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 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.
The document discusses the process of casting in dentistry. It begins with an introduction defining casting and its objective in dentistry. It then covers the history of casting in dentistry from ancient times through modern developments. The basic steps of casting are outlined, including spruing, investing, burnout, casting, recovery and cleaning. Different materials used for sprue formers, crucible formers, casting rings and liners are described. The document provides details on investing, burnout, and high and low heat techniques for casting gold and other alloys.
This document provides information about dental waxes. It discusses the history and development of dental waxes, how they are classified, their composition, desirable properties, and types. It describes how dental waxes are used to make patterns for dental restorations and appliances. It covers the thermal properties of dental waxes and how they can distort if not handled properly. The document summarizes different types of dental waxes and their uses in dentistry.
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.
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.
This document discusses different types of dental waxes, including their definitions, classifications, components, properties and uses. The main types covered are modelling wax, inlay wax, casting wax, boxing wax and sticky wax. For each type, the document outlines their composition, melting range, properties and intended uses. Thermal properties like solid-solid transition temperature, coefficient of thermal expansion and melting range are discussed for dental waxes in general.
Zinc polycarboxylate cement sets through an acid-base reaction between zinc oxide and polyacrylic acid. It exists as a powder containing zinc oxide, magnesium oxide, and polyacrylic acid, and as a liquid containing polyacrylic acid and water. The powder and liquid are mixed together, with the polyacrylic acid chelating with the zinc oxide to form a matrix of zinc polyacrylate salt surrounded by undispersed zinc oxide particles. Zinc polycarboxylate cement has mechanical strength comparable to zinc phosphate cement, adheres chemically to tooth structure and metals, and has a film thickness similar to zinc phosphate cement. It is less irritating to the pulp than zinc phosphate cement due to becoming
This document provides instructions for preparing a class II amalgam tooth restoration. It describes initially outlining the occlusal surface and including all pits and fissures. The proximal box is then prepared by isolating the proximal enamel, creating a proximal ditch, and extending the facial and lingual walls. Retention features like locks and grooves are prepared, and the walls are finished with bevels. Final steps include cleaning, inspecting, and applying varnishes or desensitizers to the prepared cavity.
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.
The document discusses the process of casting in dentistry. It begins with an introduction defining casting and its objective in dentistry. It then covers the history of casting in dentistry from ancient times through modern developments. The basic steps of casting are outlined, including spruing, investing, burnout, casting, recovery and cleaning. Different materials used for sprue formers, crucible formers, casting rings and liners are described. The document provides details on investing, burnout, and high and low heat techniques for casting gold and other alloys.
This document provides information about dental waxes. It discusses the history and development of dental waxes, how they are classified, their composition, desirable properties, and types. It describes how dental waxes are used to make patterns for dental restorations and appliances. It covers the thermal properties of dental waxes and how they can distort if not handled properly. The document summarizes different types of dental waxes and their uses in dentistry.
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.
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.
This document discusses different types of dental waxes, including their definitions, classifications, components, properties and uses. The main types covered are modelling wax, inlay wax, casting wax, boxing wax and sticky wax. For each type, the document outlines their composition, melting range, properties and intended uses. Thermal properties like solid-solid transition temperature, coefficient of thermal expansion and melting range are discussed for dental waxes in general.
Zinc polycarboxylate cement sets through an acid-base reaction between zinc oxide and polyacrylic acid. It exists as a powder containing zinc oxide, magnesium oxide, and polyacrylic acid, and as a liquid containing polyacrylic acid and water. The powder and liquid are mixed together, with the polyacrylic acid chelating with the zinc oxide to form a matrix of zinc polyacrylate salt surrounded by undispersed zinc oxide particles. Zinc polycarboxylate cement has mechanical strength comparable to zinc phosphate cement, adheres chemically to tooth structure and metals, and has a film thickness similar to zinc phosphate cement. It is less irritating to the pulp than zinc phosphate cement due to becoming
This document provides instructions for preparing a class II amalgam tooth restoration. It describes initially outlining the occlusal surface and including all pits and fissures. The proximal box is then prepared by isolating the proximal enamel, creating a proximal ditch, and extending the facial and lingual walls. Retention features like locks and grooves are prepared, and the walls are finished with bevels. Final steps include cleaning, inspecting, and applying varnishes or desensitizers to the prepared cavity.
This document discusses various materials used for fabricating dental dies, including their properties and uses. It covers gypsum products like dental stone (Type III and high-strength Type IV and V stones), electroformed dies using copper or silver plating, epoxy resins, and flexible die materials like polyvinyl and polyurethane. Each material has advantages like detail reproduction, strength and disadvantages like shrinkage, toxicity or incompatibility with some impression materials. Newer ceramic and CAD/CAM die materials are also introduced that are strong and dimensionally stable.
Fundamentals in tooth preparation, Now many indications for treatment for teeth are not due to caries and, therefore, the preparation of the tooth is no longer referred to as cavity preparation but as tooth preparation, and the term cavity is used only as a historical reference.
NOMENCLATURE
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.
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.
The cast metal restoration is versatile and is especially applicable to Class II onlay preparations. The process has many steps, involves many dental materials, and requires meticulous attention to prepration.
Tooth treatment planned to be restored with an intracoronal restoration, but the decay or fracture is so extensive that a direct restoration, such as amalgam or composite, would not be able to sustain or bear forces.
Additionally, when decay or fracture incorporate areas of cusp or remaining tooth structure that undermines perimeter walls of a tooth, an onlay might be indicated.
This document discusses dentin bonding agents. It provides background on adhesion and the challenges of bonding to dentin compared to enamel. Key points discussed include:
- Conditioning of dentin is needed to remove the smear layer and expose collagen fibers. This can be done chemically using acids or chelators.
- Primers are then used which contain both hydrophilic and hydrophobic monomers. They displace water from the moist collagen network and allow resin infiltration.
- The concept of "wet bonding" was introduced, in which acid-etched dentin is kept moist during bonding to maintain the expanded collagen network for resin penetration.
This document provides an overview of dental adhesion and dentin bonding. It discusses the basic concepts and requirements of adhesion, applications of adhesive restorative techniques, enamel and dentin adhesion mechanisms, and challenges in dentin bonding. It also summarizes the generations of dentin bonding agents from the beginning in the 1950s to current techniques, noting limitations and improvements over time in bonding strength and stability of the bond. The goal has been to develop adhesive systems that can effectively bond to tooth structure, withstand stresses from polymerization, and resist degradation in the oral cavity.
ANATOMICAL LANDMARKS OF EDENTULOUS MAXILLAAamir Godil
This document discusses the anatomical landmarks of the maxilla that are important for complete denture construction. It defines stress bearing areas, relief areas, and limiting areas. Stress bearing areas include the postero-lateral slopes of the hard palate, residual alveolar ridge, rugae, and maxillary tuberosity. Relief areas are the incisive papilla, mid-palatine raphae, zygomatic process, sharp spiny spicules, torus palatinus, and cuspid eminence. Limiting areas are the labial frenum, labial vestibule, buccal frenum, buccal vestibule, anterior and posterior vibrating lines,
An introductory and simple guide assembled by dental students and reviewed by Dr. Hasannin Al-Namel. our seminar about impression trays used in prosthodontics
The document provides an overview of denture base resins including their definition, history, classification, key ingredients, and properties. It discusses the early use of materials like ivory, bone, and porcelain for dentures and the later development of vulcanite in the 1840s as the first affordable and workable material. Polymethyl methacrylate (PMMA) was introduced in the 1930s and became the standard material by 1946, providing improved properties over previous materials. The document outlines the polymerization process and ideal requirements for denture base resins based on biocompatibility, durability, and other factors. Heat-cured PMMA denture base resin is currently the most widely used material.
This document discusses different types of compensating curves used in dental prosthetics to establish balanced articulation during jaw movements. It describes the anteroposterior and mediolateral compensating curves that begin with the first replacement tooth and continue through the second molar. It also outlines the curve of spee from the mandibular canine through the condyle, the curve of Wilson to arrange the lower molars, and the curve of Monson connecting the curve of spee and Wilson to all cusps on a 4 inch radius.
This document outlines the clinical and laboratory steps involved in fabricating complete dentures. It begins with an introduction and then describes each step in detail, including: primary and secondary impressions, making a special tray, the master cast, bite rim, jaw relations, mounting on an articulator, try in, denture processing through compression molding, and finishing and polishing. The overall process involves close collaboration between the clinician and dental technician to create functional and aesthetic complete dentures for edentulous patients.
This document provides information on partial veneer crowns, including definitions, types, indications, contraindications, advantages, disadvantages, and principles of tooth preparation. Partial veneer crowns restore all but one surface of a tooth, usually not covering the facial surface. They are indicated for teeth with moderate tooth structure loss where the buccal wall is intact. Preparation involves preserving tooth structure, creating retention forms, and maintaining marginal integrity. Proper groove placement and clearance from adjacent teeth are important.
The document discusses five factors that affect occlusal balance: condylar inclination, occlusal plane inclination, incisal guidance, cuspal inclination, and compensating curve. It explains that maintaining a balanced occlusion requires balancing these factors using Theilman's formula. If one factor such as incisal guidance is increased, another such as the compensating curve must also be increased to prevent posterior disclusion. Minimizing incisal guidance in complete dentures can help minimize imbalanced tipping forces.
This document discusses procedures for boxing master impressions and making master casts. It describes two methods for boxing maxillary impressions using either pumice and plaster or wax rods and strips. For mandibular impressions, a layer of adhesive or wax is applied to the impression border before adding a wax land and boxing wax enclosure. Master casts are poured in stone, trimmed with a 4-6mm peripheral roll and notches added for remounting. Landmarks like the incisive papilla and retromolar pad midpoint are marked on casts.
This document provides an overview of various types of dental cements. It begins with definitions and a brief history of dental cements. It then classifies cements based on their ingredients and discusses their ideal requirements. The document goes on to describe specific cement types in detail, including their characteristics, properties, and uses. It covers traditional cements like zinc phosphate, as well as contemporary materials like resin-modified glass ionomers. The document provides a comprehensive reference on the formulation and application of different dental cements.
8 - setting of teeth for class I, II and II arch relation ship (Edited)Amal Kaddah
Prosthetic Problems and possible solutions in Setting –up
of teeth for skeletal Class II and Class III arch relationship
of completely edentulous patients
Prof. Amal F. Kaddah
This document provides information about inlay restorations, including definitions, indications, contraindications, advantages, disadvantages, materials used, tooth preparation design, and impression techniques. It begins with an introduction to inlays and their history. Key points covered include that inlays are cast restorations used to restore damaged teeth while preserving tooth structure. Proper tooth preparation design with features like taper, bevels, and flares are described to maximize retention and adaptation of the inlay restoration. The document provides details on tooth preparation for class II inlays.
This document summarizes the key steps in denture processing using compression molding technique:
1. A trial denture is prepared and disarticulated from the cast.
2. The cast and trial denture are invested in dental stone in a flask.
3. The wax is boiled out of the flask. Retention grooves are placed on the artificial teeth.
4. Acrylic resin is mixed, packed into the flask, cured, cooled, and deflasked to produce the final denture.
5. The denture is then finished and polished.
This document provides information on various dental materials including:
1. Cement base materials are used for lining, luting, and temporary fillings. Investment materials like gypsum and phosphate bonded investments are used to form molds for casting gold and dental alloys.
2. Cold cure acrylic is used for trays and record bases, while heat cure acrylic is used for complete and partial dentures. Relining materials like soft acrylic are used to improve denture comfort or fit.
3. Peroxide cleansers and dilute hypochlorite solutions are used as denture cleansers, though the latter should not be used with metals. Waxes like inlay, denture casting
Condensation and firing in porcealin /certified fixed orthodontic courses by ...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
This document discusses various materials used for fabricating dental dies, including their properties and uses. It covers gypsum products like dental stone (Type III and high-strength Type IV and V stones), electroformed dies using copper or silver plating, epoxy resins, and flexible die materials like polyvinyl and polyurethane. Each material has advantages like detail reproduction, strength and disadvantages like shrinkage, toxicity or incompatibility with some impression materials. Newer ceramic and CAD/CAM die materials are also introduced that are strong and dimensionally stable.
Fundamentals in tooth preparation, Now many indications for treatment for teeth are not due to caries and, therefore, the preparation of the tooth is no longer referred to as cavity preparation but as tooth preparation, and the term cavity is used only as a historical reference.
NOMENCLATURE
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.
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.
The cast metal restoration is versatile and is especially applicable to Class II onlay preparations. The process has many steps, involves many dental materials, and requires meticulous attention to prepration.
Tooth treatment planned to be restored with an intracoronal restoration, but the decay or fracture is so extensive that a direct restoration, such as amalgam or composite, would not be able to sustain or bear forces.
Additionally, when decay or fracture incorporate areas of cusp or remaining tooth structure that undermines perimeter walls of a tooth, an onlay might be indicated.
This document discusses dentin bonding agents. It provides background on adhesion and the challenges of bonding to dentin compared to enamel. Key points discussed include:
- Conditioning of dentin is needed to remove the smear layer and expose collagen fibers. This can be done chemically using acids or chelators.
- Primers are then used which contain both hydrophilic and hydrophobic monomers. They displace water from the moist collagen network and allow resin infiltration.
- The concept of "wet bonding" was introduced, in which acid-etched dentin is kept moist during bonding to maintain the expanded collagen network for resin penetration.
This document provides an overview of dental adhesion and dentin bonding. It discusses the basic concepts and requirements of adhesion, applications of adhesive restorative techniques, enamel and dentin adhesion mechanisms, and challenges in dentin bonding. It also summarizes the generations of dentin bonding agents from the beginning in the 1950s to current techniques, noting limitations and improvements over time in bonding strength and stability of the bond. The goal has been to develop adhesive systems that can effectively bond to tooth structure, withstand stresses from polymerization, and resist degradation in the oral cavity.
ANATOMICAL LANDMARKS OF EDENTULOUS MAXILLAAamir Godil
This document discusses the anatomical landmarks of the maxilla that are important for complete denture construction. It defines stress bearing areas, relief areas, and limiting areas. Stress bearing areas include the postero-lateral slopes of the hard palate, residual alveolar ridge, rugae, and maxillary tuberosity. Relief areas are the incisive papilla, mid-palatine raphae, zygomatic process, sharp spiny spicules, torus palatinus, and cuspid eminence. Limiting areas are the labial frenum, labial vestibule, buccal frenum, buccal vestibule, anterior and posterior vibrating lines,
An introductory and simple guide assembled by dental students and reviewed by Dr. Hasannin Al-Namel. our seminar about impression trays used in prosthodontics
The document provides an overview of denture base resins including their definition, history, classification, key ingredients, and properties. It discusses the early use of materials like ivory, bone, and porcelain for dentures and the later development of vulcanite in the 1840s as the first affordable and workable material. Polymethyl methacrylate (PMMA) was introduced in the 1930s and became the standard material by 1946, providing improved properties over previous materials. The document outlines the polymerization process and ideal requirements for denture base resins based on biocompatibility, durability, and other factors. Heat-cured PMMA denture base resin is currently the most widely used material.
This document discusses different types of compensating curves used in dental prosthetics to establish balanced articulation during jaw movements. It describes the anteroposterior and mediolateral compensating curves that begin with the first replacement tooth and continue through the second molar. It also outlines the curve of spee from the mandibular canine through the condyle, the curve of Wilson to arrange the lower molars, and the curve of Monson connecting the curve of spee and Wilson to all cusps on a 4 inch radius.
This document outlines the clinical and laboratory steps involved in fabricating complete dentures. It begins with an introduction and then describes each step in detail, including: primary and secondary impressions, making a special tray, the master cast, bite rim, jaw relations, mounting on an articulator, try in, denture processing through compression molding, and finishing and polishing. The overall process involves close collaboration between the clinician and dental technician to create functional and aesthetic complete dentures for edentulous patients.
This document provides information on partial veneer crowns, including definitions, types, indications, contraindications, advantages, disadvantages, and principles of tooth preparation. Partial veneer crowns restore all but one surface of a tooth, usually not covering the facial surface. They are indicated for teeth with moderate tooth structure loss where the buccal wall is intact. Preparation involves preserving tooth structure, creating retention forms, and maintaining marginal integrity. Proper groove placement and clearance from adjacent teeth are important.
The document discusses five factors that affect occlusal balance: condylar inclination, occlusal plane inclination, incisal guidance, cuspal inclination, and compensating curve. It explains that maintaining a balanced occlusion requires balancing these factors using Theilman's formula. If one factor such as incisal guidance is increased, another such as the compensating curve must also be increased to prevent posterior disclusion. Minimizing incisal guidance in complete dentures can help minimize imbalanced tipping forces.
This document discusses procedures for boxing master impressions and making master casts. It describes two methods for boxing maxillary impressions using either pumice and plaster or wax rods and strips. For mandibular impressions, a layer of adhesive or wax is applied to the impression border before adding a wax land and boxing wax enclosure. Master casts are poured in stone, trimmed with a 4-6mm peripheral roll and notches added for remounting. Landmarks like the incisive papilla and retromolar pad midpoint are marked on casts.
This document provides an overview of various types of dental cements. It begins with definitions and a brief history of dental cements. It then classifies cements based on their ingredients and discusses their ideal requirements. The document goes on to describe specific cement types in detail, including their characteristics, properties, and uses. It covers traditional cements like zinc phosphate, as well as contemporary materials like resin-modified glass ionomers. The document provides a comprehensive reference on the formulation and application of different dental cements.
8 - setting of teeth for class I, II and II arch relation ship (Edited)Amal Kaddah
Prosthetic Problems and possible solutions in Setting –up
of teeth for skeletal Class II and Class III arch relationship
of completely edentulous patients
Prof. Amal F. Kaddah
This document provides information about inlay restorations, including definitions, indications, contraindications, advantages, disadvantages, materials used, tooth preparation design, and impression techniques. It begins with an introduction to inlays and their history. Key points covered include that inlays are cast restorations used to restore damaged teeth while preserving tooth structure. Proper tooth preparation design with features like taper, bevels, and flares are described to maximize retention and adaptation of the inlay restoration. The document provides details on tooth preparation for class II inlays.
This document summarizes the key steps in denture processing using compression molding technique:
1. A trial denture is prepared and disarticulated from the cast.
2. The cast and trial denture are invested in dental stone in a flask.
3. The wax is boiled out of the flask. Retention grooves are placed on the artificial teeth.
4. Acrylic resin is mixed, packed into the flask, cured, cooled, and deflasked to produce the final denture.
5. The denture is then finished and polished.
This document provides information on various dental materials including:
1. Cement base materials are used for lining, luting, and temporary fillings. Investment materials like gypsum and phosphate bonded investments are used to form molds for casting gold and dental alloys.
2. Cold cure acrylic is used for trays and record bases, while heat cure acrylic is used for complete and partial dentures. Relining materials like soft acrylic are used to improve denture comfort or fit.
3. Peroxide cleansers and dilute hypochlorite solutions are used as denture cleansers, though the latter should not be used with metals. Waxes like inlay, denture casting
Condensation and firing in porcealin /certified fixed orthodontic courses by ...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
construction of dental restoration Dental waxes Casting investment dental mat...Dr-Faisal Al-Qahtani
The document discusses materials used for constructing indirect metallic dental restorations using the lost wax technique. It describes the key materials needed: dental waxes to construct the wax pattern, casting investment materials to construct the mold, and metallic alloys as the restorative material. It provides details on types of dental waxes including their properties and uses. It also explains the different types of casting investment materials based on their composition and binder, and summarizes their key characteristics including dimensional changes, interfacial properties, strength, and chemical properties.
Lab procedures in complete denture prosthodontics /certified fixed orthodonti...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
This document discusses various types of waxes used in dentistry, their compositions, properties, and applications. It covers natural waxes like beeswax, paraffin wax, and carnauba wax as well as synthetic waxes. Key waxes discussed include inlay pattern wax, casting wax, and baseplate wax. Inlay pattern wax is a blend designed to have good flow properties at mouth temperature as well as dimensional stability when solidified. Casting wax is used to make patterns for crowns and bridges and must vaporize completely during the burnout process. Baseplate wax is pink-colored and formulated to be soft enough to establish jaw relations during initial denture fabrication.
This document provides information on various types of waxes used in dentistry. It discusses the composition, properties, and uses of pattern waxes, casting waxes, baseplate waxes, sticky waxes, and disclosing waxes. The key properties of waxes discussed are their melting ranges, coefficients of thermal expansion, flow, and residual stresses. Methods for manipulating waxes include using heat sources like Bunsen burners, wax annealers, and infrared lamps. Wax patterns can be made using direct or indirect techniques.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
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.
Condensation is the process of packing porcelain powder particles together and removing liquid binder. It improves bonding to the metal framework and decreases bubbles, improving strength, translucency and esthetics. Denser condensation results in less firing shrinkage and stronger porcelain. Vibration and spatulation techniques provide the densest condensation and strongest porcelain structure compared to other techniques like brush application or no condensation. Proper condensation technique and avoiding air bubbles is more important for strength and shade than the degree of condensation itself.
Factors that influence adhesive bonding include wettability, surface energy, and enamel/dentin structure. Wettability is characterized by contact angle and affects how well an adhesive can flow onto a surface. Surface energy must be high enough for attraction between substrates. Enamel etching creates irregularities that resin can infiltrate to form microtags, increasing bond strength. Dentin bonding is more complex due to its moisture and tubule structure. Pretreatment is needed to allow resin infiltration and optimize bonding to both tissues.
This document provides an overview of pit and fissure sealants. It begins with definitions of pits and fissures and discusses the morphology of pits and fissures. It then covers the history of sealants, types of sealants, indications and contraindications for sealant application. The document outlines the steps for sealant application and factors affecting retention. It also discusses cost-effectiveness and preventive resin restorations. Public health sealant programs and conclusions are briefly mentioned.
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.
The document summarizes research on factors that affect the incomplete seating of cemented crowns. It finds that film thickness of cement is often greater than ADA specifications due to a "filtration process" where cement particles accumulate at the occlusal surface as the crown is seated. Proper cement application technique and features like venting crowns or internal relief can help address this. The optimal cementation force is 5kg for 1 minute to reduce film thickness.
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
This document discusses different techniques for fabricating collarless metal-ceramic restorations with porcelain shoulders. It describes the platinum foil matrix technique, direct lift (cyanoacrylate resin) technique, and porcelain wax technique. The platinum foil technique uses a platinum matrix welded to the framework to support the porcelain during firing. The direct lift technique applies cyanoacrylate resin to the die and builds porcelain directly onto it. The porcelain wax technique uses a mixture of body porcelain and wax applied to the die for final adaptation of the porcelain margin. All three techniques aim to provide esthetic porcelain margins without compromising marginal fit or strength.
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
The document discusses Portland cement concrete (PCC) and its composition. PCC is a heterogeneous material made of aggregates, cement paste, and air voids. It exists in three states - plastic, curing, and hardened. The cement paste is a complex matrix that undergoes hydration and hardening over time. Proper mix design and curing are essential to developing the desired properties and ensuring durability of the final concrete material. Factors like water-cement ratio, aggregate selection and gradation, and void structure influence strength, permeability, shrinkage, and other characteristics.
This document discusses dentin bonding agents. It begins with an introduction to adhesive dentistry and the importance of bonding to enamel and dentin. It then covers the basic concepts of adhesion, mechanisms of dental adhesion, and factors that affect bonding. The document discusses the evolution of dentin bonding agents through multiple generations as the technology advanced. It provides details on the components of dentin bonding agents including etchants, primers, and adhesives. In summary, this document provides a comprehensive overview of dentin bonding agents and the principles behind adhesive dentistry.
This document discusses self-compacting fiber reinforced concrete (SCFRC). It defines SCFRC as concrete that can flow under its own weight and fill formwork without vibration. The document outlines different fiber types that can be used in SCFRC including steel, plastic, glass, carbon and natural fibers. It also describes tests conducted on SCFRC mixtures, such as slump flow and V-funnel tests. The document analyzes the influence of factors like aggregate size and shear span-to-depth ratio on the shear strength of SCFRC beams. It concludes that SCFRC provides benefits like higher strength and durability compared to normal concrete.
Introduction
Types Of Fibers
Production Of SCFRC
Fresh Concrete Tests
Concrete Mixing And Casting Of Beams
Influence Of Concrete Type And Coarse Aggregate Characteristics On Shear
Influence Of Shear Span To Depth Ratio On Shear
Influence Of Beam Size On Shear
Advantages
Conclusions
References
The document summarizes various physical properties of dental composites, including:
1) Working and setting time is on demand for light-cured composites, but the reaction continues for 24 hours. Incremental placement techniques are recommended to reduce polymerization shrinkage stress.
2) Water sorption and solubility can cause staining, degradation of mechanical properties, and marginal gaps over time.
3) Composites have lower hardness, strength, and elastic modulus than enamel but provide sufficient resistance to function stresses in anterior restorations. Radiopacity allows detection on x-rays.
1. The document discusses various orthodontic bonding materials and techniques, including advantages and disadvantages of different etching methods, primers, and adhesives. It provides details on bonding procedures and factors that influence bond strength.
2. Various etching agents are compared, including phosphoric acid and maleic acid. Self-etching primers are also discussed. Advantages include less discomfort, etching, and discoloration compared to conventional etching, though they have lower bond strength.
3. Adhesives covered include composites, glass ionomers, and resin-modified glass ionomers. Composites provide higher bond strength but more removal is required after debonding. Glass ionomers have lower bond strength but easier removal
1. Ceramic strengthening techniques aim to reduce tensile stresses by introducing compressive stresses. Methods include dispersion strengthening by adding crystalline particles, metal bonding, thermal tempering, and ion exchange.
2. Proper design and fabrication techniques are important to maximize ceramic strength. These include adequate thickness, rounded line angles, sufficient occlusal reduction, and controlling stresses from bonding cement.
3. Newer high-strength ceramics like zirconia use phase transformations to toughen the material. Stresses from the monoclinic to tetragonal phase change on cooling inhibit crack propagation.
Dental cements have been used for a long time in dentistry and serve purposes like retaining restorations. They are classified based on ingredients like water, oil or resin content. Zinc phosphate cement is one of the earliest and most commonly used luting agents. It consists of zinc oxide and magnesium oxide powder mixed with an acidic liquid containing phosphoric acid. The acid-base setting reaction forms a zinc aluminophosphate gel matrix that hardens. Variations include fluoridated and copper/silver versions for uses like orthodontic band cementation.
This document discusses direct posterior composite restorations. It begins with definitions of composites and their indications for class I, II, and V cavities. Details are provided on tooth preparation, bonding, layering technique, and polishing. Advantages include esthetics and conservation of tooth structure, while disadvantages include polymerization shrinkage and lower fracture toughness than indirect restorations. Posterior composites discussed include packable and flowable types, as well as bulk fill composites. Steps in placement and considerations for tooth preparation are outlined.
Similar to Condensation & firing of dental porcelains / dental lab courses (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
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
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
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.
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.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
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!"
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
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. Definition
Condensation is the process of
packing the porcelain powder particles
together and of removing the liquid
binder. The term also include any
process by which an unfired dental
porcelain paste is compacted.
www.indiandentalacademy.com
8. • Load was applied at incisal portion of porcelain on the lingual aspect at an
angle of 45’ against longitudinal axis of tooth at a rate of 1 mm/mts to
simulate the patients incisal occlusion
•Load was recorded automatically by means of a shimazu universal Testing
machine Autograph IS 200.
• Each specimen was provided with an indentation with diameter of 1mm
and a depth of 0.5mm at incisal portion to subject the specimen to a more
severe condition and to prevent tip of the loading apparatus from slipping
off.
www.indiandentalacademy.com
11. Inference: -
•Fracture or exfoliation of a ceramo metallic restoration in the mouth is
not caused by insufficient condensation in porcelain or the technique
used during its fabrication in most instances.
•Failure attributed to improper location of finish lines. Inadequate
occlusal equilibration or low bond strength or porcelain due to improper
laboratory manipulation or distortion resulting from incorrect framework
design.
•Average value in the category of “thorough condensation with ultrasonic
vibration” is considerably higher - so slightly higher breaking strength
than a crown made with other techniques.
•Breaking strength is more influenced by the state of porcelain after
condensation than by the degree of condensation.
www.indiandentalacademy.com
14. • The resulting space will cause shrinkage during firing at a ratio
corresponding to the volume that had existed before firing.
• Densely condensed porcelain built-up structure undergoes less firing
shrinkage.
• Firing shrinkage of porcelain depends on the total volume of vacant
space existing prior to firing in a built-up structure.
• Condensation in pre firing built up structure is significantly influenced
by distribution or particles size in a mass of fritted powders.
• 47.6% is the volumetric percentage of the vacant space if spherical
particles of equal size are most loosely packed.
• 25.95% if they are most densely packed.
www.indiandentalacademy.com
15. • According to Hodson (1959), porosity of porcelain mass if 45% with a
mixture of single diameter 25% with a mixture of two different diameter
and 22% with a mixture of more than two different diameter particles.
• Generally particles bridge over each other during condensation.
• The resulting cross linking produces large vacant spaces and actual
porosity usually is more than expected.
• Condensation is the application of vibration and pressure to the
aggregate of cross-linked particles to break these bridges and to obtain
a high density built-up structure with low porosity
www.indiandentalacademy.com
17. • If porcelain is built upto a layer of 2mm on a framework, it contracts
to 1.75mm during firing after condensation. While 1.72mm without
condensation.
• Porcelain powder is usually kneaded with water. The porcelain mass
containing water becomes a paste like aggregate due to binding force
of surface tension of water.
• Surface tension is a force acting to reduce volume. Water serves as
a force in reducing porosity in porcelain.
www.indiandentalacademy.com
18. Condensation – Adding water to porcelain.
+
Vibration applied
Cross-linked structure broken
Small particles move into vacant space
between large particles because of surface
tension.
Vacant space is reduced
+
Water existing is expelled floating up to
surface of porcelain structure as excess
Floating water absorbed
(dry paper tissue / gauze)
Pressure between porcelain particles is
reduced (Bernoulli’s Theorem)
More densely interlocked porcelain particles
www.indiandentalacademy.com
19. Explained by skinner taking a brush made from camel’s hair as an example.
An intentional increase in the number of applications of vibration is clinically
insignificant with respect to degree of firing shrinkage and strength.
Shade:
• The result of shade variation is because of translucency which in turn
depends on presence of bubbles in porcelain material.
• Effect of condensation on the shade of porcelain is clinically insignificant.
www.indiandentalacademy.com
20. • Attributed to incorrect or obscurely demarcated layer construction of
erroneous porcelain, reduction in content of coloring particles from
erroneous condensation operations and inclusion of air bubbles during
kneading or building of porcelain.
• Small bubbles have an effect on translucency and on shade.
• Care must be taken so to avoid inclusion of small bubbles during
buildup rather than trying to eliminate them by through condensation.
• Spatulation and vibration should be done carefully to avoid such
inclusions during porcelain mixing process.
• A quantity of porcelain which approximately corresponds to the
volume of built up body for a single tooth should be built up at one time
with a spatula.
www.indiandentalacademy.com
21. • Porcelain slurry should be scooped to avoid strongly pressing the
spatula and causing a crevice in the slurry. A crevice may include air,
which will be a cause of bubbles in the slurry.
• When building porcelain with a brush, it should be scooped so as to
put a ball of porcelain slurry on the fine tip of the brush whose hairs
must be always finely arranged.
• Irregularly arranged tip may easily include air bubbles in a built up
structure.
• Porcelain should be kept properly moist always, as it is once dried,
air bubbles will be include when water is added.
• Added water invade from one direction causing secondary bubbles to
remain in the porcelain structure.
www.indiandentalacademy.com
22. • For this reason porcelain should be built up quickly with water being
supplied constantly.
• Covering with most paper tissue / gauze/ placing in humidified box if
it’s a long span bridge.
• Translucency decreased with decreased in pressure reduction as
more small bubbles remain in fired porcelain because of the difficulty of
reducing dimensions of voids.
• Selection of the time at which reduction of pressure starts also is
important.
www.indiandentalacademy.com
23. • Once an independent void has formed, air will no longer be
evacuated from the void even under strongly reduced pressure.
• If the timing of pressure reduction is delayed translucency will
reduced due to increased in number of small air bubbles remaining in
the porcelain structure after firing.
• Instruments used for kneading porcelain (metal spatula used metal
powder is mixed in this way, fired porcelain will have a shade more
graying than usual).
• In clinical striations, it is more important to control build-up and firing
carefully, rather than condensation itself.
www.indiandentalacademy.com
25. From a technical viewpoint, following requirements are
important:-
1. Contour of porcelain structure should be retained as it has been
built up, without deformation.
2. Porosity of the porcelain structure should be reduced by bringing
porcelain particles in close contact with each other and with metal
as well.
3. Condensation should be performed without changing the location
of each layer (dentin, enamel, special colour and transparent) the
layer should be kept clearly demarcated and regularly arranged to
obtain desirable shade.
www.indiandentalacademy.com
26. 4. Condensation should be performed without causing separation of
particles into groups of different particles size which have been
originally mixed randomly to reduce porosity.
5. If vibration and absorption of water are repeated unnecessarily,
contour or layer construction or both – may be modified and
separation of particles into groups of different particles sizes occur.
Spattering and fixation by adding water are not effective.
Tapping techniques is performed by tapping and patting the
surface of a built-up porcelain structure with a dry brush to absorb
water rising to the surface. Not adequately effective used a
secondary procedure.
Primary procedure involves vibration and spatulation technique.
www.indiandentalacademy.com
27. Indirect (Model)
Vibration technique
Direct (Crown/ bridge)
Use of hammer (or) the serrated end of Lecron carver.
Spatulation technique currently is often abused and misused.
Spatulation is accomplished by patting and tapping and surface of built-up porcelain gently
with the flat surface of a porcelain carver to form the correct coronal contour and to absorb
water rising to its surface.
Variation of vibration technique.
Misuse occurs when porcelain powder is condensed tightly by applying pressure with the
spatula.
www.indiandentalacademy.com
28. Pressure applications moves the porcelain, not only altering the
correctly formed layer construction but also producing a number of fine
cracks in the built-up structure which has already lost much water
through absorption.
When most porcelain is pressured with a spatula, the surrounding
area appears dry because of retreating water. This may give an illusion
that porcelain has been tightly condensed. If a mass of powder has
been condensed, excess water must rise to the surface because of
reduction in porosity. This phenomenon is known as “Dilatancy”.
Vibration technique causes vibration of the porcelain crown / model
while spatualtion accomplishes vibration of the porcelain structure itself
more directly.
www.indiandentalacademy.com
29. Various vibration techniques:-
1. Impact given by striking the model on the bench or tapping it with a
hammer (hammer technique).,
2. The model or articulator is vibrated stroking with the serrated end
of a lecron carver (Lecron technique).
3. Mechanical vibration (50-60 Hz) is applied by means of an
electromagnetic vibrator (vibrator techniques).
4. Ultrasonic vibration (above 20,000 Hz) is applied (ultrasonic
techniques).
www.indiandentalacademy.com
30. A technique, which causes relatively weak vibration continuously
and requires some time before breaking the contour of a structure is
easy to control and unlikely to cause destruction of the contour.
Vibration with small amplitude is recommended for condensation of
porcelain to minimize the chance of dislocations between different
layers of porcelain material as well as separation into groups of
different particles size.
Oscillographic wave patterns indicated that hammer technique and
lecron technique produce apparently intermittent impacts strokes upto
80-100 mm in amplitude so that the entire crown will be shaken
strongly.
• Contour broken easily
• Layer construction modified
• Mutual relationship between different layers & between particles
change easily.
www.indiandentalacademy.com
31. Vibrator technique : Continuously vibration amplitude as small as
about 30 mm
Masakaetal, advantages of less bubble formation at the interface
between porcelain and metal and between porcelain particles & high
translucency obtained.
But oscillographic wave pattern similar to Lecron’s technique.
Each of these three types of condensation technique cause vibration
with long strokes and intermittent impact which causes separation of
particles easily into groups of different size in such a way that large and
heavy particles are apt to sink while small and light particles are apt to
float up.
Most coloring materials for porcelain are very small particles and may
be separated through this tendency for aggregation leading to irregular
colour distribution particularly in opaque layer (increased conc. of
colouring materials).
www.indiandentalacademy.com
32. “Grouping effect“ - Very fine particles float up together with
excess water rising to the surface if
condensation is applied by intermittent impacts
Change in porosity & firing shrinkage, crack formation.
Ultrasonic vibrations – homogeneous, Continuous vibrations with
strokes limited to 10 as displayed in oscillographs.
Acoustic effect of sound waves.
www.indiandentalacademy.com
33. Ratio of the amplitude of the particles Xp to the amplitude of the
medium Xg is given by Xp 1
Xg
=
r p = Density of particles 1 + (p r p d2
f)2 1/2
d = Diameter 9 mm
f = Frequency
m = vis costy of the medium
Xp approaches Xg if d, f, r p decreases and viscosity increases.
Effective range of condensation 0.2 < . 8 in which particles move
with various (Xp/Xg ) amplitudes.
<.2 and >.8 effective condensation does not occur owing to
insufficient vibration (or) displaced particles by excessive agitation.
Recommended frequency as to achieve 0.5 = Xp/Xg.
Acoustic pressure + hydro mechanical effects bring about
condensation.
www.indiandentalacademy.com
34. Advantages (i) Less grouping effect
(ii) proper layer construction
(iii) Without causing irregular distribution of colours.
(iv)No deformation of layer during condensation.
(v) Greatest effect with small amplitude as
vibrations are continues and quite even
Small cavities produced when an ultrasonic waver is emitted into
water (cavitations).
Ultrasonic wave is a compression wave - over pressure and
negative pressure are caused in water. The elasticity of water cannot
respond to ultrasonic vibration because its cycle is very small & rapid.
This leads to be pressure which tears water and produce cavities
throughout.
www.indiandentalacademy.com
35. Pressure in cavities are very low, its often regarded as a vaccum
state. This is helpful in removing small bubbles contained in porcelain
and minute bubbles attached to porcelain particles together with air in
depressions on metal surface are eliminated
The framework is held by a locking tweezer and being in contact
with an ultrasonic applicator instead of a Lecron carver.
Tweezer must be held on place where vibrations are present, only
then is audible sound heard & sufficient condensation can take place.
www.indiandentalacademy.com
36. FIRING
This is a the process of porcelain fusion, in dentistry, specifically to
produce porcelain restorations (GPT-6).
After condensation and building of a crown it is fired to high density and
correct form.
Initially the unfired or “Green” Porcelain is placed on a sagger and
introduced into either a drying chamber or the entrance of a furnace muffle.
The liquid binder drives off and the porcelain becomes brittle and
chalky.
At this stage green porcelain is introduced into hot zone of furnace and
firing process starts.
During firing, glass particles soften at their contact areas (grain
boundaries) and fuse together.
The partial fusion of a compact of glass is often referred to as sintering.
www.indiandentalacademy.com
37. As the furnace temperature is raised to the manufacturer’s
recommended maturing temperature, the porosity in the porcelain
powder escapes in a the grain boundaries of the glass powder by
action of surface tension.
The Porcelain will shrink and become denser.
In air fired porcelain, flow of the glass grains around the air spaces
traps air remaining in the porcelain and it cannot escape. On cooling,
spherical bubbles are left in the porcelain.
In vaccum firing, the air/atmosphere is removed from the interstitial
spaces before sealing of the surface occurs and hence a dense
porcelain mass obtained.
The “Green” Crown must be dried slowly to eliminate all binder /
water vapour before porcelain enters the hot zone of the furnace.
www.indiandentalacademy.com
38. Types of binders :-
1. Distilled waters – dentine + enamel porcelain
2. Propylene glycol – alumina core buildup
3. Alcohol / formaldehyde based liquids – opaque or core build-up.
4. Proprietary formaldehyde based liquids – opaque or core built up.
5. Paint – liquids for stain application.
• Do not use rapid cycle. Internal pores can be trapped if the surface
skin seals off the interior too rapidly.
• Do not prolong vaccum firing at the manufacturer’s recommended
maturing temperature, surface blistering occurs as the residual air
bubbles try to rise to the surface through molten porcelain .
1. Do not fire at temperatures in excess of those recommended by
manufacturer. The ceramic may “bloat” or swell (decrease in
viscosity)
www.indiandentalacademy.com
39. Always break vaccum whilst the work is in the not zone of furnace.
The dense surface skin of porcelain will then hydraulically compress
residual air bubbles left in interior of denser ceramic results.
Vaccum firing will not remove large air bubbles left by faulty
condensation.
Always glaze in normal atmosphere. Repeated vaccum firing cause
blistering.
If possible, always add porcelain at high bisque stage. Avoid adding
porcelain to a glazed surface, it may peel or blister.
Fewer the number of bakes, always better the product. Repeated
firing cause layering & porosity due to contamination.
www.indiandentalacademy.com
40. Classification of stage in maturity:-
Low Bisque :
• Surface of porcelain very porous
• Will easily absorb a water soluble die.
• Grains of porcelain start to soften
• Shrinkage minimal
• Fired body extremely weak + friable.
Medium Bisque:-
• Still slightly porous
• Flow of glass grain increased
• Any entrapped furnace atmosphere that hasn’t escaped via grain
boundaries will be trapped and become sphere shaped
• Definite shrinkage occurs.
www.indiandentalacademy.com
44. Thermal shock:
Caused by uneven or rapid heating or cooling of the fired crown.
Cracking of enamel veneers occurs because of a differential
thermal expansions stresses that will set up.
Thermal shock is more severe on reheating or glazing a crown than
when cooling it. Insert the crown very slowly in to hot zone of furnace &
give it a thorough pre-heat.
Cool the crown at the muffle entrance. Donot remove it and place
under a glass jar or cool rapidly.
Even thickness of porcelain over the metal or core porcelain
maintained to balance any discrepancies in the thermal diffusivity,
Never handle a hot crown.
www.indiandentalacademy.com
45. Lighting:
• Northern day – light is the best light for seeing colour in porcelain
crown.
• Artificial day light lamps – colour corrected lights the also used.
• Waldman Leuchten lamp (Laboratory)
Firing Temperatures :
High fusing 13000
C (23720
F)
Medium fusing 1101-13000
C (2013 – 20720
F)
Low fusing 850 – 11000
C (1562 – 20120
F)
Ultra Low fusing – 8500
C (15620
F)
www.indiandentalacademy.com
47. 5. Firing programme should be able to be discontinued during the firing
cycle if required.
6. Vaccum pump should be able to be switched off manually during
firing cycle without altering the programme.
7. Firing temperatures should be completely controllable independent
of age of muffle winding.
8. Muffle should be large enough to accommodate two or three six unit
bridges with out losing heat control.
9. Automatic compensation for line voltage fluctuations and a timer
control over 24 hrs to allow the furnace to be switched on in the
absence of operator.
www.indiandentalacademy.com
48. Types of Furnaces
(i) Vita- Vaccumat “S”:
Horizontal Muffle.
1. Semi-automatic furnace with a horizontal muffle with a mechanically
operator firing platform to transport the ceramic work in to the muffle.
2. No controlled pre-drying system apart from introducing the work into
the furnace opening and delaying the introduction of the work into
the firing platform.
3. The firing platform has a surface of 75 X 83 mm which allows large
bridges to be fired in one piece.
4. Firing controlled by pre-selection of firing temperature and is
therefore automatic. Vaccum is applied prior to the introduction of
the work into the muffle.
www.indiandentalacademy.com
49. (ii) DeTrey Biodent Systomat:
Vertical Muffle:
1. The muffles on this furnace are mounted vertically above a moving platform.
2. They’re cylindrical and so give a better heat distribution than the horizontal
types.
1. Preheating the green porcelain
3. Two muffles
2. Vaccum firing.
4. When preheating the porcelain the drying muffle radiates heat in to the
moving platform. After 5 minutes the plat form automatically introduces itself into
the muffle which has been set at a temperature of about 6000
C.
5. It remains in the muffle for a length of time which is controlled by the
operator. When the specified time is completed, the platform automatically drops
down and the articles to be fired is transferred to the other platform by the
technician.
www.indiandentalacademy.com
50. (iii) Unitek Ultra – Mat Furnace
Horizontal muffle furnace – fully automatic.
Single muffle with a firing table of diameter 83.mm
Muffle will rise from 00
C to a working temperature of 7000
C in about
4 minutes and since the muffle insulation reflects heat rather than
absorbing it the muffle will cool rapidly upon completion of any firing
cycle.
Pre-drying and all subsequent firing operations are carried out in
automatic sequences by preselected programmes.
Two push-buttons are pressed and if the selected programme has
to be cancelled there is another push-button for this purpose.
Firing table movement is set to give a slow rise of 5.5 minutes and a
fast rise of 12 seconds.
www.indiandentalacademy.com
51. (iv) Rapid cycle Furnace (Doxc Euromat):-
1. The term “rapid cycle: does not mean quick firing.
2. In this furnace the heat is brought to the porcelain, not the
porcelain to the heat.
3. Muffle is of the vertical type but the work to be fired is inserted via
the top of the furnace muffle which greatly assists viewing.
4. The programme will not start if the temperature is above 200’C.
5. To programme the furnace there are 5 settings to be made:
6. Drying time 5-10 minutes according to bulk
7. Temperature to be set for introduction of vaccum
8. Time required to reach firing temperature
9. Firing temperature
10. Time set after release of vaccum.
www.indiandentalacademy.com