The document provides information on the casting procedure, including casting rings, ring liners, investing, burnout, and casting. Key points include:
- Casting rings are used to contain the investment around the wax pattern and come in various sizes and materials.
- Ring liners provide a buffer for investment expansion and are usually made of cellulose or ceramic materials.
- The investing procedure involves cleaning the wax pattern, mixing and applying the investment material, and allowing it to set fully.
- Burnout prepares the mold by eliminating the wax pattern and allowing for thermal expansion through controlled heating to high temperatures.
- Casting machines, like centrifugal or pressure types, are then used to introduce the molten
Academic presentation prepared for the final professional of BDS. The presentation talks about casting and investing techniques used in the Conservative Dentistry and Endodontics.
This document discusses the process of dental casting. It begins by defining casting and listing the main steps: preparing the wax pattern, spruing, investing, burnout, casting, recovery, and finishing. It then provides details on each step, including preparing the wax pattern, sprue design and materials, investing techniques, burnout methods, and common casting defects like porosity and distortion. The document is intended as an overview and guide for the dental casting procedure.
This document provides information on spruing and investing for fixed prosthodontics. It discusses attaching a sprue former to wax patterns, and describes the purpose and proper attachment technique. It also discusses investing materials and techniques, including the components and purposes of gypsum-bonded and phosphate-bonded investments. The document provides step-by-step instructions for the vacuum-mix, vacuum-pour technique of investing a single-tooth wax pattern using a gypsum-bonded investment.
The document discusses the process of investing and casting dental restorations, including the steps of investing wax patterns, burnout of the patterns to create molds, and casting molten alloys into the molds. It describes the requirements and mechanisms for investments to properly expand molds to compensate for alloy shrinkage during solidification. Details are provided on techniques, materials, and armamentarium for investing patterns using gypsum-bonded and phosphate-bonded investments.
Casting procedures/cosmetic dentistry course by Indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
This document discusses casting procedures and defects in dentistry. It begins with definitions of casting and provides a brief history. It then outlines the key steps in the casting process including spruing, investing, burnout, casting machines, and defects. The main steps are spruing the wax pattern, investing it, burning out the wax during heating, and using casting machines to pour molten alloy into the mold. Common defects include distortion, surface roughness, porosity, and incomplete casting details. The document provides causes and prevention of defects.
Casting procedures /certified fixed orthodontic courses by Indian dental aca...Indian dental academy
Page 17
Casting procedures
The document discusses the procedures for dental castings using the lost wax technique. It covers preparation of the master die from dental stone, fabrication of the wax pattern, design of the sprue and investing procedure. The key steps include:
1. Preparing an accurate wax pattern on the stone die with sprues attached in strategic locations.
2. Investing the pattern in a specialized dental investment material like gypsum or phosphate bonded investment using vacuum mixing.
3. Allowing the investment to set fully before slowly heating it to burn out the wax pattern, leaving a mold to pour the molten dental alloy into.
4. Careful control of
dental Investment materials/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Academic presentation prepared for the final professional of BDS. The presentation talks about casting and investing techniques used in the Conservative Dentistry and Endodontics.
This document discusses the process of dental casting. It begins by defining casting and listing the main steps: preparing the wax pattern, spruing, investing, burnout, casting, recovery, and finishing. It then provides details on each step, including preparing the wax pattern, sprue design and materials, investing techniques, burnout methods, and common casting defects like porosity and distortion. The document is intended as an overview and guide for the dental casting procedure.
This document provides information on spruing and investing for fixed prosthodontics. It discusses attaching a sprue former to wax patterns, and describes the purpose and proper attachment technique. It also discusses investing materials and techniques, including the components and purposes of gypsum-bonded and phosphate-bonded investments. The document provides step-by-step instructions for the vacuum-mix, vacuum-pour technique of investing a single-tooth wax pattern using a gypsum-bonded investment.
The document discusses the process of investing and casting dental restorations, including the steps of investing wax patterns, burnout of the patterns to create molds, and casting molten alloys into the molds. It describes the requirements and mechanisms for investments to properly expand molds to compensate for alloy shrinkage during solidification. Details are provided on techniques, materials, and armamentarium for investing patterns using gypsum-bonded and phosphate-bonded investments.
Casting procedures/cosmetic dentistry course by Indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
This document discusses casting procedures and defects in dentistry. It begins with definitions of casting and provides a brief history. It then outlines the key steps in the casting process including spruing, investing, burnout, casting machines, and defects. The main steps are spruing the wax pattern, investing it, burning out the wax during heating, and using casting machines to pour molten alloy into the mold. Common defects include distortion, surface roughness, porosity, and incomplete casting details. The document provides causes and prevention of defects.
Casting procedures /certified fixed orthodontic courses by Indian dental aca...Indian dental academy
Page 17
Casting procedures
The document discusses the procedures for dental castings using the lost wax technique. It covers preparation of the master die from dental stone, fabrication of the wax pattern, design of the sprue and investing procedure. The key steps include:
1. Preparing an accurate wax pattern on the stone die with sprues attached in strategic locations.
2. Investing the pattern in a specialized dental investment material like gypsum or phosphate bonded investment using vacuum mixing.
3. Allowing the investment to set fully before slowly heating it to burn out the wax pattern, leaving a mold to pour the molten dental alloy into.
4. Careful control of
dental Investment materials/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The document discusses the process of casting in dentistry. It begins with an introduction defining casting and its objective in dentistry. It then covers the history of casting in dentistry from ancient times through modern developments. The basic steps of casting are outlined, including spruing, investing, burnout, casting, recovery and cleaning. Different materials used for sprue formers, crucible formers, casting rings and liners are described. The document provides details on investing, burnout, and high and low heat techniques for casting gold and other alloys.
The document provides steps for duplicating dental molds, preparing refractory casts, waxing patterns, spruing patterns, and investing patterns. It includes:
1. Melt duplicating material and soak master cast before securing it in the duplicating flask with wax or clay. Pour duplicating material until vent holes are plugged.
2. Trim and dry refractory casts before dipping in beeswax to prepare for wax patterns.
3. Attach sprues to thick areas of wax patterns and attach to crucible former before investing in plaster-bound silicate material inside a metal ring.
This document provides details on dental casting procedures. It discusses the steps involved, including making a wax pattern, attaching a sprue and crucible former, investing, burnout to remove the wax, casting using various machines to inject molten metal, recovering the casting from the mold, finishing and polishing. Key steps are wax pattern formation, attaching the pattern to a sprue and crucible, investing in refractory material, burning out the wax, melting and injecting dental alloys using different casting methods, and finalizing the surface.
The document discusses dental casting procedures, including the lost wax technique involving investing, burnout, and casting. Key steps include selecting a sprue, investing the wax pattern, heating to eliminate wax (burnout), and casting with molten alloy. Potential defects like distortions, porosities, and incomplete castings can occur if procedures are not followed correctly, such as with improper expansion compensation, heating rates, or alloy temperatures. Attention to each technique step is important to produce accurate, smooth restorations.
The document provides an overview of the process of spruing, investing, and casting. It discusses constructing a wax pattern, creating a sprue to allow molten metal to flow into the mold, using a casting ring and liner to contain the investment material. It also covers investing materials, the investing process, burnout to eliminate wax, casting including melting alloys and techniques, quenching, pickling, divesting, and finishing processes like polishing. The overall process involves surrounding a wax pattern with a refractory investment material, heating to remove wax, and introducing molten metal to create a dental restoration.
The document discusses the lost wax casting technique used to produce metal dental restorations. It involves:
1. Surrounding a wax pattern with an investment material mold.
2. Heating to eliminate the wax pattern.
3. Introducing molten metal into the mold through a sprue channel.
The key steps are preparing the wax pattern, attaching a sprue, investing the pattern, burning out the wax, and introducing molten metal. Factors like sprue design, investment type, and casting machine type are considered to optimize the process.
The lost wax casting technique involves:
1. Surrounding a wax pattern with an investment material mold.
2. Heating to eliminate the wax.
3. Introducing molten metal into the mold through a sprue channel.
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
IIIE SECTION A MANUFACTURING TECHNOLOGY NOTES 6.investment castingBhaskar Nagarajan
Investment casting, also known as lost-wax casting, is a process for producing metal parts with high dimensional accuracy and intricate details. It involves creating a wax pattern, coating it with ceramic slurry to create an outer mold, melting out the wax, and pouring molten metal into the empty mold cavity. The process allows for complex internal and external geometries without parting lines. Investment casting is well-suited for small, precision parts, especially those made of high-melting point alloys, and is used in industries like aerospace and firearms manufacturing.
Lo #3b (common)manufacturing technology (jan 2016) part 2Abdulaziz AlSuwaidi
This document provides information on various casting and molding manufacturing processes, including shell molding, investment casting, lost foam casting, and die casting. It describes the key steps for each process, as well as their advantages and disadvantages. Shell molding involves creating a hardened sand shell around a pattern, which is then used to make castings. Investment casting, also known as lost-wax casting, uses wax patterns invested in refractory materials to create molds. Lost foam casting uses polystyrene foam patterns that vaporize when molten metal is poured. Die casting involves injecting molten metal into steel dies under high pressure to form parts.
This document discusses the process of casting in dentistry. It begins with definitions of casting and a brief history, noting it has been used for thousands of years. It then discusses the key steps in detail, including the lost wax technique, sprue formation, reservoirs, investing wax patterns, venting, casting machines and techniques, cleaning castings, and addressing shrinkage and defects. The overall process involves making a wax pattern, investing it in ceramic material, burning out the wax, and replacing it with molten metal to form a dental restoration.
Sizing is the process of applying an adhesive coating to yarn to improve properties like strength and smoothness. The objectives of sizing include protecting yarn from abrasion and decreasing static electricity. A sizing machine coats yarn with size ingredients like adhesives and lubricants in the size box, then dries the yarn on cylinders before winding it onto beams. Key components are creels for unwinding yarn, size boxes for coating, drying cylinders, and headstocks for winding yarn onto beams. Process parameters like size viscosity and squeezing pressure affect the amount of size picked up by the yarn.
Investment casting, also known as lost-wax casting, is an industrial process over 5000 years old. It involves creating a wax pattern, coating it with ceramic slurry to create a mold, heating to remove the wax, and pouring molten metal. This allows for intricate, accurate parts with smooth surfaces and dimensional precision. Though expensive for large volumes, investment casting is well-suited for complex aerospace and firearms components where other methods are infeasible.
This document provides an overview of dental casting procedures and defects. It defines casting and describes the main steps which include making a wax pattern, spruing, investing, burnout of the wax, casting with different methods, cleaning the casting, and finishing and polishing. It also discusses common casting defects such as distortion, surface roughness, porosity, and missing details. The document is intended to educate dental students and professionals about casting techniques and potential defects.
IIIE SECTION A MANUFACTURING TECHNOLOGY NOTES 5.shell moulding.Bhaskar Nagarajan
Shell moulding is a casting technique used for mass production that provides a smooth finish. It was invented in Germany during World War 2 by Mr. J. Corning. The process uses thin resin-bonded sand shells that are clamped together to form a mould. Patterns are made of metal and heated before applying the sand mixture. Zircon or silica sand is used with thermosetting resin as the binder. The shells provide excellent surface finish and dimensional accuracy for casting thin sections. Some advantages are lower costs, less space and labor required, and flexibility in scheduling. However, it is more suited to larger production quantities due to high initial costs.
Investment casting, also known as lost-wax casting, is an industrial process for making small, accurate castings. It involves creating a wax or plastic pattern, coating it with ceramic slurry to create a mold, heating to remove the wax, and pouring molten metal into the mold cavity. This allows for casting intricate metal parts with complex internal features and good dimensional accuracy. Common applications include turbine blades, firearms parts, and small precision components.
This document provides information on the casting procedure for dental restorations. It discusses the history of casting, defines key terms, and outlines the basic steps of the casting process including fabrication of the wax pattern, spruing, investing, casting, and finishing. The optimal sprue design is described, noting that the sprue should be attached to the bulkiest part of the pattern away from margins, directed at a 45 degree angle, and of a length that positions the pattern 6mm from the casting ring. Proper sprue design is important to allow gases to escape and molten metal to fully enter the mold cavity.
Expandable Pattern Casting and Plaster Mold CastingMarry Sol Lare
Expandable pattern casting and plaster mold casting are two types of expendable mold casting processes. Expandable pattern casting uses an expandable polystyrene pattern that is coated, embedded in sand in a flask, and then vaporized when molten metal is poured, leaving an exact replica of the pattern. Plaster mold casting similarly uses a plaster mold instead of sand and is best for smaller, non-ferrous metal castings due to temperature limitations of plaster. Both methods can produce complex, close-tolerance castings with minimal finishing required.
The document discusses the process of investing and casting in fixed prosthodontics. Key steps include:
1. Attaching a wax pattern to a sprue former and investing it in dental stone.
2. Eliminating the wax pattern by heating the stone mold to burn out the wax.
3. Pouring molten dental alloy into the mold cavity using a centrifugal casting machine to produce a dental casting.
4. Finishing the casting by removing the sprue and investing material and polishing the surfaces.
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
AMIT POWERPOINA doctor appointment booking system is an online system that al...saiproject
BUSINESS PROJECT GOOD branchhas successfully completed the major project work A doctor appointment booking system is an online system that allows patients to easily book their appointment
Visual Communication and Design for PowerPoint Presentations .pptsaiproject
This document provides guidance on effective PowerPoint presentation design. It recommends using PowerPoint to enhance an oral presentation rather than replace it. Presenters should use bulleted points, visual communication tools, and maintain consistency in themes, designs, fonts and colors. Text should be at least 24pt and have high contrast with backgrounds. Graphics and images should relate to the information and reinforce key points. Presenters should keep animation, transitions and non-essential content to a minimum. The goal is to communicate information to the audience effectively through the presentation.
The document discusses the process of casting in dentistry. It begins with an introduction defining casting and its objective in dentistry. It then covers the history of casting in dentistry from ancient times through modern developments. The basic steps of casting are outlined, including spruing, investing, burnout, casting, recovery and cleaning. Different materials used for sprue formers, crucible formers, casting rings and liners are described. The document provides details on investing, burnout, and high and low heat techniques for casting gold and other alloys.
The document provides steps for duplicating dental molds, preparing refractory casts, waxing patterns, spruing patterns, and investing patterns. It includes:
1. Melt duplicating material and soak master cast before securing it in the duplicating flask with wax or clay. Pour duplicating material until vent holes are plugged.
2. Trim and dry refractory casts before dipping in beeswax to prepare for wax patterns.
3. Attach sprues to thick areas of wax patterns and attach to crucible former before investing in plaster-bound silicate material inside a metal ring.
This document provides details on dental casting procedures. It discusses the steps involved, including making a wax pattern, attaching a sprue and crucible former, investing, burnout to remove the wax, casting using various machines to inject molten metal, recovering the casting from the mold, finishing and polishing. Key steps are wax pattern formation, attaching the pattern to a sprue and crucible, investing in refractory material, burning out the wax, melting and injecting dental alloys using different casting methods, and finalizing the surface.
The document discusses dental casting procedures, including the lost wax technique involving investing, burnout, and casting. Key steps include selecting a sprue, investing the wax pattern, heating to eliminate wax (burnout), and casting with molten alloy. Potential defects like distortions, porosities, and incomplete castings can occur if procedures are not followed correctly, such as with improper expansion compensation, heating rates, or alloy temperatures. Attention to each technique step is important to produce accurate, smooth restorations.
The document provides an overview of the process of spruing, investing, and casting. It discusses constructing a wax pattern, creating a sprue to allow molten metal to flow into the mold, using a casting ring and liner to contain the investment material. It also covers investing materials, the investing process, burnout to eliminate wax, casting including melting alloys and techniques, quenching, pickling, divesting, and finishing processes like polishing. The overall process involves surrounding a wax pattern with a refractory investment material, heating to remove wax, and introducing molten metal to create a dental restoration.
The document discusses the lost wax casting technique used to produce metal dental restorations. It involves:
1. Surrounding a wax pattern with an investment material mold.
2. Heating to eliminate the wax pattern.
3. Introducing molten metal into the mold through a sprue channel.
The key steps are preparing the wax pattern, attaching a sprue, investing the pattern, burning out the wax, and introducing molten metal. Factors like sprue design, investment type, and casting machine type are considered to optimize the process.
The lost wax casting technique involves:
1. Surrounding a wax pattern with an investment material mold.
2. Heating to eliminate the wax.
3. Introducing molten metal into the mold through a sprue channel.
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
IIIE SECTION A MANUFACTURING TECHNOLOGY NOTES 6.investment castingBhaskar Nagarajan
Investment casting, also known as lost-wax casting, is a process for producing metal parts with high dimensional accuracy and intricate details. It involves creating a wax pattern, coating it with ceramic slurry to create an outer mold, melting out the wax, and pouring molten metal into the empty mold cavity. The process allows for complex internal and external geometries without parting lines. Investment casting is well-suited for small, precision parts, especially those made of high-melting point alloys, and is used in industries like aerospace and firearms manufacturing.
Lo #3b (common)manufacturing technology (jan 2016) part 2Abdulaziz AlSuwaidi
This document provides information on various casting and molding manufacturing processes, including shell molding, investment casting, lost foam casting, and die casting. It describes the key steps for each process, as well as their advantages and disadvantages. Shell molding involves creating a hardened sand shell around a pattern, which is then used to make castings. Investment casting, also known as lost-wax casting, uses wax patterns invested in refractory materials to create molds. Lost foam casting uses polystyrene foam patterns that vaporize when molten metal is poured. Die casting involves injecting molten metal into steel dies under high pressure to form parts.
This document discusses the process of casting in dentistry. It begins with definitions of casting and a brief history, noting it has been used for thousands of years. It then discusses the key steps in detail, including the lost wax technique, sprue formation, reservoirs, investing wax patterns, venting, casting machines and techniques, cleaning castings, and addressing shrinkage and defects. The overall process involves making a wax pattern, investing it in ceramic material, burning out the wax, and replacing it with molten metal to form a dental restoration.
Sizing is the process of applying an adhesive coating to yarn to improve properties like strength and smoothness. The objectives of sizing include protecting yarn from abrasion and decreasing static electricity. A sizing machine coats yarn with size ingredients like adhesives and lubricants in the size box, then dries the yarn on cylinders before winding it onto beams. Key components are creels for unwinding yarn, size boxes for coating, drying cylinders, and headstocks for winding yarn onto beams. Process parameters like size viscosity and squeezing pressure affect the amount of size picked up by the yarn.
Investment casting, also known as lost-wax casting, is an industrial process over 5000 years old. It involves creating a wax pattern, coating it with ceramic slurry to create a mold, heating to remove the wax, and pouring molten metal. This allows for intricate, accurate parts with smooth surfaces and dimensional precision. Though expensive for large volumes, investment casting is well-suited for complex aerospace and firearms components where other methods are infeasible.
This document provides an overview of dental casting procedures and defects. It defines casting and describes the main steps which include making a wax pattern, spruing, investing, burnout of the wax, casting with different methods, cleaning the casting, and finishing and polishing. It also discusses common casting defects such as distortion, surface roughness, porosity, and missing details. The document is intended to educate dental students and professionals about casting techniques and potential defects.
IIIE SECTION A MANUFACTURING TECHNOLOGY NOTES 5.shell moulding.Bhaskar Nagarajan
Shell moulding is a casting technique used for mass production that provides a smooth finish. It was invented in Germany during World War 2 by Mr. J. Corning. The process uses thin resin-bonded sand shells that are clamped together to form a mould. Patterns are made of metal and heated before applying the sand mixture. Zircon or silica sand is used with thermosetting resin as the binder. The shells provide excellent surface finish and dimensional accuracy for casting thin sections. Some advantages are lower costs, less space and labor required, and flexibility in scheduling. However, it is more suited to larger production quantities due to high initial costs.
Investment casting, also known as lost-wax casting, is an industrial process for making small, accurate castings. It involves creating a wax or plastic pattern, coating it with ceramic slurry to create a mold, heating to remove the wax, and pouring molten metal into the mold cavity. This allows for casting intricate metal parts with complex internal features and good dimensional accuracy. Common applications include turbine blades, firearms parts, and small precision components.
This document provides information on the casting procedure for dental restorations. It discusses the history of casting, defines key terms, and outlines the basic steps of the casting process including fabrication of the wax pattern, spruing, investing, casting, and finishing. The optimal sprue design is described, noting that the sprue should be attached to the bulkiest part of the pattern away from margins, directed at a 45 degree angle, and of a length that positions the pattern 6mm from the casting ring. Proper sprue design is important to allow gases to escape and molten metal to fully enter the mold cavity.
Expandable Pattern Casting and Plaster Mold CastingMarry Sol Lare
Expandable pattern casting and plaster mold casting are two types of expendable mold casting processes. Expandable pattern casting uses an expandable polystyrene pattern that is coated, embedded in sand in a flask, and then vaporized when molten metal is poured, leaving an exact replica of the pattern. Plaster mold casting similarly uses a plaster mold instead of sand and is best for smaller, non-ferrous metal castings due to temperature limitations of plaster. Both methods can produce complex, close-tolerance castings with minimal finishing required.
The document discusses the process of investing and casting in fixed prosthodontics. Key steps include:
1. Attaching a wax pattern to a sprue former and investing it in dental stone.
2. Eliminating the wax pattern by heating the stone mold to burn out the wax.
3. Pouring molten dental alloy into the mold cavity using a centrifugal casting machine to produce a dental casting.
4. Finishing the casting by removing the sprue and investing material and polishing the surfaces.
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
AMIT POWERPOINA doctor appointment booking system is an online system that al...saiproject
BUSINESS PROJECT GOOD branchhas successfully completed the major project work A doctor appointment booking system is an online system that allows patients to easily book their appointment
Visual Communication and Design for PowerPoint Presentations .pptsaiproject
This document provides guidance on effective PowerPoint presentation design. It recommends using PowerPoint to enhance an oral presentation rather than replace it. Presenters should use bulleted points, visual communication tools, and maintain consistency in themes, designs, fonts and colors. Text should be at least 24pt and have high contrast with backgrounds. Graphics and images should relate to the information and reinforce key points. Presenters should keep animation, transitions and non-essential content to a minimum. The goal is to communicate information to the audience effectively through the presentation.
This document describes a project to build a machine learning model for predicting laptop prices. It involves collecting a dataset of laptop specifications and prices, analyzing the data, developing predictive models using techniques like linear regression and random forests, and creating a web application using Flask that allows users to input laptop features and receive predicted prices. The project aims to help consumers and retailers make more informed purchasing and pricing decisions. Future work may include incorporating real-time data streams, enhancing the ML models, and obtaining user feedback to improve accuracy.
This document presents a case study of a 64-year-old male farmer diagnosed with verrucous leukoplakia. It summarizes the patient's medical history, including a long-term tobacco chewing habit. The clinical examination revealed grayish-white patches on the tongue and inner cheek. A biopsy was performed and histopathological examination confirmed the diagnosis of leukoplakia. The patient's long-term tobacco use likely caused the potentially malignant disorder, and he was prescribed medication and advised to quit chewing tobacco to prevent progression to oral cancer.
This document presents a major project report on developing an online medical shop. It discusses the objectives, modules, scope, and design of the proposed online shopping system. The key modules are registration, administration, and customer. The registration module allows customers to create accounts. The administration module allows managing products, categories, and orders. The customer module allows viewing products and placing orders. It covers system design aspects like use case diagram, sequence diagram, class diagram, data flow diagram, and entity relationship diagram. Technologies used include PHP, MySQL, HTML, CSS, JavaScript, and Bootstrap. Screenshots of the developed system are also included.
This report summarizes an experimental study on modifying the geotechnical properties of expansive soil through coconut fibre and lime. Laboratory tests were conducted on expansive soil samples with additions of 4% lime and varying amounts (0.5-2%) of coconut fibre. Results showed increases in the California Bearing Ratio (CBR) values of the stabilized soil samples compared to the expansive soil alone, with the highest CBR values obtained with 4% lime and 2% coconut fibre. The study concluded that lime and coconut fibre are effective and economical materials for stabilizing expansive soils by reducing their shrinkage and swelling behavior.
Study and evaluation of Pulsatile Drug delivery system.docxsaiproject
This document discusses pulsatile drug delivery systems. It begins with introducing concepts in chronobiology like biological rhythms, chronotherapeutics, and circadian rhythms. It then discusses how diseases like rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis show circadian patterns that can benefit from pulsatile drug delivery. The document covers classification and design of single-unit and multiple-unit pulsatile systems, which aim to release drugs after a lag time to match biological rhythms. It concludes by discussing advantages of pulsatile systems and their increasing importance in drug development.
This document describes a street lighting system that uses infrared sensors and LEDs to save energy. IR sensors detect passing vehicles and signal microcontroller-controlled LEDs to increase intensity ahead on the road. This allows lights to operate at low intensity when no vehicles are present, saving energy compared to always-on streetlights. The system uses an ATmega8 microcontroller programmed to control LED intensity based on signals from IR sensors placed along the road.
- The document describes the design and testing of a homemade PVC wind turbine by students at Sagar Institute of Research & Technology in Bhopal.
- It includes sections on the components of wind turbines, how PVC was used for the turbine blades, and the experimental setup testing the turbine's ability to generate power from wind energy using PVC blades.
- The students found that the PVC blade profile generated better power capacity as the rotational speed of the rotor increased. Further testing is needed to confirm these initial results showing the potential of PVC blades for small wind turbines.
The document discusses the skin layers and composition, emulgels as a topical drug delivery system, advantages and disadvantages of emulgels, and previous research on lornoxicam formulations. It then outlines a proposed research plan to develop emulgel formulations of ivermectin, a poorly soluble drug, for topical delivery. The plan includes preformulation studies of ivermectin, preparation and evaluation of emulgel formulations, and in vitro drug release testing. The goal is to develop ivermectin emulgels for topical treatment of parasites that reside in the skin to avoid systemic side effects.
This document presents a proposed algorithm for removing Gaussian noise from images using shift invariant wavelet transform. It begins with an introduction that outlines the objectives of noise removal and discusses image noise and types of noise. It then covers wavelet transforms, discrete wavelet transform, wavelet-based image denoising techniques including thresholding. The proposed algorithm applies shift invariant denoising using soft or hard thresholding. Experimental results on various test images like Cameraman, Baboon and Lena show that the shift invariant wavelet denoising provides better PSNR and MSE values compared to traditional wavelet denoising.
This document summarizes water validation and the types of water used in pharmaceuticals. It discusses the reasons for performing water validation when installing a new water system or making changes. The types of water according to IP, BP, and USP standards are described. The key steps in water purification and validation are outlined, including design qualification, installation qualification, operational qualification and performance qualification. Sampling programs are discussed to demonstrate a system is operating under the same conditions as validation. In conclusion, the document covers water standards, uses, equipment, manufacturing processes, and grades of pharmaceutical water specified in key pharmacopeias.
This document describes a prototype alcohol detection system to prevent drunk driving accidents. The system uses an alcohol sensor to detect alcohol levels in a driver's breath. If the alcohol detected exceeds a threshold, the Arduino microcontroller will activate an alert and stop the vehicle's engine. The system aims to automatically lock vehicle engines when a drunk driver tries to drive, in order to reduce accidents caused by drunk driving.
WATER CONSERVATION TANANJAY RICCHARIYA.pptxsaiproject
This document provides information about water conservation. It discusses strategies for water conservation like rainwater harvesting, protecting groundwater, and using water-saving technologies in households, commercial, and agricultural applications. It also discusses reusing water to address water shortages and reducing water wastage through efforts like fixing leaks. The key message is that water conservation aims to sustainably manage freshwater resources to meet current and future human demand through various policies and activities.
Management involves achieving organizational goals through people. It includes planning, organizing, staffing, leading, and controlling. Early management theories focused on increasing efficiency and productivity. Scientific management emphasized analyzing tasks and establishing standards to optimize workflow. While increasing output, it was criticized for being too controlling and reducing creativity. Administrative management took a broader view of managing whole organizations. It laid the foundation for viewing management as a distinct function.
Smart Health Disease Prediction django machinelearning.pptxsaiproject
This document presents a smart health disease prediction system that uses machine learning. The system allows users to input their symptoms and predicts the potential illness. It uses data mining techniques like Naive Bayes classification to match symptoms with diseases. Key features include doctors accessing patient details, administrators adding disease data, and a user-friendly interface for disease prediction and searching doctors. The system aims to provide timely medical guidance when users specify symptoms. It was developed using Python, Django, SQLite, HTML, CSS and machine learning algorithms like Naive Bayes, Random Forest and Support Vector classifiers.
The document discusses various data types in Python including float, complex, bool, and str (string) types. It provides details on how each data type stores and represents values. For float, it notes they have a precision of 16 digits and can be represented exponentially. Complex numbers are written as x + yj. Bool only allows True or False values. Strings use Unicode encoding and can be delimited by either single or double quotes, using escape characters when needed. It also discusses accessing individual characters within a string using indexes.
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Macroeconomics- Movie Location
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বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
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3. CASTING RINGS
Casting rings are used to confine the fluid investment
around the wax pattern while the investment sets
They are available as:-
1. complete rings:
a)rigid –metal
--plastic
b)flexible – rubber
2. split rings –metal
--plastic
3. shape – round
--oval
4.
5. SELECTION OF CASTING
RINGS
The internal diameter of casting ring should be 5-
10 mm greater than the widest measurement of
the pattern and about 6mm higher.
For single crown/inlay – ring diameter-32mm
For large FPD – ring diameter- 63mm, shape –
round/oval
6. CASTING RING LINERS
PURPOSE: to provide a buffer of pliable material
against which the investment can expand to
enlarge the mould.
If there is no room for expansion outwards, the
expansion forces will be exerted inwards towards
the mould, resulting in distortion of the casting.
Ring liners:
1. Asbestos liner
2.cellulose (paper) liner
3.aluminosilicate ceramic liner
7. Asbestos liner – not used anymore because of its
carcinogenic potential.
Ceramic liners- kaoliner, densply . . Ceramic material does
not readily absorb water except under vaccume . It does
not absorb water like cellulose liner, its network of fibers
can retain water on the surface.
{it has been pointed out, however,that ceramic material
contains fibers in the size range likely to produce lung
tumors in rats and therefore may be no less hazardous
than asbestos}.
Cellulose liners: absorbs water- becomes thicker and more
compressible. It burns out before the casting is made and
allowing unrestricted thermal expansion and easy escape
of gases from the mould during casting.
8. PROCEDURE
The liner is cut to fit the inside diameter of the
casting ring with no overlap.
The dry liner is tacked in position with stickey
wax, and then it is used dry or wet.
Wet liner technique: the lined ring is immersed in
water for a time, and excess water is shaken
away (squeezing the liner is avoided because this
leads to variable amounts of water removal and
nonuniform expansion).
This absorbed water causes semi-hygroscopic
expansion as it is drawn into the investment
during setting (for gypsum bonded investments)
9.
10. Using a thicker liner material or two layers of liner
provides even greater semihygroscopic expansion
and also affords a more unrestricted normal setting
expansion of the investment.
Thickness of the liner should not be less than
approximately 1mm.
The expansion of the investment is always greater in
the unrestricted longitudinal direction than in the
radical direction, that is, towards the ring. Therefore it
is desirable to reduce the expansion in the
longitudinal direction.
Placing the liner somewhat short (3.25mm) of the
ends of the ring tends to produce a more uniform
expansion; thus there is less chance for distortion of
11. RINGLESS CASTING SYSTEM
The high strength of the phosphate bonded
investment material makes it possible to abandon the
use of casting ring.
Plastic ring with rubber crucible former are used. The
ring is conical in shape with tapering walls. As the
investment sets the investment is tapped out of ring.
Then burnout is done without casting ring, this causes
greater expansion.
ADVANTAGES
-allows unrestricted thermal expansion
-smaller marginal discrepancy
-easier technique
-easy to divest
-health hazard of liners are avoided
12. INVESTING PROCEDURE
wax pattern should be cleaned of any debris,
grease or oils using – a commercially wax pattern
cleaner
--a dilute synthetic detergent.
Excess liquid is shaken off
Pattern is left to air-dry while the investment is
being prepared.
The thin film of cleanser left on pattern
- reduces the surface tension- allows wetting of
the wax pattern by investment material to ensure
complete coverage of the intricate portions of the
pattern.
13. MIXING OF INVESTMENT
Hand mixing
Vacuum mixing
Hand mixing:- appropriate amount of
water(gypsum investment) or colloidal silica
special liquid(phosphate investment)is dispensed
in a clean dry mixing bowl.
-powder is gradually added to the
liquid with caution to avoid air entrapment until all
the powder has been wet
-hand mixing is an option but
vacuum mixing is more common.
14. Vacuum mixing
Mechanical mixing under vaccum removes air
bubbles better.
Once mixing is completed, the pattern may be-
-hand invested
-vacuum invested
Hand investment: entire pattern is painted (inside
out) with a thin layer of investment.the casting
ring in positioned on the crucible former, the
remainder of the investment is vibrated slowly into
the ring.
Vacuum investment: the same equipment used to
15.
16. In one study it was found that 95% of vacuum-
invested casting were free of nodules, whereas 17%
of castings made in hand-invested moulds were
entirely free of defects.
PRECAUTIONS
Air bubbles may can be entrapped on flat or concave
surfaces (not oriented suitably for air evacuation) :
tilting the ring slightly aids in releasing these bubbles
so that they can rise to the surface.
Exessive vibration should be avoided: it causes solids
in investment to settle down and free water
accumulation adjacent to the wax pattern, resulting in
surface roughness.
Exessive vibration may also dislodge small pattern
from the sprue ,resulting in miscast.
17. HYGROSCOPIC TECHNIQUE: the filled casting
ring is immediately placed in 37 degree water
bath with crucible former side down.
HIGH HEAT TECHNIQUE: the invested ring is
allowed to bench set undisturbed for the
manufacturer recommended time.
18. Once the investment is set for an appropriate amount
of time- approximately 1 hr. for most gypsum and
phosphate bonded investment – it is ready for
burnout.
Crucible former and any metal sprue former are
carefylly removed.
Any debris from the ingate area (funneled opening at
the end of the ring) is cleaned with a brush.
If burnout is not carried out immediately ,the
investment is stored in a humidor at 100% humidity.
Do not let the investment to dry out
Rehydration of set investment that has been stored
for an extended period may not replenish all of the
lost water.
19. BURNOUT
It prepares the mould for the molten alloy and allows thermal
expansion to occur.
It is advisible begin the burnout procedure while the mould is still
wet.
Water trapped in the pores of the investment reduces the
absorption of wax, and as the water vaporizes, it flushes wax
from the mould.
This process is facilitated by placing the ring with the sprue hole
down over a slot in a ceramic tray in the burnout furnace.
When high heat technique is used, the mold temperature
generates enough heat to convert carbon to either carbon
monoxide or carbon dioxide. These gases can then escape
through the pores in the heated investment.
Gypsum bonded investment: 500˚C (hygroscopic technique) &
700˚ (thermal expansion technique)
Phosphate bonded investment – 700˚ to 1030˚ C, depending on
the type of alloy selected.
20.
21. Wax elimination and heating
techniques:
Hygroscopic low heat technique
High-heat thermal expansion technique
Hygroscopic low heat technique:
here the compensation expansion is from 3 sources:
1)37 degree Celsius water bath expands the wax pattern
2)Hygroscopic expansion
3)Thermal expansion at 500 degree Celsius.
ADVANTAGES:
-less investment degradation.
-cooler surface for smoother castings
-convenience of placing the mould directly in the 500 degree
Celsius furnace.
22. The mold should remain in the furnace for at least
60 mis , they may be held up to 5 hrs.
Even though the mold is usually held at this
temperature for 60 to 90 mins, sufficient residual
fine carbon may be retained to reduce the venting
of the mold thereby causing backpressure
porosity.
High-heat thermal expansion technique: uses
high heat burnout to obtain the required thermal
expansion , while at the same time eliminating the
wax pattern.
23. Time allowable for casting
No more than 30 seconds should be allowed to
elapse between the time the ring is removed from
the oven and the molten alloy is centrifuged into
the mold.
Any undue delay will cause heat loss and
resultant mold contraction.
24. Casting process and equipment
Casting machines (based on the method of
casting)
1. centrifugal type
2. air pressure type
CENTRIFUGAL TYPE:
May be spring driven or motor driven
Can cast both large and small castings on the
same machine
25. AIR PRESSURE TYPE :
Either compressed air or gasses like carbon
dioxideor nitrogen can be used to force the
molten metal into the mould.
Satisfactory to make small castings
Some systems use argon gas to protect the alloy
from oxidation
(specially useful of melting titanium)
26. ATTACHED VACUUM SYSTEM:
both centrifugal or air presure type are available
with an attached vaccum system
Vacuum creates a negative pressure within the
mould, which helps to draw the alloy into the mold
CASTING MACHINES CAN BE GROUPED
BASED ON HEATING SYSTEM EMPLOYED
1. Torch melted
2. Induction melted
3. Arc melted
27. Torch melting of noble metal alloy
Fuel used is a mixture of natural or artificial gas and air. Or
oxygen and acetylene gas (high fusion alloys)
Parts of the flame:
1. mixing zone- first long cone emanating directly from the
nozzle. Here the air and gas are mixed before
combustion. No heat is present in this zone.
2. Combustion zone-green color, immediately surrounding
the inner cone. Here the gas and air are partially burned.
This zone is oxidizing, should always be kept away from
the molten alloy during fusion.
3. Reducing zone- dimly blue in color. Located just beyond
the tip of the green combustion zone. Hottest part of the
flame. This zone is used for melting alloy.
4. Oxidizing zone-the outer cone. Area in which
combustion occurs with the oxygen in the air. Should not
be used. Oxidises the alloy
The air and gas mixture is adjusted to get a reducing flame,
28.
29. Induction melting
It is the process of heating an electrically
conducting object (metal) by electromagnetic
induction, where eddy currents are generated
within the metal and resistance leads to Joule
heating of the metal.
An induction heater consists of an electromagnet,
through which a high frequency alternating
current is passed.
Induction melting is useful for high fusing alloys
like metal-ceramic and base metal alloys.
30. Arc melting
Direct current is passed between two electrodes-
a tungsten electrode and the alloy.
Arc melting produces very high temperatures and
is used to melt high fusion metals like titanium.
Arc melting may be done under vacuum or an
inert atmosphere like argon.
Numerous combinations of these principles are
employed in different machines.
31. Casting crucibles
4types:-
1. Clay
2. Carbon
3. Quartz
4. Zirconia-alumina
Clay crucible is used for high noble and noble
alloys.
Carbon crucible for high noble crown and bridge
alloys and higher fusing gold based metal ceramic
alloys
Quartz and zircinia-alunina crucible are
recommended for high fusing alloys of any type.
(specially those which are sensitive to carbon
contamination)
32.
33. CLEANING THE CASTING
After the casting has solidified, the ring is removed
and quenched in water as soon as the button exhibits
a dull-red glow
ADVANTAGES
1. the noble metal alloy is left in an annealed condition
for burnishing, polishing and similar procedures
2. when the water contacts the hot investment , a
violent reaction ensues, resulting in a soft, granular
investment that is easily removed.
Queching is done to achive the best grain structure.
If it is quenced while it is too hot, the gold will be
softer and weaker.
If it is allowed to bech cool completely, the grain
structure will be too large
34. The ring is removed from the water, and the
investment and casting are pushed out of the
ring.
As much of the investment as possible is broken
off by hand or with old instrument, then the
casting and button are scrubbed with a stiff
brush.the casting should appear smooth, with a
dull, dark oxide layer.
The oxide layer and any remaining particles of
investment areremoved by lightly air abrading all
surfaces with a 50µm abrasive, taking care not to
abraid thin margins.
35. Often the surface of the casting appers dark with
oxides and tarnish. This can be removed by a
process known as pickling.
Pickling consists of heating the discolored casting
in an acid.
For gypsum bonded investments 50%
hydrochloric acid solution is used. Disadvantage
is the acid fumes are a health hazard.
Pickling process can be performed ultrasonically
while the prosthesis is sealed in a teflon
container.
A solution of sulfuric acid may also be more
advantageous in this respect.
Only gold castings may be cleaned by pickling.
36. CASTING DEFECTS
any irregularity in the metal casting process that is
undesired is called Casting Defect.
Casting defects can be classified under four
headings:
1. Distortion
2. Surface roughness and irregularities
3. Porosity
4. Incomplete or missing details.
37. Distortion
Related to distortion of the wax pattern
Can be prevented by proper manipulation of the
wax and handling the pattern
Some distortion of the wax pattern occurs as the
investment around it hardens.
Distortion increases as the thickness of the
pattern decreases.
Generally, it is not a serious problem.
38. Surface roughness, irregularities and
discoloration.
Excessive roughness or irregularities on the outer
surface of the casting necessitate additional
finishing and polishing, whereas irregularities on
the cavity surface prevent proper seating of an
otherwise accurate casting.
Surface roughness is defined as relatively finely
spaced surface imperfections whose height,
width, and direction establish the predominant
surface pattern.
Surface irregularities are isolated imperfections,
such as nodules, that are not characteristic of the
entire surface area
39. Types of Surface Roughness
1. Nodules- Small nodules on the casting are
caused by air bubbles that become attached
to the pattern during or subsequent to the
investing procedure.
40. Types
a) Large nodules: Air trapped during investing
procedure.
b) Multiple nodules:
- Inadequate vacuum during investing
- Improper brush technique
- Lack of surfactant
41. c) Nodules on occlusal surface: due to excessive
vibration
d)Nodules on underside: prolonged vibration after
pouring.
42. Avoided by:
The best method to avoid air bubbles is to
use the vacuum investing technique.
If manual method is used:
1. Use of mechanical mixer with vibration both
before and after mixing
2. Surfactant may be used. Surfactant should
be applied in thin layer and air – dried
because any excess liquid dilutes the
investment.
43. When nodules are large
or situated on a margin,
they usually necessitate
remaking of the
restoration.
When small, they can
often be removed with a
No. ¼ or No. ½ round
bur.
A slight excess of metal
should be removed to
ensure that the nodule
does not interfere with
complete seating.
Contemporary fixed prosthodontics –
Rosensteil
44. 2. Ridges or Veins
Wax is repellent to water, if the investment
becomes separated from the wax pattern in
some manner, a water film may form
irregularly over the surface.
45. This condition occurs:
-If the pattern is slightly moved, jarred or vibrated after
investing.
- If there is no intimate contact of the investment and
the pattern
- Too high a liquid /powder ratio
-Use of surfactant help prevent such irregularities.
46. 3. Fins are caused by cracks in the investment
that have been filled with molten metal.
47. Cause of Fins:
- Weak mix of the investment i.e. high water/
powder ratio.
- Improper positioning of the pattern in investment
i.e. pattern placed too near the edge of the
investment
- Too rapid heating
- Premature heating
48. -Excessive casting force
- Rough handling of the ring after investing
- Liner flushed with the end of the ring.
49. 4. Spines
Rapid heating of investment results in spines.
Sometime a characteristic surface roughness
may also be evident because of flaking of the
investment when the water/steam pours into
the mold.
Ideally, 60 min should elapse during the
heating of the investment filled ring from room
temperature to 700°C.
51. Foreign Body Inclusions
Any casting that shows sharp, well defined
deficiencies indicates the presence of some
foreign particles in the mold, such as;
I. Pieces of investment
II. Bits of carbon from flux
52. A rough crucible former with bits of investment
clinging to it may roughen the investment on its
removal so that small particles of investment are
carried into mold with molten alloy.
53. 6.Porosities
Solidification porosity-
Localized shrinkage porosity
Shrink – Spot Porosity
Suck Back Porosity
Microporosity
Trapped Gases-
Pin hole porosity
Gas Inclusions
Sub surface porosities
Residual Air
Back pressure porosity
54. Shrink Spot Porosity
Cause:
Premature termination of flow of metal during
solidification.
Linear contraction of noble metal alloys in
changing from liquid to solid is 1.25%. Therefore
continual feeding of molten metal through the
sprue must occur to compensate for casting
shrinkage i. e. shrinkage during solidification.
If the sprue solidifies before casting it usually
results in localized shrinkage porosity.
55.
56.
57. It can be avoided by:
- Using sprue of correct thickness
-Attaching the sprue at the thickest portion of the
wax pattern
- Flaring the sprue at the point of attachment
- Placing the reservoir close to the wax – pattern
58. Suck-Back Porosity
Localized shrinkage may also occur in the interior
of crown near the area of the sprue .
The entering metal impinges on to the mold
surface at occlusoaxial/ incisoaxial line angle and
creates a higher localized mold temperature at
this region known as “Hot Spot”.
A hot spot may retain a localized pool of molten
metal after other areas of the casting have
solidified. This in turn creates shrinkage void or
sucks back porosity.
59. These porosities can be eliminated:
- By flaring the point of sprue attachment
- Reducing the mold melt temperature differential
i.e. lowering the casting temperature by about 30°
60. Left coping was casted at 1370 degree C
and right coping at 1340 degree C
61. Microporosity
Occurs from solidification shrinkage but is
generally present in fine grain alloy casting
when the solidification is too rapid for the
microvoids to segregate to the liquid pool.
Microporosity voids are irregular in shape.
This defect is not detectable unless casting is
sectioned.
63. Pinhole and Gas Inclusion Porosity
Both these porosities are related to the
entrapment of gas during solidification.
Both these are characterized by spherical
contour but size is varied i.e. gas inclusion is
larger in size compared to pinhole.
Many metals dissolve or occlude gases in
their molten state. On solidification, absorbed
gases are expelled resulting in these
porosities.
These can be minimized by Premelting the
alloy, and by correctly adjusting the torch
flame during melting.
64. Alloy after heat treatment at 725
degree C for 70 min. Pinhole
Grain structure of the alloy
65. Subsurface Porosity
Caused by simultaneous nucleation of solid
grains and gas bubbles at the first moment
that the alloy freezes at the mold walls.
Can be minimized by controlling the rate at
which the molten metal enters the mold.
67. Back Pressure Porosity
Also known as entrapped air porosity. It can
produce large concave depression.
Caused by inability of air to escape through
pores of investment or by pressure gradient
that displaces air towards end of the
investment via molten sprue and button.
Occasionally found on the outer surface of
casting when the casting or mold temperature
is low that the solidification occurs before the
entrapped air can escape
69. The incidence of entrapped air has increased by
use of:
- Dense modern investment
- Increase in mold density
- By tendency of mold to clog with residual carbon
when low heat technique is used
- Proper burnout, an adequate mold and casting
temperature, a sufficiently high casting pressure
and proper L/P ratio can help to eliminate
entrapped air porosity
- Thickness of investment between the tip of
pattern and end of ring should be not more than
70. Incomplete Casting
When due to some reason molten alloy is prevented
from completely filling the mold.
Causes:
i. Insufficient venting of mold
ii. Incomplete elimination of wax residue
iii. High viscosity of fused metals
iv. Inadequate metal
v. Cool mold or melt
vi. Wax pattern too thin
vii. If there is marginal discrepancy due to wax
pattern distortion and uneven expansion
71. If short rounded margins with lumpy/ rounded
button- alloy not hot enough/ inadequate
casting force.
If short rounded margins with sharp button-
pattern too far from the end of ring.
If casting is shiny- incomplete burnout.
72. Incomplete casting resulting from
incomplete wax elimination is
characterized by rounded margins
and shiny appearance.
73. References
Anusavice KJ, Shen C, Rawls HR. Phillips'
science of dental materials. Elsevier Health
Sciences; 2013.
Shillingburg HT, Sather DA, Wilson EL, Cain JR,
Mitchell DL, Blanco LJ, Kessler JC.
Fundamentals of fixed prosthodontics.
Quintessence Publishing Company; 2012.
Rosenstiel SF, Land MF. Contemporary fixed
prosthodontics. Elsevier Health Sciences; 2015
Jul 28.
Morrow RM, Rudd KD. Dental Laboratory
Procedures: Fixed partial dentures. Mosby
Incorporated; 1986.