This document provides information on gypsum products used in dentistry. It discusses the chemical and physical nature of gypsum, describing how it is derived from calcium sulfate and can be manufactured into dental plaster or stone through heating processes. It also outlines the desirable properties of gypsum products, types of products including impression plaster, model plaster, and different classes of dental stone, and theories behind the setting reaction.
This document provides an overview of inelastic impression materials. It defines impression materials and their requirements. Impression compound is discussed, including its composition, properties, manipulation, and uses. It is a reversible, rigid material that sets by temperature change. Impression compound comes in sheets, cakes, sticks, and cones and is used for preliminary impressions, individual tooth impressions, border moulding, and special trays. Green stick compound is a type of impression compound supplied in cylinders for uses like border moulding.
Investment materials are used to form molds for dental casting. They are composed of refractory materials like quartz or cristobalite, a binder like gypsum or phosphate, and other chemicals. Gypsum-bonded investments are commonly used for gold alloy casting while phosphate-bonded investments can withstand higher temperatures for casting alloys like cobalt-chromium. Ethyl silicate investments are used for high-fusing base metal alloys. The investments require properties like stability at high temperatures, sufficient expansion to compensate for metal shrinkage, and ease of removal after casting.
The document discusses dental casting investments which are materials used to form molds for casting dental alloys. It describes the key properties investments should have including being easily manipulated, having sufficient strength and stability at high temperatures, and allowing for gas escape. It classifies investments based on processing temperature and binder used, and describes the main components - refractory material, binder, and other chemicals. Gypsum-based and phosphate-bonded investments are commonly used for casting gold alloys. The document discusses factors that influence the investments' setting expansion, hygroscopic expansion, and thermal expansion properties.
This document provides information on gypsum products that are used in dentistry. It discusses the chemical and physical properties of gypsum and how it is manufactured into different dental materials like plaster, stone, and impression materials. The key types of gypsum products include impression plaster, model plaster, dental stone of varying strengths, and special high strength stones. The document also examines the setting reaction of gypsum products and various theories to explain this reaction.
Denture base resins are typically made of polymethyl methacrylate (PMMA) and are fabricated using heat- or chemically- activated resins. PMMA denture bases are hard, transparent, and resistant to discoloration. The resins undergo polymerization shrinkage of around 21% as the monomer methyl methacrylate forms chains and evaporates slightly during processing. Proper mixing and compression molding can minimize porosity and achieve adequate polymerization for optimal denture fit and function.
Gypsum Products commercially available are hemihydrate form of calcium sulfate. Gypsum products used in Dentistry are broadly classified into 5 types
Type 1- Impression Plaster
Type 2- Model Plaster
Type 3- Dental stone
Type 4- Die Stone high strength low expansion
Type 5- Die Stone high Strength High Expansion
This document summarizes the key properties and characteristics of different elastomeric impression materials, including polysulfide, condensation silicone, addition silicone, and polyether elastomers. It describes the composition, setting reactions, available consistencies, and mechanical properties of each material. Properties like viscosity, working and setting times, dimensional stability, hardness, tear strength, and detail reproduction are compared between the different elastomers. The document also discusses techniques for mixing and using impression materials, as well as their wettability and hydrophilicity.
An investment is a refractory material that is used to form a mould around a wax pattern.
Following the production of a wax pattern either by direct or indirect method; the next stage in many dental procedures involves the investment of the pattern to form a mould.
A sprue is attached to the pattern and the assembly is located in a casting ring. Investment material is poured around the wax pattern while still in a fluid state.
When the investment sets hard, the wax and sprue former are removed by burning out to leave a mould which can be filled with an alloy or ceramic using a casting technique.
This document provides an overview of inelastic impression materials. It defines impression materials and their requirements. Impression compound is discussed, including its composition, properties, manipulation, and uses. It is a reversible, rigid material that sets by temperature change. Impression compound comes in sheets, cakes, sticks, and cones and is used for preliminary impressions, individual tooth impressions, border moulding, and special trays. Green stick compound is a type of impression compound supplied in cylinders for uses like border moulding.
Investment materials are used to form molds for dental casting. They are composed of refractory materials like quartz or cristobalite, a binder like gypsum or phosphate, and other chemicals. Gypsum-bonded investments are commonly used for gold alloy casting while phosphate-bonded investments can withstand higher temperatures for casting alloys like cobalt-chromium. Ethyl silicate investments are used for high-fusing base metal alloys. The investments require properties like stability at high temperatures, sufficient expansion to compensate for metal shrinkage, and ease of removal after casting.
The document discusses dental casting investments which are materials used to form molds for casting dental alloys. It describes the key properties investments should have including being easily manipulated, having sufficient strength and stability at high temperatures, and allowing for gas escape. It classifies investments based on processing temperature and binder used, and describes the main components - refractory material, binder, and other chemicals. Gypsum-based and phosphate-bonded investments are commonly used for casting gold alloys. The document discusses factors that influence the investments' setting expansion, hygroscopic expansion, and thermal expansion properties.
This document provides information on gypsum products that are used in dentistry. It discusses the chemical and physical properties of gypsum and how it is manufactured into different dental materials like plaster, stone, and impression materials. The key types of gypsum products include impression plaster, model plaster, dental stone of varying strengths, and special high strength stones. The document also examines the setting reaction of gypsum products and various theories to explain this reaction.
Denture base resins are typically made of polymethyl methacrylate (PMMA) and are fabricated using heat- or chemically- activated resins. PMMA denture bases are hard, transparent, and resistant to discoloration. The resins undergo polymerization shrinkage of around 21% as the monomer methyl methacrylate forms chains and evaporates slightly during processing. Proper mixing and compression molding can minimize porosity and achieve adequate polymerization for optimal denture fit and function.
Gypsum Products commercially available are hemihydrate form of calcium sulfate. Gypsum products used in Dentistry are broadly classified into 5 types
Type 1- Impression Plaster
Type 2- Model Plaster
Type 3- Dental stone
Type 4- Die Stone high strength low expansion
Type 5- Die Stone high Strength High Expansion
This document summarizes the key properties and characteristics of different elastomeric impression materials, including polysulfide, condensation silicone, addition silicone, and polyether elastomers. It describes the composition, setting reactions, available consistencies, and mechanical properties of each material. Properties like viscosity, working and setting times, dimensional stability, hardness, tear strength, and detail reproduction are compared between the different elastomers. The document also discusses techniques for mixing and using impression materials, as well as their wettability and hydrophilicity.
An investment is a refractory material that is used to form a mould around a wax pattern.
Following the production of a wax pattern either by direct or indirect method; the next stage in many dental procedures involves the investment of the pattern to form a mould.
A sprue is attached to the pattern and the assembly is located in a casting ring. Investment material is poured around the wax pattern while still in a fluid state.
When the investment sets hard, the wax and sprue former are removed by burning out to leave a mould which can be filled with an alloy or ceramic using a casting technique.
The document provides information on impression materials, including their history, classification, and properties. It discusses both reversible (agar) and irreversible (alginate) hydrocolloid impression materials. For agar, it describes the composition, mode of supply, uses, advantages, and disadvantages. For alginate, it outlines the composition, setting reaction, classification according to setting time, manipulation, and properties. The document thus summarizes the key types of impression materials and their characteristics.
The document provides a history of denture materials and techniques from ancient times to modern day. It begins with early dentures made of materials like wood, bone, ivory and human teeth. Important developments include the introduction of porcelain and vulcanite dentures in the 18th-19th centuries. In the 1930s, polymethyl methacrylate (PMMA) was introduced and became the standard denture material due to its strength, biocompatibility and ease of use. The document also describes the compression molding technique for fabricating PMMA dentures, involving steps like flasking, packing, curing and finishing. Alternative techniques like injection molding are also mentioned.
This document provides an overview of different types of dental cements, including their composition, properties, and applications. It discusses zinc phosphate cement, the oldest cement still in use today. It also covers silicate cement, one of the first direct tooth-colored materials; zinc polycarboxylate cement, the first cement with adhesive properties; and zinc oxide eugenol cement, commonly used as a temporary cement. Modified versions of these traditional cements are also presented, along with other contemporary cements like glass ionomer cement and resin cements.
This document discusses dental investment materials and procedures used for lost wax casting. It begins with an introduction and history of lost wax casting. It then defines dental investment and discusses the requirements, material science, and types of investments including composition, setting reactions, and properties. The document outlines the investing procedure and potential defects. It concludes with an overview of dental investment materials for lost wax casting.
This document discusses dental casting investments, which are materials used to make molds for casting dental restorations. It describes the key properties investments must have, such as reproducing detail, withstanding heat, and compensating for casting shrinkage. It explains the components of investments, including refractory materials like silica, binders like gypsum or phosphate, and additives. It also covers the setting expansion, thermal expansion, and strengths of different investment types for casting various alloys.
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
The document provides an overview of investment materials used in dental casting. It discusses the history of lost wax casting, defines investments, and outlines the key properties and composition of investments including refractory materials, binders like gypsum and phosphates, and other additives. It then classifies and describes different types of investments including gypsum-bonded, phosphate-bonded, and ethyl silicate-bonded investments.
The document provides information on various dental impression materials, including their history, composition, properties and uses. It discusses early materials like beeswax and impression compounds. It also covers alginate, which is the most widely used material due to its ease of use. Other elastic materials discussed include polysulfide, which was the first synthetic elastomer, and condensation silicone. The ideal properties of impression materials and their classifications are also outlined.
Impression materials are used to make negative reproductions or imprints of teeth and surrounding structures. They are classified based on their rigidity, setting mechanism, viscosity, interaction with water, and chemical composition. Desirable qualities include accuracy, elasticity, and dimensional stability. Common impression materials include alginate (hydrocolloid), impression plaster, impression compound, zinc oxide eugenol paste, polysulfides, condensation silicones, addition silicones, polyethers, and light-cured polyethers. Tissue conditioners provide temporary soft lining for irritated denture-bearing tissues.
This document provides an overview of gypsum products used in dentistry. It discusses the properties and manufacturing of various types of gypsum, including plaster, dental stone, die stone. It describes how gypsum sets through a hydration reaction and how factors like water-powder ratio, temperature, and additives can control the setting time. The document also outlines the uses of different gypsum products for impressions, models, dies and other dental applications.
The document discusses the classification, composition, properties and history of precious metal alloys used in dentistry. It covers noble metals like gold, platinum, palladium and their alloys. It describes how these alloys are classified based on their noble metal content and properties. The various heat treatments used to alter the properties of gold alloys are also summarized. Important alloys used for metal-ceramic restorations and their typical compositions are highlighted.
The document discusses dental casting investments, which are ceramic materials used to form molds for casting dental restorations. It covers the history of lost wax casting techniques from ancient civilizations to modern developments. It also describes the ideal requirements, composition, classification, and properties of different types of dental casting investments. The main types discussed are calcium sulfate-bonded investments, which are gypsum-based and used for casting gold alloys, and their thermal expansion properties.
Gypsum products-a topic of dental materials for dental students....
lots of knowledge...includes classification,uses,manufacturing processes etc.
COURTESY: My college friends....
This document discusses various dental cement materials. It begins by defining dental cement as a biomaterial composed of an acid and base component that react to set. There are three main categories of dental cements: silicate cements, zinc phosphate cement, and zinc polycarboxylate cement. The document then discusses specific applications of dental cements and provides details on the composition, setting reactions, characteristics and uses of zinc phosphate cement, zinc polycarboxylate cement, zinc oxide eugenol cement and calcium hydroxide cement.
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.
Physical properties of dental material [autosaved]shailjakatiyar2
The document discusses various physical properties of dental materials that are important for clinicians to understand. It describes properties like abrasion and abrasion resistance, viscosity, structural and stress relaxation, and creep and flow. Hardness tests are also covered, including macrohardness tests like Brinell and Rockwell, and microhardness tests like Knoop and Vickers. Understanding these physical properties helps clinicians select appropriate materials and improves the success of dental treatments.
INTRODUCTION
HISTORY
REQUISITES FOR IDEAL DENTURE BASE MATERIAL
CLASSIFICATION
METAL DENTURE BASE
DENTURE BASE POLYMERS
RECENT ADVANCES
CONCLUSION
REFERANCES
The document discusses the denture base, which is the part of a removable partial denture that rests on oral mucosa and attaches to artificial teeth. It describes the requirements and functions of an ideal denture base, and discusses the main types of denture bases which are plastic (acrylic, polystyrene, valplast) and metal (gold, cobalt-chromium, titanium). Metal denture bases have advantages like accuracy and thermal conductivity, while plastic acrylic bases are better for esthetics and relining.
This document provides information on various types of dental waxes. It begins with definitions of waxes in general and an introduction to dental waxes. It then describes the typical composition of dental waxes which includes a base wax, modifiers, and colorants. Several types of dental waxes are discussed, including pattern waxes for inlays, castings, and baseplates as well as processing waxes for tasks like boxing and utility uses. The document concludes with a brief section on impression waxes used for bite registration and corrections.
This document provides an overview of dental waxes. It discusses the history, definition, classification, components, characteristics, properties and types of dental waxes. Dental waxes are combinations of various types of waxes compounded to provide desired physical properties. They are classified according to origin as mineral, plant, insect or animal waxes. Key properties include thermal properties like melting range and coefficient of thermal expansion. Ideal waxes are easy to mold, capable of being melted/solidified without change, and have low thermal contraction.
Gypsum is a mineral that is processed and used to make gypsum board (drywall). Gypsum board has several advantages such as ease of installation, fire resistance, sound isolation, durability and economy. It is available in various thicknesses for different applications. Regular gypsum board is used for walls and ceilings. Multi-ply systems use two or more layers of gypsum board to increase fire resistance and soundproofing. Gypsum board installation requires basic tools and is applied either directly to framing or with furring strips to surfaces like masonry.
1. Gypsum materials like dental plaster and stone are commonly used in dentistry to make casts and models due to their low cost, ease of use, and ability to accurately reproduce fine details from impressions.
2. There are 5 types of gypsum materials defined by ISO standards for different applications based on their strength and expansion properties. Type I is rarely used for impressions while Types II-V are used for models, study casts, and fabricating crowns and bridges.
3. Gypsum materials set via a hydration reaction where calcium sulfate hemihydrate reacts with water to form calcium sulfate dihydrate. Factors like water-powder ratio, mixing time, and additives can affect properties like setting
The document provides information on impression materials, including their history, classification, and properties. It discusses both reversible (agar) and irreversible (alginate) hydrocolloid impression materials. For agar, it describes the composition, mode of supply, uses, advantages, and disadvantages. For alginate, it outlines the composition, setting reaction, classification according to setting time, manipulation, and properties. The document thus summarizes the key types of impression materials and their characteristics.
The document provides a history of denture materials and techniques from ancient times to modern day. It begins with early dentures made of materials like wood, bone, ivory and human teeth. Important developments include the introduction of porcelain and vulcanite dentures in the 18th-19th centuries. In the 1930s, polymethyl methacrylate (PMMA) was introduced and became the standard denture material due to its strength, biocompatibility and ease of use. The document also describes the compression molding technique for fabricating PMMA dentures, involving steps like flasking, packing, curing and finishing. Alternative techniques like injection molding are also mentioned.
This document provides an overview of different types of dental cements, including their composition, properties, and applications. It discusses zinc phosphate cement, the oldest cement still in use today. It also covers silicate cement, one of the first direct tooth-colored materials; zinc polycarboxylate cement, the first cement with adhesive properties; and zinc oxide eugenol cement, commonly used as a temporary cement. Modified versions of these traditional cements are also presented, along with other contemporary cements like glass ionomer cement and resin cements.
This document discusses dental investment materials and procedures used for lost wax casting. It begins with an introduction and history of lost wax casting. It then defines dental investment and discusses the requirements, material science, and types of investments including composition, setting reactions, and properties. The document outlines the investing procedure and potential defects. It concludes with an overview of dental investment materials for lost wax casting.
This document discusses dental casting investments, which are materials used to make molds for casting dental restorations. It describes the key properties investments must have, such as reproducing detail, withstanding heat, and compensating for casting shrinkage. It explains the components of investments, including refractory materials like silica, binders like gypsum or phosphate, and additives. It also covers the setting expansion, thermal expansion, and strengths of different investment types for casting various alloys.
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
The document provides an overview of investment materials used in dental casting. It discusses the history of lost wax casting, defines investments, and outlines the key properties and composition of investments including refractory materials, binders like gypsum and phosphates, and other additives. It then classifies and describes different types of investments including gypsum-bonded, phosphate-bonded, and ethyl silicate-bonded investments.
The document provides information on various dental impression materials, including their history, composition, properties and uses. It discusses early materials like beeswax and impression compounds. It also covers alginate, which is the most widely used material due to its ease of use. Other elastic materials discussed include polysulfide, which was the first synthetic elastomer, and condensation silicone. The ideal properties of impression materials and their classifications are also outlined.
Impression materials are used to make negative reproductions or imprints of teeth and surrounding structures. They are classified based on their rigidity, setting mechanism, viscosity, interaction with water, and chemical composition. Desirable qualities include accuracy, elasticity, and dimensional stability. Common impression materials include alginate (hydrocolloid), impression plaster, impression compound, zinc oxide eugenol paste, polysulfides, condensation silicones, addition silicones, polyethers, and light-cured polyethers. Tissue conditioners provide temporary soft lining for irritated denture-bearing tissues.
This document provides an overview of gypsum products used in dentistry. It discusses the properties and manufacturing of various types of gypsum, including plaster, dental stone, die stone. It describes how gypsum sets through a hydration reaction and how factors like water-powder ratio, temperature, and additives can control the setting time. The document also outlines the uses of different gypsum products for impressions, models, dies and other dental applications.
The document discusses the classification, composition, properties and history of precious metal alloys used in dentistry. It covers noble metals like gold, platinum, palladium and their alloys. It describes how these alloys are classified based on their noble metal content and properties. The various heat treatments used to alter the properties of gold alloys are also summarized. Important alloys used for metal-ceramic restorations and their typical compositions are highlighted.
The document discusses dental casting investments, which are ceramic materials used to form molds for casting dental restorations. It covers the history of lost wax casting techniques from ancient civilizations to modern developments. It also describes the ideal requirements, composition, classification, and properties of different types of dental casting investments. The main types discussed are calcium sulfate-bonded investments, which are gypsum-based and used for casting gold alloys, and their thermal expansion properties.
Gypsum products-a topic of dental materials for dental students....
lots of knowledge...includes classification,uses,manufacturing processes etc.
COURTESY: My college friends....
This document discusses various dental cement materials. It begins by defining dental cement as a biomaterial composed of an acid and base component that react to set. There are three main categories of dental cements: silicate cements, zinc phosphate cement, and zinc polycarboxylate cement. The document then discusses specific applications of dental cements and provides details on the composition, setting reactions, characteristics and uses of zinc phosphate cement, zinc polycarboxylate cement, zinc oxide eugenol cement and calcium hydroxide cement.
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.
Physical properties of dental material [autosaved]shailjakatiyar2
The document discusses various physical properties of dental materials that are important for clinicians to understand. It describes properties like abrasion and abrasion resistance, viscosity, structural and stress relaxation, and creep and flow. Hardness tests are also covered, including macrohardness tests like Brinell and Rockwell, and microhardness tests like Knoop and Vickers. Understanding these physical properties helps clinicians select appropriate materials and improves the success of dental treatments.
INTRODUCTION
HISTORY
REQUISITES FOR IDEAL DENTURE BASE MATERIAL
CLASSIFICATION
METAL DENTURE BASE
DENTURE BASE POLYMERS
RECENT ADVANCES
CONCLUSION
REFERANCES
The document discusses the denture base, which is the part of a removable partial denture that rests on oral mucosa and attaches to artificial teeth. It describes the requirements and functions of an ideal denture base, and discusses the main types of denture bases which are plastic (acrylic, polystyrene, valplast) and metal (gold, cobalt-chromium, titanium). Metal denture bases have advantages like accuracy and thermal conductivity, while plastic acrylic bases are better for esthetics and relining.
This document provides information on various types of dental waxes. It begins with definitions of waxes in general and an introduction to dental waxes. It then describes the typical composition of dental waxes which includes a base wax, modifiers, and colorants. Several types of dental waxes are discussed, including pattern waxes for inlays, castings, and baseplates as well as processing waxes for tasks like boxing and utility uses. The document concludes with a brief section on impression waxes used for bite registration and corrections.
This document provides an overview of dental waxes. It discusses the history, definition, classification, components, characteristics, properties and types of dental waxes. Dental waxes are combinations of various types of waxes compounded to provide desired physical properties. They are classified according to origin as mineral, plant, insect or animal waxes. Key properties include thermal properties like melting range and coefficient of thermal expansion. Ideal waxes are easy to mold, capable of being melted/solidified without change, and have low thermal contraction.
Gypsum is a mineral that is processed and used to make gypsum board (drywall). Gypsum board has several advantages such as ease of installation, fire resistance, sound isolation, durability and economy. It is available in various thicknesses for different applications. Regular gypsum board is used for walls and ceilings. Multi-ply systems use two or more layers of gypsum board to increase fire resistance and soundproofing. Gypsum board installation requires basic tools and is applied either directly to framing or with furring strips to surfaces like masonry.
1. Gypsum materials like dental plaster and stone are commonly used in dentistry to make casts and models due to their low cost, ease of use, and ability to accurately reproduce fine details from impressions.
2. There are 5 types of gypsum materials defined by ISO standards for different applications based on their strength and expansion properties. Type I is rarely used for impressions while Types II-V are used for models, study casts, and fabricating crowns and bridges.
3. Gypsum materials set via a hydration reaction where calcium sulfate hemihydrate reacts with water to form calcium sulfate dihydrate. Factors like water-powder ratio, mixing time, and additives can affect properties like setting
This document discusses different types of gypsum products used in dentistry, including dental plaster, stone, and improved stone. It describes the differences between these products in terms of their crystal structure, density, strength, and setting properties. Dental plaster is the most porous and weakest, while improved stone has the densest and strongest crystals. The document also explains how the setting times and strengths of gypsum products can be modified by adjusting the water-powder ratio or adding chemicals during mixing.
The document discusses various materials used for dental casts and dies, including their properties and applications. It covers both non-metallic and metallic materials. The main non-metallic materials discussed are gypsum products, resin dies, and investment materials. Gypsum products include dental stones and plaster, which are derived from calcium sulfate hemihydrate. Their setting reaction involves crystallization to form calcium sulfate dihydrate. Resin dies such as epoxy resins are stronger than gypsum but less dimensionally stable. Metallic materials include electroplated nickel-chromium alloys and low-fusing dental alloys.
Gypsum products such as plaster, stone, and die stone are used in dentistry to make casts and dies. Plaster is the weakest and most porous, while die stone is the densest. Different gypsum products are used for different applications based on their strength and accuracy properties. Gypsum is mined and calcined to form hemihydrate, then mixed with water which causes it to crystallize back into dihydrate. The water-powder ratio, particle size, and other factors affect the strength and setting time of the final material. Proper manipulation and timing are required to produce functional casts and dies from gypsum.
This document discusses gypsum products used in dentistry. It begins with definitions of key terms like gypsum, models, casts, impressions, and dies. It then outlines the major types of gypsum products including dental plaster, dental stone, die stone, and improved dental stone. The document describes the setting reactions of gypsum, how setting expansion is controlled, and factors that affect the dimensional stability of dental stone. It provides example questions that could be asked in essays about gypsum products, their classification, tests for setting, and specific types like dental plaster and stone.
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 acrylic resins / dental implant courses by Indian dental academy Indian 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
Gypsum products /certified fixed orthodontic courses by Indian dental academy Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
00919248678078
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.
Gypsum products final / dental implant 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.for more details please visit
www.indiandentalacademy.com
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 discusses the uses and properties of gypsum in dentistry. Gypsum is used to make impression materials, casts, dies and dental molds. There are different types of gypsum products used, including plaster, dental stone, die stone and high strength stones. The properties of these gypsum products such as porosity, strength and setting expansion determine their applications. Plaster is used for diagnostic casts while dental stone is used for full and partial denture models. Die stone is specifically used for fabricating dental restorations and implants.
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
Tech. for immediate core build up in endo treated teeth/ dental implant coursesIndian dental academy
This document discusses techniques for immediate core buildup of endodontically treated teeth. It reviews the microbiological, prosthetic, and mechanical aspects of various core buildup materials including amalgam, resin composite, and glass ionomer cement. Three clinical cases are presented using different techniques for core buildups with short chair times, including the use of provisional acrylic resin shells and a copper band. Factors like maintaining the biologic width and providing an adequate ferrule are also addressed.
Glass ionomer cements were introduced in 1972 as tooth-colored restorative materials that bond chemically to dental tissues and release fluoride over time. They are classified into conventional, resin-modified, and metal-reinforced types. Glass ionomer cements set via an acid-base reaction between a fluoroaluminosilicate glass powder and an aqueous polyalkenoic acid liquid. They offer advantages like adhesion, fluoride release, and marginal sealing but are also brittle and soluble. Glass ionomer cements are used for luting, restorations, liners, fissure sealants, orthodontic applications, and core buildups.
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.
A comprehensive lecture by Dr Rashid Hassan covering all the aspects of different types of model and die materials. Easy ti understand ans recall.
For video lectures on different topics of Dental Materials visit and follow Dr Rashid Lectures on Dental Materials (dmbydrrashid) on Facebook.
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
Die materials in fpd /certified fixed orthodontic courses by Indian dental ac...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: 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.
Cements in orthodontics (2) /certified fixed orthodontic courses by Indian de...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 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
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 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.
MLA Group is a leading manufacturer of additives in India established in 1975. It caters to industries such as rubber, detergent, paint, plastics, pesticide, and others. The company has 400 employees and an annual turnover of 20 million USD. It has 4 manufacturing units certified to ISO 9001 standards. The company's in-house R&D division is recognized by the Department of Scientific and Industrial Research. MLA Group produces a range of products including precipitated silica, zinc oxide, stearates, PVC stabilizers, and micronized minerals.
Similar to Gypsum / dental implant courses by Indian dental academy (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
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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
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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
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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
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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
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
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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.
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 Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
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.)
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
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
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.
2. IntroductionIntroduction
Desirable PropertiesDesirable Properties
Chemical & Physical nature of gypsum productsChemical & Physical nature of gypsum products
Manufacture of dental plaster & stoneManufacture of dental plaster & stone
Types of gypsum productsTypes of gypsum products
Setting ReactionSetting Reaction
Theories of Setting ReactionTheories of Setting Reaction
Setting TimeSetting Time
Control of Setting TimeControl of Setting Time
Setting ExpansionSetting Expansion
Control of Setting ExpansionControl of Setting Expansion
Hygroscopic Setting ExpansionHygroscopic Setting Expansion
StrengthStrength
Surface Hardness & Abrasion ResistanceSurface Hardness & Abrasion Resistance
ViscosityViscosity
Reproduction of DetailsReproduction of Details
Proportioning, Mixing & Caring for Gypsum ProductsProportioning, Mixing & Caring for Gypsum Products
Special gypsum productsSpecial gypsum productswww.indiandentalacademy.comwww.indiandentalacademy.com
3. INTRODUCTIONINTRODUCTION
Gypsum is a naturally occurring whiteGypsum is a naturally occurring white
powderypowdery mineralmineral mined in various parts of themined in various parts of the
world, with chemical name calcium sulfateworld, with chemical name calcium sulfate
dihydrate ( CaSOdihydrate ( CaSO44.2H.2H22O ).O ).
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4. FORMSFORMS
1. ROCK :- Dull colored rock.1. ROCK :- Dull colored rock.
2. ALABLASTER2. ALABLASTER :- Fine grained variety.:- Fine grained variety.
3. GYPCRETE (gypcrust) :- Hard layer3. GYPCRETE (gypcrust) :- Hard layer
formed on soil.formed on soil.
4. SELENITE4. SELENITE
5. SATIN SPUR :- Fibrous with silky luster.5. SATIN SPUR :- Fibrous with silky luster.
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5. USESUSES
1. For construction purposes.1. For construction purposes.
2. Used in industry for making pottery, moulds etc.2. Used in industry for making pottery, moulds etc.
3. Used in orthopedics to make plaster casts.3. Used in orthopedics to make plaster casts.
APPLICATION IN DENTISTRYAPPLICATION IN DENTISTRY
1. For cast preparation.1. For cast preparation.
2. Models and dies.2. Models and dies.
3. Impression Material.3. Impression Material.
4. As Investment Material.4. As Investment Material.
5. Mounting of Casts.5. Mounting of Casts.
6. As a mold material for processing of complete dentures.6. As a mold material for processing of complete dentures.
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6. CHEMICAL & PHYSICAL NATURE OFCHEMICAL & PHYSICAL NATURE OF
GYPSUM PRODUCTSGYPSUM PRODUCTS
Gypsum – Calcium Sulphate Dihydrate
CaSO4. 2H2O on heating CaSO4. ½H2O + 1½H2O
(Gypsum) (Calcium Sulphate (water)
Hemi hydrate)
CaSO4.½H2O + 1½H2O CaSO4. 2H2O + 3900
(plaster of paris) (water) (gypsum) (cal)
Reaction is exothermic
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7. MANUFACTURE OF DENTAL PLASTER &MANUFACTURE OF DENTAL PLASTER &
STONESTONE
Formed by calcining of gypsumFormed by calcining of gypsum
110-130ºC 130-200ºC 200-1000ºC110-130ºC 130-200ºC 200-1000ºC
CaSOCaSO44. 2H. 2H22O (CaSOO (CaSO44).1/2 H).1/2 H22O CaSOO CaSO44 CaSOCaSO44
Gypsum plaster/stone (hexagonal (ortho-rhombicGypsum plaster/stone (hexagonal (ortho-rhombic
(Calcium Sulphate (Calcium Sulphate anhydrite) anhydrate)(Calcium Sulphate (Calcium Sulphate anhydrite) anhydrate)
Dihydrate) HemihydrateDihydrate) Hemihydrate
α or β)α or β)
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8. β-hemihydrateβ-hemihydrate((plasterplaster)-)-
- Gypsum is heated in a kettle, vat or rotatory kiln open- Gypsum is heated in a kettle, vat or rotatory kiln open
to air.to air.
- Crystals – spongy & irregular.- Crystals – spongy & irregular.
Powder particles of
plaster of paris
Scanning electron micrograph of
dental plaster powder particles
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9. α-hemihydrate (stone)-α-hemihydrate (stone)-
- Gypsum is- Gypsum is heated to 125heated to 12500
C under steam pressure in anC under steam pressure in an
autoclave or boiled in a solution of CaClautoclave or boiled in a solution of CaCl22 ..
- Crystals- more dense & prismatic.- Crystals- more dense & prismatic.
Powder particles of
dental stone
Scanning electron micrograph of
dental stone powder particles
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10. DESIRABLE PROPERTIES:-DESIRABLE PROPERTIES:-
1. Accuracy1. Accuracy
2. Dimensional Stability2. Dimensional Stability
3. Ability to reproduce fine detail.3. Ability to reproduce fine detail.
4. Strength & resistance to abrasion.4. Strength & resistance to abrasion.
5. Compatibility with the impression materials.5. Compatibility with the impression materials.
6. Color6. Color
7. Biological safety7. Biological safety
8. Ease of use8. Ease of use
9. Cost.9. Cost.
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11. HYDRATES OF CALCIUM SULPHATEHYDRATES OF CALCIUM SULPHATE
Mineral source By product of otherMineral source By product of other
IndustriesIndustries
Calcium Sulphate dihydrate (Gypsum)Calcium Sulphate dihydrate (Gypsum)
Heat in an open Heat in autoclave Heat ground gypsum Heat in a boilingHeat in an open Heat in autoclave Heat ground gypsum Heat in a boiling
vessel at120ºC under steam in H2O with small aqueous solution 30%vessel at120ºC under steam in H2O with small aqueous solution 30%
pressure, 120-130ºC quantity of organic of CaClpressure, 120-130ºC quantity of organic of CaCl22/ MgCl/ MgCl22
acid or salt, in anacid or salt, in an
Autoclave, 140ºCAutoclave, 140ºC
Calcined CaSOCalcined CaSO44 Autoclaved CaSOAutoclaved CaSO44 Autoclaved CaSOAutoclaved CaSO44 CaSOCaSO44 hemihydratehemihydrate
hemihydrate hemihydrate hemihydrate ( DENSITE)hemihydrate hemihydrate hemihydrate ( DENSITE)
(β- hemihydrate) (HYDROCAL or (α- hemihydrate)(β- hemihydrate) (HYDROCAL or (α- hemihydrate)
α- hemihydrate)α- hemihydrate)
Heat < 200º CHeat < 200º C
Hexagonal CaSOHexagonal CaSO44 (sometimes called ‘soluble anhydrite’)(sometimes called ‘soluble anhydrite’)
CaSOCaSO44
Heat > 200º CHeat > 200º C
Ortho-rhombic CaSOOrtho-rhombic CaSO44
(sometimes called ‘insoluble anhydrite’)(sometimes called ‘insoluble anhydrite’)
Calcium sulphate anhydrite
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12. TYPES OF GYPSUM PRODUCTSTYPES OF GYPSUM PRODUCTS
Classification-Classification-
According toAccording to ADA specification No.25-ADA specification No.25-
Type 1- Impression plasterType 1- Impression plaster
Type 2- Lab or model plasterType 2- Lab or model plaster
Type 3- Dental stone ordinary or model stoneType 3- Dental stone ordinary or model stone
Type 4- Dental stone with high strength and low expansionType 4- Dental stone with high strength and low expansion
Type 5-Dental stone with high strength and high expansionType 5-Dental stone with high strength and high expansion
Type 4 and type 5 dental stones are known as die stonesType 4 and type 5 dental stones are known as die stones
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13. IMPRESSION PLASTER Type 1IMPRESSION PLASTER Type 1
--They are composed of Plaster of Paris to which modifiers have been added toThey are composed of Plaster of Paris to which modifiers have been added to
regulate the setting time & setting expansion. Crystalline form of hemihydrate isregulate the setting time & setting expansion. Crystalline form of hemihydrate is
known as beta-hemihydrate. The particles are irregular in shape and porous. W/Pknown as beta-hemihydrate. The particles are irregular in shape and porous. W/P
ratio is 0.5 i.e 50ml/100gm.ratio is 0.5 i.e 50ml/100gm.
- Hemihydrate plaster is produced by dry calcination methods and are powders- Hemihydrate plaster is produced by dry calcination methods and are powders
with a low apparent density. A relative high surface area and poor packingwith a low apparent density. A relative high surface area and poor packing
ability.ability.
- Microscopically the beta form is a fibrous aggregate of fine crystals with- Microscopically the beta form is a fibrous aggregate of fine crystals with
capillary pores.capillary pores.
-- ModifiersModifiers such as:-such as:-
-Potassium sulphate-Potassium sulphate
-Borax-Borax
-- Advantage:Advantage: - Records excellent fine details.- Records excellent fine details.
-- Disadvantages: -Disadvantages: - Small dimensional changes.Small dimensional changes.
Fracture on removal from undercutsFracture on removal from undercuts
Separating media is requiredSeparating media is requiredwww.indiandentalacademy.comwww.indiandentalacademy.com
14. 2. MODEL PLASTER2. MODEL PLASTER
( Type 2):-( Type 2):-
- β – hemi hydrate- β – hemi hydrate
- Powder particles are porous & irregular.- Powder particles are porous & irregular.
-It is usually white in color.-It is usually white in color.
-- Use: -Use: - For primary cast for complete dentures.For primary cast for complete dentures.
- For articulation purposes.- For articulation purposes.
- For flasking in denture construction.- For flasking in denture construction.
-- Advantage: -Advantage: - InexpensiveInexpensive
- Disadvantage: -- Disadvantage: - Low strengthLow strength
High PorosityHigh Porosity
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15. 3. DENTAL STONE (Type 3):-3. DENTAL STONE (Type 3):-
Medium strength stoneMedium strength stone
- Discovered in 1930- Discovered in 1930
- Gypsum is calcined under steam pressure in an autoclave at a- Gypsum is calcined under steam pressure in an autoclave at a
temperature of 120 C to 130 C for 5-7 hours.temperature of 120 C to 130 C for 5-7 hours.
- α – hemihydrate or Hydrocal- α – hemihydrate or Hydrocal
- Powder particles are more uniform, dense & prismatic in shape.- Powder particles are more uniform, dense & prismatic in shape.
- Comes in different colors like yellow, green, etc.- Comes in different colors like yellow, green, etc.
- Accelerator – K- Accelerator – K22SOSO44
- Retarder – Sodium Citrate- Retarder – Sodium Citrate
-- Uses: -Uses: - Making casts for diagnostic purposes & forMaking casts for diagnostic purposes & for
complete or partial denture construction.complete or partial denture construction.
-- Advantages: -Advantages: - Greater strength & surface hardnessGreater strength & surface hardness
-- Disadvantage: -Disadvantage: - More expensive than plaster.More expensive than plaster.
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16. 4. DENTAL STONE,4. DENTAL STONE, HIGHHIGH
STRENGTH (Type 4):-STRENGTH (Type 4):-Die stoneDie stone
- Modified α – hemi hydrate, Densite or Die stone.Modified α – hemi hydrate, Densite or Die stone.
- Gypsum is calcined by boiling it in 30%calcium chloride orGypsum is calcined by boiling it in 30%calcium chloride or
MgClMgCl22 and autoclaved in presence of sodium succinate 0.5%and autoclaved in presence of sodium succinate 0.5%
- Powder particles are very dense, cuboidal in shape &- Powder particles are very dense, cuboidal in shape &
has reduced surface area.has reduced surface area.
-- Use: -Use: - For making casts or dies for crown, bridge &For making casts or dies for crown, bridge &
Inlay fabrication.Inlay fabrication.
-- AdvantagesAdvantages -High strength-High strength
-Surface hardness-Surface hardness
-Abrasion resistant-Abrasion resistant
-Minimum setting expansion-Minimum setting expansion
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17. 5. Dental stone ,5. Dental stone , High strength,High strength,
High expansion (Type v);High expansion (Type v);
-- Most recent gypsum productMost recent gypsum product
- Higher compressive strength than Type 4- Higher compressive strength than Type 4
- Lower the W/P ratio more strength is- Lower the W/P ratio more strength is
attainableattainable
- Higher setting expansion- Higher setting expansion
- They are expensive, easy to use and- They are expensive, easy to use and
compatible to all impression materials.compatible to all impression materials.
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19. THEORIES FOR SETTINGTHEORIES FOR SETTING
REACTION:-REACTION:-
1. Colloidal/ Gel Theory.1. Colloidal/ Gel Theory.
2. Hydration Theory.2. Hydration Theory.
3. Crystalline Theory3. Crystalline Theory
4. Dissolution- precipitation Theory.4. Dissolution- precipitation Theory.
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20. Colloidal/ Gel Theory:-Colloidal/ Gel Theory:-
-- Originated in 1893 by M. Michaelis.Originated in 1893 by M. Michaelis.
- When plaster is mixed with water, plaster enters- When plaster is mixed with water, plaster enters
into the colloidal state through a sol- gelinto the colloidal state through a sol- gel
mechanism.mechanism.
- In the sol state, hemi hydrate particles are hydrated- In the sol state, hemi hydrate particles are hydrated
to form dihydrate, thereby entering into an activeto form dihydrate, thereby entering into an active
state.state.
- As the measured amount of water is consumed, the- As the measured amount of water is consumed, the
mass converts to a solid gel.mass converts to a solid gel.www.indiandentalacademy.comwww.indiandentalacademy.com
21. Crystalline Theory:-Crystalline Theory:-
-- Originated in 1887 by Henry Louis Le ChatelierOriginated in 1887 by Henry Louis Le Chatelier
- In 1907, supported by Jacobus Hendricus van’t Hoff - TheIn 1907, supported by Jacobus Hendricus van’t Hoff - The
difference in the solubilities of calcium sulphate dihydrate &difference in the solubilities of calcium sulphate dihydrate &
hemi hydrate causes setting differences. -hemi hydrate causes setting differences. -
Dissolved CaSO4 precipitates as calcium sulphate dihydrate,Dissolved CaSO4 precipitates as calcium sulphate dihydrate,
since it is less soluble than hemi hydrate. - X-raysince it is less soluble than hemi hydrate. - X-ray
diffraction studies – not all hemi hydrate is converts todiffraction studies – not all hemi hydrate is converts to
dihydrate.dihydrate.
In a setting mass of plaster 2 types of centers are there:-In a setting mass of plaster 2 types of centers are there:-
a) Dissolution center- around CaSO4 hemi hydratea) Dissolution center- around CaSO4 hemi hydrate
b) Precipitation center- around CaSO4 dihydrateb) Precipitation center- around CaSO4 dihydrate
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22. Dissolution- PrecipitationDissolution- Precipitation
Theory:-Theory:-
Based on dissolution of plaster & instant re-crystallization of gypsumBased on dissolution of plaster & instant re-crystallization of gypsum
interlocking of crystalsinterlocking of crystals
The Setting Reaction is as follows:-The Setting Reaction is as follows:-
1. When the hemi hydrate is mixed with water, a suspension is formed1. When the hemi hydrate is mixed with water, a suspension is formed
that is fluid & workable.that is fluid & workable.
2. The hemi hydrate dissolves until it forms a saturated solution.2. The hemi hydrate dissolves until it forms a saturated solution.
3. This saturated solution of hemi hydrate, supersaturated in dihydrate,3. This saturated solution of hemi hydrate, supersaturated in dihydrate,
precipitates out dihydrate.precipitates out dihydrate.
4. As the dihydrate precipitates, the solution is no longer saturated with4. As the dihydrate precipitates, the solution is no longer saturated with
the hemi hydrate, so it continues to dissolve. Dissolution of hemithe hemi hydrate, so it continues to dissolve. Dissolution of hemi
hydrate & precipitation of dihydrate as either new crystals or furtherhydrate & precipitation of dihydrate as either new crystals or further
growth to the already present. The reaction continues until no furthergrowth to the already present. The reaction continues until no further
dihydrate precipitates out of solution.dihydrate precipitates out of solution.
The reaction rate is followed by the exothermic heat evolved as shown inThe reaction rate is followed by the exothermic heat evolved as shown in
fig.fig. www.indiandentalacademy.comwww.indiandentalacademy.com
24. Stages During CrystallizationStages During Crystallization
DissolutionDissolution
SuspensionSuspension
SaturationSaturation
Super saturationSuper saturation
Nuclei formationNuclei formation
Growth of nucleiGrowth of nuclei
CrystallizationCrystallization
Spherulite formationSpherulite formation
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25. The particles or crystals of hemi hydrate are first dissolved in water toThe particles or crystals of hemi hydrate are first dissolved in water to
form a suspension that soon becomes saturatedform a suspension that soon becomes saturated
In this saturated solution nuclei of crystallization appear and crystalsIn this saturated solution nuclei of crystallization appear and crystals
of dihydrate begin to form until time the whole mass becomesof dihydrate begin to form until time the whole mass becomes
supersaturated with dihydrate.supersaturated with dihydrate.
Since dihydrate is less soluble than hemi hydrate, the dihydrateSince dihydrate is less soluble than hemi hydrate, the dihydrate
crystals precipitate out leaving the remaining solution to dissolvecrystals precipitate out leaving the remaining solution to dissolve
more hemi hydrate crystals into it.more hemi hydrate crystals into it.
The precipitated dihydrate crystals begin to grow in size throughoutThe precipitated dihydrate crystals begin to grow in size throughout
the mix as needle like crystals.the mix as needle like crystals.
This process is repeated until all the hemi hydrate is converted toThis process is repeated until all the hemi hydrate is converted to
dihydrate.dihydrate.
The needle like crystal grow long, intermesh and intertwine with eachThe needle like crystal grow long, intermesh and intertwine with each
other. This stage is called Spherulite formation- and it indicates thatother. This stage is called Spherulite formation- and it indicates that
material has set.material has set. www.indiandentalacademy.comwww.indiandentalacademy.com
26. Clusters of needle like
crystals
Dark- field photomicrograph
of set plaster
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27. SETTING TIMESETTING TIME
Measured by “Penetration Test” (time taken from the start of mix until theMeasured by “Penetration Test” (time taken from the start of mix until the
needle no longer penetrates to the bottom) with the help of Vicat &needle no longer penetrates to the bottom) with the help of Vicat &
Gillmore needles.Gillmore needles.
There are number of stages in the setting of a gypsum product:-There are number of stages in the setting of a gypsum product:-
MIXING TIME:-MIXING TIME:- The time from the addition of powder to the waterThe time from the addition of powder to the water
until the mixing is completed.until the mixing is completed.
Mechanical mixing – 20-30 secs.Mechanical mixing – 20-30 secs.
Hand spatulation - 1 min.Hand spatulation - 1 min.
WORKING TIME: -WORKING TIME: - The time available to use a workable mix.The time available to use a workable mix.
Working time – 3min.Working time – 3min.
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29. -- LOSS OF GLOSS TEST FOR INITIAL SET:-LOSS OF GLOSS TEST FOR INITIAL SET:- Some of the excess water isSome of the excess water is
taken by forming the dihydrate so that the mix loses its gloss.taken by forming the dihydrate so that the mix loses its gloss.
-- INITIAL GILLMORE TEST FOR INITIAL SET:-INITIAL GILLMORE TEST FOR INITIAL SET:- The mixture is spread out, &The mixture is spread out, &
the needle is lowered onto the surface. The time at which it no longer leaves anthe needle is lowered onto the surface. The time at which it no longer leaves an
impression is called the “Initial Set.”impression is called the “Initial Set.”
This is marked by a definite increase in strength.This is marked by a definite increase in strength.
- VICAT TEST FOR SETTING TIME: -- VICAT TEST FOR SETTING TIME: - In thisIn this Vicat Penetrometer is used.Vicat Penetrometer is used.
The needle with a weighed plunger rod is supported & held just in contact with theThe needle with a weighed plunger rod is supported & held just in contact with the
mix. After the gloss is lost, the plunger is released.mix. After the gloss is lost, the plunger is released.
The time elapsed until the needle no longer penetrates to the bottom of the mix isThe time elapsed until the needle no longer penetrates to the bottom of the mix is
known as the “Setting Time.”known as the “Setting Time.”
- GILLMORE TEST FOR FINAL SETTING TIME:-- GILLMORE TEST FOR FINAL SETTING TIME:-
Heavier Gillmore Needle is used.Heavier Gillmore Needle is used.
The time elapsed at which this needle leaves only a barely perceptible mark on theThe time elapsed at which this needle leaves only a barely perceptible mark on the
surface is called the “surface is called the “Final Setting TimeFinal Setting Time.”.”
- READY- FOR- USE CRITERION:-- READY- FOR- USE CRITERION:- The subjective measure of the time atThe subjective measure of the time at
which the set material may be safely handled in the usual manner.which the set material may be safely handled in the usual manner.
Ready for use state is reached in approx. 30 min.Ready for use state is reached in approx. 30 min.
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30. CONTROL OF SETTING TIMECONTROL OF SETTING TIME
TemperatureTemperature
W:P ratioW:P ratio
phph
FinenessFineness
Modifiers, Accelerators and RetardersModifiers, Accelerators and Retarders
Mixing and spatulationMixing and spatulation
Manufacturing processManufacturing process
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31. SETTING EXPANSIONSETTING EXPANSION
-- Expansion may vary from 0.06% to 0.5%Expansion may vary from 0.06% to 0.5%
- Volume of dihydrate formed is less than equal to- Volume of dihydrate formed is less than equal to
the volume of hemi hydrate & water i.e. actually athe volume of hemi hydrate & water i.e. actually a
volumetric contraction should occur during settingvolumetric contraction should occur during setting
reaction, but instead a setting expansion is observed.reaction, but instead a setting expansion is observed.
PHENOMENON:-PHENOMENON:- Based on crystallizationBased on crystallization
mechanism.mechanism.
RESULT:-RESULT:-
The set material must be porous.The set material must be porous.
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32. CONTROL OF SETTING EXPANSIONCONTROL OF SETTING EXPANSION
1. Increased spatulation increases setting expansion1. Increased spatulation increases setting expansion
2. Increase in W: P ratio reduces the setting expansion2. Increase in W: P ratio reduces the setting expansion
3. Accelerators & Retarders:-3. Accelerators & Retarders:-
Accelerators:-Accelerators:-
- Sodium Chloride (up to 2% of hemi hydrate)- Sodium Chloride (up to 2% of hemi hydrate)
- Sodium Sulfate (max. effect at 3.4%)- Sodium Sulfate (max. effect at 3.4%)
- Potassium Sulfate (>2%)- Potassium Sulfate (>2%)
- Potassium Tartrate- Potassium Tartrate
Retarders: -Retarders: - Citrates, acetates & boratesCitrates, acetates & borates
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33. HYGROSCOPIC SETTINGHYGROSCOPIC SETTING
EXPANSIONEXPANSION
Setting expansion that occurs under water isSetting expansion that occurs under water is
called as “Hygroscopic Setting Expansion.”called as “Hygroscopic Setting Expansion.”
Setting expansion without water immersion isSetting expansion without water immersion is
called “Normal Setting Expansion.”called “Normal Setting Expansion.”
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34. Stages of Hygroscopic settingStages of Hygroscopic setting
expansionexpansion:-:-
STRENGTH:STRENGTH: The greater the amount of free water, the lessThe greater the amount of free water, the less
the strength.the strength.
There are 2 Strength properties of gypsumThere are 2 Strength properties of gypsum
--
1.1. WET STRENGTH (Green Strength):-WET STRENGTH (Green Strength):-Strength obtainedStrength obtained
when the water in excess of that required for hydration ofwhen the water in excess of that required for hydration of
the hemi hydrate is left in the test specimen.the hemi hydrate is left in the test specimen.
2.2. DRY STRENGTH: -DRY STRENGTH: - Strength obtained when the excessStrength obtained when the excess
water in the specimen has been driven off by drying.water in the specimen has been driven off by drying.
Strength depends upon:-Strength depends upon:-www.indiandentalacademy.comwww.indiandentalacademy.com
36. SURFACE HARDNESS & ABRASIONSURFACE HARDNESS & ABRASION
RESISTANCERESISTANCE
Surface hardness of gypsum materials is related toSurface hardness of gypsum materials is related to
their compressive strength.their compressive strength.
Surface hardness increases at a faster rate than theSurface hardness increases at a faster rate than the
compressive strength.compressive strength.
Abrasive Resistance of gypsum product is increasedAbrasive Resistance of gypsum product is increased
by impregnating the set gypsum with epoxy resins.by impregnating the set gypsum with epoxy resins.
Surface hardness of set gypsum is improved bySurface hardness of set gypsum is improved by
mixing stone with a hardening solution containingmixing stone with a hardening solution containing
colloidal silica (about 30%)colloidal silica (about 30%)
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37. VISCOSITY-VISCOSITY-It is the resistance of a fluid to flow.It is the resistance of a fluid to flow.
REPRODUCTION OF DETAILREPRODUCTION OF DETAIL
Gypsum dies do not reproduce surface detail as wellGypsum dies do not reproduce surface detail as well
as electroformed or epoxy dies.as electroformed or epoxy dies.
Air bubbles are formed at the interface of impressionAir bubbles are formed at the interface of impression
& gypsum cast.& gypsum cast.
Contamination of the impression (by saliva orContamination of the impression (by saliva or
blood) in which the gypsum die is poured can alsoblood) in which the gypsum die is poured can also
affect the detail reproduction.affect the detail reproduction.
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38. PROPORTIONING, MIXING & CARINGPROPORTIONING, MIXING & CARING
FOR GYPSUM PRODUCTSFOR GYPSUM PRODUCTS
--PROPORTIONING:-PROPORTIONING:- Strength of a stone isStrength of a stone is
inversely proportional to the W:P ratio.inversely proportional to the W:P ratio.
--MIXING:-MIXING:-
Trapping of air should be avoided while mixing toTrapping of air should be avoided while mixing to
avoid porosity weak spots & surface inaccuracies.avoid porosity weak spots & surface inaccuracies.
Longer spatulation decreases the working timeLonger spatulation decreases the working time
-- Method of mixing:-Method of mixing:-
Add measured amount of water.Add measured amount of water.
GradualGradualwww.indiandentalacademy.comwww.indiandentalacademy.com
39. CARING FOR THE CAST:-CARING FOR THE CAST:-
Once the setting reaction in the cast is completed,Once the setting reaction in the cast is completed,
its dimensions remain constant under roomits dimensions remain constant under room
temperature & humidity.temperature & humidity.
If stone cast is immersed in running water, its linearIf stone cast is immersed in running water, its linear
dimensions may vary 0.1% for every 20min. ofdimensions may vary 0.1% for every 20min. of
immersion.immersion.
If storage temperature is raised from 90ºC to110ºCIf storage temperature is raised from 90ºC to110ºC
– shrinkage occurs– shrinkage occurs
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40. CARING FOR GYPSUMCARING FOR GYPSUM
PRODUCT:-PRODUCT:-
- All types of gypsum products should be stored in aAll types of gypsum products should be stored in a
dry atmosphere.dry atmosphere.
- Products should be sealed in a moisture proof metal- Products should be sealed in a moisture proof metal
container.container.
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41. INFECTION CONTROL:-INFECTION CONTROL:-
If an impression has not been disinfected, it isIf an impression has not been disinfected, it is
necessary to disinfect the stone cast.necessary to disinfect the stone cast.
Disinfection solutions that do not adversely affectDisinfection solutions that do not adversely affect
the quality of the gypsum product can be used.the quality of the gypsum product can be used.
Dental stone containing a disinfectant may also beDental stone containing a disinfectant may also be
used.used.
Useful disinfectants for stone casts include sprayUseful disinfectants for stone casts include spray
disinfectants, hypochlorites, & iodophores.disinfectants, hypochlorites, & iodophores.
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42. Difference between dental plaster andDifference between dental plaster and
dental stone.dental stone.
ManufactureManufacture –– dental stone by wet calcinations and dental plaster bydental stone by wet calcinations and dental plaster by
dry calcinations.dry calcinations.
Particle shape and size-Particle shape and size- dental plaster- particles are larger, irregulardental plaster- particles are larger, irregular
and porous while dental stone – particles are smaller, regular and non-and porous while dental stone – particles are smaller, regular and non-
porous.porous.
W/P ratioW/P ratio—— Dental plaster- 0.5 (50ml/100gm)Dental plaster- 0.5 (50ml/100gm)
Dental stone – 0.3 (30ml/100gm)Dental stone – 0.3 (30ml/100gm)
Mechanical properties of set material-Mechanical properties of set material- the strength and hardnessthe strength and hardness
depends on the density of the material, thus stone is harder anddepends on the density of the material, thus stone is harder and
stronger than plaster.stronger than plaster.
Application-Application- when strength and hardness are required, stone iswhen strength and hardness are required, stone is
material of choice e.g. denture construction, dies for crowns, bridgesmaterial of choice e.g. denture construction, dies for crowns, bridges
and inlay work. When mechanical properties is not of primaryand inlay work. When mechanical properties is not of primary
importance plaster can be used e.g. mounting models, orthodonticimportance plaster can be used e.g. mounting models, orthodontic
study models.study models. www.indiandentalacademy.comwww.indiandentalacademy.com