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
Trefoil Dental Implant from Nobel biocare | Trefoil: a new solution for the e...Dr. Rajat Sachdeva
Trefoil from Nobel Biocare, where 3 Implants attached with prefabricated Titanium Bar attached to Mandible. Here Prosthesis is attached with titanium Bar in place, Titanium Bar is attached with 3 Screws.
This document discusses terminology and techniques for dental implant impressions. It defines terms like cover screws, healing caps, transfer copings, and implant analogues. It explains that impressions are needed to capture the implant position, depth, axis, and soft tissue contour. The document outlines two main impression techniques - open tray (using pick-up copings) and closed tray (using transfer copings). It notes the advantages and disadvantages of each technique. Abutment level impressions are also discussed for customization and laboratory abutment selection. Gingival simulation is described as a technique to simulate the soft tissue around implants.
This document discusses pontic and retainer designs for fixed partial dentures. It describes various pontic shapes including saddle, modified ridge lap, conical, and ovate designs. Considerations for pontic design include biologic factors like tissue contact, oral hygiene, and material biocompatibility as well as mechanical factors like rigidity and esthetic factors like replicating the natural tooth. Retainers are fixed restorations on abutment teeth that provide stabilization and are classified by location and degree of tooth coverage. Connectors unite the retainer and pontic.
A- Retention of Removable Partial DenturesAmal Kaddah
1. Retention of removable partial dentures depends on mechanical and physiological factors. Mechanical retention includes direct retainers, indirect retainers, and frictional fit provided by parts of the denture engaging tooth and tissue undercuts.
2. Common means of mechanical retention are clasps and attachments. Clasps have a retentive arm, bracing arm, and occlusal rest. Properly designed clasps follow principles like encircling teeth, providing retention in undercuts, supporting occlusal rests, and having reciprocal and bracing arms.
3. Factors like amount of undercut, angle of convergence, clasp flexibility, and material affect a clasp's retentive force.
Complete denture fabrication By Dr. Armaan SinghDr. Armaan Singh
This document outlines the steps involved in fabricating complete dentures from taking the initial impression to the follow up appointment. It involves taking a primary impression, pouring it to create a mold, arranging teeth and waxing them into place, doing a try in with the patient, packaging the mold and wax setup into a flask, eliminating the wax, packing and curing acrylic resin, finishing and polishing the dentures, and following up with the patient. The goal is to restore form, function, and esthetics through the denture fabrication process.
The document provides an overview of esthetics with veneers. It discusses the definitions, history, indications and contraindications of veneers. It describes the processes of shade selection, tooth preparation including principles, rationale and types of preparation. It also discusses provisional restorations, cementation, maintenance and failures of veneers. Recent advancements discussed include feldspathic, lithium disilicate and minimally invasive veneers. In conclusion, veneers are a conservative treatment for improving aesthetics when done according to principles of preparation, cementation and maintenance.
Luting agents for fixed prosthodontics/ orthodontic course by indian dental a...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.
Trefoil Dental Implant from Nobel biocare | Trefoil: a new solution for the e...Dr. Rajat Sachdeva
Trefoil from Nobel Biocare, where 3 Implants attached with prefabricated Titanium Bar attached to Mandible. Here Prosthesis is attached with titanium Bar in place, Titanium Bar is attached with 3 Screws.
This document discusses terminology and techniques for dental implant impressions. It defines terms like cover screws, healing caps, transfer copings, and implant analogues. It explains that impressions are needed to capture the implant position, depth, axis, and soft tissue contour. The document outlines two main impression techniques - open tray (using pick-up copings) and closed tray (using transfer copings). It notes the advantages and disadvantages of each technique. Abutment level impressions are also discussed for customization and laboratory abutment selection. Gingival simulation is described as a technique to simulate the soft tissue around implants.
This document discusses pontic and retainer designs for fixed partial dentures. It describes various pontic shapes including saddle, modified ridge lap, conical, and ovate designs. Considerations for pontic design include biologic factors like tissue contact, oral hygiene, and material biocompatibility as well as mechanical factors like rigidity and esthetic factors like replicating the natural tooth. Retainers are fixed restorations on abutment teeth that provide stabilization and are classified by location and degree of tooth coverage. Connectors unite the retainer and pontic.
A- Retention of Removable Partial DenturesAmal Kaddah
1. Retention of removable partial dentures depends on mechanical and physiological factors. Mechanical retention includes direct retainers, indirect retainers, and frictional fit provided by parts of the denture engaging tooth and tissue undercuts.
2. Common means of mechanical retention are clasps and attachments. Clasps have a retentive arm, bracing arm, and occlusal rest. Properly designed clasps follow principles like encircling teeth, providing retention in undercuts, supporting occlusal rests, and having reciprocal and bracing arms.
3. Factors like amount of undercut, angle of convergence, clasp flexibility, and material affect a clasp's retentive force.
Complete denture fabrication By Dr. Armaan SinghDr. Armaan Singh
This document outlines the steps involved in fabricating complete dentures from taking the initial impression to the follow up appointment. It involves taking a primary impression, pouring it to create a mold, arranging teeth and waxing them into place, doing a try in with the patient, packaging the mold and wax setup into a flask, eliminating the wax, packing and curing acrylic resin, finishing and polishing the dentures, and following up with the patient. The goal is to restore form, function, and esthetics through the denture fabrication process.
The document provides an overview of esthetics with veneers. It discusses the definitions, history, indications and contraindications of veneers. It describes the processes of shade selection, tooth preparation including principles, rationale and types of preparation. It also discusses provisional restorations, cementation, maintenance and failures of veneers. Recent advancements discussed include feldspathic, lithium disilicate and minimally invasive veneers. In conclusion, veneers are a conservative treatment for improving aesthetics when done according to principles of preparation, cementation and maintenance.
Luting agents for fixed prosthodontics/ orthodontic course by indian dental a...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.
Impression materials /certified fixed orthodontic courses by Indian dental a...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
Classification and impression techniques of implants/ dentistry dental implantsIndian 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.
The document discusses overdentures, which are removable partial or complete dentures that cover and rest on one or more remaining natural teeth, tooth roots, or dental implants. Key points include:
- Retaining natural teeth can preserve alveolar bone and periodontal receptors important for function.
- Abutment teeth are prepared with short copings or left uncovered, and attachments may be added to improve retention.
- Overdentures can improve retention, stability, support and proprioception compared to conventional dentures.
- Proper case selection and maintenance are important for long term success.
This document discusses tissue conditioners and soft denture liners. It defines tissue conditioners as temporary resilient materials placed inside a denture for a short period to allow healing of traumatized tissues. Soft denture liners provide long-term cushioning and are made of materials like silicone or soft acrylic. The document outlines the ideal properties, uses, and application process for tissue conditioners. It also discusses the requirements for resilient denture liners to be biologically compatible, resilient, dimensionally stable, and resistant to staining and abrasion.
This document discusses attachments used in prosthodontics. It begins with an introduction to attachments, defining them as mechanical devices used to retain and stabilize prostheses. The document then covers the history, classification, indications, disadvantages, and selection of attachments. It discusses both intracoronal and extracoronal attachments. In summary, the document provides an overview of attachments, their uses in prosthodontics, and factors to consider in selecting the appropriate attachment.
Design of a fixed Partial Denture (with Abutment Tooth Preparation)Taseef Hasan Farook
A simplified take on the steps to designing a Fixed partial denture. This presentation also includes an overview of abutment preparation, associated finishes and methods of impression taking prior to the designing of the prosthesis itself
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.for more details please visit
www.indiandentalacademy.com
Resin bonded prosthesis /certified fixed orthodontic courses by Indian dental...Indian dental academy
This document discusses resin bonded prostheses. It begins with the history of acid etching of enamel by Buonocore in 1955. It then describes the evolution of resin bonded prostheses from early bonded pontics to modern techniques like etched cast resin retained FPDs, macroscopic mechanical retention FPDs, and fiber reinforced composite resin FPDs. The document outlines the advantages and disadvantages, indications, contraindications, and design concepts for resin bonded prostheses. It also discusses laboratory procedures, bonding techniques, cements used, and the longevity of resin bonded prostheses.
Implant abutment and implant abutment connectionsDR.BHAVESH JHA
this ppt enlightened with different types of implant abutment connection. Detailed classification of abutments. Different types of abutments. Latest trends of abutments. Smart abutments. Platform switching, rationale of platform switching and related articles.
The document lists 90 seminar topics related to prosthodontics. The topics cover a wide range of subjects including: facial muscles, impression making techniques, dental occlusion and jaw relations, removable partial dentures, fixed partial dentures, dental implants, maxillofacial prosthetics, dental materials, and treatment planning.
This document outlines the planning sequence for designing removable partial dentures (RPDs). It begins with a diagnostic assessment and preliminary impressions to obtain diagnostic casts. The casts are then mounted in centric relation. The ideal RPD design is then drawn on paper, considering factors like abutment teeth, the dental arch, and occlusion. The design is surveyed on the study casts to determine the most advantageous path of insertion and withdrawal. The design is then revised and finalized. Key steps in the design process are discussed, including the use of rests, connectors, and different types of retainers for mandibular and maxillary designs. Issues to consider for each component are also outlined.
This document discusses dental ceramics, including their composition, microstructure, properties, applications, and fabrication techniques. It describes the three main types of dental ceramics: predominantly glass ceramics, particle-filled glasses, and polycrystalline ceramics. Predominantly glass ceramics are based on glass and mimic enamel properties. Particle-filled glasses add particles like leucite or aluminum oxide to improve strength. Polycrystalline ceramics like alumina and zirconia are very strong but opaque. Fabrication techniques include conventional sintering, pressure molding, casting, and CAD-CAM milling.
types of materials in dental implants , includes a brief history of dental implants
also watch for more
https://youtu.be/aaJ6gpQohcs
https://youtu.be/REMKSUty0cE
https://youtu.be/fv3_tWZPJIU
https://youtu.be/GeZIbCwqKYU
if you want me to make ppt on some topic do let me know on the comment section of my youtube channel
INTRODUCTION TO PROSTHODONTICS AND COMPLETE DENTURESAamir Godil
This document provides an introduction to prosthodontics and complete dentures. It defines prosthodontics as the branch of dentistry concerned with replacing missing teeth and oral tissues with dental prostheses. Complete dentures are described as prostheses that replace the entire dentition. The key steps in fabricating complete dentures are outlined, including taking impressions, constructing dental casts, arranging teeth on the cast, processing the denture, and inserting the final prosthesis. Proper maintenance of complete dentures is emphasized.
The scope of fixed prosthodontics treatment can range from the restoration of a single tooth to the rehabilitation of the entire occlusion. Single teeth can be restored to full function, and improvement in
esthetics can be achieved. Missing teeth can be replaced with fixed prostheses that will improve patient comfort and masticatory ability, maintain the health and integrity of the dental arches, and, in many instances, elevate the patient’s self-image.
The document discusses various implant components including fixtures, abutments, gold cylinders, and analogs. It describes the original Brånemark implant design and newer implant systems with enhanced surfaces and internal connections. The document also outlines different types of abutments from healing abutments to custom UCLA abutments and discusses techniques for impression taking and creating prosthetics on implants.
The document discusses fibre reinforced composite fixed prostheses. It provides background on the materials used such as glass fibres embedded in a resin matrix. Fibre reinforced composites provide an alternative to traditional metal-ceramic restorations. They are esthetic, bond well to tooth structure, and have improved mechanical properties over particulate composites alone. Indications for fibre reinforced composite fixed prostheses include conservative tooth preparations and situations where a metal-free prosthesis is desired. Case studies and clinical trials show promising results for survival and quality of fibre reinforced composite bridges.
Lab steps mould preparation to finish/ dental crown & bridge 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
Impressions in fixed partial dentures/dental crown &bridge course by Indian d...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.
This document provides an overview of different elastomeric impression materials used in dentistry, including their composition, setting reactions, properties, advantages, and disadvantages. It discusses polysulfide rubber, condensation silicone, addition silicone, and polyether impression materials. It also covers general properties like working and setting times, dimensional stability, reproduction of details, disinfection, tear strength, biocompatibility, and effects of mishandling. Recently, visible light-cured polyether urethane dimethacryl materials have been introduced as well.
Impression materials /certified fixed orthodontic courses by Indian dental a...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
Classification and impression techniques of implants/ dentistry dental implantsIndian 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.
The document discusses overdentures, which are removable partial or complete dentures that cover and rest on one or more remaining natural teeth, tooth roots, or dental implants. Key points include:
- Retaining natural teeth can preserve alveolar bone and periodontal receptors important for function.
- Abutment teeth are prepared with short copings or left uncovered, and attachments may be added to improve retention.
- Overdentures can improve retention, stability, support and proprioception compared to conventional dentures.
- Proper case selection and maintenance are important for long term success.
This document discusses tissue conditioners and soft denture liners. It defines tissue conditioners as temporary resilient materials placed inside a denture for a short period to allow healing of traumatized tissues. Soft denture liners provide long-term cushioning and are made of materials like silicone or soft acrylic. The document outlines the ideal properties, uses, and application process for tissue conditioners. It also discusses the requirements for resilient denture liners to be biologically compatible, resilient, dimensionally stable, and resistant to staining and abrasion.
This document discusses attachments used in prosthodontics. It begins with an introduction to attachments, defining them as mechanical devices used to retain and stabilize prostheses. The document then covers the history, classification, indications, disadvantages, and selection of attachments. It discusses both intracoronal and extracoronal attachments. In summary, the document provides an overview of attachments, their uses in prosthodontics, and factors to consider in selecting the appropriate attachment.
Design of a fixed Partial Denture (with Abutment Tooth Preparation)Taseef Hasan Farook
A simplified take on the steps to designing a Fixed partial denture. This presentation also includes an overview of abutment preparation, associated finishes and methods of impression taking prior to the designing of the prosthesis itself
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.for more details please visit
www.indiandentalacademy.com
Resin bonded prosthesis /certified fixed orthodontic courses by Indian dental...Indian dental academy
This document discusses resin bonded prostheses. It begins with the history of acid etching of enamel by Buonocore in 1955. It then describes the evolution of resin bonded prostheses from early bonded pontics to modern techniques like etched cast resin retained FPDs, macroscopic mechanical retention FPDs, and fiber reinforced composite resin FPDs. The document outlines the advantages and disadvantages, indications, contraindications, and design concepts for resin bonded prostheses. It also discusses laboratory procedures, bonding techniques, cements used, and the longevity of resin bonded prostheses.
Implant abutment and implant abutment connectionsDR.BHAVESH JHA
this ppt enlightened with different types of implant abutment connection. Detailed classification of abutments. Different types of abutments. Latest trends of abutments. Smart abutments. Platform switching, rationale of platform switching and related articles.
The document lists 90 seminar topics related to prosthodontics. The topics cover a wide range of subjects including: facial muscles, impression making techniques, dental occlusion and jaw relations, removable partial dentures, fixed partial dentures, dental implants, maxillofacial prosthetics, dental materials, and treatment planning.
This document outlines the planning sequence for designing removable partial dentures (RPDs). It begins with a diagnostic assessment and preliminary impressions to obtain diagnostic casts. The casts are then mounted in centric relation. The ideal RPD design is then drawn on paper, considering factors like abutment teeth, the dental arch, and occlusion. The design is surveyed on the study casts to determine the most advantageous path of insertion and withdrawal. The design is then revised and finalized. Key steps in the design process are discussed, including the use of rests, connectors, and different types of retainers for mandibular and maxillary designs. Issues to consider for each component are also outlined.
This document discusses dental ceramics, including their composition, microstructure, properties, applications, and fabrication techniques. It describes the three main types of dental ceramics: predominantly glass ceramics, particle-filled glasses, and polycrystalline ceramics. Predominantly glass ceramics are based on glass and mimic enamel properties. Particle-filled glasses add particles like leucite or aluminum oxide to improve strength. Polycrystalline ceramics like alumina and zirconia are very strong but opaque. Fabrication techniques include conventional sintering, pressure molding, casting, and CAD-CAM milling.
types of materials in dental implants , includes a brief history of dental implants
also watch for more
https://youtu.be/aaJ6gpQohcs
https://youtu.be/REMKSUty0cE
https://youtu.be/fv3_tWZPJIU
https://youtu.be/GeZIbCwqKYU
if you want me to make ppt on some topic do let me know on the comment section of my youtube channel
INTRODUCTION TO PROSTHODONTICS AND COMPLETE DENTURESAamir Godil
This document provides an introduction to prosthodontics and complete dentures. It defines prosthodontics as the branch of dentistry concerned with replacing missing teeth and oral tissues with dental prostheses. Complete dentures are described as prostheses that replace the entire dentition. The key steps in fabricating complete dentures are outlined, including taking impressions, constructing dental casts, arranging teeth on the cast, processing the denture, and inserting the final prosthesis. Proper maintenance of complete dentures is emphasized.
The scope of fixed prosthodontics treatment can range from the restoration of a single tooth to the rehabilitation of the entire occlusion. Single teeth can be restored to full function, and improvement in
esthetics can be achieved. Missing teeth can be replaced with fixed prostheses that will improve patient comfort and masticatory ability, maintain the health and integrity of the dental arches, and, in many instances, elevate the patient’s self-image.
The document discusses various implant components including fixtures, abutments, gold cylinders, and analogs. It describes the original Brånemark implant design and newer implant systems with enhanced surfaces and internal connections. The document also outlines different types of abutments from healing abutments to custom UCLA abutments and discusses techniques for impression taking and creating prosthetics on implants.
The document discusses fibre reinforced composite fixed prostheses. It provides background on the materials used such as glass fibres embedded in a resin matrix. Fibre reinforced composites provide an alternative to traditional metal-ceramic restorations. They are esthetic, bond well to tooth structure, and have improved mechanical properties over particulate composites alone. Indications for fibre reinforced composite fixed prostheses include conservative tooth preparations and situations where a metal-free prosthesis is desired. Case studies and clinical trials show promising results for survival and quality of fibre reinforced composite bridges.
Lab steps mould preparation to finish/ dental crown & bridge 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
Impressions in fixed partial dentures/dental crown &bridge course by Indian d...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.
This document provides an overview of different elastomeric impression materials used in dentistry, including their composition, setting reactions, properties, advantages, and disadvantages. It discusses polysulfide rubber, condensation silicone, addition silicone, and polyether impression materials. It also covers general properties like working and setting times, dimensional stability, reproduction of details, disinfection, tear strength, biocompatibility, and effects of mishandling. Recently, visible light-cured polyether urethane dimethacryl materials have been introduced as well.
Polysulphides, condensation silicones, addition silicones, and polyethers were compared. Polysulphides have the best tear resistance but the worst dimensional stability. Condensation silicones have adequate tear resistance and elasticity nearing silicones, but greater dimensional changes than polysulphides. Addition silicones have near ideal elasticity and the best dimensional stability as they produce no byproducts. Polyethers have adequate properties but can absorb water, swelling in high humidity.
Impression materials /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.for more details please visit
www.indiandentalacademy.com
Elastomeric Impression Materials by Dr Rashid HassanDr Rashid Hassan
A comprehensive lecture on Elaastomers by Dr Rashid Hassan covering all the aspects of all the elastomers used to record DeNRAL iMPRESSION.
For more lectures on Dental Materials Follow Dr Rashid Lectures on Dental Materials on Facebook (dmbydrrashid)
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 discusses elastomeric impression materials and impression techniques. It defines elastomeric impression materials as flexible polymers that are chemically or physically cross-linked and can be stretched and recover their original shape. It then covers the history, classification, properties and uses of various elastomeric materials like polysulfides, condensation and addition silicones, and polyethers. It also discusses tissue management techniques like surgical widening and the use of electrosurgery for gingival troughing.
This document provides an overview of dental impression materials, including their definition, classification, history, mixing systems, properties, and techniques. It discusses the main types of materials - polysulfide, condensation silicone, addition silicone, and polyether. For each, it outlines their composition, advantages, disadvantages, and properties like tear strength and dimensional stability. The document also reviews factors that affect impressions like temperature, viscosity, and storage conditions. It provides recommendations to control dimensional changes and concludes with a literature review on improving the accuracy of elastomeric impression 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.
Impression materials /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.for more details please visit
www.indiandentalacademy.com
1. The document discusses different types of elastic impression materials used in dentistry including their history, properties, and recent advances.
2. The main elastic impression materials discussed are elastomers/rubber base materials like polysulfides, condensation silicones, addition silicones, and polyethers.
3. Recent advances include visible light cured impression materials which offer controlled working times and excellent properties but require special trays and can be difficult to cure in all areas.
Elastomeric impression materials are flexible polymers that can be stretched and recover their original shape. Key materials include polysulfides (introduced in 1950s), condensation silicones, addition silicones, and polyethers (introduced later). They are supplied in various consistencies and used for impressions. Addition silicones have high accuracy while polysulfides have longer working time. Proper technique is required to mix, apply, and remove the materials. Advancements include light-cured and hydrophilic materials. Mishandling can cause defects like bubbles, rough surfaces, or lack of adhesion to trays.
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.
1. Elastomers are polymers that are crosslinked and easily stretched and recover their original shape when stress is released. There are four main types: polysulfides, condensation silicones, polyethers, and addition silicones.
2. Polysulfides impressions involve mixing a base paste with a catalyst paste containing lead dioxide. The lead dioxide reacts with sulfide groups on the polymer chains, lengthening and crosslinking them into a network.
3. Condensation silicones involve crosslinking a polydimethylsiloxane polymer with alkyl silicates using stannous octoate. Ethyl alcohol is a byproduct, causing shrinkage. They require a putty
This document outlines the objectives and content of a lecture on dental cements. It discusses the definition of cements, their history from early discoveries to modern developments, and classifications according to bonding mechanisms and intended uses. The document also covers the chemistry of cements including powder and liquid components, reactions, and ratios. It describes the uses of different cements, order of placement, and concludes by thanking the audience.
The document discusses dental impression materials. It provides details on the classification, composition, properties, manipulation and applications of various impression materials including alginate, agar, impression compound, zinc oxide eugenol and silicone impressions materials. Impression materials are classified based on their setting mechanism and elasticity into rigid or elastic materials that set via a chemical reaction or temperature change. The document describes the key ingredients, setting reactions, advantages and disadvantages of different impression materials.
The document discusses dental impression materials. It provides details on the classification, composition, properties, manipulation and applications of various impression materials including alginate, agar, impression compound, zinc oxide eugenol and silicone impressions materials. Impression materials are classified based on their setting mechanism and elasticity into rigid or elastic materials that set via a chemical reaction or temperature change. The document outlines the characteristics required of impression materials and provides formulations and setting reactions for several common materials.
Elastomeric impression materials include polysulfide, condensation silicone, addition silicone, and polyether rubbers. They set via polymerization reactions, with setting times of 8-12 minutes on average. Polysulfide and condensation silicone set via condensation reactions producing water or alcohol as byproducts, while addition silicone and polyether set via addition reactions without byproducts. Polysulfide has the highest detail reproduction but all materials exhibit some polymerization shrinkage. Materials are available in light, medium, heavy or putty consistencies for use with stock or custom trays. Proper manipulation is required for accurate impressions.
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.
This document discusses the properties and uses of polysulfide impression materials. Polysulfide impressions materials are liquid polymers that harden at room temperature when mixed with a catalyst. They consist of long polymer chains that are cross-linked. When the base and accelerator pastes are mixed, a chemical reaction occurs due to oxidation that causes the material to set within 5-8 minutes. Polysulfide impressions are dimensionally stable and accurate, with high tear strength, and are commonly used for final impressions in dentistry.
Similar to Impressions in fixed partial dentures/certified fixed orthodontic 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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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
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.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Training: ISO/IEC 27001 Information Security Management System - EN | PECB
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This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
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.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
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.
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.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
2. IMPRESSIONS IN FIXED PARTIAL DENTURES
CONTENTS
DEFINITIONS
IDEAL REQUIREMENTS OF IMPRESSION MATERIALS
CLASSIFICATION OF IMPRESSION MATERIALS
IMPRESSION TRAYS
IMPRESSION TECHNIQUES FOR DIFFERENT IMPRESSION
MATERIALS
SPECIAL CONSIDERATIONS
CONCLUSION
REFERENCES
2
3. Definitions
Impression
An imprint or negative likeness of the teeth and/or edentulous areas
where the teeth have been removed, made in a plastic material which
becomes relatively hard or set while in contact with these tissues.
Impression material
Any substance or combination of substances used for making a
negative reproduction or impression.
Impression tray
A device which is used to carry, confine and control an impression
material while making an impression.
Ideal requirements of impression material (According to Tylman)
Complete plasticity before use
Sufficient fluidity to record fine detail
The ability to wet the oral tissues
Dimensional accuracy
Dimensional stability
Complete elasticity after cure
Optimal stiffness
Have a good shelf life
Be non-toxic and non-irritating
3
4. Have acceptable taste and odor
Have suitable working and setting times
Have strength to resist tearing
Be compatible with model and die material
Facilitate clinical identification of beginning and end of cure
Facilitate visualization of the finish line
An impression
for a
fixed
restoration
should
meet
the
following
requirements
It should be an exact duplication of the prepared tooth, including all
of the preparation and enough uncut tooth surface beyond the
preparation for the dentist and technician to be certain of the
location and configuration of the finish line.
Teeth and tissues adjacent to the prepared tooth must be accurately
reproduced to permit proper articulation of the cast and contouring
of the restoration.
It must be free of bubbles, especially in the area of the finish line
and occlusal surfaces of other teeth in the arch.
Impression materials that are used in fixed prosthodontics are
Reversible hydrocolloids
Polysulfide
Condensation silicone
Addition silicone
4
5. Polyether
urethane dimethacryalte
Classification
According to chemical nature
Hydrocolloid impression material
Elastometric impression material
Each of them are further classified according to the viscosity
•
Heavy body
•
Regular/ medium body
•
Light body
•
Very heavy/ putty
Reversible hydrocolloid (Agar)
The credit for its first use in United States for fabricating cast
restorations is given to J.D. Hart (1930). It is a polysaccharide extracted
from certain types of seaweed.
Composition
Ingredients
Agar
Borates
Percentage by
w eight
13 – 17%
0.2 – 0.5%
Potassium sulfate
1 – 2%
Wax hard diatomaceous earth 0.5 – 1.1%
Silica
Function
Basic constituent
Improves strength of the gel
retards plaster or stone
Gypsum hardener
Filler
5
6. Clay
Alkyl benzoates
Thizotrophic materials
Coloring agents
Water
0.1%
0.3%
Balance
Preservatives
Plasticizers
Dispersion medium
Gellation process
The setting process of reversible hydrocolloid is called as a
gellation process it is due to change in temperature.
It is available as tray material, or as syringe material as semi-solid
gel in polyethylene tubes.
The cycle is
Gel
(Tube)
----------
Sol
------------- Gel
(Conditioner)
(Tray)
Agar requires a conditioning unit which has three compartments one
for liquefying were the tubes are placed at 1000C as it is too hot for intra
oral use it is cooled in two stages: storage and tempering. Addition to
lowering the temperature it also increases the viscosity. The storage
temperature is 700C and can be kept for 5 days. Tempering is done just
before the impression is made that is between 370C – 500C. After loading
in the tray and placing in the mouth water is circulated at 170C – 210C
6
7. until the material is completely gelled. This is done using water cooled
rimlock tray
Elastomeric impression materials
Polysulfide (Mercaptan, Thiokol)
Composition
Base
Liquid polysulfide polymer 80 – 85%
Inert fillers (TiO, Zn Sulfate, Copper carbonate) 16 – 18%
Plasticizers (Dibutyl phathalate)
Accelerator paste
Lead di-oxide 60 – 68% - Reactor
Dibutyl phathalate 30 – 35% - Plasticizer
Sulfur 3% - Retarder
Setting reaction
This polymer is usually cross linked with an oxidizing agent such as
lead dioxide. It is this lead dioxide that gives polysulfide its characteristic
brown color. This is a condensation reaction where all the polymer chains
grow simultaneously and a reaction by product is formed like water.
They are available as
Light body
7
8. Regular body
Heavy body
Polysulfide impression material is hydrophobic and should be
poured within 1 hour of removal from the mouth and it is a radio opaque
impression material because of the presence of lead dioxide.
Condensation silicone
Composition
Base paste
Poly dimethyl siloxane
25 – 65%
Colloidal silica or micronize metal oxide filler (Depending upon the
viscosity) 35 – 75%
Coloring agents
Accelerator paste
Orhtoethyl silicate – cross linking agent
Stannous octate – catalyst
Available as
Light body
Regular body
Heavy body
Putty
8
9. Setting reaction
This is condensation polymerization reaction which reacts with
trifunctional and tetrafunctional alkyl silicates like orthoethyl silicate in
the presence of stannous octate. Ethyl alcohol is a by product which is
responsible for shrinkage of the material.
The condensation silicone impression materials are supplied as a
base paste and a low-viscosity liquid or catalyst paste. Since ethyl alcohol
is the by product they are dimensionally stability is poor and they should
be poured immediately after the removal from the mouth. They have a
very poor shelf life because of the instability of alkyl silicates in the
presence of organo-tin compounds, which may result in the oxidation of
tin.
Addition silicone
Base paste
Poly methyl hydrogen siloxane
Other siloxane polymers
Fillers
Accelerator paste
Divinyl siloxane
9
10. Other siloxane prepolymers
Platinum salt (chloroplatinic acid) catalyst
Palladium – hydrogen absorber
Fillers
Available as
Light body
Regular / medium body
Heavy body
Putty
Setting reaction
It is addition polymerization reaction terminated with vinyl groups
and is cross linked with hydride groups activated by a platinum salt
catalyst. There is no reaction by products as long as correct proportions of
vinyl silicone and hydride silicone are manipulated and there are no
impurities, if the proportion is out of balance or impurities are present
then side reactions will produce hydrogen gas. This is avoided by the
manufacturer adding noble metals or palladium or platinum to act as
scavengers another way is to wait for 1 hour before pouring up the
impression.
10
11. Trays used
Custom tray / resin tray
Stock tray
Polyether
Base paste
Polyether polymer
Collidal silica
Glycoether or dibutyl phathlate
Accelerator paste
Aromatic sulfonate ester – cross linking agent
Collidal silica
Dibutyl phathalae or glycoether
Available
Single viscosity (both syringe and tray material)
Regular
Setting reaction
It is a addition polymerization reaction with no by products the
reaction is between aziridine rings which are at the end of branched
polyether molecules. The main chain is a copolymer of ethyle oxide and
tetrahydrofuran. Cross linking and setting is brought about by an aromatic
11
12. sulfonate which Acts as an initiator by releasing a cation R+ an alkyl
group. This produce the cross linking by cationic polymerization via the
imine end groups.
Trays used
Custom / resin trays
Stock tray
Comparison of advantages and disadvantages
Material
Reversible and
hydr ocolloid
Advantages
Disadvantages
Hydrophili
c
Pour
i mme diatel y
use onl y with
stone
Multiple
preparations
Problems
with
moisture
Most
impressions
Latex gloves
use in contraindicated for
all the
elastomers.
Pour within 1
hour.
Most
impressions
Dela y pour
some
Long
working ti me
Low
stabilit y
Low cost
Equipmen
t needed
Mess y
Unpleasa
nt odor
Long
setting ti me
Stabilit y
onl y fair
No custom
tra y required
High tear
strength
Addition silicone
Precautions
Low tear
resistance
Pol ysulfide
Recomme nded
uses
Easier to
pour than
other
elastomers
Dimension
al stabilit y
Hydropho
bic
12
13.
Short
setting ti me
Automix
available
Some
material
release
hydrogen
Pleasant
to use
Short
setting ti me
Poor
wetting
Low
stabilit y
Set
material ver y
stiff
Pol yether
materials,
care to avoid
bubbles when
working
Poor
wetting
Condensation
silicone
Pleasant
to use
Dimension
al stabilit y
Accurac y
Most
impressions
Pour
i mme diatel y,
care to avoid
bubbles when
pouring
Most
impressions
Care not to
break teeth
when
separating
cast
bic
Short
setting ti me
Hydropho
Automix
available
Trays
Various type of trays are used for fixed partial dentures impression
procedures.
1. Stock tray
Metallic
Non metallic
2. Custom made trays
Autopolymerizing acrylic resin
Thermoplastic or photo initiated resin
13
14. 3. Water cooled rim lock trays
Custom trays
Advantages
Improves the accuracy of an elastomeric impression by limiting the
volume of the material, thereby reducing the 2 sources of error
a. Stress during removal
b. Thermal contraction
No need for sterilization
Uniform thickness of the impression material minimizes distortions
resulting from curing shrinkage
Procuring of the tray material is not required
Disadvantages
Time taken for the fabrication
Aging for 24 hours to minimizes the distortion
Sensitivity to monomer
Steps in fabrication
Soak replicas of diagnostic casts in slurry water for 10 mins.
Tray extensions are marked with the pencil line at either the
cervical region of the teeth or 5mm below the cervical line.
Base plate wax is adapted (for 2 sheets thickness – 2-3mm) after
softening on the Bunsen burner and trim the excess with the knife
14
15. until the marked pencil line .(Rigid or stiff material like polyether
requires of wax spacer of 4mm thickness).
Cover the wax with tin foil, or aluminium foil for preventing the
wax to melt during the exothermic heat produced during the
polymerization of the resin (autocuring).
Wax is removed either in 4 or 3 tripodal areas 3 sq.mm and located
not on the prepared tooth but on non-functional or non-centric
cusps. If all the teeth are prepared then soft tissues stops either on
the palatal area or the crest of the ridge is placed.
Needed amount of polymers and monomers of autopolymerizing
resin is mixed as per manufacturer instructions till the dough stage
is attained.
Then it is flattened to almost 4mm thick putty. It is then adapted
and molded over the tin foil separation and excess is trimmed off.
A handle is formed along with 2 buccal wings or ridges on either
side for the easy removal.
After the set it is slowly removed form the cast, check if the stops
are proper.
It can then be placed in the water for 9 – 24 hours (Rosenstiel) or 5
minutes in boiling water before use.
A tray adhesive can be applied 15 minutes before placing the
impression material and allow it to dry (inside and outside the bond
of the tray)
15
16. Advantages of stock tray
Eliminating the time and expenses of fabricating a customized tray.
They are rigid metal and susceptible to distortion.
Impression techniques
For reversible hydrocolloid
It requires a hydrocolloid conditioning unit. A conditioning unit has
three units.
Liquefying bath
Storage bath
Tempering bath
1. Liquefying bath
Tubes of impression materials and syringes are boiled at 2120F
(1000C) for 10 – 12 minutes.
2. Storage bath
Stored at 1500F (650C) at least for 10 minutes. The material can be
stored for 5 days.
3. Tempering bath
Loaded impression trays are tempered in this bath at 1100F to
1150F (about 400C) for 5 – 10 minutes immediately before placing in the
mouth.
Procedure
16
17. Because only one accurate cast can be made from a hydrocolloid
impression, two impressions are made
1. A sectional impression for making a die (made first)
2. A full arch impression for the working cast
After selecting a proper tray and placing stops in the proper area.
Tray material is kept on the tray for tempering.
Low viscosity syringe material is placed in the bath which is then
removed and applied after the retraction cord is removed and then
the tray with heavy body is placed into the mouth and cold water is
circulated.
It is then removed after holding without movement with a rapid
motion,
washed
with
cold
water,
inspected,
disinfected
and
immediately type 4 stone is poured.
Wet field technique
The areas of the teeth and tissues are flooded with warm water.
Syringe material is taken directly from tempering compartment and
added to prepared cavities, first at base of preparation and then the
tooth is covered.
The material used to fill the tray should be cooler or tempered.
Gelation is accelerated by circulating cool water, through the tray
for 3 – 5 minutes.
17
18. It is postulated that the hydraulic pressure of the viscous tray
material forces the fluid syringe hydrocolloid into the area to be
restored.
Laminate technique
A recent modification to the traditional agar procedure is the
combination of agar and alginate impression materials.
The tray hydrocolloid is replaced with a mix of chilled alginate,
that bonds with the syringe agar.
The alginate gels by chemical reaction, but agar gels by means of
contact with cool alginate rather than water circulating through the
tray
Advantages
Less preparation time and less complicated when compared to the
wet field technique.
Disadvantages
Bond between agar and alginate is not strong
High viscosity alginate displaces agar during seating
Dimensional inaccuracy of alginate limits the use to single units.
Techniques for electrometric impression materials
1. Using stock tray
Synonyms – Putty wash
Mixing method – double mix and single mix
18
19. Advantages
Eliminates time and expense of fabricating custom tray
Metal stock trays are rigid and are not susceptible to distortion.
Disadvantages
More impression material is required.
Must be sterilized
Technique
Select a stock tray and coat with adhesive
Mix high viscosity l putty and roll it in the shape of the cylinder
and load it on the tray, give a space which is a sheet of polyethylene
and seat with rocking motion and wait till the initial set (2 minutes)
and then remove from the mouth with the minimal sideward
movement.
Gingival retraction done
After lubricating the O-ring of the syringe, the needed amount of
the low viscosity material is mixed on a pad and either loaded in the
syringe by scraping or by making a paper cone and then filling the
syringe.
Remove the retraction cord gently and syringe inaccessible areas
first (e.g.) disto lingual finish lines.
Now insert the tray with low viscosity impression material
19
20. Position the tray over the arch
Apply
force
in
a
vertical
direction
until
further
seating
is
impossible.
After material is set, insert two index fingers under each side of the
tray to break the seal.
Remove the tray in the direction parallel to the preparation.
Evaluate the set impressions.
Difference between single mix and double mix technique
In single mix technique one viscosity material (regular body) is
used to fill the tray and load the syringe.
In double mix technique, the light body is loaded in the syringe and
syringed around the tooth prepared and heavy body is mixed and
loaded in the tray.
2. Using custom tray
Procedure
Do the gingival retraction and Prepare the syringe
In a mixing pad mix the low viscosity impression material as per
manufacturer’s instruction. First use circular motion combining the
two strands then a finger of eight motion, obtaining a streak free
mixture in a less than 1 minute.
Load the syringe as well as the tray.
20
21. Syringe the material in the inaccessible area first then subsequently
removing the retraction cord gently and then syringe the impression
material.
Now insert the tray. Seal from posterior to anterior allowing excess
to extrude in an anterior direction.
Continue seating in a vertical direction until the trays stops prevent
further progress.
After the material is completely set, remove the impression parallel
to the preparation path.
Evaluate the impression.
Closed bite double arch method
Also called as Dual Quad tray, double arch, triple arch and closed
mouth impression.
Minimum conditions
Either natural teeth or an incisal pin and table should be provided in
the articulator as vertical stops.
Sufficient space distal to the last tooth should be present to allow
tray approximation.
Intact dentition, class I occlusion, bounded on either side by intact
teeth, opposing tooth having intact occlusal contact is ideal.
Advantages
21
22. Physical deformation of the impression by mandible during opening
is minimized.
Seating of teeth during maximum intercuspation is captured.
Less material is needed and patient is more comfortable.
Disadvantages
Tray is not rigid and it depends on the impression materials rigidity.
Not a functionally generated technique – so limited to one casting
per quadrant.
Types of dual arch trays
Metal
Plastic (both with or without side wall)
Depending on the location
Posterior / anterior sexant
Quadrant
¾ of an arch
Full arch
Technique
Fit of the tray is checked such that the tray extend distal to the last
teeth of the arch by and then ask the patient to close, observe for
the bilateral closure and see that the patient is comfortable.
22
23. Gingival retraction is done.
Ready the tray material and the syringe material which is placed on
the tooth after cord removal.
Tray placed inside mouth while observing the distal extent and
slowly asking the patient to close the mouth.
After waiting for the set (2 minutes), the patient is asked to open
the mouth, and then the tray adheres to one arch. After placing
fingers on either side of the tray it is removed with equal pressure
bilaterally to minimize the distortion of the tray.
The handle should not be used for removal of the tray and the
material is removed from the sulcus the impression is then washed
and the retraction cords is removed and checked.
Different techniques for making a dual arch impression
One step technique
Stock trays are used, light body is injected around the prepared
tooth and putty or bite registration paste is inserted on both sides of the
tray and the patient is asked to bite in centric occlusion.
Dual arch – hydraulic pressure technique
Low or medium viscosity impression material is injected on the
prepared and preoperative impression of the unprepared tooth. The tray is
placed and patient is asked to bite in centric occlusion, the hydraulic
pressure created, will force the material into the sulcus and through the
23
24. vent holes created in the buccal or the lingual sides of the pre-operative
impression.
Dual arch – laminar impression technique
A pre-operative impression is made. The post operative impression
of the tooth to be prepared is relieved to a depth of 0.5mm in the cervical
area. Two holes are drilled from the buccal surface and one on the mesial
and one of the distal.
Auto-mix technique
Several manufacturers often supply impression material in prepackage cartridges to which a disposable mixing tip is attached.
The cartridge is inserted in a caulking-gun like device, and the base
and catalyst are extruded into the mixing tip, where mixing occurs
as they progress to the end of the tube.
The homogenously incorporated material can be directly placed on
the prepared tooth and impression tray.
Matrix impression system
This is a new system that requires a series of three impression
procedures using three types and/or viscosities of impression materials.
Steps
24
25. A matrix of occlusal registration elastomeric material is made over
the tooth preparation.
Matrix is trimmed to prescribed dimension and retraction cord is
removed.
A definitive impression is made in matrix of the preparation with a
low viscosity elastomeric impression material.
After the matrix impression is seated, a stock tray is filled with a
medium viscosity elastomeric impression material is seated over the
matrix and remaining teeth to create an impression of the entire
arch.
Advantages
This
system
effectively
controls
the
four
forces
(relapsing,
retraction, displacement and collapsing) that impact on the gingiva
during the critical phase of making impression when attempting to
register the subgingival margins.
The design of the matrix also gently forces the high viscosity
impression materials along the preparations and in to the sulcus
where it cleanses the sulcus of unwanted debris and fills the sulcus.
The high viscosity material gently extends into the sulcus and does
not permit it to collapse as the medium viscosity material in the
stock tray a seated for the pick up impression.
The matrix facilitates the formation of the optimum flange.
25
26. Tearing
is
virtually
eliminated
because
of
the
improved
configuration of the sulcular flange and by the elimination of voids
or contaminants in the sulcus.
Copper band impression
Fitting copper band to preparation
Select a copper band of correct diameter by trial and error method.
Deform the tubes to semi ellipsoidal cross section and try in.
Approximate position of the finish line and mark it on the band with
an explorer and cur with a scissors. Smoothen the rough edges using
a carborundom stone.
Evaluate the fit of the band such that it extends 1mm beyond the
finish line.
Orientation holes are cut on the top one fifth of facial surface of the
tube.
Make compound plug
Fingers are covered with petrolactum jelly
A warm red stick compound is inserted in the top one third of the
copper tube. The compound should touch the occlusal surface. It is
26
27. then cooled and removed by Bachins towel clamp by grasping top
one fifth of the copper band.
Excess is relieved by cutting with a no. 6 or no. 8 round bur and
under slow speed and by frequently removing debris. 0.2mm of
compound is removed from the impressed occlusal surface. This
creates a space for the heavy body polyvinyl siloxane.
Making an impression
Coat the inner surface with adhesive
Mix heavy body polyvinyl siloxane
Load it in the copper band
Position the finger and on the top of band, orient and seat
customized copper band
Stabilize the band
Wait till the final set. Using towel clip remove the band evaluate
the impression and followed the orientation impression.
Special considerations
Pin retained restorations
Elastomeric impression materials are strong enough to be used in
these situations but should be introduced with
Cement tube or Lentulo spiral to avoid any bubbles
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28. Special nylon bristles or Prefabricated plastic pinscan be put in the
pin hole and the impression is made
Post and cores
This procedure involves reinforcing the impression with a plastic
pin or suitable wire (e.g. orthodontic wire) – elastomeric impression
materials can be used.
Impression technique with the use of preformed crow n shells
Select preformed crowns (polycarbonate) adjust the gingival margin
slightly apical to finish line.
Adhesive applied to inner side
Regular body is loaded
Then seated properly
Wait till it sets and remove
Then full arch pick up impression made
Impression procedure for a subgingivally prepared shoulder margin
An individual tray is prepared directly with acrylic, which should
not cover the shoulder margin. Gingival retraction done.
The tray is rebased with fluid resin and some placed on the teeth
and pressed till contact is felt wait till the acrylic becomes hard.
An outline is marked and excess is removed. Space is created for
the impression materials except the shoulder margin area.
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29. An adhesive is then applied and the tray filled with elastomer. This
impression is then picked up with elastomer or hydrocolloid in a
stock tray.
Impressions for CAD/CAM procedures
Prepared tooth
↓
Apply rubber dam
↓
Imaging powder + liquid is coated on the prepared area for photo
receptivity
↓
Symmetrical optic beam is passed
↓
3D picture is produced on a computer for milling procedure
This technique is mostly advocated for the CEREC II system.
Evaluation of impression
Upon removal the impression must be inspected for accuracy.
Bubbles
or
voids
in
the
margin
necessitate
discarding
the
impression and starting over.
An intact uninterrupted cuff of impression material should be
present beyond every margin.
Streaks of base and catalyst material indicate improper mixing and
may render an impression useless.
Immediately after removal from the mouth impression is rinsed
under tap water and dried with an air syringe.
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30. Disinfection is an essential step for prevention of cross infection
and exposure of laboratory personnel.
Impression material
1. Reversible hydr ocolloid
2.Irreversible hydr ocolloid
3. Pol ysulfide
4. Addition silicone
5. Condensation silicone
6. Pol yether
Recomme nded disinfection procedures
Diluted bleach, Iodophor spra y
Diluted bleach, Iodophor spra y
I mme rsion in iodophor or 2% glutaraldehyde
I mme rsion in 2% glutaraldehyde or hypochloride solution
I mme rsion in 2% glutaraldehyde or hypochlorite solution
Iodophor spra y or chloride dioxide
Done properly it has no clinically significant effects on the
accuracy or surface reproduction of the elastomers.
Conclusion
Devan states that the impression should be in the dentists mind before it is in his
hand. Based on this statement I conclude the use of impression material and technique
should be purely the dentists choice.
REFERENCES:
1. Restorative Dental materials:G Craig & John M Powers11th edition2002, pg 329-378
2. Phillips science of dental materials:11th edition
3. GPT Academy of prosthodontics JPD,july 2005 vol 94
30
31. 4. Tylman’s Theory and Practice Of Fixed Prosthodontics, 8th
edition, pg 237-254.
5. Fundamentals Of Fixed Prosthodontics by Herbert T.
Shillingburg, 3rd edition, pg 281
6. Contemporary Fixed Prosthodontics, by Rosenstiel, 4th
edition, pg452- 462.
7. Notes on dental materials by E.C. Combe, 6th edition,pg
115- 126.
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