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 cast metal restorations, specifically class II inlay cavity preparation. It discusses the introduction of inlays in dentistry, materials used for cast metal restorations, definitions, indications and contraindications. It also covers principles of cavity preparation, types of bevels and flares, tooth preparation for class II inlay cavities, and modifications that can be made.
The document discusses common failures of dental amalgam restorations. It states that while amalgams initially perform well, over time technical issues can lead to fracture, recurrent caries, discoloration and corrosion. Failures are often due to faulty cavity preparation, poor matrix adaptation, or improper amalgam manipulation. Specifically, inadequate extension or retention forms during cavity preparation increase risks of secondary caries and fracture. Contamination or delayed condensation of amalgam can also weaken restorations.
The document discusses pulp pathology and its sequelae. It covers the response of the pulp to dental caries, including immune response, hard tissue response to irritation, and histologic changes in acute and chronic inflammation. It also discusses neural changes during pulpal inflammation, antiinflammatory mechanisms, less common responses, iatrogenic effects, systemic factors, and pulpal sequelae to trauma. Causes of pulp inflammation, necrosis, and dystrophy include bacterial, traumatic, iatrogenic, chemical, and idiopathic factors.
Temporary Crown and Bridge Resins by Dr Rashid HassanDr Rashid Hassan
A comprehensive lecture by Dr Rashid Hassan on Temporary crown and bridge resins . The lecture covers the materials used as temporary crown & bridge, the technique of using and the general properties of materials used.
Matrices, retainers and wedges /certified fixed orthodontic courses by India...Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
Bleaching of tooth endodontics best pdfEphrem Tamiru
This document discusses the classification, causes, and management of tooth discoloration. It begins by classifying discoloration as intrinsic, extrinsic, or a combination. Intrinsic discoloration is caused by incorporation of stains during tooth development or after eruption, while extrinsic stains are deposited on the enamel surface. A variety of bleaching techniques are then described to lighten both types of discoloration, including home bleaching kits, in-office bleaching, walking bleach, and laser bleaching. Contraindications for bleaching such as poor case selection, dentin hypersensitivity, and extensively restored teeth are also noted.
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 cast metal restorations, specifically class II inlay cavity preparation. It discusses the introduction of inlays in dentistry, materials used for cast metal restorations, definitions, indications and contraindications. It also covers principles of cavity preparation, types of bevels and flares, tooth preparation for class II inlay cavities, and modifications that can be made.
The document discusses common failures of dental amalgam restorations. It states that while amalgams initially perform well, over time technical issues can lead to fracture, recurrent caries, discoloration and corrosion. Failures are often due to faulty cavity preparation, poor matrix adaptation, or improper amalgam manipulation. Specifically, inadequate extension or retention forms during cavity preparation increase risks of secondary caries and fracture. Contamination or delayed condensation of amalgam can also weaken restorations.
The document discusses pulp pathology and its sequelae. It covers the response of the pulp to dental caries, including immune response, hard tissue response to irritation, and histologic changes in acute and chronic inflammation. It also discusses neural changes during pulpal inflammation, antiinflammatory mechanisms, less common responses, iatrogenic effects, systemic factors, and pulpal sequelae to trauma. Causes of pulp inflammation, necrosis, and dystrophy include bacterial, traumatic, iatrogenic, chemical, and idiopathic factors.
Temporary Crown and Bridge Resins by Dr Rashid HassanDr Rashid Hassan
A comprehensive lecture by Dr Rashid Hassan on Temporary crown and bridge resins . The lecture covers the materials used as temporary crown & bridge, the technique of using and the general properties of materials used.
Matrices, retainers and wedges /certified fixed orthodontic courses by India...Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
Bleaching of tooth endodontics best pdfEphrem Tamiru
This document discusses the classification, causes, and management of tooth discoloration. It begins by classifying discoloration as intrinsic, extrinsic, or a combination. Intrinsic discoloration is caused by incorporation of stains during tooth development or after eruption, while extrinsic stains are deposited on the enamel surface. A variety of bleaching techniques are then described to lighten both types of discoloration, including home bleaching kits, in-office bleaching, walking bleach, and laser bleaching. Contraindications for bleaching such as poor case selection, dentin hypersensitivity, and extensively restored teeth are also noted.
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 various root canal preparation techniques including step-back, crown-down, and balanced force techniques. It provides details on each technique's procedures, advantages, and limitations. The step-back technique involves initial apical preparation followed by step-wise coronal preparation to create tapers. Crown-down starts with coronal flaring before apical instrumentation to minimize debris extrusion. Hybrid and balanced force techniques combine aspects of different methods.
This document discusses non-carious lesions of the teeth. It describes various types of tooth wear including erosion, attrition, abrasion, and abfraction. Erosion can be caused by regurgitation of gastric acids, dietary acids from foods and drinks, or industrial acids. Attrition results from tooth-to-tooth contact during grinding or bruxism. Abrasion is caused by external abrasive agents like toothbrushes or pipes. Abfraction involves microstructural loss of tooth structure in areas of stress concentration. The document outlines factors that contribute to each type of wear and their presentations in the oral cavity. It emphasizes that tooth wear often results from combinations of these mechanisms.
This document provides information on post and core procedures for restoring endodontically treated teeth. It discusses various post types and materials, as well as factors to consider for post selection and tooth preparation. The key points covered include the importance of ferrule effect for reinforcement, minimizing tooth structure removal, and using post designs and materials that distribute stresses evenly to reduce risk of root fracture. Both prefabricated and custom cast post and core fabrication techniques are described.
Attrition, abrasion, and erosion are the three main causes of tooth wear. Attrition occurs from tooth-to-tooth contact during chewing. Abrasion is the wearing away of tooth structure from mechanical processes like improper brushing. Erosion results from the dissolution of enamel by acidic substances in the diet or stomach. Symptoms include tooth sensitivity, pain, discoloration, and reduced chewing ability. These issues can be prevented by proper brushing technique, avoiding abrasives, limiting acidic foods and drinks, and using a mouthguard for teeth grinders.
This document discusses pits and fissure sealants. It explains that pits and fissures are difficult to clean and can accumulate plaque and debris, leading to caries development. Sealants were developed in the 1960s using acid etching to seal pits and fissures with resin. Children with special needs or extensive caries are indicated for sealants. Molars with localized occlusal caries confined to the outer third of dentin can be sealed, while deeper caries requires restoration first. Resin and glass ionomer based sealants are described, with resin being preferred. The application process involves cleaning, etching, washing, applying sealant and curing.
This document discusses dental composite materials. It provides a brief history, noting their introduction in the 1960s and improvements over time, including the development of microfilled and hybrid composites in the 1980s-1990s. The document outlines the composition of dental composites, including monomers, photo initiators, fillers like silica and glass. It also discusses different filler types and particle sizes, as well as setting mechanisms like chemical, light, and dual cures. Advantages include esthetics, bonding to tooth structure, and disadvantages include shrinkage and required skill. The document classifies composites by handling characteristics and location of restoration fabrication. It concludes with the method and clinical application of dental composites.
Copy of fundamentals of cavity preparations / dental implant 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.
Cavity preparation for cast metal restorationschatupriya
This document discusses cavity preparation for cast metal restorations. It begins by introducing cast metal restorations and their history. It then defines inlays and onlays. The document discusses various materials used for cast restorations including gold, platinum, and nickel-chromium alloys. It covers the requirements, properties, and classes of different dental casting alloys. The document provides details on cavity preparation principles, outline forms, and features to provide resistance and retention. It also discusses preparation modifications and secondary retention methods.
Kennedy’s Classification in Cast Partial DentureAamir Godil
This document discusses Kennedy's classification system for partially edentulous arches and Applegate's rules for applying the Kennedy classification. It provides details on Kennedy's four basic classes for partial edentulism and Applegate's eight rules to govern the application of Kennedy's classification. Examples are given to demonstrate how to use Kennedy's classification and Applegate's rules to classify different clinical scenarios of partial edentulism.
The document discusses various systems for classifying malocclusion. It begins by describing Angle's classification system, which is based on the anteroposterior relationship of the maxillary first molars. It describes the different classes of malocclusion under Angle's system. The document then discusses modifications to Angle's system by researchers like Lischer, Dewey, Howard, and Taylor. It also covers Simon's classification system, which relates the dental arches to the three planes of space. Other classification systems described include Baume's for primary dentition, Moyer's etiological system, Ballard's incisor classification, and Ackermann and Profitt's diagrammatic system.
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.
Retention in fixed partial dentures / cosmetic dentistry courseIndian 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.
A root canal is a treatment to remove the infected or inflamed pulp from the inside of a tooth. The pulp contains blood vessels, nerves, and connective tissue. Reasons for needing a root canal include deep tooth decay, cracks, injuries, or electively to better retain a crown. Left untreated, infection from the pulp can spread and cause bone loss around the tooth. During a root canal, an endodontist carefully cleans, shapes, and seals the inside of the tooth to prevent further infection.
The document discusses fixed partial dentures (FPDs). FPDs are indicated when teeth are missing, damaged, or diseased. They are contraindicated for young patients, long spans between teeth, or teeth that require excessive preparation. FPDs are more stable and comfortable for patients than removable partial dentures, but they require more tooth structure removal and are more expensive and time-consuming to place.
Different gingival finish lines (margins) of crowns and bridgesSana Mateen Munshi
The document discusses various considerations for margin placement in tooth preparations, including biological, mechanical, and aesthetic factors. It describes advantages and disadvantages of different margin types such as supragingival and subgingival margins. Common margin designs like shoulder, bevel, and chamfer margins are explained. Guidelines are provided for reducing tooth structure during preparation in a systematic manner.
Pulp protection in operative dentistry Nivedha Tina
This document discusses various materials used for pulp protection and their properties. It describes how remaining dentin thickness, depth of preparation, and prevention of bacterial microleakage are important factors for pulp health. Common pulp protection materials discussed include bases, liners, varnishes, and sealers. Calcium hydroxide and glass ionomer cements are highlighted as they promote reparative dentin formation, adhere to dentin, and release fluoride. The document emphasizes that proper isolation and sealing of restorations is key to preventing pulpal injury from bacteria and toxins.
Prosthodontics is the dental specialty pertaining to the diagnosis, treatment planning, rehabilitation, and maintenance of patients with missing or deficient teeth using substitutes. It includes fixed and removable prostheses. A fixed partial denture is a partial denture that is securely attached to abutment teeth, roots, or implants to replace one or more missing teeth. Successful treatment requires attention to patient assessment, diagnosis, treatment planning, operative skills, and follow-up care.
Smear layer is a controversial topic in the field of operative dentistry and endodontics. This presentation includes composition, concepts, structure, advantages, disadvantages, and removal methods of smear layer.
Liners and bases are placed between dentin (or pulp) and a restoration to provide pulpal protection. Liners are thin layers that provide a barrier against residual reactants and oral fluids penetrating between the restoration and tooth. Bases are thicker (1-2mm) and provide additional thermal protection and support restoration forces. The need for liners depends on the restoration material and cavity location/depth. Newer liners focus on chemical protection through sealing and adhesion rather than pulpal medication. The choice of liner depends on remaining dentin thickness and restoration material.
This document discusses the failures of amalgam restorations. It outlines several signs of restoration failure such as fracture lines, marginal ditching, and recurrent caries. The reasons for amalgam restoration failure are then explained as improper case selection, faulty cavity preparation that does not follow best practices, errors in amalgam placement and manipulation, issues with matrixing procedures, and postoperative factors.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
The goals of endodontic access cavity preparation are to remove all debris and microorganisms from the root canal system, and to create a direct line of access to allow for thorough cleaning, shaping, and filling of the canals. Proper visualization, location of all canal orifices, and flaring of the cavity are essential to achieve these aims. Adequate taper, smooth walls, and space for coronal restoration are also important to optimize disinfection and long-term sealing of the treated tooth.
This document discusses various root canal preparation techniques including step-back, crown-down, and balanced force techniques. It provides details on each technique's procedures, advantages, and limitations. The step-back technique involves initial apical preparation followed by step-wise coronal preparation to create tapers. Crown-down starts with coronal flaring before apical instrumentation to minimize debris extrusion. Hybrid and balanced force techniques combine aspects of different methods.
This document discusses non-carious lesions of the teeth. It describes various types of tooth wear including erosion, attrition, abrasion, and abfraction. Erosion can be caused by regurgitation of gastric acids, dietary acids from foods and drinks, or industrial acids. Attrition results from tooth-to-tooth contact during grinding or bruxism. Abrasion is caused by external abrasive agents like toothbrushes or pipes. Abfraction involves microstructural loss of tooth structure in areas of stress concentration. The document outlines factors that contribute to each type of wear and their presentations in the oral cavity. It emphasizes that tooth wear often results from combinations of these mechanisms.
This document provides information on post and core procedures for restoring endodontically treated teeth. It discusses various post types and materials, as well as factors to consider for post selection and tooth preparation. The key points covered include the importance of ferrule effect for reinforcement, minimizing tooth structure removal, and using post designs and materials that distribute stresses evenly to reduce risk of root fracture. Both prefabricated and custom cast post and core fabrication techniques are described.
Attrition, abrasion, and erosion are the three main causes of tooth wear. Attrition occurs from tooth-to-tooth contact during chewing. Abrasion is the wearing away of tooth structure from mechanical processes like improper brushing. Erosion results from the dissolution of enamel by acidic substances in the diet or stomach. Symptoms include tooth sensitivity, pain, discoloration, and reduced chewing ability. These issues can be prevented by proper brushing technique, avoiding abrasives, limiting acidic foods and drinks, and using a mouthguard for teeth grinders.
This document discusses pits and fissure sealants. It explains that pits and fissures are difficult to clean and can accumulate plaque and debris, leading to caries development. Sealants were developed in the 1960s using acid etching to seal pits and fissures with resin. Children with special needs or extensive caries are indicated for sealants. Molars with localized occlusal caries confined to the outer third of dentin can be sealed, while deeper caries requires restoration first. Resin and glass ionomer based sealants are described, with resin being preferred. The application process involves cleaning, etching, washing, applying sealant and curing.
This document discusses dental composite materials. It provides a brief history, noting their introduction in the 1960s and improvements over time, including the development of microfilled and hybrid composites in the 1980s-1990s. The document outlines the composition of dental composites, including monomers, photo initiators, fillers like silica and glass. It also discusses different filler types and particle sizes, as well as setting mechanisms like chemical, light, and dual cures. Advantages include esthetics, bonding to tooth structure, and disadvantages include shrinkage and required skill. The document classifies composites by handling characteristics and location of restoration fabrication. It concludes with the method and clinical application of dental composites.
Copy of fundamentals of cavity preparations / dental implant 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.
Cavity preparation for cast metal restorationschatupriya
This document discusses cavity preparation for cast metal restorations. It begins by introducing cast metal restorations and their history. It then defines inlays and onlays. The document discusses various materials used for cast restorations including gold, platinum, and nickel-chromium alloys. It covers the requirements, properties, and classes of different dental casting alloys. The document provides details on cavity preparation principles, outline forms, and features to provide resistance and retention. It also discusses preparation modifications and secondary retention methods.
Kennedy’s Classification in Cast Partial DentureAamir Godil
This document discusses Kennedy's classification system for partially edentulous arches and Applegate's rules for applying the Kennedy classification. It provides details on Kennedy's four basic classes for partial edentulism and Applegate's eight rules to govern the application of Kennedy's classification. Examples are given to demonstrate how to use Kennedy's classification and Applegate's rules to classify different clinical scenarios of partial edentulism.
The document discusses various systems for classifying malocclusion. It begins by describing Angle's classification system, which is based on the anteroposterior relationship of the maxillary first molars. It describes the different classes of malocclusion under Angle's system. The document then discusses modifications to Angle's system by researchers like Lischer, Dewey, Howard, and Taylor. It also covers Simon's classification system, which relates the dental arches to the three planes of space. Other classification systems described include Baume's for primary dentition, Moyer's etiological system, Ballard's incisor classification, and Ackermann and Profitt's diagrammatic system.
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.
Retention in fixed partial dentures / cosmetic dentistry courseIndian 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.
A root canal is a treatment to remove the infected or inflamed pulp from the inside of a tooth. The pulp contains blood vessels, nerves, and connective tissue. Reasons for needing a root canal include deep tooth decay, cracks, injuries, or electively to better retain a crown. Left untreated, infection from the pulp can spread and cause bone loss around the tooth. During a root canal, an endodontist carefully cleans, shapes, and seals the inside of the tooth to prevent further infection.
The document discusses fixed partial dentures (FPDs). FPDs are indicated when teeth are missing, damaged, or diseased. They are contraindicated for young patients, long spans between teeth, or teeth that require excessive preparation. FPDs are more stable and comfortable for patients than removable partial dentures, but they require more tooth structure removal and are more expensive and time-consuming to place.
Different gingival finish lines (margins) of crowns and bridgesSana Mateen Munshi
The document discusses various considerations for margin placement in tooth preparations, including biological, mechanical, and aesthetic factors. It describes advantages and disadvantages of different margin types such as supragingival and subgingival margins. Common margin designs like shoulder, bevel, and chamfer margins are explained. Guidelines are provided for reducing tooth structure during preparation in a systematic manner.
Pulp protection in operative dentistry Nivedha Tina
This document discusses various materials used for pulp protection and their properties. It describes how remaining dentin thickness, depth of preparation, and prevention of bacterial microleakage are important factors for pulp health. Common pulp protection materials discussed include bases, liners, varnishes, and sealers. Calcium hydroxide and glass ionomer cements are highlighted as they promote reparative dentin formation, adhere to dentin, and release fluoride. The document emphasizes that proper isolation and sealing of restorations is key to preventing pulpal injury from bacteria and toxins.
Prosthodontics is the dental specialty pertaining to the diagnosis, treatment planning, rehabilitation, and maintenance of patients with missing or deficient teeth using substitutes. It includes fixed and removable prostheses. A fixed partial denture is a partial denture that is securely attached to abutment teeth, roots, or implants to replace one or more missing teeth. Successful treatment requires attention to patient assessment, diagnosis, treatment planning, operative skills, and follow-up care.
Smear layer is a controversial topic in the field of operative dentistry and endodontics. This presentation includes composition, concepts, structure, advantages, disadvantages, and removal methods of smear layer.
Liners and bases are placed between dentin (or pulp) and a restoration to provide pulpal protection. Liners are thin layers that provide a barrier against residual reactants and oral fluids penetrating between the restoration and tooth. Bases are thicker (1-2mm) and provide additional thermal protection and support restoration forces. The need for liners depends on the restoration material and cavity location/depth. Newer liners focus on chemical protection through sealing and adhesion rather than pulpal medication. The choice of liner depends on remaining dentin thickness and restoration material.
This document discusses the failures of amalgam restorations. It outlines several signs of restoration failure such as fracture lines, marginal ditching, and recurrent caries. The reasons for amalgam restoration failure are then explained as improper case selection, faulty cavity preparation that does not follow best practices, errors in amalgam placement and manipulation, issues with matrixing procedures, and postoperative factors.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
The goals of endodontic access cavity preparation are to remove all debris and microorganisms from the root canal system, and to create a direct line of access to allow for thorough cleaning, shaping, and filling of the canals. Proper visualization, location of all canal orifices, and flaring of the cavity are essential to achieve these aims. Adequate taper, smooth walls, and space for coronal restoration are also important to optimize disinfection and long-term sealing of the treated tooth.
The document defines operative dentistry and describes the process of cavity preparation. It discusses the indications for operative treatment including caries, malformed or fractured teeth. The stages of cavity preparation are outlined including initial preparation, final preparation, and finishing. Key steps like resistance form, retention form, and convenience form are explained. Common cavity classifications and the use of matrices to restore cavities are also summarized.
The document discusses the steps involved in tooth preparation for restorative procedures. It begins by defining tooth preparation as the mechanical alteration of defective, injured, or diseased teeth to reestablish form and function. It then describes the conventional and modified approaches. The key steps in tooth preparation are then outlined, including establishing the outline form and initial depth. Various factors that influence the outline form are discussed. Finally, specific rules for establishing the outline form for pit-and-fissure tooth preparations are provided.
Fundamentals of cavity preparation /certified fixed orthodontic courses by I...Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
This document discusses various classifications and principles of cavity preparation in dentistry. It describes Black's classification which categorizes cavities into classes I-V based on their location. It also discusses modifications to Black's classification by Charbeneau and Sturdevant. The document outlines principles of cavity preparation for different classes of cavities, including the goals of preserving tooth structure and maintaining proper cavity design and margins. It compares cavity preparation techniques for primary and permanent teeth. In summary, the document provides an overview of common cavity classification systems and guidelines for preparing cavities based on their location and extent in the tooth structure.
1. Access cavity preparation is the first and most important phase of root canal treatment, with the goals of achieving straight line access to the apical foramen, locating all root canal orifices, and conserving sound tooth structure.
2. The principles of access cavity preparation include establishing an outline form based on pulp chamber size and shape and the number/direction of root canals, providing a convenience form for improved visibility and instrumentation, and removing caries/defective restorations and debris from the pulp chamber.
3. Key steps in access cavity preparation depend on the specific tooth but involve using burs and instruments to locate and prepare access to all root canal orifices while avoiding errors like
This document provides guidance on accessing tooth canals during root canal treatment. It discusses locating all canals, removing pulp tissue while conserving tooth structure. Access openings should be made under rubber dam isolation using high-speed instruments with good illumination. Tooth anatomy and pre-operative x-rays are used to determine the number and location of canals. Care must be taken to locate extra canals which may be present, especially in teeth with complex anatomy.
1. The document provides guidance on class I cavity preparation for amalgam and composite restorations. It describes the different types of class I preparations including conservative and extensive preparations.
2. Guidelines are provided on ideal outline form, resistance and retention forms, tooth preparation sequence, and use of liners and bases. Considerations for tooth preparation with amalgam versus composite are also discussed.
3. The summary focuses on key steps and guidelines for class I cavity preparation to help the reader understand the essential information for restoring class I lesions.
The document provides information on endodontic access cavity preparation for various types of teeth. It discusses the major objectives of straight-line access and conservation of tooth structure. It then describes the anatomy, root canal morphology, and preparation techniques for maxillary and mandibular anterior teeth, premolars, and molars. Common errors in cavity preparation are also highlighted, including inadequate removal of tooth structure, ledges, and perforations.
This document defines key terms related to cavity preparation and outlines the objectives and basic principles and steps of cavity preparation. It discusses definitions of cavities and tooth preparation. The objectives of cavity preparation are to remove caries and create a foundation for the restoration. The basic principles outlined by GV Black include biologic, mechanical, and esthetic principles. The main steps are 1) outline form, 2) resistance and retention form, 3) convenience form, 4) removal of remaining caries, 5) finishing cavity walls, and 6) toilet of the cavity. Resistance and retention forms are designed to resist forces and retain the restoration.
This document provides an overview of principles of cavity preparation. It defines cavity preparation and discusses its history and objectives. Factors affecting cavity preparation and various classification systems are described, including those proposed by G.V. Black and G.J. Mount. Terminology related to cavity preparation such as tooth preparation walls, angles, and classifications of cavities are defined. The stages of cavity preparation including initial outline form and depth are outlined. Key principles for preserving cuspal strength and marginal ridge strength are discussed.
The document discusses access cavity preparation for endodontic treatment. It provides guidelines for preparing access cavities, including removing caries and restorations, locating all canal orifices, and achieving straight line access to the canals. Specific steps are outlined for preparing access cavities in anterior and posterior teeth, including maxillary and mandibular molars as well as maxillary central incisors. The goal of access cavity preparation is to allow for thorough cleaning, shaping, and filling of the root canal system.
This document provides information on the steps of cavity preparation, including defining cavity preparation, the objectives and principles. It describes Black's classification system for cavities in 6 classes. The steps of cavity preparation outlined include obtaining the outline form and initial depth, primary resistance and retention forms, and convenience form. It also discusses final cavity preparation steps like removing remaining decay, providing pulp protection, and finishing enamel walls and margins.
The document discusses the fundamentals of tooth preparation. It defines tooth preparation as the mechanical alteration of a tooth to receive a restorative material. The objectives are to remove defects, extend restorations conservatively, form preparations to resist fracture under force and allow for esthetic and functional placement of material. Key terminology includes walls, angles, and classifications of different types of restorations. The stages of initial preparation establish outline and resistance form, while final preparation focuses on secondary features, finishing, and cleaning.
This document provides definitions of key terminology used in operative dentistry for describing tooth surfaces, dental caries, cavity preparations, and classifications of cavity preparations. It defines surfaces of the tooth like mesial, distal, facial, lingual, incisal, and occlusal. It describes primary and secondary caries and classifications based on extent and rate. It also defines preparation walls, angles, cavosurface angle and margin, and Black's classification system for cavity preparations including Class I-VI.
This document discusses restorative and esthetic dentistry. It describes conditions that require restorative treatment like decay, worn tooth structure, and discoloration. It outlines principles of cavity preparation including establishing resistance and retention forms. It also describes components of a typical restorative procedure and different types of dental restorations including class I-V, complex restorations, and direct bonded veneers.
This document discusses fundamentals of tooth preparation. It defines tooth preparation as the mechanical alteration of a tooth to receive a restorative material. The objectives are to remove defects, extend restorations conservatively, and allow for esthetic/functional placement. Terminology includes walls, angles, floors, and classifications of different types of restorations. The stages of initial and final tooth preparation are outlined in steps such as establishing form/depth, adding resistance/retention forms, and finishing walls.
This document discusses the process of tooth preparation for restorations. It begins by defining tooth preparation and its objectives. It then covers factors to consider, terminology, classifications of cavity designs, and the stages of tooth preparation. The stages include initial preparation, primary resistance and retention forms, convenience form, and final procedures. Each stage is defined and discusses principles, features, and rules. The document provides a comprehensive overview of tooth preparation, outlining the key steps, considerations, and techniques involved to best prepare a tooth for restoration.
tooth preparation and maintaining pulp vitality Aqdas Niazi
This document discusses the steps involved in tooth preparation and maintaining pulp vitality. It defines tooth preparation as the mechanical alteration of a tooth to allow for restoration. The objectives of tooth preparation are to remove defects, protect the pulp, extend restorations conservatively, prevent fracture under force, and allow for esthetic placement of restorative material. There are two stages to tooth preparation - initial preparation and final preparation. Initial preparation establishes outline and depth, while final preparation removes remaining defects and old material, provides pulp protection if needed, and adds resistance and retention features. Proper tooth preparation is important for successful restoration.
This document discusses dental nomenclature and terminology. It covers topics like tooth numbering systems, terminology for tooth surfaces and dental caries, non-carious tooth defects, and cavity/tooth preparation classifications. The three most popular tooth numbering systems - Zsigmondy/Palmer, ADA, and FDI - are described. Terminology for locations, extent, and rates of dental caries are defined. Non-carious defects and their terminology include abrasion, attrition, erosion, and fractures. Cavity preparation terminology includes definitions for walls, floors, angles, and cavosurface margins. Classifications of tooth preparations are by anatomic area and type of treatment.
The document discusses the fundamentals of cavity preparation, including its definition, objectives, and historical development. It covers factors that affect cavity preparation as well as terminology, classification, and the stages of initial and final tooth preparation. The key principles of cavity preparation are to remove all defective tooth structure, protect the pulp, and provide retention for the restorative material. Modern cavity preparation techniques favor prevention of extension and minimal intervention.
The document defines and discusses the objectives, terminology, classification, and stages of tooth preparation including the initial and final stages. It describes the steps in initial tooth preparation including outline form, primary resistance form, primary retention form, and convenience form. The goal of tooth preparation is to conserve tooth structure, remove defects, and form the preparation to support restoration under forces of mastication.
Operative dentistry involves the diagnosis, treatment, and prognosis of tooth defects not requiring full coverage restorations. The goals are to restore proper form, function, and aesthetics while maintaining tooth health. Cavity preparations aim to remove diseased tissue, locate conservative margins, ensure forces do not affect the restoration, and allow functional placement of restorative materials. Procedures include cavity classification, stages of preparation, resistance and retention forms, and pulp protection.
Restoration of endodontically treated teethIAU Dent
This document summarizes the effects of endodontic treatment on teeth and considerations for restoring endodontically treated teeth. Key points include:
- Endodontic treatment can result in loss of tooth structure, altered physical properties making teeth more brittle, and discoloration.
- Remaining tooth structure, function, and aesthetics must be evaluated to determine the appropriate restoration. Teeth with minimal structure may be restored with composites while those with heavier function typically need crowns.
- Temporary cements must be completely removed before bonding permanent restorations to avoid inhibiting the bond. Teeth exposed to sodium hypochlorite also require treatment to reverse its oxidizing effects.
- Common restorative
Operative dentistry involves the diagnosis and treatment of tooth defects without full coverage restorations. The objectives of cavity preparation are to remove defects, locate conservative margins, withstand forces of chewing, and allow for esthetic/functional restorations. Factors like pulpal/periodontal status, dental anatomy, patient factors, and restorative materials influence tooth preparation. Cavity preparation involves initial and final stages, including outline form, resistance form, retention form, convenience form, infected dentin removal, pulp protection, and finishing. Proper cavity preparation is essential for restoring teeth effectively.
Unidad 1 intro to restorative concepts revisitedDonto2
1. The document discusses the history and principles of operative planning and cavity preparation for direct dental restorations. It covers topics like defining cavities versus preparations, principles of cavity design put forth by Black and others, classification of cavities, and methods for detecting and removing decay while protecting the pulp.
2. Modern cavity preparations aim to be minimally invasive using techniques like adhesive dentistry, laser diagnosis, and pulp protection with sealants or glass ionomer cements. Cavities can be classified based on location, size, depth and other factors to guide the preparation.
3. Outline, resistance, retention, convenience and cleaning steps are discussed as the logical sequence for cavity preparations to efficiently and effectively access decay while
Noncarious lesions and their managementSaurav Paul
This document discusses the classification and management of noncarious lesions, including abrasion, erosion, attrition, and abfraction. It describes the etiology, clinical presentation, and treatment considerations for each condition. For treatment, the goal is to modify the etiologic factors and restore defects when they compromise tooth structure or function. Class V cervical lesions are typically restored with composites or resin-modified glass ionomers, with detailed preparation and restoration techniques provided.
This document discusses the principles and steps of tooth preparation for dental restorations. It describes 10 steps in the initial and final stages:
1) Outlining the preparation margins and initial depth
2) Establishing primary resistance form with a box shape and flat floor
3) Providing primary retention form with converging walls for amalgam or etching for composite
4) Ensuring convenience form for access
5) Removing any remaining enamel, infected dentin or old materials
6) Applying pulp protection if needed with liners or bases
7) Adding secondary retention/resistance features like locks or grooves
8) Finishing external walls considering enamel rod direction and restorative material
9) Cleaning,
1. Management of dental caries includes identifying an individual's risk, understanding the disease process, and active surveillance to assess progression and provide preventive services or restorative therapy when needed.
2. Decisions for restoring carious lesions should consider visual detection of enamel cavitation, shadowing, or radiographic enlargement over time.
3. Evidence shows incomplete caries excavation in primary and permanent teeth with normal or reversible pulps results in fewer pulp exposures and less pulpal disease than complete excavation, and restoration failure rates are no higher after incomplete versus complete excavation. Partial (one-step) excavation leads to higher pulp vitality maintenance than stepwise (two-step) excavation.
This document defines key terminology used in operative dentistry for cavity preparation and restoration. It discusses terms like cavity, cavity preparation, simple/compound/complex cavity preparations, intracoronal and extracoronal preparations, walls (internal, external, floors), angles (line, point, cavosurface), and junctions (dentinoenamel, cementoenamel). Simple cavity involves one surface, compound two surfaces, and complex three or more surfaces. Internal walls are inside the tooth while external walls contact the tooth surface. Angles are where walls meet, and junctions define boundaries between tooth structures.
This document outlines the key steps in cavity preparation, including establishing the initial outline and depth, providing primary resistance and retention forms, convenience form, and finishing procedures. It discusses principles for each step, such as using a box shape with flat floors to resist forces along the tooth's long axis for primary resistance form. Retention is provided by convergence of walls for amalgam and micromechanical bonding for composites. Remaining decay, old materials and pulp protection are addressed in the final preparation stage before finishing external walls.
Complete denture theory and practice 2011.Mostafa Fayad
COMPLETE DENTURE THEORY AND PRACTICE
1 introduction
2 Anatomy and Physiology in Complete Denture
3 diagnosis
4 Impression Trays and techniques
5 Relief Areas and post dam
6 Record Base and occlusion rim
7 JAW RELATION
8 Occlusion & articulators
9 SELECTION , arrangement of artificial teeth and WAXING-UP
10 try in
11 Processing Dentures
12 Denture insertion
13 Complaints
14 SEQUALAE OF WEARING CD
15 PREPARATION OF THE MOUTH
16 Management of Problematic patients
17 FAILURE OF C. D
18 Nausea & gagging
19 SINGLE COMPLETE DENTURE
20 Combination syndrome
21 TEETH supported OVERDENTURE
22 Implant Overdentures
23 Geriatric Edentulous Patient
24 Duplication
25 Relining and rebasing
26 Repair
27 Biomechanics
28 Neutral Zone
29 Esthetics in Complete Denture
30 phonetics in Complete Denture
31 masticatory function
The document discusses principles of tooth preparation for dental restorations. It covers biological considerations like preserving tooth structure, margin placement, and preventing pulp injury. Mechanical considerations include providing retention and resistance form to prevent restoration deformation or displacement. Ideal preparation taper is 2.5-6.5 degrees. Surface area and roughness increase retention while resistance depends on forces and preparation geometry. Margin types include featheredge, chamfer, bevel and shoulder. Occlusal and axial reduction are needed with functional cusp bevels. Esthetic results factor preparation for all-ceramic, metal-ceramic or partial coverage restorations.
Similar to Fundamentals of cavity preparations varghese (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.
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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.
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This document discusses dental casting investment materials. It describes the three main types of investments - gypsum bonded, phosphate bonded, and ethyl silicate bonded investments. For gypsum bonded investments specifically, it details their classification, composition including the roles of gypsum, silica, and modifiers, setting time, normal and hygroscopic setting expansion, and thermal expansion. It provides information on how the properties of gypsum bonded investments are affected by their composition. The document serves as a comprehensive overview of dental casting investment materials.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
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The skin is the largest organ and its health plays a vital role among the other sense organs. The skin concerns like acne breakout, psoriasis, or anything similar along the lines, finding a qualified and experienced dermatologist becomes paramount.
These lecture slides, by Dr Sidra Arshad, offer a simplified look into the mechanisms involved in the regulation of respiration:
Learning objectives:
1. Describe the organisation of respiratory center
2. Describe the nervous control of inspiration and respiratory rhythm
3. Describe the functions of the dorsal and respiratory groups of neurons
4. Describe the influences of the Pneumotaxic and Apneustic centers
5. Explain the role of Hering-Breur inflation reflex in regulation of inspiration
6. Explain the role of central chemoreceptors in regulation of respiration
7. Explain the role of peripheral chemoreceptors in regulation of respiration
8. Explain the regulation of respiration during exercise
9. Integrate the respiratory regulatory mechanisms
10. Describe the Cheyne-Stokes breathing
Study Resources:
1. Chapter 42, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 36, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 13, Human Physiology by Lauralee Sherwood, 9th edition
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
Discover the benefits of homeopathic medicine for irregular periods with our guide on 5 common remedies. Learn how these natural treatments can help regulate menstrual cycles and improve overall menstrual health.
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The biomechanics of running involves the study of the mechanical principles underlying running movements. It includes the analysis of the running gait cycle, which consists of the stance phase (foot contact to push-off) and the swing phase (foot lift-off to next contact). Key aspects include kinematics (joint angles and movements, stride length and frequency) and kinetics (forces involved in running, including ground reaction and muscle forces). Understanding these factors helps in improving running performance, optimizing technique, and preventing injuries.
How to Control Your Asthma Tips by gokuldas hospital.Gokuldas Hospital
Respiratory issues like asthma are the most sensitive issue that is affecting millions worldwide. It hampers the daily activities leaving the body tired and breathless.
The key to a good grip on asthma is proper knowledge and management strategies. Understanding the patient-specific symptoms and carving out an effective treatment likewise is the best way to keep asthma under control.
STUDIES IN SUPPORT OF SPECIAL POPULATIONS: GERIATRICS E7shruti jagirdar
Unit 4: MRA 103T Regulatory affairs
This guideline is directed principally toward new Molecular Entities that are
likely to have significant use in the elderly, either because the disease intended
to be treated is characteristically a disease of aging ( e.g., Alzheimer's disease) or
because the population to be treated is known to include substantial numbers of
geriatric patients (e.g., hypertension).
Are you looking for a long-lasting solution to your missing tooth?
Dental implants are the most common type of method for replacing the missing tooth. Unlike dentures or bridges, implants are surgically placed in the jawbone. In layman’s terms, a dental implant is similar to the natural root of the tooth. It offers a stable foundation for the artificial tooth giving it the look, feel, and function similar to the natural tooth.
1. COLLEGE OF DENTAL SCIENCES
DEPARTMENT OF CONSERVATIVE DENTISTRY
AND ENDODONTICS
SEMINAR ON
“FUNDAMENTALS OF
CAVITY PREPARATIONS”
Presented By : -
Dr. Sharno Mathai Varghese
3. CONTENTS
INTRODUCTION
DEFINITION
NEED FOR RESTORATIONS
OBJECTIVES OF CAVITY PREPARATION
FACTORS AFFECTING CAVITY PREPARATION
CARIES TERMINOLOGY
TOOTH PREPARATION TERMINOLOGY
CLASSIFICATION OF TOOTH PREPARATION
INITIAL TOOTH PREPARATION STAGE
o OUTLINE FORM AND INITIAL DEPTH
o PRIMARY RESISTANCE FORM
o PRIMARY RETENTION FORM
o CONVENIENCE FORM
FINAL TOOTH PREPARATION STAGE
o REMOVAL OF ANY REMAINING INFECTED DENTIN
/OLD RESTORATIVE MATERIAL
o PULP PROTECTION
o SECONDARY RESISTANCE AND RETENTION FORMS
o PROCEDURES FOR FINISHING EXTERNAL WALLS
o CLEANING, INSPECTING AND SEALING
ADDITIONAL CONCEPTS IN TOOTH PREPARATION
o AMALGAM RESTORATIONS
o COMPLETE RESTORATIONS
CONCLUSION
4. INTRODUCTION :
The basic principles governing the design of cavities and steps in their
preparation was first suggested by American Dentist and teacher Dr.G.V.Black
in the first decade of the last century. He based these principles on what was
known at time about the natural history of caries and the restorative material
available. The wisdom of his work was such that it remained unchallenged for
more than half a century but now with new materials, a better understanding of
caries and research findings into the success of various restorative procedure,
his principles have been largely revised. Modification and rearrangement of
these original principles have been largely revised.
DEFINITION OF CAVITY PREPARATIONS :
“Mechanical alteration of a defective, injured or diseased tooth in order
to best receive a restorative material which will reestablish a healthy state for
the tooth including esthetic corrections where indicated along with normal form
and function”.
NEED FOR RESTORATIONS :
Teeth needs restorative intervention for a variety of reasons which are as
follows ;
1. Repair of tooth after destruction from carious lesions.
2. Replacement / repair of restorations with serious defects such as
improper proximal contacts, gingival excess, poor esthetics etc.
3. Restoration of proper form and function of fractured teeth.
4. Restoration of form and function as a result of congenital malformations
5. To fulfill the esthetic demands
6. Restoration for preventive measures
OBJECTIVES OF CAVITY PREPARATIONS :
1. Removal of all the defects and give the necessary protection to the pulp.
2. Location of margins of the restorations as conservative as possible.
4
5. 3. Form the cavity so that under forces of mastication the tooth or the
restoration or both will not fracture and the restoration will not be
displaced.
4. Esthetic and functional placement of a restorative material.
FACTORS AFFECTING CAVITY PREPARATIONS
GENERAL FACTORS PATIENTS FACTORS
1. Diagnosis :
1. Prior to any restorative procedure a complete and through diagnosis
must be made assessment of both pulpal and periodontal status will
influence the potential treatment of tooth especially in terms of the
choice of restorative materials as well as the design of cavity
preparation.
2. Assessment of occlusal relationships must be made.
3. Patient concern for esthetics should be considered
4. Other planned treatment should be considered for e.g. such as when
tooth is used as an abutment for FPD or RPD, design of restoration is
altered to accommodate maximum effectiveness of that prosthesis.
5. Risk assessment find out with dietary habits. DMFT index and
microbiological examination.
2. Knowledge of Dental Anatomy :
Direction of enamel rods, thickness of enamel and dentin, position of
pulp relationship of tooth to the investing tissue.
PATIENTS FACTORS :
1) Patients knowledge and appreciation of good Dental Health Influences the
choice of restorative material.
2) Patients economic status
5
6. 3) Age of the patient
Elderly patient who are physically or medically compromised require
special positioning for restorative procedure plus less stressful and shorter
appointments.
CARIES TERMINOLOGY :
Caries can be located according to location, extend and rate.
According to Location :
1) Primary caries : Original carious lesion of the tooth. They originate
basically at three sites – pit and fissure, smooth surface, root surface.
2) Forward caries : Is seen when the caries cone in enamel is larger as
atleast the same size as that in dentin.
3) Backward caries- when spread of caries along DEJ exceeds the caries in
contiguous enamel, caries extends into this enamel from the function.
4) Residual caries - Caries that remains in a completed tooth preparation
whether by operator intention or by accident.
5) Secondary caries : Occurs at junction of a restoration and tooth and may
progress sunder the restoration.
According to Extend :
1) Incipient caries (Reversible) : It is the first evidence of caries activity in
the enamel.
2) Cavitated caries (Irreversible) : The enamel surface is broken, and
usually the lesion has advanced into dentin.
According to Rate :
1) Acute caries (Rampant caries) : In this, the disease is rapid in damaging
the tooth.
2) Chronic caries (Arrested caries) : The slow rate results form periods
when demineralized tooth structure is almost remineralized.
Enameloplasty :
6
7. It is the removal of a shallow, enamel developmental fissure or patient
to create a smooth, saucer shaped surface that is self cleansing or easily
cleaned.
Prophylactic Odontotomy :
It is characterized by minimally preparing and filling with amalgam any
pits and fissures to prevent caries originating in these sites. It is no longer
advocated as a preventive measure.
Affected Dentin And Infected Dentin :
Affected dentin has no bacteria, is reversibly denatured, remineralizable
and should be preserved.
Infected dentin has bacteria present and the collagen is irreversibly
denatured. It is not remineralizable and must be removed.
TOOTH PREPARATION TERMINOLOGY :
1) Simple, tooth preparation – Only one tooth surface is involved.
2) Compound tooth preparation – Only two tooth surface is involved.
3) Complex tooth preparation – Involves three or more surfaces.
CLASSIFICATION OF TOOTH PREPARATION (According to
G.V.Black)
1) Class I Restorations : Restoration on occlusal surface of premolars and
molars.
Restorations on occlusal two thirds of facial and lingual surface of
molars. (8 line angles, 4 point angles)
Restorations on lingual surface of maxillary incisors (6 point angles, 11
line angles).
2) Class II restorations : Restorations on proximal surface of posterior
teeth.
3) Class III restorations : Restorations on proximal surface of anterior teeth
that do not involve the incisal angle (6 line angles, 3 point angles).
7
8. 4) Class IV restorations : Restorations on proximal surface of anterior teeth
that involve the incisal angle (11 line angles, 6 point angles).
5) Class V restorations : Restorations on the gingival third of facial or
lingual surfaces of all teeth (except pit and fissure lesions) (8 line
angles, 4 point angles).
Class VI Restorations : Restorations on the incisal edge of anterior teeth or the
occlusal cusp heights of posterior teeth.
COMPONENTS OF A CAVITY PREPARATION :
Cavity Wall Cavity Preparation Angle Miscellaneous Component
1. Retention groove
External Internal 2. Dovetail
1. Enamel wall 1. Axial 3. Bevel-short
2. Dentin wall 2. Pulpal Long and Full
Line Angles Point Angle Cavosurface Angle
1. Internal
2. External
A) WALLS :
1. Cavity wall
External Internal
Enamel wall Axial
Dentin wall Pulpal
Floor / Seat
One of the enclosing sides of a prepared cavity (it takes the name of the
surface of the tooth adjoining the surface involved towards which it is placed).
EXTERNAL WALL :
8
9. An external wall is a prepared cavity surface that extends to the external
tooth surface and such a wall takes the name of the tooth surface that the wall is
towards.
Enamel Wall : Wall of the prepared cavity that is made up of enamel.
Dentin Wall : The portion of the will of a prepared cavity that is made tip of
dentin.
INTERNAL WALL :
An internal wall is a prepared cavity surface that does not extend to the
external tooth surface.
a) Axial wall : it is an internal wall parallel with the long axis of the tooth.
b) Pulpal wall : It is an internal wall that is perpendicular to the long axis
of the tooth and occlusal to the pulp.
CAVITY PREPARATION ANGLES :
The junction of two or more prepared cavity surfaces is referred to as an
angle which includes line angles and point angles.
a) Line angle : It is the junction of two planar surfaces of different
orientation along a line, which is again classified as internal line angle
and an external line angle.
i) Internal line angle : Is a line angle whose apex points into the
tooth e.g. FP.
ii) External line angle : Is a line angle whose apex points away
from the tooth e.g. ap.
b) Point angle : It is a junction of 3 planal surfaces of different orientation
e.g. mFP (designated by combining the names of the walls forming
angels).
c) Cavo surface angle / Cavo surface margins : The cavo surface angle is
the angle of the tooth structure formed by the junction of a prepared
cavity wall and the external surface of the tooth.
9
10. RETENTION AND RESISTANCE FORM :
1) Undercut : Portion of prepared cavity confined by walls which coverage
towards the surface.
2) Retention groove : Linear channel within a cavity preparation.
3) Dovetail : Widened or fanned out portion of a prepared cavity
established to increase the resistance and retention form.
Miscellaneous Components :
1) Margins : Junction of the wall of the cavity with the surface of the tooth
2) Bevel : Inclination that one surface makes with another when not at right
angle or in cavity preparation a cut that procedure an angle other than
90o
with a cavity wall.
a) Short bevel : Bevel involving not more than external one third of
a cavity wall.
b) Long bevel : Bevel involving more than external 1/3 but not more
than external 2/3 of a cavity wall.
c) Full bevel : Bevel which involves the entire wall
STAGES AND STEPS IN CAVITY PREPARATION :
The stages and steps in cavity preparation are as follows ;
INITIAL CAVITY PREPARATION
STAGE
FINAL CAVITY PREPARATION
STAGE
Step-1 Outline form and initial
depth
Step-5 Removal of any remaining
enamel pit fissure and or
infected dentin and /or old
restorative material if
indicated.
Step-2 Primary Resistance form Step-6 Pulp protection
Step-3 Primary Retention form Step-7 Secondary resistance and
retention form
Step-4 Convenience form Step-8 Procedure for finishing
external walls
Step-9 Final procedure; cleaning
inspecting; varnishing
conditioning
10
11. INITIAL CAVITY PREPARATION STAGE :
Definition :
Initial cavity preparation is the extension and initial design of the
external walls of the preparation at a specified, limited depth so as to provide
access to the cavity or defect, reach sound tooth structure, resist fracture of the
tooth or restorative material form masticatory forces principally directed with
long axis of the tooth and retain the restorative material in the tooth.
STEP 1 : OUTLINE FORM / INITIAL DEPTH :
a) Definition :
The outline forms means placing the cavity margins in the position they
will occupy in the final preparation except for finishing enamel walls and
margins.
Initial depth 0.2 – 0.5 mm below D.E. junction (0.5 when restoring with direct
gold).
0.2 – 0.8 mm into dentin for smooth surface caries.
If there is need for additional deepening of the preparation in the assess
of excavation of any remaining faulty tooth structure faulty old restorative or
infected dentin it is carried out during the final stage of cavity preparations.
b) Principles :
There are 3 general principles on which outline from is established
regardless of the type of cavity being prepared.
1) All friable / or weakened enamel should be removed.
2) All faults should be included
3) All margins should be placed in a position to afford good finishing of the
margins of the restoration i.e. extension of the margins of the preparation
far enough on the tooth surface so that the margins of the preparations will
11
12. be located on finishable, self cleansable area because all the restorations
will be surrounded by a microleakage space between itself and adjacent
tooth structure ranging between 20-120 microns in width which can
accommodate micro organisms and food substance thus predisposing to
recurrent decay. Thus this space should be placed in the areas that are
easily cleansable by natural / artificial means. This principle is called as
“extension for prevention”.
c) Factors :
* These factors will affect the outline form of the proposed cavity preparation
and will dictate the extensions, these are as follows
1. Extent of the carious lesions, defect or faulty old restorations.
• Will affect the outline form because the objective is to
extend preparation to sound tooth structure except in a
pulpal direction.
2. Esthetic considerations
• Will not only affect the choice of restorative material but
also the design of cavity preparation in an effort to
maximize the esthetic result of the restoration.
3. Occlusal relationship
• Determines the outline form by avoiding the placement
of cavity margins (outline) in an area of heavy occlusal
contacts such as centric holding area.
4. Proximal tooth contour
5. Cavosurface margin configurations
• Restorative materials which are more effective when
having beveled margins will require cavity preparation
outline form that must anticipate the final Cavo surface
position and form.
d) Features :
12
13. There are six specific, typical features of establishing outline forms
initial depth. There are :
1) Preserving cuspal strength
2) Preserving marginal ridge strength
3) Minimizing the facio-lingual extension
4) Using enameloplasty
5) Connecting two close (less than 0.5 mm apart) faults or cavity
preparations
6) Restricting the depth of the preparations into dentin to a maximum of
0.2 mm for pit and fissure caries and 0.2 to 0.8 mm for the axial wall of
smooth surface caries.
e) Rules :
=> Rules to follow in establishing the outline form for pit and fissure cavities.
1) Extension of the cavity margin until sound tooth structure is obtained.
There should not be any weakened or unsupported enamel.
2) Avoid terminating the margins on extreme eminence such as cusp
heights or ridge crest.
3) Consider the cusp capping : Rule for cusp capping, if the extension form
a primary groove towards the cusp tip is no more than half the distance
then no cusp capping, if this extension is from 1/2 to 2/3 the distance,
then consider cusp capping, If the extension is more than 2/3 the
distance then cusp capping is mandatory.
4) Use of enameloplasty when pit or groove does not penetrate more than
1/3 the thickness of the enamel. Enameloplasty is a procedure of
reshaping / rounding/saucerization of the enamel surface with suitable
rotary cutting instrument (it does not extend the outline form and
restorative material is not placed in recontoured area thus the thickness
of restorative material at enameloplasty margin is decreased.
5) When pit and fissure involve more than 12 of enamel thickness, extend
the cavity margins to include all of them.
13
14. 6) To be as conservative as possible the preparation of an occlusal surface
pit and fissure cavity is first prepared to a depth of 1.5 mm as measured
at the central fissure.
(Restrict the depth of the preparation to a maximum of 0.2 m into dentin
and if gold it should be 0.5 mm).
However if the amount of pit/fissure remaining is greater than 50% of
the pulpal floor the entire floor is deepened to maximum initial depth of
0.2 mm into dentin. Thus the actual depth of the preparation varies form
1.5 mm depending on thickness of enamel and steepness of cusp
inclines.
7) When two pits fissure cavities have less than 0.5 mm of sound tooth
structure between them they should be joined to eliminate a weak
enamel wall between them.
8) Extension of outline form to provide sufficient access for proper cavity
preparation, restoration placement and finishing procedure.
Rules Governing Outline form and initial depth for smooth surface cavities :
Smooth surface cavities are in two different locations.
Proximal surfaces Gingival portion of the facial and Ig surface
For proximal surface cavities (Class II, III, IV) :
1) Extension of cavity margins until sound tooth structure is obtained, all
unsupported to weakened enamel should be removed.
2) Avoid terminating the margins on extreme eminence such as cusp
heights or ridge crest.
3) Extent the margins to allow sufficient access for proper manipulative
procedures.
4) Restriction of axial wall pulpal depth of proximal preparation when it is
in crown 0.5 – 0.6 mm and on root 0.75 – 0.8 mm = (0.2 – 0.8 mm).
14
15. 5) Extend the gingival margins of the cavities apically of the contact to
provide a minimum clearance of 0.5 mm between gingival margins and
adjacent tooth and the gingival margins or finish line on the proximal
tooth surface should be 0.5 – 1 mm apical to the crest of healthy free
gingiva with in the gingival crevices, it should not extend to the bottom
of crevice because ;
a) The alkalinity of the crevicular fluid can neutralize acids
produced from plaque activity an d
b) The knife edge relationship of healthy free gingiva to the adjacent
tooth surface will discourage food accumulation on adjacent
restored surface occlusal to the sulcus for considerable period
during after food ingestion.
6) Extension of facial and lingual margins in proximal cavity preparation
into the respective embrasures to provide specified clearance between
the prepared margins adjacent within order to place the margins in self
cleansable area.
When extending the proximal surface incisally in Class III preparation it
is acceptable to position the incisal margins in the area of contact
especially when an esthetic restorative material is used.
Gingival Portion of Facial and Lingual Surface :
1) Outline form is governed by the extend of the lesion, except Pulpally so
extension mesially, lingually, distally and occlusally is limited to that
when sound tooth structure is reached.
2) Depth is no deeper than 0.8 – 1.25 mm Pulpally.
• Lesser axial wall depth (0.8 mm) at Gg wall with out an
enamel portion (i.e. the margin on root.
• The axial wall depth at occlusal wall is 0.5 mm in dentin
and remaining in enamel.
STEP 2 : PRIMARY RESISTANCE FORM :
15
16. DEFINITION :
Primary resistance form may be defined as that shape and placement of
the cavity walls that best enables both the restoration and the tooth to
withstand, without fracture, masticatory forces delivered principally in the long
axis of the tooth.
Principles :
The fundamental principles involved in obtaining primary resistance
form follow :
1) Box shape with relatively flat floors. Flat floor prevents restoration
movement where as rounded pulpal floor is conductive to rocking action
of restoration – producing a wedging force, resulting in shearing of
tooth structure.
2) Restrict the extension of external walls to allow sufficient dentin
support for strong cusp and ridges (resistance against oblique forces and
forces in long axis).
3) Straight rounding / coving of internal line angles reduces stress
concentration in tooth structure (rounding of internal line angles reduces
stress on tooth thus resistance to # of tooth, increased rounding of
external faced angle reduces stress on porcelain and amalgam thus
resistance to fracture of restoration increases).
4) Consider cusp capping for weak cusp according to rule.
5) Placement of enough thickness of restorative material to prevent its
fracture under load. The minimal occlusal thickness for amalgam for
appropriate resistance to fracture is 1.5 mm, cast metal = 1-2 mm and
porcelain = 2 mm.
Factors :
The need to develop resistance form in a cavity preparation is a result of
several factors, which are as follows :
a) Occlusal contact : the greater the occlusal force and contacts, the
greater is the potential for future fracture. (The further posterior
16
17. the tooth, the greater is the effective masticatory forces since the
tooth is closer to the condyle head).
b) Amount of remaining tooth structure also impacts the need and
type of resistance form.
e.g. Very large teeth even though extensively involved with
caries or defects may require less resistance from consideration
because remaining tooth structure is still bulky and strong enough
to resist fracture.
c) Type of restorative material used
Amalgam : 1.5 mm for adequate strength and longevity.
Cast metal : 2 mm
Composites : Dimensional needs of composites are more
dependent on the occlusal wear potential of the restored area. In
posterior teeth thickness requirement is more than the anterior
teeth.
Features :
The design features of cavity preparation that enhances primary
resistance form are as following :
1) Relatively flat floors : If large excavation site of infected dentin is
present incorporate at least 3 seats on sound dentin so that restorative
material will have stable contact with tooth so the occlusal forces
directed parallel to the tooth long axis will not cause rocking of
restoration.
2) Box shape
3) Inclusion of weakened tooth structure
4) Preservation of cusp and marginal ridges
5) Rounded internal line angles
6) Adequate thickness of restorative materials
7) Seats on sound dentin periphery to excavation site
8) Reduction of cusp for capping when indicated.
17
18. STEP 3 : PRIMARY RETENTION FORM :
Definition :
Primary retention form is that shape or form of the prepared cavity that
resists displacement or removal of the restoration from tipping or lifting forces.
Principles :
Sincere tension needs are related to the restorative material used, the
principles of primary retention form may vary depending on the material used.
For Amalgam :
a) Convergence of external cavity walls occlusally(Class I and Class II) :
So once the amalgam is placed in the cavity and hardens, it cannot come
out without some type of fracture occurring.
b) Occlusal dovetail which aids in preventing the tipping of the restoration
by occlusal forces.
c) Adhesive systems for bonding amalgam to tooth structure.
d) In other preparation for amalgam such as Class III and V, the external
wall diverge outward to provide strong enamel margins therefore
retention grooves and covers are prepared in dentin.
For Composite :
Retention by mechanical bond that develops between the material and
the conditioned / prepared tooth structure (enamel is etched by an acid and the
dentin is conditioned for a dentin bonding agents) so bevel enamel margins are
kept to increase the surface area to be etched.
For Cast Metals :
1) Parallel, vertical and longitudinal walls to provide retention of the
casting in the tooth.
2) Small angle of divergence 2-5o
per wall is placed which will enhance
the retention form. (Retention is developed by frictional resistance and
18
19. mechanical locking of the cement into the minute irregularities of both
the casting and the cavity wall to counter act the pull of sticky food).
For Gold Foil :
Retention is from elastic compression developed in the dentin as a result
of condensation of the foil.
MEANS OF RETENTION :
- Frictional retention
- Elastic deformation
- Inverted truncated cone
- Dove tail
Frictional Retention : Depends on 4 factors
a) Surface area of contact between tooth and restoration
More surface area more retention.
b) Opposing walls
More opposing walls more retention
c) Parallelism and non parallelism
Higher degree of parallelism increases retention
d) Proximity
Elastic Deformation of dentin : Changing the position of dentinal walls and
floors microscopically by using condensation energy with in dentin limit can
add more gripping action by the tooth on the restorative material. This occurs
when dentin regains its original position while the restorative material remains
rigid, thereby completely obliterating any remaining space in the cavity
preparation.
STEP 4 : CONVENIENCE FORM :
DEFINITION :
19
20. Is that shape or form of the cavity that provides for adequate
observation, accessibility and ease of operation in preparing and restoring the
cavity.
Modifications in tooth preparation for convenience form :
Modification includes flaring some walls more than otherwise necessary
for resistance and retention form such as divergences of vertical walls of cavity
preparation for Class II cast restoration.
Placement of convenience points for starting the foil condensation.
Extending proximal preparations beyond proximal contacts.
Separation : Done by wedging of teeth makes interproximal
instrumentation convenient.
STEP 5 : FINAL CAVITY PREPARATION STAGE :
Removal of any remaining enamel pit or fissure and or infected dentin
or old restorative materials if indicated.
DEFINITION :
It is the elimination of any infected carious tooth structure or faulty
restorative material left in the tooth after initial cavity preparation.
Any old restorative material should be removed if any of the following
conditions are present.
1. The old material may affect negatively the esthetic result of the new
restoration.
2. The old material may compromise the amount of anticipated needed
retention.
3. There is radiographic evidence of caries under the old restorative
material.
4. The tooth was symptomatic preoperatively
5. The periphery of the remaining old restorative material is not intake.
If none of these conditions are present the operator may elect to leave
the remaining old restorative material to serve as a liner or base rather than risk
20
21. unnecessary excavation nearer to the pulp which may result in exposure or
pulpal irritation.
FOR DENTIN :
- The exception to the removal of infected carious dentin is when it has
been decided to perform an indirect pulp capping.
- Its accepted and appropriate practice to allow affected dentin to remain
in a prepared tooth.
- It is not acceptable to leave carious dentin at D.E. junction.
Technique :
When a pulpal or axial wall has been established at the proper initial
cavity preparation position and a small amount of infected carious material
remains, only this material should be removed, leaving a rounded, concave area
in the wall and floor, thus placing the pulpal floor at more than one level. The
first level will be ideal depth of 1.5 mm and other will be at caries cone level.
This shallow (initial depth i.e. 1 mm) level will create flat pulpal floor at
definite angle to surrounding wall thus resist the occlusal forces and laterally
locking the restoration without impinging on pulp this placement of second seat
at caries cone level is called as ledge it can be (1) Circumferential, (2)
Interrupted or (3) Opposing.
CARIES CONTROL TECHNIQUE :
When patient is having numerous teeth with extensive caries in one
sitting or appointment, infected dentin is removed from several teeth and
temporary restorations are placed and then individual teeth are restored as
definitively planned. This procedure stops the progress of caries and is often
referred to as the caries control technique.
If the decay’s soft removal should be done with spoon excavators by
flaking up the caries around the periphery of the infected mass and peeling it
off in layers.
21
22. If the decayed dentin is hard, the excavator may not be sufficient to
remove the diseased tissue, so a large round carbide bur revolving slowly
should be moved in burnishing strokes from the peripheries of cavity
preparation to the center. These strokes should be done with minimal pulpal or
axial pressure and with a water coolant in order to minimize thermal irritation
to the near by pulp tissue.
Removal of remaining old restorative material; when indicated is
accomplished with use of a round carbide bur, at slow speed with air or air
water coolant. The water spray along with high volume evacuation is used
when removing old amalgam material to reduce the amount of mercury vapor.
STEP 6 :
FROM MECHANICAL
PULP PROTECTION THERMAL INSULTS such as
CHEMICAL
1) Some ingredients of various materials.
2) Thermal changes conducted through restorative material
3) Forces transmitted through materials to the dentin
4) Galvanic shock
5) Ingress of noxious products and bacteria through microleakage.
For pulp protection traditional liners or bases are used either to protect
the pulp or to aid pulpal recovery or both.
When the thickness of remaining dentin is less than 2 mm, heat
generated by injudicious cutting can result in a pulpal burn lesion
abscess formation death of pulp.
Thus a water or air water spray coolant must be used with the high speed
rotary instrument.
22
23. If the remaining dentin thickness is 1.5 mm or more and the cutting was
done atraumatically using high speed with water or air water spray, the
pulp is not irritated enough to form replacement odontoblasts and
therefore no reparative dentin is formed to seal the pulpal side of dead
tracts. Thus it is more important to place a liner or bases to protect the
pulp.
Liners :
Are those volatile or aqueous suspensions or dispersions of zinc oxide or
calcium hydroxide that can be applied to a cavity surface in a relatively thin
film and are used to effect a particular pulpal response.
Liners Provides :
1. A barrier which protects the dentin from noxious agents from either the
restorative material or oral fluids.
2. Electric insulation
3. Thermal protection
Bases :
Bases are considered to be those cements commonly used in thicker
dimensions beneath permanent restoration to provide for mechanical, chemical
and thermal protection of the pulp.
Example are ;
1. Zinc phosphate
2. Zinc oxide eugenol
3. Calcium hydroxide
4. Polycarboxylate
5. Glass ionomer
23
24. If the removal of infected dentin does not extend deeper than 1 mm from
initially prepared pulpal or axial wall. NO LINER IS INDICATED. If
excavation extends into or very close to the pulpal tissue, a calcium hydroxide
liner is selected in order to stimulate reparative dentin, if the excavation depth
is between above two eg. Zn oxide eugenol liner is selected (except for
composite restoration where it may impide the polymerization process) to
provide a palliative sedative pulpal response.
As a general rule it is desirable to have atleast a 0.5 – 0.75 thickness of
base dimension of bulk between the pulp and a metallic restorative
material. This bulk may include remaining dentin, liner, or bases.
The ability of calcium hydroxide to stimulate the formation of reparative
dentin when its in contact with pulpal tissue makes it the material of
choice for application to very deep excavation and known pulpal
exposures.
Liners and bases in exposure areas should be applied with out pressure,
Atleast a 1 mm thickness of calcium hydroxide is placed over near or an
actual exposure which is than over laid with a base.
In deep excavation where no exposure of suspension of exposure exist,
Zn oxide eugenol is used for its mildly anesthetic effect on the pulp.
For composite restorations which are thermal insulators and passively
inserted, liner of calcium hydroxide is indicated only when there is a
pulpal exposure of the excavation is judged to be within 0.5 mm of the
pulp.
Cast restorations : In cavity preparation for casting, deeply excavated
areas in preparation must be covered with suitable retained liners or
bases materials that will withstand the forces. Zn ph. Glass ionomer and
polycarboxylate cements serves this purpose.
Cavity Varnishes :
It is a solution liners which seals most of the dentinal tubules and is
placed on all cavity preparation walls for amalgam and on dentinal walls of
24
25. cavity preparation for cast gold but not used for composites, (it prevents
penetration of materials into the dentin and helps to prevent microleakage and
reduces post operative sensitivity by reducing the infiltration of fluids and
salivary components at the margins of newly placed restoration.
For Amalgam : Two coats should be applied to the prepared surface in shallow
excavation is the only material of choice.
For cast gold : Two coats on dentin surface reduces pulpal irritation from luting
cements.
For Composite : Should not be used because solvent in varnish may react with
or soften the resin component in the composite and thus affecting
polymerization or free monomer of resin may dissolve varnish film and
rendering it ineffective.
STEP 7 : SECONDARY RESISTANCE AND RETENTION FORMS :
Secondary resistance and retention forms are of 2 types :
a. Mechanical features
b. Cavity wall conditioning features
1. Mechanical features includes :
• Retention / locks, grooves, and coves
• Longitudinally oriented provides retention to proximal
portions of cavity preparations. Locks are for amalgam,
they increases retention of the proximal portion against
movement proximally due to creep and are believed to
increase the resistance form of the restoration against
fracture at the junction of the proximal and occlusal
portions.
• Grooves of cast metal restorations.
25
26. • Horizontally oriented grooves – for Class III and Class V
amalgam.
• Root surface cavity preparation for composites.
• These are placed undercuts for the incisal retention of
Class III amalgams and for Class V and occasionally for
facilitating the start of insertion of certain gold foil
restorations.
• Retention cones – Undercuts placed for incisal retention
of Class III amalgams, occlusal portion of some
amalgam restorations, some Class V amalgams.
Groove Extensions :
Obtained by extending the cavity preparation for molars on to the facial
and lingual surface to include the facial and lingual grooves mainly used for
cast metal restorations (results in parallel wall retention) also enhances
resistance form due to envelopment.
Skirts :
Mainly used in cast gold restorations. In which extension of preparation
is done around all the transitional longitudinal angles of tooth, adds retention
form by opposed longitudinal walls and resistance form by enveloping the
tooth thus resisting fracture of the remaining tooth from occlusal forces.
Beveled Enamel Margins :
Used for cast gold or composites. For cast metal retention form is
improved when there are opposing bevels and provides better junctional
relationship between metal and the tooth.
In case of composite restoration, it increase both the surface area of
etchable enamel and maximize the effectiveness of the bond by etching more
enamel rods.
26
27. Pins, Slots, Steps and Amalgam Pins :
Used to increase resistance and retention form for amalgam.
2. Cavity Wall conditioning features
Enamel Wall Conditioning Dentin Wall Conditioning
Conditioned for bonded restorations
such as porcelain, composites,
amalgam or give (condition consist
of etching the enamel by an
appropriate acids resulting in
microscopic undercuts in which
bonding is mechanical bond.
Conditioned for bonded restoration
such as porcelain, composites,
amalgam or GIC (condition consist
of etching the enamel by an
appropriate acids resulting in
microscopic undercuts in which
bonding material is mechanically
bonds).
STEP 8 : PROCEEDINGS FOR FINISHING THE EXTERNAL WALLS
OF CAVITY PREPARATION :
DEFINITION :
It is the further development when indicated of a specific cavo surface
design and degree of smoothness that produces the maximum effectiveness of
the restorative material being used.
Objectives :
1. To create he best marginal seal possible between the restorative
material and the tooth structure.
2. To afford a smooth marginal junction
3. To provide maximum strength of both the tooth and the
restoration at and near the margin.
Factors :
1. Direction of enamel rods :
Enamel rods radiate from the dentin enamel junction to the external
surface of the enamel and are perpendicular to the tooth surface, all rods
extends full length from the dentin to the enamel surface. The rods converge
towards the center of development grooves i.e. from the dentino enamel
27
28. junction towards concave enamel surface and diverge towards the height of
cusp and ridges i.e. diverge outwardly toward convex surface. In gingival third
rods incline slightly apically.
Finishing of enamel wall should be such that the cavity should have
strongest enamel margin (i.e. margin which is composed of full length of
enamel rods that are supported on the cavity side by shorter enamel rods all of
which extend to sound dentin) thus increasing the strength of enamel margin.
2. Support enamel rods both at the Dent-E junction and laterally on cavity side.
3. Type of restorative material used
4. Location of margin
5. Degree of smoothness desired
Features :
There are two primary features to the finishing of the external walls.
1. Design of cavo surface angle.
2. Degree of smoothness of the walls.
1. Design of Cavosurface Angle :
It depends on type of restorative material used.
For amalgam : Because of low edge strength or friability of amalgam
cavosurface of angle of 90o
produces maximal strength for both the amalgams
tooth and prevents fracture.
For cast restorations and composites : Beveling the external walls used for intra
coronal cast gold and composite restoration.
Beveling can serve 4 useful purposes in the cavity preparation for
casting.
1. Produces stronger enamel margins.
2. Permit marginal seal in slightly undersized casting
3. Provides marginal metal that is more easily burnished and adapted.
28
29. 4. Assists in adaptation of gingival margins of cating that fail to seat by a
very slight amount.
For casting, bevel should produce a cavosurface angle that will result in 30-40o
marginal metal.
Gingival Margin :
For amalgam in Class II restoration 15-20o
bevel on the enamel portion
of the wall in order to remove unsupported enamel rods (because of gingival
orientation of enamel rods).
For casting, 30o
will result in sliding, lap fit that improves adaptation of
metal to this margin.
Degree of Smoothness :
It is dictated primarily by the restorative material being used.
Inlay or onlay preparation requires a smooth surface to permit
undistorted impressions and close adaptation of the casting to the enamel
surface.
With gold foil, amalgam and composite very smooth preparation wall is
not as desirable as cast gold.
STEP 9 : FINAL PROCEDURE CLEANING, INSPECTING,
VARNISHING, CONDITIONING :
DEFINITION :
Cleaning or debridement is the act of freeing the preparation walls and
margins from the objects that may interfere with the proper adaptability and
behaviour of the restorative material.
There are 3 main objectives for debriding the preparations.
a) Freeing of all preparation walls, floors and margins from enamel
and dentin chips resulting form excavation and grinding.
29
30. b) Drying the preparation walls, floor and margins from any
moisture, saliva, blood, exudates.
c) Sterilization of preparation walls and floors.
Methods :
1. Water, air or combination of air water jets, use of air water syringe or
the water and air accompanying any rotary cutting with a high speed
handpiece will be efficient in removing gross debris.
2. Dry cotton pellet (best way no chance of desiccation).
3. Cavity cleansers – Solution of low concentration of
Citric acid + ascorbic and acetic acid (1-10%) followed by long period
of water jet only used in shallow cavities (can irritate P-D organ).
4. Scarping of walls, floors and margins with sharp instruments.
Whichever debridement technique used, microscopic layer of dentinal
smear will be always present on cut dentin and can be eliminated with a
10o
EDTA.
ADDITIONAL CONCEPTS IN CAVITY PREPARATIONS FOR
AMALGAM RESTORATION :
a. Box Only Cavity Preparation :
Given for those posterior teeth in which proximal surface requires
restoration but occlusal surface does not.
Proximal box is prepared without occlusal step.
b. Tunnel Cavity Preparations :
Preparation joins an occlusal lesion with a proximal lesion by means of
prepared tunnel under the involved marginal ridge.
Marginal ridge remains intact.
c. Bonded amalgam
Use of various bonding agents which bonds amalgam to tooth structure.
More weakened, remaining tooth structure is retained.
For Composite Restorations :
30
31. 1. Box only type of cavity preparation
2. Tunnel preparations
3. Sandwich technique
Use of glass ionomer liner material
Advantages are :
1. Glass ionomer bonds both to tooth structure and composite and thus
increases in retention.
2. Fluoride content in the GIC reduces caries (recurrent).
3. Provides a better seal when seal when used at non enamel margins.
CONCLUSION :
A cavity preparation is determined by many factors and each time a
tooth is to be restored each of these factors must be assessed. If the principles
of cavity preparation are adhere to, the success of restoration is great increased.
The factor that should be considered before initiating a cavity
preparation are as follows :
1. Extent of caries
2. Occlusion
3. Pulpal involvement
4. Esthetics
5. Patients age
6. Patients home care
7. Gingival status
8. Anesthesia
9. Bone support
10.Patients desires
11.Operation skill
31
32. 12.Pulp protection
The improved ability to bond restoration with tooth structure will likely
to alter significantly the entire cavity preparation procedure and thus the
emphasis will shift away form cavity preparation to knowledge of restorative
materials and dental anatomy.
32