a perfect seal and may permit microorganism & their toxins along the canal walls to their periapical tissue, leading to the failure of the treatment. So the quality of the coronal seal should be adequate to prevent micro leakage in to the canal space.Thus the concept of double seal came . Lack of satisfactory temporary restoration during endodontic therapy ranked second amongst the contributing factors in continuing pain after commencement of treatment.
Over the years various materials referred to as ‘Intra-orifice barriers’ have been sought by investigators to prevent coronal micro leakage & help produce a secondary seal for obturated canal. Thus along with time many sealing material for coronal sealing was tested. This also implies that an adequate coronal filling or restoration be placed to prevent oral bacterial microleakage. It has been shown that endodontic treatment success is dependent both on the quality of the obturation and the final restoration.1
Definition:
A DOUBLE seal consisting of gutta percha underneath material such as temporary cement ; used to close the coronal opening in a tooth during endodontic treatment. A DOUBLE seal consisting of gutta percha underneath material such as temporary cement ; used to close the coronal opening in a tooth during endodontic treatment.
• Many materials can be used to achieve some of these goals for effective inter-
appointment temporization. It is essential to have adequate knowledge of temporization techniques and material properties in order to satisfy a wide variety of clinical requirements such as time , occlusal load and wear ,complexity of access and absence of tooth structure.
Coronal 3-4 mm should be left for the placement of this double seal.
This document discusses the history and composition of dental amalgam. It describes the three "amalgam wars" where the safety of amalgam was debated. Amalgam is an alloy of silver, tin, copper and sometimes other metals like zinc. The document outlines the different generations of amalgam alloys and how composition affects properties. High copper alloys aim to improve strength and corrosion resistance over traditional low copper alloys. Both admixed and unicompositional high copper alloys are discussed in terms of their microstructure and reaction with mercury during setting. The physical properties of dimensional stability, strength and corrosion resistance are also summarized.
Dental 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
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
brief description about pressable ceramicsCONTENTS: • Introduction • Definition For Dental Ceramics • Definition For Pressable Ceramics • History • Various All Ceramic Systems • Classification • Pressable Ceramics • History • Generation Of Pressable Ceramics • Cerestore – Development Fabrication Advantage Disadvantage 2
3. IPS Empress - Materials And Composition Special Furnace Fabrication Advantage Disadvantage IPS Empress 2- INDICATION Properties Fabrication Method Advantage Disadvantage IPS Emax Press - Microstructure Composition Properties OPC 3G- Development Indication Properties 3
4. INTRODUCTION There have been significant TECHNOLOGICAL advances in the field of dental ceramics over the last 10 years which have made a corresponding increase in the number of materials available. Improvements in strength, clinical performance, and longevity have made all ceramic restorations more popular and more predictable 4
5. DEFINITION FOR DENTAL CERAMICS⁶ An inorganic compound with non metallic properties typically consisting of oxygen and one or more metallic or semi metallic elements (e.g ;Aluminium, Calcium, Lithium, Mangnesium, Potassium, Sodium, Silicon, Tin , Titanium And Zirconium)that is formulated to produce the whole or part of a ceramic based dental prosthesis 5
6. DEFINITION FOR PRESSABLE CERAMICS ⁶ • A ceramic that can be heated to a specified temperature and forced under pressure to fill a cavity in a refractory mold 6
7. HISTORY OF DENTAL CERAMICS ⁶ • 1789-first porcelain tooth material by a French dentist De Chemant • 1774- mineral paste teeth by Duchateau in England • 1808-terrometallic porcelain teeth by Italian dentist Fonzi • 1817- Planteu introduced porcelain teeth in US • 1837- Ash developed improved version of porcelain teeth 7
8. • 1903 – Dr.Charless introduced ceramic crowns in dentistry he fabricate ceramic crown using platinum foil matrix and high fusing feldspathic porcelain excellent esthetics but low flexural strength resulted in failure • 1965- dental aluminous core Porcelain by Mclean and Huges • 1984- Dicor by Adair and Grossman 8
9. 9
10. VARIOUS ALL CERAMIC SYSTEMS Aluminous core ceramics Slip cast ceramics Heat pressed ceramics Machined ceramics Machined and sintered ceramics Metal reinforced system 10
11. MICROSTRUCTURAL CLASSIFICATION⁵ Category 1: Glass-based systems (mainly silica) Category 2: Glass-based systems (mainly silica) with fillers usually crystalline (typically leucite or a different high-fusing glass) a) Low-to-moderate leucite-
This document discusses root canal sealers, including their definition, requirements, functions, and classifications. It describes various common sealers such as zinc oxide eugenol sealers like Kerr Pulp Canal Sealer, Procosol, and Grossman Sealer. It also discusses non-eugenol sealers, medicated sealers, and calcium hydroxide based sealers. The document provides details on the composition, properties, advantages, disadvantages and uses of different sealers.
This document outlines the steps in the lost wax casting procedure for dental restorations. It begins by introducing lost wax casting and describing the key steps: 1) Wax pattern removal, 2) Spruing, 3) Investing, 4) Burnout, 5) Casting. It then provides details on wax patterns, sprue formers, crucible formers, casting rings, and the investing procedure. Important considerations for each step are highlighted to produce an accurate casting.
This document discusses metal-free ceramics used in dentistry. It provides definitions of various types of ceramics like feldspathic porcelain, glass ceramics, and zirconia. The document discusses the history, classification, composition, properties and strengthening techniques of ceramics. It also compares different metal-free ceramic systems and discusses their clinical applications and cementation.
The document provides an overview of occlusion including general aspects, clinical significance, forces acting on restored teeth, occlusal considerations for restoring individual teeth, modes of recording occlusal relations, and checking castings for occlusion. It discusses supporting and non-supporting cusps, functional and non-functional occlusion, centric relation, centric occlusion, occlusal schemes, and guidance of occlusion. Qualitative and quantitative methods for analyzing occlusion are also presented including articulating paper, foils, pastes, silk strips, photocclusion, and computer-assisted dynamic analysis.
This document discusses acid etching of dental surfaces. It describes how acid etching was first proposed in 1955 to increase bond strength between composite resin and enamel. Acid etching removes enamel and creates an irregular porous surface that allows resin to penetrate through micromechanical interlocking, improving bond strength. Factors like acid type/concentration, etching duration, and fluoride levels can affect bonding. While acid etching is effective, some alternatives under investigation include crystal growth solutions, air abrasion, and lasers, but they have not achieved bond strengths as high as acid etching.
The document provides an overview of all-ceramic dental restorations. It discusses the history of ceramics in dentistry, different ceramic materials used including aluminous core ceramics, heat pressed ceramics, machinable ceramics, and zirconia ceramics. It also outlines the different all-ceramic restoration types including crowns, fixed partial dentures, inlays, onlays, and veneers. The clinical procedures for fabricating and cementing all-ceramic restorations are described including tooth preparation, impression taking, temporization, try-in, finishing, and cementation. Factors affecting the selection of all-ceramic restorations are also
This document provides information on preparing class I amalgam cavity restorations. It discusses the materials used for amalgam fillings, including their advantages and disadvantages. It describes the Black system for cavity preparation, which involves establishing an outline, resistance, retention, and convenience form. It provides details on preparing simple, compound, and complex class I cavities, including removing caries, obtaining the proper depth and angles, and finishing cavity walls. Enameloplasty and cusp capping techniques are also covered. The goal is to conserve tooth structure while ensuring the restoration is retained and can withstand occlusal forces.
The document outlines the steps for tooth preparation for a restoration, including checking the reduction with a matrix, cutting grooves 1mm deep in three planes, reducing the incisal edge by 2-3mm, cutting interproximally to produce a 1mm chamfer and prepare the axial walls at 10 degree inclination and 20 degree convergence, checking even labial reduction of 1.0-1.2mm including a labial chamfer, preparing palatally with 1mm depth grooves, placing retraction cords, taking impressions, and removing the impression.
The document discusses tooth preparation for dental amalgam restorations. It defines tooth preparation and its goals. It describes the general factors to consider like diagnosis, occlusion, esthetics, and patient/material factors. It outlines the specific tooth preparation steps for Class I and Class II amalgam restorations, including extending the outline, preparing the proximal walls and boxes, finishing line angles and margins. Primary resistance and retention forms are achieved through features like box shape, 90 degree cavosurface angles, rounding internal angles, and minimal tooth reduction.
This document provides guidelines for preparing class II inlay restorations. It describes initial procedures like evaluating occlusion and administering anesthesia. It discusses preparing the occlusal outline, proximal box, bevels, and flares. Modifications for specific tooth shapes and situations are covered. Preparation variations like slices and flares are explained. Special considerations for abutment teeth and root surface lesions are also summarized. The document provides a thorough overview of class II inlay preparation techniques.
This document discusses different types of connectors used in fixed partial dentures (FPDs). It defines connectors and lists their requirements. Rigid connectors include cast, soldered, welded, and loop connectors. Non-rigid connectors involve dovetail, split pontic, cross pin, and wing connectors. Design considerations for connectors include hygiene, biomechanics, aesthetics, and strength. Common rigid connector fabrication methods and their pros and cons are outlined. Indications for different connector types depend on factors like abutment alignment and span length.
laboratory procedures in make of complete dentureddert
Upload By : Ahmed Ali Abbas
Babylon University College of Dentistry
download this file from Website on google is
theoptimalsmile.wix.com/dentistry
تحميل بقلم: أحمد علي عباس
جامعة بابل كلية طب الأسنان
تحميل هذا الملف من موقع على جوجل
theoptimalsmile.wix.com/dentistry
Ceramics have many applications in dentistry due to their esthetic qualities, strength, and biocompatibility. Ceramics are used in crowns, bridges, veneers, dentures, and more. There are several types of ceramics including metal-ceramics, which combine a ceramic material fused to a metal framework for strength, and all-ceramic options made of materials like alumina and zirconia. Ceramic materials are fabricated through processes like sintering, heat pressing, slip-casting, and CAD/CAM milling. Ceramics provide natural-looking and long-lasting restorations but also have limitations like brittleness which new materials continue to address
Wax patterns fabrication for fixed partial denturesShebin Abraham
This document provides information on the principles and techniques for fabricating wax patterns for crowns and fixed dental prostheses using the lost wax technique. It discusses the prerequisites for wax patterns including correcting defects on dies, providing cement space, and marking margins. Details are given on materials used for wax patterns and different waxing techniques. The sequence of wax pattern fabrication is outlined including coping formation, evaluation, shaping proximal, axial, and occlusal surfaces, and finishing margins. Occlusal schemes and developing cusp-fossa and cusp-marginal ridge relationships during waxing are also described. The goal is to produce highly accurate wax patterns to result in well-fitting cast restorations.
This document provides instructions for constructing a special tray for making final impressions for complete dentures. It describes how to outline and fabricate rigid trays made of light-cured resin for the maxillary and mandibular arches using a preliminary cast. The trays are trimmed to be 2mm short of the vestibule with clearance for frenal attachments. Handles are added to the trays for positioning in the mouth during the impression. Wax spacers are then used on the casts under the trays to provide a uniform 3mm space for impression material.
The document discusses the history and generations of dentin bonding agents. It describes the challenges of bonding to dentin due to its composition and structure. Early bonding agents bonded weakly to the smear layer rather than dentin. Current bonding agents condition and prime the dentin surface to allow resin infiltration and strong bonding. They are classified based on their treatment of the smear layer and number of clinical steps.
Double seal in endodontics and conservative dentistrydrepsitaghosh
Introduction:
The ultimate goal of root canal therapy is to conquer the complex root canal system by perfect obturation. The primary objectives of operative endodontics are total debridement of the pulpal space, development of a fluid–tight seal at the apical foramen and total obturation of the root canal. Earlier, root canals have been reported to be filled with Amalgam, Asbestos, Balsam, Bamboo, Cement, Copper, Gold Foil, Iron, Lead, OxyChloride of Zinc, Paraffin, Pastes, Plaster of Paris, Resin, Rubber, Silverpoints, Tin foil etc., Among all these materials tried, none of them met the requirements of an ideal obturating material.
Even after a three dimensional obturation of the system, coronal restoration may fail to provide a perfect seal and may permit microorganism & their toxins along the canal walls to their periapical tissue, leading to the failure of the treatment. So the quality of the coronal seal should be adequate to prevent micro leakage in to the canal space.Thus the concept of double seal came . Lack of satisfactory temporary restoration during endodontic therapy ranked second amongst the contributing factors in continuing pain after commencement of treatment.
Over the years various materials referred to as ‘Intra-orifice barriers’ have been sought by investigators to prevent coronal micro leakage & help produce a secondary seal for obturated canal. Thus along with time many sealing material for coronal sealing was tested. This also implies that an adequate coronal filling or restoration be placed to prevent oral bacterial microleakage. It has been shown that endodontic treatment success is dependent both on the quality of the obturation and the final restoration.1
Definition:
A DOUBLE seal consisting of gutta percha underneath material such as temporary cement ; used to close the coronal opening in a tooth during endodontic treatment. A DOUBLE seal consisting of gutta percha underneath material such as temporary cement ; used to close the coronal opening in a tooth during endodontic treatment.
• Many materials can be used to achieve some of these goals for effective inter-
appointment temporization. It is essential to have adequate knowledge of temporization techniques and material properties in order to satisfy a wide variety of clinical requirements such as time , occlusal load and wear ,complexity of access and absence of tooth structure.
Coronal 3-4 mm should be left for the placement of this double seal.
This document discusses the history and composition of dental amalgam. It describes the three "amalgam wars" where the safety of amalgam was debated. Amalgam is an alloy of silver, tin, copper and sometimes other metals like zinc. The document outlines the different generations of amalgam alloys and how composition affects properties. High copper alloys aim to improve strength and corrosion resistance over traditional low copper alloys. Both admixed and unicompositional high copper alloys are discussed in terms of their microstructure and reaction with mercury during setting. The physical properties of dimensional stability, strength and corrosion resistance are also summarized.
Dental 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
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
Dental ceramics include porcelain and are used for dental restorations. Porcelain is made from a glass matrix containing mineral phases and feldspars. It is used for dental crowns, veneers, dentures, and other prosthetics. Porcelain has good biocompatibility and esthetics but is brittle. Metal-ceramic restorations combine a metal substructure with porcelain for strength. All-ceramic restorations are made entirely of ceramic materials and provide superior esthetics but require more tooth reduction. Common all-ceramic systems include machinable blocks, castable ceramics, pressable ceramics, and infiltrated glass ceramics.
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.
Metal free ceramics /certified fixed orthodontic courses by Indian dental aca...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.
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 provides an overview of dental ceramics. It defines ceramics as inorganic compounds formed from metallic, semi-metallic, and nonmetallic elements that are subjected to high heat. Dental ceramics are commonly used for crowns, bridges, inlays and other restorations. They are composed mainly of feldspars, quartz, and kaolin that undergo firing and produce a vitreous glassy phase and crystalline phase. Dental ceramics are strengthened through various techniques to increase their durability for use in load-bearing applications in the mouth.
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.
The document discusses different types of dental ceramics, including their compositions, properties, and applications. It describes four main categories of ceramics used in dentistry: silicate ceramics, oxide ceramics, nonoxide ceramics, and glass ceramics. The document also covers the use of ceramics in dental prosthetics like crowns, bridges, veneers, and how they can be classified based on their intended use, composition, processing method, and other properties.
This document discusses different fabrication techniques for ceramics used in dentistry. The main techniques covered are conventional powder/slurry, castable ceramics, pressable ceramics, infiltrated ceramics, and machinable ceramics. The conventional powder/slurry technique involves compounding, packing, preheating, sintering, and glazing porcelain layers. Castable ceramics like Dicor are produced using lost wax casting. Pressable ceramics like IPS Empress are pressed into a die under heat and pressure. Infiltrated ceramics like In-Ceram have a porous core infiltrated with glass. Machinable ceramics can be milled from a block or
12.dental ceramics /certified fixed orthodontic courses by Indian dental academyIndian dental academy
Description :
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
Description :
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 dental ceramics and their use and processing in dentistry. It begins by providing background on the history and early uses of ceramics. It then defines ceramics and classifies them according to their composition, use, processing method, and other properties. The remainder of the document discusses the properties of dental ceramics, their uses in dentistry, processing methods, and ways to strengthen ceramics including developing residual compressive stresses and minimizing tensile stresses through design.
Allceramic restorations /certified fixed orthodontic courses by Indian dental...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.
Mechanical properties of dental materials / dental courses in indiaIndian 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.
Dental 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.
This document provides an overview of dental ceramics and CAD-CAM systems. It discusses the historical background, classification, composition, properties, and fabrication methods of ceramic restorations. Key points include that ceramics are classified based on their content, use, processing method, and firing temperature. Their composition includes feldspar, kaolin/clay, quartz, glass formers, modifiers, and coloring agents. Fabrication involves condensation, firing, and glazing techniques. All-ceramic restorations such as porcelain jacket crowns, alumina-reinforced ceramics, castables, pressables, infiltrated ceramics, and CAD-CAM systems are summarized.
Dental ceramics have been used in dentistry for hundreds of years, with early attempts to imitate Chinese porcelain in the 1700s. Modern dental ceramics are classified based on their composition, firing temperature, microstructure, and intended use. They provide esthetic and durable alternatives to metallic restorations due to properties like biocompatibility, color stability, and strength. Common types include feldspathic porcelain, lithium disilicate glass ceramic, and zirconia.
This document provides an overview of dental ceramics. It discusses the history of ceramics in dentistry from ancient times to modern developments. Key topics covered include the definition of ceramics, their basic constituents and structure, different classifications of ceramics based on composition and processing methods, advantages and disadvantages of metal-ceramic and all-ceramic restorations, and modern ceramic systems like CAD-CAM processed ceramics. The document also examines the composition, fabrication, and technical aspects of metal-ceramic prostheses.
Porcelains used in metal ceramics /certified fixed orthodontic courses by Ind...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
Dental implants are prosthetic devices implanted into the oral tissue or bone to support fixed or removable prosthetics. They can be classified based on design, attachment mechanism, body design, surface, or material. Common implant materials include titanium and its alloys, zirconium, stainless steel, cobalt-chromium alloys, and gold alloys. Ceramics and polymers are also used, such as glass ceramics containing leucite or lithium disilicate fillers. Implant design and materials have evolved significantly over time from early designs using materials like ivory, stone, and bone to modern titanium implants developed in the 1950s.
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.
1. Ceramics are inorganic, non-metallic materials made by heating materials like clay and feldspar at high temperatures.
2. The document discusses the history, structure, properties and classifications of dental ceramics.
3. It describes the advantages of ceramics in dentistry like biocompatibility and esthetics, and disadvantages like brittleness.
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.
Metal free ceramics /certified fixed orthodontic courses by Indian dental aca...Indian dental academy
This document provides information on metal-free ceramics used in dentistry. It defines ceramics as compounds containing metals and nonmetals like oxygen. Porcelain is a ceramic material formed from infusible elements joined by lower-fusing materials. All-ceramic restorations without metal substructures have better esthetics than metal-ceramic options. The document discusses the history and development of dental ceramics from the 18th century to modern systems. It also classifies and describes different ceramic types like feldspathic porcelain, alumina, and glass ceramics as well as processing methods.
Metal free ceramics /certified fixed orthodontic courses by Indian dental aca...Indian dental academy
This document discusses various types of dental ceramics, including their composition, properties and uses. It describes porcelain and glass ceramics, noting that porcelain is a ceramic material formed from infusible elements joined by lower fusing material. The document outlines the history of dental ceramics and provides classifications including types, uses, processing methods and substructure materials. It also compares metal ceramics to all-ceramic systems, discussing advantages and disadvantages of each.
This document discusses various types of dental ceramics, including their composition, properties and uses. It describes porcelain and glass ceramics, noting that porcelain is formed from infusible elements joined by lower fusing material. The history of dental ceramics is reviewed from early uses of human, animal and ivory teeth to modern porcelain and glass formulations. Advantages of all-ceramic restorations over metal-ceramic are listed. Classification systems for dental ceramics include type, use, processing method and substructure material. Properties like strength and factors affecting it are also covered.
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.
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.
Recent advances in dental porcelain materials / cosmetic dentistry coursesIndian dental academy
Ceramic materials have a long history dating back thousands of years. Modern dental ceramics are used for restorations like crowns, veneers, and inlays. They have excellent aesthetics and biocompatibility but are brittle. Techniques have been developed to strengthen dental ceramics, including using metal substructures, incorporating crystalline phases, thermal treatment to induce compressive stresses, and designs that minimize tensile stresses. Composition and processing of dental ceramics have continually evolved to improve strength, translucency, and fit.
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.
This document provides a detailed history and overview of dental ceramics. It discusses the origins and composition of different types of ceramics used in dentistry like feldspathic porcelain, leucite-reinforced porcelain, and aluminous porcelain. The document also outlines the various methods used to classify and fabricate dental ceramics, including processes like condensation and sintering, casting and ceramming, machining, pressure molding, and glass infiltration. Key developments in the history of using ceramics in dentistry are highlighted from the 1700s to present day.
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 from the late 1700s. Key developments include McLean and Hughes' aluminous core porcelain in 1965, In-Ceram in the 1980s using slip casting, and machinable ceramics in the 1990s using CAD/CAM. The document also examines methods to strengthen porcelain, all-ceramic systems like In-Ceram, castable ceramics including Di-Cor and Cerestore, and machinable ceramics. It provides details on the composition, fabrication process, properties and clinical performance of various ceramic materials.
This document provides an overview of ceramics used in orthodontics, specifically ceramic brackets. It discusses the history of ceramics, the types of ceramic brackets including polycrystalline and monocrystalline, their manufacturing techniques, and properties such as hardness, tensile strength, fracture toughness, bond strength, and frictional resistance. The document also covers topics like bracket placement, debonding techniques, abrasion, fracture, recycling brackets, and clinical implications.
The presentation deals with dental ceramics from a material aspect and discusses various types of metal - ceramic and all - ceramic systems available in dentistry with their advantages and drawbacks. It is well supported with illustrations..
This document provides an overview of dental ceramics, including their history, classification, composition, properties, and methods of strengthening. It discusses the basic components of dental porcelain, including feldspar, kaolin, silica, and other additives. The document also covers various classification schemes for dental ceramics based on their content, use, processing method, firing temperature, and microstructure. Strengthing methods like ion exchange, thermal tempering, and disrupting crack propagation are described.
Similar to Dental ceramics / cosmetic dentistry course in india. (20)
Opportunity for Dentists (BDS/MDS )to relocate to United kingdom -Register as a DENTAL HYGIENIST/ DENTAL THERAPIST without Board exams and after approval you can register in GDC as a DH/DT and start working as a DH/DT Immediately and get paid.
You can complete the whole process in 3-4 months.Salary range for DH/DT is around 2500-3500 Pounds per month.
Eligibility / requirements-
1. An International English Language Testing System (IELTS) certificate
at the appropriate level.(Within 2 yrs of application date )
2: A recent primary dental qualification that has been taught and examined in English..(Within 2 yrs of application date )
3: A recent pass in a language test for registration with a regulatory authority in a country where the first language is English.
If you are interested Please contact us for more details.
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...Indian 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.
I –Aligners are made with FDA approved transparent thermoplastic materials using 3D scanning, 3D Printing and finally Trays with Pressure vacuum formers.
Dear Doctor,
Indian Dental Academy Now offers comprehensive online Orthodontics course.
Course includes:
1.whiteboard lecture presentations
2.Case Discussions
3.with hundreds of pictures.
4.Demo on Models
5.Demo on Patients
6. subtitles in your own language
12 months unlimited access and support @350 USD only.
For Demo please visit :www.idalectures.com/preview/
For more details visit: www.idalectures.com
Please contact us for any clarifications:
idalectures@gmail.com
indiandentalacademy@gmail.com
Thanks & Regards
Indian Dental Academy
--
Indian Dental Academy
Leader in continuing dental education
www.indiandentalacademy.com
skype:indiandentalacademy
+919248678078
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 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
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...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.for more details please visit
www.indiandentalacademy.com
Diagnosis and treatment planning in completely endntulous arches/dental 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
Properties of Denture base materials /rotary endodontic 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
Use of modified tooth forms in complete denture occlusion / dental implant...Indian dental academy
This document discusses dental occlusion concepts and philosophies for complete dentures. It introduces key terms like physiologic occlusion and defines different occlusion schemes like balanced articulation and monoplane articulation. The document discusses advantages and disadvantages of using anatomic versus non-anatomic teeth for complete dentures. It also outlines requirements for maintaining denture stability, such as balanced occlusal contacts and control of horizontal forces. The goal of occlusion for complete dentures is to re-establish the homeostasis of the masticatory system disrupted by edentulism.
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 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 dental casting investment materials. It describes the three main types of investments - gypsum bonded, phosphate bonded, and ethyl silicate bonded investments. For gypsum bonded investments specifically, it details their classification, composition including the roles of gypsum, silica, and modifiers, setting time, normal and hygroscopic setting expansion, and thermal expansion. It provides information on how the properties of gypsum bonded investments are affected by their composition. The document serves as a comprehensive overview of dental casting investment materials.
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 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 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 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
Dentalcasting alloys/certified fixed orthodontic courses by Indian dental aca...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.for more details please visit
www.indiandentalacademy.com
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
-------------------------------------------------------------------------------
Find out more about ISO training and certification services
Training: ISO/IEC 27001 Information Security Management System - EN | PECB
ISO/IEC 42001 Artificial Intelligence Management System - EN | PECB
General Data Protection Regulation (GDPR) - Training Courses - EN | PECB
Webinars: https://pecb.com/webinars
Article: https://pecb.com/article
-------------------------------------------------------------------------------
For more information about PECB:
Website: https://pecb.com/
LinkedIn: https://www.linkedin.com/company/pecb/
Facebook: https://www.facebook.com/PECBInternational/
Slideshare: http://www.slideshare.net/PECBCERTIFICATION
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptxEduSkills OECD
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
2. Keramos: Greek
Keramika: Sanskrit
A material produced by firing or burning
” a combination of one or more metals with
a non metallic element, usually oxygen.”
Gilman 1967.
www.indiandentalacademy.com
3. Phillips. 11th
Ed.
An inorganic compound with nonmetallic properties
typically consisting of oxygen and one or more metallic
or semimetallic elements( Eg: Aluminium, calcium,
lithium, magnesium, potassium, silicon, sodium, tin,
titanium and zirconium) that is formulated to produce
the whole or
part of a ceramic based prosthesis.
Definition: Dental Ceramics
www.indiandentalacademy.com
4. Definition: Dental Ceramics
0’Brien:
Combination of one or more metals with non
metallic elements especially oxygen, larger
atoms of oxygen serving as a matrix with
smaller metal atoms tucked into the spaces
between oxygen.
www.indiandentalacademy.com
5. Ceramics : A historical perspective……
23,000BC
5500BC:
100BC:
1000AD:
White china clay + “Chine stone”
Ceramic so white that it was comparable only to snow,
So strong that vessels needed walls only 2-3 mm thick,
and consequently light could shine through it. So continuous
was the internal structure that a dish, if lightly struck,
would ring a bell. This is Porcelain!
Earthernware:
Stoneware:
Chinese porcelain
www.indiandentalacademy.com
6. Attempts to imitate the Chinese Porcelain……
1717: Pere, Francois Xavier d’ Entrecolles
In less than 60 years, dental restorative material!
1728: Pierre Fauchard.
1774: Alexis Duchateau: Porcelain dentures.
1791: Nicholas Dubois de Chemant of Paris
Paris Faculty of Medicine :
“united the qualities of beauty, solidity and comfort to the
exigencies of hygiene.”
www.indiandentalacademy.com
7. 1806: Giuseppangelo Fonzi : Terrometallic teeth.
1817: Antoine Plantou : porcelain teeth to America
1830: Samuel Stockton: produces first porcelain teeth in the US.
1845: SS White : Porcelain teeth on a commercial basis.
1864: Claudius Ash : Tube Teeth
1882: William Herbst : Inlays of pulverized glass.
1884: Charles H Land : Platinum foil technique.
1886 : First successful inlays.
1894: Custer :Porcelain furnace.
1898: Jenkins :low fusing porcelain
1903: Land :porcelain jacket crown
Dental Ceramics :a historical perspective….
www.indiandentalacademy.com
8. 1956: Brecker :ceramometal restorations
1962: Patents of Weinstein and Weinsteinand Weinstein et
al( 1962)
1963: First commercial porcelain :Vita Zahnfabrik
1965: Mc lean and Hughes :aluminous porcelain
1968: Mc Culloch Glass ceramic in dentistry.
1984: Grossman and Adair :Dicor
1985: Hobo and Iwata (Kyocera Bioceram group): Cerapearl.
1983: O’ Brien :high expansion magnesia core
1983: Sozio and Riley : Cerestore.
1984: Corning glass Company( Stookey): First commercial glass
ceramic
1988 :Mormann and Brandestini :CADCAM.
Dental Ceramics :a historical perspective….
www.indiandentalacademy.com
10. Classification of Dental Ceramics: Phillips’
According to use or indications
Anterior
Posterior
Crowns
Veneers
Post and Cores
FPDS
Stain Ceramic
Glaze Ceramic.
www.indiandentalacademy.com
11. According to firing temperature:
Ultralow fusing< 8500
C
Low fusing 850-11000
C
Medium fusing 11010
C-13000
C
High fusing>13000
C:
Classification of Dental Ceramics: Phillips’
High fusing 1200/14500
C.
Medium fusing 1050/12000
C.
Low fusing 850/1050 0
C
High fusing( 850-1100)
Low fusing( < 850)
www.indiandentalacademy.com
12. High fusing:
Minimizing the additives such as sodium or potassium,
Maximizing the silicate cross links.
Low solubility, high strength and high stability.
Hardness exceeds enamel by 30%.
Classification of Dental Ceramics:
www.indiandentalacademy.com
13. Medium fusing:
fired under vacuum with air admitted at the end of
firing
Low fusing:
increasing the amount of additives in porcelain
reducing the number of crosslinks within the silicate network
It helps to avoid overheating the metal framework
slightly weaker and less stable than high fusing
fired under vacuum.
Classification of Dental Ceramics:
www.indiandentalacademy.com
14. Ultra low fusing:
Coefficient of thermal expansion match titanium
alloys.
Lower firing temperatures -less oxide formation.
Classification of Dental Ceramics: Phillips’
www.indiandentalacademy.com
15. According to the
processing method:
Sintering
Partial sintering
Glass infilteration
CADCAM
Copy milling.
According to microstructure
Glass
Crystalline.
Crystal containing glass.
Classification of Dental Ceramics: Phillips’
www.indiandentalacademy.com
16. According to composition/Type:
Feldspathic porcelain
Leucite-reinforced
porcelain
Aluminous porcelain
Alumina
Glass-infiltrated alumina
Glass-infiltrated spinel
Glass-infiltrated zirconia
Glass ceramic
According to translucency
Opaque
Translucent
Transparent.
Classification of Dental Ceramics: Phillips’
www.indiandentalacademy.com
17. According to application:
Core Porcelain.
Dentin or Body Porcelain
Enamel or incisal porcelain
According to the method of firing
Air fired.
Vacuum fired.
Classification of Dental Ceramics: Phillips’
www.indiandentalacademy.com
18. Craig:
All ceramic
Machined
Slip cast
Heat pressed
Sintered.
Ceramic- metal
Sintered.
Denture teeth.
Manufactured.
Classification of Dental Ceramics:
www.indiandentalacademy.com
19. Silicate ceramics Oxide ceramics Glass ceramics
Principal AMORPHOUS
glass phase with porous
structure i.e. mainly silica
(SiO2)
Principal CRYSTALLINE
phase e.g. Al2O3, MgO,
ZrO2
Principal AMORPHOUS
glass phase
Also contain crystals e.g.
K2O, Al2O3, MgO, ZrO2
None or small glass
phase content
Crystal phase induced
by controlled
crystallization
(feldspathic or
aluminous)
e.g.zirconia (ZrO2)
Pure alumina
e.g. Dicor glass ceramic
www.indiandentalacademy.com
20. Single unit crowns.
Porcelain Jacket Crowns.
Metal Ceramic Crown or PFMcrowns.
Castable glass ceramic crowns.
Veneers for crowns and bridges.
Artificial teeth.
Inlays and Onlays.
Ceramic Brackets used in Orthodontia.
Applications of dental ceramics:
www.indiandentalacademy.com
24. Esthetic alternative to discolored teeth.
Esthetic alternative :grossly decayed carious teeth.
Congenital anamolies
Veneers
Inlays
Onlays
Abutment retainers
Denture tooth materials.
Orthodontics as ceramic brackets.
Indications for ceramics:
www.indiandentalacademy.com
25. Young permanent teeth.
Small short or thin crowns( relative contraindications)
PFM not indicated in high lip line patients.
Teeth round in cross section OR
Teeth more axially tapered than usual.
Abusive bite.
Patient’s lifestyle susceptible to trauma.
Contraindications:
www.indiandentalacademy.com
26. Biocompatibility
Esthetics:
Color and translucency
Capable of being pigmented.
Colour stability.
Stain resistance.
Chamaleon like effect
Durability: Wear resistance and low solubility.
Ability to form precise shapes
High stiffness
High melting point.
Low thermal conductivity
Low electrical conductivity.
Advantages
www.indiandentalacademy.com
27. Brittle: Low fracture toughness.
High firing shrinkage of conventional porcelains.
Attrition of opposing teeth.
More tooth reduction.
Cervical bulge and metal line in case of PFM restoration
Technique sensitive.
Specialized training required.
Expensive equipment required.
Difficult to repair if fails.
Cannot be repaired if the shade is altered.
Patient may complain of crackling sound on biting.
Disadvantages:
www.indiandentalacademy.com
29. Composition of various porcelains( %)
Material Kaolin Silica
( Quartz)
Feldspar
( Binder)
Glasses
Decorative
porcelain
50 25 25 0
High fusing
dental
4 15 80 0
Low fusing
dental
0 25 60 15
www.indiandentalacademy.com
30. Tile sanitory ware
Porcelain artware
Bone china
dinnerware
Dental
porcelain
Silica
ClayFeldspar
www.indiandentalacademy.com
31. Composition of Dental Porcelain
Feldspar 60-80%( Basic glass former)
Kaolin- 3-5%( Binder)
Quartz- 15-25%( Filler)
Alumina-8-20%( Glass former)
Boric oxide-2-7%(Glass former and fluxes)
Oxides of Na, K and Ca -9-15%(Fluxes or glass
modifiers)
Metallic pigments less than 1%(Color matching)
www.indiandentalacademy.com
32. Naturally occurring double silicate of potassium and
aluminium.K20.Al2O36SiO2
Dentistry: Potash Feldspar:
Increased resistance to pyroplastic flow
Increased viscosity.
Functions of Feldspar:
Basic Glass former.
During firing fuses to form a matrix and the porcelain
powder particles will fuse together by a process of liquid
phase sintering.
Acts as a flux and surface glaze.
Feldspar (60-80%) Basic glass former
www.indiandentalacademy.com
33. Resistance to pyroplastic flow
Incongruent melting (11500
C and 15300
C )
Leucite:
Large coefficient of thermal expansion (20-25 ppm/0
C.)
thermally compatible with dental casting alloys.
Strengthening material.
Incongruent melting( Peritectic transformation)
Feldspar: Properties
www.indiandentalacademy.com
34. Hydrated aluminium silicate.
Functions:
Binder.
Pyrochemical reaction: rigidity.
Opacity to the mass.
Disadvantages:
White :reduces the translucency of porcelain.
added in small amounts.
Starch or sugar.
Kaolin( 3-5%)Binder
www.indiandentalacademy.com
35. O2
Si4+
Si4+
Si4+
Tetrahedral Silica
Quartz/ Silica (15-25%) Filler
Crystalline quartz
Cristobalite
Tridymite
Amorphous fused quartz.
Below 5750
C Alpha quartz
Above 5750
C Beta quartz
Above 8700
C Tridymite
Above 1470o
C Crystobalite
www.indiandentalacademy.com
36. Functions:
Refractory skeleton
Provides strength and hardness to porcelain during fusing.
Unchanged at the usual firing temperatures : stability to the
mass during heating.
Quartz/ Silica (15-25%)
Grinding Pure Quartz
www.indiandentalacademy.com
37. Functions:
Strength and opacity to the porcelain.
Alters softening point
increases the viscosity of porcelain during firing.
Aluminium oxide( 8-20% glass former)
www.indiandentalacademy.com
38. O2
Si4+
Si4+
Si4+
Sodium carbonate
Lithium carbonate
low fusing glasses.
Function:
Lower the sintering temperature
and increase flow of porcelain.
They also absorb and remove
impurities.
Excess flux:
Reduces the chemical durability
Crystallization and devitrification
Fluxes (9-15%)
Interrupts silica network.
www.indiandentalacademy.com
39. Glass modifiers
Lower the softening temperature.
Increase the CTE.
Decrease viscosity.
Oxides : Sodium, Potassium and Calcium oxide( 9-15%)
Boric oxide- 2-7% is also added for the same purpose.
Water is an important but a weaker glass modifier.
When porcelains are exposed to tensile stresses in moist
environment for long periods
H30+ replaces alkali metal ions in porcelain
slow crack growth
New ultra low fusing porcelains : large amount of sodium oxide and
hydroxyl group to lower the fusion temperature to as low as 6600
C.
www.indiandentalacademy.com
40. Pigments
Feldspars are colorless or greyish.
Color frits
Metallic oxides Glass Feldspar
Ferric oxide, platinum Grey.
Chromium oxide, copper oxide Green
Cobalt salts Blue
Ferrous oxide,nickel oxide Brown
Titanium oxide Yellowish brown
Manganese oxide Lavender
Chromium tin, Chromium alumina Pink
Indium Yellow, ivory
www.indiandentalacademy.com
41. Opacifiers:
Oxides of Cerium, titanium, zirconium and tin.
Ground to a particle size of less than 5 µm.
Differenc in the RI between glass and opacifiers cause more
opalescence.
Fluorescing agents:
Cerium oxide ( eg. Fluorescent bulbs and sunlight).
Fluorescence is the phenomenon in which an object emits light
when it is illuminated by a specific light source, in case of teeth, it
gives an appearance of vitality.
Uranium compounds: Health hazard.
Opacifiers and Fluorescing agents.
www.indiandentalacademy.com
42. Fritting:
•Combination of blending, melting and quenching the glass
components
Frit:
•The resultant product after fritting.
•Components are mixed, fused and quenched
•Cracking and fracturing throughout the fused mass.
•Frit then ground to fine powder.
Manufacture
www.indiandentalacademy.com
43. Pyrochemical reaction occurs and much of the shrinkage is
complete
Technician fuses the porcelain powder, he simply remelts the
fluxes without causing significant increase in reaction
between the components.
Glaze:
• Overglaze.
• Selfglaze.
www.indiandentalacademy.com
44. Overglazes :
Ceramic powders containing more glass modifiers
Lower fusion temperatures.
The coefficient of thermal expansion slightly lower than that of
the body porcelain.
Self glaze:
Constituents of porcelain frit completely melted to form a
single phase glass.
Chemical durability is better due to higher fusion temperature.
Glazes
www.indiandentalacademy.com
45. Strengthening of the material perse.
Methods of designing components.
Methods of strengthening porcelain
www.indiandentalacademy.com
46. Introduction of residual
compressive stresses into the
surface of the material
Interruption of crack propogation
Ion exchange
Thermal tempering
Thermal expansion
coefficient mismatch
Polishing
Dispersion of a crystalline phase
Transformational toughening
Hydrothermal porcelain
www.indiandentalacademy.com
47. Introduction of Residual Compressive Stresses:
The restoration will not yield and fracture due to tensile stress.
The residual stresses must first be negated by developing tensile
stresses before any net tensile stress develop.
www.indiandentalacademy.com
49. Ion Exchange:
GC’s Tuf Coat.
Internal surface of an all ceramic crown
Not recommended for new high- strength porcelains
( i.e. aluminous porcelain, Procera, In- Ceram)
Major Application:
Anterior porcelain jacket crown made from a feldspathic
porcelain without a core.
www.indiandentalacademy.com
50. Thermal Tempering:
Quench hot molten glass in silicone oils or other liquids so as to
uniformly cool the surface.
www.indiandentalacademy.com
51. Thermal Expansion coefficient mismatch:
Fabrication of glass or ceramic in combination with metal.
Ceramic in combination with metal are heated and cooled
The metal of the MCRs has a slightly higher CTE
It contracts more than the porcelain on cooling after firing.
Residual compressive stresses in porcelain.
www.indiandentalacademy.com
52. Advantage:
No major investments
reduces the surface flaws.
dramatically increases the strength by 50- 100%
Shofu or Soflex finishing disks-Reglazing .
Polishing
www.indiandentalacademy.com
54. Dispersion of a crystalline phase
Aluminous Porcelain:
Alumina( Al203) is added in particulate form.
Dicor:
Mica crystals grow in situ when the cast crown in subjected
to heat treatment.
The coefficient of thermal expansion between the crystalline
material and the surrounding glass matrix require a close
match. Eg. Alumina and zirconium.
www.indiandentalacademy.com
55. Transformation Toughening
Transformation toughened Zirconia: a polycrystalline material
Firing temperature:
Tetragonal
Room temperature
Monoclinic( 4.4%)
Stabilization of tetragonal form at room temp.
( 3-8% mass) of calcium and later yttrium or cerium.
Metastable: The trapped energy drives it back to monoclinic under stress
www.indiandentalacademy.com
56. Disadvantages:
Long term instability in the presence of water.
Porcelain compatibility issues
Opacity.
Transformation Toughening
Change in crystal structure under stress to absorb energy from the
crack
www.indiandentalacademy.com
57. Hydrothermal Porcelain
Duceram LFC.
specialized nonfeldspathic composition
forms a plasticized surface layer when hydrated.
Surface hardness is reduced.
Flexural strength is increased.
The increase in strength is due to the plastic nature of
the hydrated surface, which allows for deformation of
surface flaws and prevents them from propogating
through the bulk.
www.indiandentalacademy.com
59. The design should not be subjected to tensile stress.
Sharp line angles on the preparation and coping avoided.
The porcelain thickness should be uniform.
In PJC,the tensile stresses avoided by having favorable occlusion
In PFM, metal should be strong and ductile not allowing flexing.
In brigdes, use greater connector height( 4mm) ,broader connctor
Designing of the components:
www.indiandentalacademy.com
60. Esthetic Properties:
Colour, translucency and vitality .
Chemical stability:
Chemically inert
Some form of fluoride can damage porcelain.
1.23 % ( APF)
8% stannous fluoride Dull and rough within min.
Hydrofluoric acid.
Stannous fluoride( 0.4%) or sodium fluoride(2%) :will not etch .
The etching of the interior with hydrofluoric acid: Bonding.
Phosphoric acid, has very little effect on dental porcelain.
Properties of Ceramics.
www.indiandentalacademy.com
61. Shrinkage on heating:
The linear shrinkage : 11.5% for high fusing porcelain
14% for low fusing porcelain.
CTE should match tooth structure to minimize shrinkage and gap
CTE should be slightly lower than that of the casting alloy
keeping the porcelain in residual compression upon cooling from
firing temperatures.
CTE: 12-13X 10-60
C
Thermal shock failure:
Caused by uneven heating or cooling.
More severe on reheating or glazing a crown than cooling.
Thermal properties:
www.indiandentalacademy.com
62. Compressive strength :good.
Tensile strength: Poor.
Unavoidable surface defects like porosities and microscopic cracks.
When porcelain is placed under tension, stress concentrates around
these imperfections resulting in brittle fracture.
Shear strength: low :due to the lack of ductility
Mechanical properties:
www.indiandentalacademy.com
64. Property Value
Coefficient of thermal
expansion
Feldspathic:6.4-7.8x10-60
C.
Reinforced:12.38-16.23 x10-60
C
Thermal conductivity 2.39 Mcal/s(cm2)( 0C/cm)
Specific gravity 2.2-2.3( true is 2.242)
www.indiandentalacademy.com
65. Fabrication of metal fused to ceramic restoration
Fabrication of coping for metal ceramic prosthesis:
Casting a pure metal( Titanium) or an alloy( High noble, noble
or predominantly base meta) through lost wax process.
Electrodeposition of gold or other metal on a duplicate die.
Burnishing and heat treating metal foils on a die.
CAD- CAM processing of a metal ingot.
The platinum foil matrix is a thin sheet of pure platinum 0.001” thick that is
swaged over a die to form a support for firing the porcelain.
www.indiandentalacademy.com
66. Cleaned by air blasting or sand- blasting.
Degassing:
Formation of an oxide layer.
Removes impurities, prevents formation of bubbles on the oxide surface
This oxide is responsible for the development of a bond between the
metal and porcelain.
Noble metals: Indium and tin
Base metal: Alloys do not need such additions.
Too thick oxide layer leads to poor bond formation.
Degassing
www.indiandentalacademy.com
67. Building up of porcelain:
A plastic mass : Powder and liquid.
With a brush, the plastic mass is applied over the matrix. It is built
to the shape of a crown in layers of core, dentin and enamel.
www.indiandentalacademy.com
68. Application of Wash Opaque
Powder opaque Paste opaque Spray on method
www.indiandentalacademy.com
69. Application of opaque: Hides color and forms bond.
Dentin Layering: Body porcelain Enamel: Incisal porcelain.
www.indiandentalacademy.com
70. The process of bringing the particles closer and of removing the liquid
binder is known as condensation.
Liquid binder :
Distilled water.
Propylene glycol :alumina core build up.
Alcohol or formaldehyde based liquids :opaque or core build up.
Aim : To pack the particles as close as possible in order to reduce the
amount of porosity and shrinkage during firing.
Factors determining the effectiveness of condensation:
Size of the particles:
One size: void space of 45%
Two sizes : 25%
Three or more sizes:22%. Gap Grading System.
Shape of the particles: Round particles :better packing compared to
angular particles.
Condensation
www.indiandentalacademy.com
72. creamy
capable of being transferred in small increments.
High quality sable hair brushes
Advantages of wet brush technique:
Maintains the moisture content in the porcelain.
Metal spatulas causes more rapid drying out.
The brush can be used to introduce enamel colors, effect
masses or stains without changing instruments.
Greater control over small increments.
Blending of enamel veneers
Wet brush technique/
Brush additive technique:
www.indiandentalacademy.com
73. Mild vibration to densely pack the wet powder
upon the underlying matrix.
The excess water :blotted with a tissue.
Serrated handle of a porcelain instrument
lightly passed over the model or die pin.
Vibration:
www.indiandentalacademy.com
74. Spatulation:
Spatula used to apply and
smoothen the porcelain
Disadvantages:
Danger of dislodging the porcelain
particles ,may cause invisible cracks.
The sandpaper like effect of
porcelain on metal
Discoloration of the final product.
www.indiandentalacademy.com
75. Dry Brush technique:
Dry powder sprinkled over the wet porcelain
Disadvantage:
It enhances the risk of porcelain drying out
Control of powder :difficult ,time consuming.
Ultrasonic:
Vibrator.
The low amplitude with high rate of vibrations
per second pulls the liquid to the surface with
almost no disturbance in porcelain contour.
This is a final condensing procedure.
Condensation Methods:
www.indiandentalacademy.com
76. A large soft brush moved in light dusting action over the wet porcelain
Brings excess water to the surface,
Same brush can be used to remove any coarse surface particles along
with excess water.
Combination of vibration and the whipping.
Disadvantage:
This method works best with fine grain,
Excess manipulation could allows these fine particles to float away with
liquid during blotting.
Surface tension of water is the driving force for condensation.
Whipping
www.indiandentalacademy.com
77. Internal or External Stains:
Intrinsic Stain Extrinsic Stain.
Built into the succesive layers of
porcelain.
Placed on the surface of
the final layer.
must be stripped completely
and rebuilt if modifications
are found necessary.
Susceptible to dissolution in
oral fluids as the fusion
temperatures of glazes are
reduced by the addition of
glass modifiers, which
unfortunately lower the
chemical durability.
www.indiandentalacademy.com
78. Pre firing procedures:
If directly in a hot furnace:
it will evolve steam rapidly ,crumble or
explode.
Dry the wet structure in a warm atmosphere
before placing into the hot furnace.
At the elevated temperatures of the furnace,
the starch or sugar binder ignites ;
the surface of the structure blackens.
The door of the furnace is slightly left ajar.
www.indiandentalacademy.com
79. Sintering/ Firing Procedure of Dental Porcelain:
The temperature raised to the firing temperature of the porcelain
10660
C : aluminous core porcelain
9820
C :opaque porcelains.
Densification : Sintering
Partial fusion and bonding of adjacent surfaces of particles rather
than complete melting.
www.indiandentalacademy.com
80. Firing shrinkage: 30-40% by volume.
32-37% :low fusing
28-34% :high fusing. Due to loss of water and sintering.
Porcelain is built up of a larger size before firing.
Porosity:
Air inclusion during firing: Reduce the translucency.
Firing Shrinkage and Porosity:
www.indiandentalacademy.com
82. Electrically heated muffle
Pyrometer :indicates the temperature.
Most furnaces :firing under vacuum.
Reduction in porosity: 4.6% to about 0.5%.
1 Horizontal muffle:
2.Vertical muffle:
Porcelain Furnace:
www.indiandentalacademy.com
83. Air firing :
Voids or bubbles
Inclusion of air during firing
Byproduct of vitrification of feldspar.
Reduced translucency and strength.
Coarse porcelain particles are air fired.
Vacuum:
Dense pore free mass.
Reduced firing temperature.
Diffusible glass:
Diffusible gas like helium, hydrogen or steam.
Media used for firing:
www.indiandentalacademy.com
84. Surface appearance of an unglazed porcelain : “bisque”.
Low Bisque:
Rigid and porous.
Little shrinkage.
Particles lack cohesion
Do not have translucency or glaze.
The grains begin to lense at their contact points.
Medium Bisque:
Cohesion between the particles.
Still porous, lacks translucency and high glaze.
Definite shrinkage.
High Bisque stage:
Shrinkage is complete ,mass exhibits a smooth surface.
Slight porosity.
The body does not appear to be glazed.
Stages in maturity:
Lesser firing: Higher strength and esthetics.www.indiandentalacademy.com
87. Advantages:
High strength.
Ideal for long span bridges.
Excellent fit.
Disadvantages:
Appearance of metal margins.
Discoloration by metals.
Difficulty in producing an appearance of translucency.
Bond failure with metals.
Possible disadvantages of alloys used.
Extensive tooth reduction( 1.75 mm).
Porcelain- Fused- to Metal Alloys:
www.indiandentalacademy.com
88. Indications for metal ceramic restorations.
Discolored teeth.
Grossly decayed carious teeth.
Congenital anamolies.
Abutment retainers.
Splinting mobile teeth.
Occlusal corrections.
Contraindications:
Active caries or untreated periodontal disease.
In young patient with large pulp chambers.
Enamel wear is high and there is insufficient room for M and P.
High lip line.
Where esthetics is of prime importance.
Short and thin crowns.
Metal Ceramic Restorations.
www.indiandentalacademy.com
89. Requirements for alloys for porcelain bonding.
Coefficient of thermal expansion of alloy close or nearly the same
as that of porcelain. High tensile stresses will otherwise develop.
Fusion temperature of the alloy higher than that of the porcelain
so that it resists melt or sag at the firing temperature of porcelain.
The modulus of elasticity: should be high to prevent flexing of metal
framework and hence avoid fracture of porcelain.
Capable of forming bond with porcelain.
Oxide formation which provide a chemical bond.
Capable of wetting porcelain :mechanical bonding.
Should not contain copper or silver.
Should have a high proportional limit, to avoid excess stress on the
porcelain, which is brittle.
www.indiandentalacademy.com
90. Changes in alloys for PFM Restorations.
Platinum
Palladium
Copper
Silver
Melting temperature
1200-13000
C.
Higher elastic properties.
Greater sag resistance.
CTE matching the porcelains.
Poor castability.
www.indiandentalacademy.com
91. Noble metal alloy systems:
High gold: Gold platinum palladium
Low gold: Gold palladium silver
Gold free: Palladium silver
Palladium Copper.
Base metal alloys:
Nickel Chromium alloys without beryllium.
Nickel Chromium alloys with beryllium.
Co- Cr based alloys.
Foil copings
Bonded platinum foil coping.
Swaged gold alloy foil coping.
Cast metal ceramic alloys:
www.indiandentalacademy.com
92. Typical composition for alloys for PFM restorations
% Au Pt Pd Cu Ag Others
High gold 86 9 5 - - -
Low gold 52 38 - - - 9% In
Pd Ag - - 65 - 35 -
Pd Cu - - 80 15 - 5% others
Ni Cr - - - - - 65%Ni,17%Cr
www.indiandentalacademy.com
93. Composition of ceramic for metal ceramic restoration.
Increased CTE.
Tendency to devitrify and appear cloudy.
Should not be subjected to repeated firing cycles.
Soda
Potash
www.indiandentalacademy.com
94. Nature of the metal ceramic bond:
Chemical bonding:
•Primary bonding mechanism for most dental ceramics.
•Adherent oxide layer is essential for good bond formation.
•Precious metal alloy: tin and iridium oxide
•Base metal alloys :chromium oxide.
For good chemical bonding:
•Sandblasting,
•Ultrasonic cleaner
•Oxidation.
www.indiandentalacademy.com
95. Procedure recommended to clean the metal of organic debris and
remove entrapped surface gases such as hydrogen.
Advantage:
Removes volatile contaminants not eliminated by Steam or air abrasion.
Allows specific oxides to form on the surface which help in bonding.
Post oxidation treatment:
To reduce oxide layer:
Acid treatment: Hydroflouric, Hydrochloric or dilute sulfuric acids.
Non acid treatment: Air abrasion with pure 50 μm aluminium oxide.
Oxidation or degassing:
www.indiandentalacademy.com
96. Oxide layer is permanently bonded to the metal substructure
on one side while dental porcelain remains on the other.
Oxide layer sandwiched between the M and P.
Surface oxides dissolve or are dissolved by the opaque layer.
Porcelain is brought into atomic contact with the metal
surface for enhanced wetting by the metal, and direct
chemical bonding by sharing of electrons between porcelain
and metal.
Both covalent and ionic bonds are thought to form, but only a
monomolecular layer of oxide is thought to be responsible for
bonding.
www.indiandentalacademy.com
97. A layer of pure gold is deposited onto the cast metal,
short flash deposition of tin.
Cobalt chromium, stainless steel.
Palladium silver, high and low gold content alloys
Titanium.
Advantages:
Improved wetting of the metal by porcelain.
Electrodeposited layer acts as a barrier to inhibit ion penetration by
the metal
Gold color of the oxide film :vitality and esthetics.
Color control of the oxidated surface from gray to reddish brown to gold
Deposited layer acts as a buffer zone to absorb stresses.
The maturation time and temperature of the porcelain is reduced :highly
reflective surface of the gold layer, and the infrared radiation emitted by
the gold on heating.
Bonding using electrodeposition:
www.indiandentalacademy.com
98. Mechanical interlocking:
Presence of surface roughness
Wettability is important for bonding.
Smaller the contact angle: better is the wetting efficiency.
3. Vanderwaals Forces:
Secondary forces generated by a physical attraction between the
charged particles rather than by actual sharing of electrons
4. Compressive Forces:
Ceramic is strongest under compression and weakest under tension
Hence if the coefficient of thermal expansion of the metal substrate is
greater than the porcelain fired over it, porcelain is under compression.
Nature of the metal ceramic bond
www.indiandentalacademy.com
99. Bond failure classification:
Type I: Metal porcelain:
When the metal surface is totally depleted of
oxide prior to firing porcelain, or
When no oxides are available( Gold alloys).
Also on contaminated porous surface.
Type II: Metal oxide- porcelain:
Base metal alloy system.
The porcelain fractures at the metal oxide
surface
leaving the oxide firmly attached to the metal.
Type III: Cohesive within porcelain:
Tensile fracture within the porcelain when the
bond strength exceeds the strength of the
Metal
Porcelain
Metal
Porcelain
Metal oxide
Metal
Porcelain
Porcelain
Metal oxide
www.indiandentalacademy.com
100. Type IV: Metal- metal oxide:
Base metal alloys
Due to the overproduction of Ni and Cr oxides
The metal oxide is left attached to ceramic.
5.Type V: Metal oxide- Metal oxide
Fracture occurs through the metal because of
the overproduction of oxide causing a sandwich
between porcelain and metal
6. Type VI :Cohesive within metal
Unlikely in individual metal ceramic crowns.
Connector area of bridges.
Metal
Porcelain
Metal oxide
Metal
Porcelain
Metal oxide
Metal oxide
Metal
Porcelain
Metal oxide
www.indiandentalacademy.com
102. Improved bonding on the bondable surface of the metal
can be achieved by the following ways:
•Grit blasting with 30-50µm alumina particles at an air pressure of
0.4 to 0.7 Mpa .
•Electrochemical etching.
•Naturally formed oxides on the base metal surface also contributes
to the bonding when MDP or 4 META based resins are used.
•In noble metals :electrochemically deposit a thin layer of tin( 0.5µm)
on noble metal and heat it to an appropriate temperature to
form metal oxide.
A silica coating can be used to improve bonding to noble and
base metal alloys
Bonding of metallic prosthesis
www.indiandentalacademy.com
103. Bonded platinum foil coping:
Defects originating from the internal
surface of the crown:
Fracture of porcelain.
Tinplating the platinum foil.
Laying down 2 platinum foils in close
approximation with each other.
Inner foil: 0.025 mm platinum
provides a matrix for baking ceramic
Outer foil: forms the inner skin to the crown
tin plated and oxidized
strong chemical bond with aluminous
porcelain crown.
Bonded alumina crown/ twin foil technique: Mc Lean and Sced( 1976)
The inner foil is then removed after porcelain firing.
Bonded gold foil coping: Rogers 1979. UMK68www.indiandentalacademy.com
104. To prevent porcelain from lifting the platinum skirt and spoling the fit:
Cervical Contact technique:
Application of a layer of porcelain on the shoulder area to shrink first.
The second bake will then shrink towards the cervical porcelain and
maintain the fit.
Cervical ditch technique:
Porcelain is removed from the shoulder area after the initial build up is
complete, such that a thinnest ditch possible is made to expose the
cervical platinum at the shoulder.
www.indiandentalacademy.com
105. Removal of platinum foil:
Soaking the crown in water.
A fine pointed tweezer is used to lift the skirt away from the edge.
Peel the platinum away from the entire circumference without
damaging the fine porcelain edge (internally towards the incisal
edge).
www.indiandentalacademy.com
106. Porcelain veneer crowning of adolescent teeth where
minimal tooth preparation is necessary.
Anterior teeth, when metal reinforcement is essential.
In heavily worn teeth, thin or short teeth where minimal
occlusal clearance present (not less than 0.8mm), porcelain
crowning of all anterior teeth is indicated.
Repair of fractured metal- ceramic bridges, when removal of
bridge or splint is undesirable.
Coping jacket crowns on unit built bridge -work
Indications for bonded alumina crowns
www.indiandentalacademy.com
107. In periodontally involved teeth, where preparations extend
deeply into root- face and no shoulder preparations are
possible.
Posterior teeth where large areas of tooth are missing and
uneven bulk of porcelain is inevitable.
If lingual shoulder preparations are impossible particularly in
molar region.
Contraindications for bonded alumina crowns
www.indiandentalacademy.com
108. Dr. Itzhak Shoher and Mr. Aaron Whiteman in Europe
Fabrication of PFM restorations without waxing, investing or casting.
Pleated gold and palladium foil consisting of four layers.
Technology of Clad metals:
4 layers clad in a sandwich fashion under high pressure.
Renaissance Crown( Non cast metal ceramic
system)
0.997 Pure palladium
Gold ceramic alloy
Gold ceramic alloy
24k Pure gold.
The pleats are folded, crimped , burnished and swagged.
Heat treated to permit diffusion of the layers to form a interfacial
material.
www.indiandentalacademy.com
109. Initial adaptation:
The form is placed on the die until it
touches the occlusal or incisal surface
The pleats of the form are then closed
with crimping forceps.
Cutting the folds:
The midpoint of each pleat is determined
Cut is made through the pleat with the
crown scissors provided.
Simultaneously twisted to allow for the
final alloying of the metal during
alloying process.
Renaissance Crown fabrication:
www.indiandentalacademy.com
110. Folding the pleats:
Pleats are then folded in the same direction
with the crimping forceps.
Burnishing the form:
Burnished and closely adapted
Swagging:
After appropriate die spacing,
form and the die and placed in a swagger
Renaissance Crown fabrication:
www.indiandentalacademy.com
111. Alloying:
Propane torch for 4-6 Sec.
Glow brightly , gold will diffuse through the cuts
Interfacial alloy:
It is a metal ceramic solder in powder form
produced by precipitation,
mixed into a creamy paste
applied onto the form.
Renaissance Crown fabrication:
www.indiandentalacademy.com
112. “Capillary casting technology”.( Captek, Davis
Schottlander and Davis, Letchworth, UK)
Principle of capillary attraction to produce a gold
composite metal.
Elimination of casting process .
Procedure:
Adaptation of a wax strip, impregnated with a
gold- platinum- palladium powdered alloy, to a
refractory die. ( Captek P)
Firing procedures produce a rigid porous layer
which is then infilled with gold from a 2ND
wax strip
( Captek G) by capillary action
The finalized metal coping is then veneered
with porcelain.
CAPTEK
www.indiandentalacademy.com
113. Fig shows the metal coping after firing.
The shear bond strength values atleast equal to PFM.
Composite
Gold matrix reinforced with small particles of Pt-Pd- Au
alloy
The inner and outer surfaces contain approximately
97% Au. The grain size of the foil is 15-20µm.
High melting temperature
Capillary effect when ceramic is applied.
Advantages of CAPTEK:
Improve marginal fit(capillary cast, rather than lost wax )
Enhanced esthetics.
Biocompatibility.
www.indiandentalacademy.com
Editor's Notes
If the surface is treated to introduce a residual compressive stress which is higher than tensile stress, the resultant stress on the surface would still be a compressive stress.
During the exchange process, the larger potassium ions squeeze into the spaces occupied by smaller sodium ions ( Stuffing) and exert residual compressive stress on the surface. Consequently, the flexural strength of the porcelain is increased as long as the surface is not damaged by grinding.
In this process, the outer ‘skin’ of molten glass is frozen rapidly by jets of air. Later when the inner core solidifies, it ‘pulls’ on the outer skin, creating residual compressive stresses.
In crown fractures, failure is often initiated from scratches on the internal surface of the crowns.It is foolish to place an expensive high strength ceramic material in the mouth in roughened state. PFM restorations are much less sensitive to these flaws
It is another method of strengthening ceramics by reinforcing it with a dispersed phase of a different material that is capable of hindering a crack from propagating through the material.
Unlike alumina, zirconium oxide is transformed from one crystalline state to another during firing. At firing temperature Zirconia is tetragonal and at room temperature it is monoclinic, with a unit cell of monoclinic occupying about 4.4% more volume than when tetragonal. Unchecked, this transformation was unfortunate because it led to the crumbling of the material on cooling. In the late 1980s, ceramic engineers learned to stabilize the tetragonal form at room temperature by adding small amounts( 3-8% mass) of calcium and later yttrium or cerium. Although stabilized at room temperature, the tetragonal form is “ metastable”, meaning that trapped energy exists within the material to drive it back to the monoclinic state. The highly localized stress ahead of the propogating crack will transform the ceramic back to monoclinic. The 4.4% volume increase becomes beneficial, essentially squeezing the crack closed.
Molecular water has been detected in the glass structure.
When a crown is removed from the surface and cooled in air, the surface will be losing heat more rapidly and contract faster than the interior and will be placed in compression by balancing tensile stress developed either in the core porcelain or metal coping due to their high thermal expansion.
High quality sable hair brushes are used to rapidly transfer small increments of wet porcelain to the metal substructure using the fine point of a sable brush.
The brush can be used to introduce enamel colors, effect masses or stains without changing instruments.
The door of the furnace is slightly left ajar during this stage to allow the products of combustion to escape. The furnace door is then closed and firing is completed.
The furnace temperature is raised at a constant rate until a specific temperature is reached: Temperature method.
Temperature time method:This method involves raising the temperature at a given rate until certain levels are reached, after which the temperature is maintained for a measured period of time until the desired reactions are completed.
completed.
Large sized particles have fewer but larger air voids between them compared to the small sized particles. Fewer bubbles, even of large size give improved translucency.
On the other hand, fine sized particles have multiple small air bubbles present in between the, which makes them slightly opaque. It is therefore clear that porcelain powders fired in air must be necessarily of coarse nature.
Prior to the first dentine firing, the individual units
of bridges must be separated in the interproximal areas
down to the substructure.
Prior to the first dentine firing, the individual units
of bridges must be separated in the interproximal areas
down to the substructure. Cooling:
Whenever porcelain work is heated or cooled, the process must be carried out slowly. Porcelain is a poor conductor of heat and is brittle. Rapid cooling would result in cracking and loss of strength.
Prior to glaze firing,
the entire surface must be ground evenly and then grinding
dust must be thoroughly removed.