The document discusses dentin bonding agents and adhesion to tooth structures. It begins with an introduction on the history and advantages of adhesive dentistry. It then discusses the composition and structure of enamel and dentin, and how adhesion occurs to each. For enamel, acid etching is used to condition the surface and increase bonding. For dentin, multiple generations of dentin bonding agents have been developed to facilitate adhesion. The document covers topics like mechanisms of bonding, classifications of agents, and challenges of the bonding procedure.
This document discusses dentin bonding systems and adhesion. It provides a history of dentin bonding development and covers topics like acid etching, enamel etching patterns, smear layer removal, dentin problems, and classifications of bonding systems. The ideal characteristics of dentin bonding agents are also outlined.
Dental ceramics include porcelain and are used for dental restorations. Porcelain is made from a glass matrix containing mineral phases and feldspars. It is used for dental crowns, veneers, dentures, and other prosthetics. Porcelain has good biocompatibility and esthetics but is brittle. Metal-ceramic restorations combine a metal substructure with porcelain for strength. All-ceramic restorations are made entirely of ceramic materials and provide superior esthetics but require more tooth reduction. Common all-ceramic systems include machinable blocks, castable ceramics, pressable ceramics, and infiltrated glass ceramics.
This document provides an overview of dentin bonding agents. It discusses the history and development of bonding agents from the 1950s to present. Key topics covered include the bonding mechanism, ideal requirements, microstructure of dentin, smear layer, etching of enamel and dentin, hybridization, reverse hybrid layer, wet vs dry bonding, and classifications of dentin bonding agents. The document aims to describe the important concepts and advances in dentin bonding for adhesive dentistry.
Root canal sealers are used with obturating materials to seal the root canal system. They serve functions like filling irregularities, sealing lateral canals, and assisting with microbial control. Ideal sealers provide an excellent seal, adhere well to canal walls and filling material, are radiopaque, and more. Common types include zinc oxide-eugenol, calcium hydroxide, and resin-based sealers. Resin sealers like AH Plus and AH 26 offer advantages like good adhesion, antibacterial properties, and biocompatibility but must be mixed properly to avoid adverse reactions. Proper application of sealers within the canal is important to avoid irritation.
Bonding to Enamel and Dentin Bonding to Enamel and DentinStephanie Chahrouk
1. Bonding agents allow for placement of aesthetic restorations like composites by bonding to enamel and dentin. Developments in bonding agents and composite materials as well as increased focus on aesthetics have boosted adhesive dentistry.
2. Bonding techniques minimize removal of tooth structure, manage sensitivity, reduce microleakage, and expand aesthetic options. Conditioning enamel with phosphoric acid increases surface area for bonding through resin tags.
3. Dentin requires both acid conditioning to remove the smear layer and expose collagen and priming to promote resin infiltration into demineralized dentin. Maintaining a moist environment is important for optimal dentin bonding.
This document discusses dentin bonding agents. It begins with an introduction to adhesive dentistry and the importance of bonding to enamel and dentin. It then covers the basic concepts of adhesion, mechanisms of dental adhesion, and factors that affect bonding. The document discusses the evolution of dentin bonding agents through multiple generations as the technology advanced. It provides details on the components of dentin bonding agents including etchants, primers, and adhesives. In summary, this document provides a comprehensive overview of dentin bonding agents and the principles behind adhesive dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This document provides an overview of dental ceramics. It discusses the history, structure, composition, properties, classification, and fabrication of dental ceramics. The key points are: Dental ceramics can be crystalline or non-crystalline. Common components include feldspar, silica, alumina, and color pigments. Ceramics are classified based on firing temperature, microstructure, and indications. Metal-ceramic systems involve a cast metal framework with ceramic layers bonded to it. The fabrication process involves building and firing layers of ceramic powder to form the final restoration.
This document discusses dentin bonding systems and adhesion. It provides a history of dentin bonding development and covers topics like acid etching, enamel etching patterns, smear layer removal, dentin problems, and classifications of bonding systems. The ideal characteristics of dentin bonding agents are also outlined.
Dental ceramics include porcelain and are used for dental restorations. Porcelain is made from a glass matrix containing mineral phases and feldspars. It is used for dental crowns, veneers, dentures, and other prosthetics. Porcelain has good biocompatibility and esthetics but is brittle. Metal-ceramic restorations combine a metal substructure with porcelain for strength. All-ceramic restorations are made entirely of ceramic materials and provide superior esthetics but require more tooth reduction. Common all-ceramic systems include machinable blocks, castable ceramics, pressable ceramics, and infiltrated glass ceramics.
This document provides an overview of dentin bonding agents. It discusses the history and development of bonding agents from the 1950s to present. Key topics covered include the bonding mechanism, ideal requirements, microstructure of dentin, smear layer, etching of enamel and dentin, hybridization, reverse hybrid layer, wet vs dry bonding, and classifications of dentin bonding agents. The document aims to describe the important concepts and advances in dentin bonding for adhesive dentistry.
Root canal sealers are used with obturating materials to seal the root canal system. They serve functions like filling irregularities, sealing lateral canals, and assisting with microbial control. Ideal sealers provide an excellent seal, adhere well to canal walls and filling material, are radiopaque, and more. Common types include zinc oxide-eugenol, calcium hydroxide, and resin-based sealers. Resin sealers like AH Plus and AH 26 offer advantages like good adhesion, antibacterial properties, and biocompatibility but must be mixed properly to avoid adverse reactions. Proper application of sealers within the canal is important to avoid irritation.
Bonding to Enamel and Dentin Bonding to Enamel and DentinStephanie Chahrouk
1. Bonding agents allow for placement of aesthetic restorations like composites by bonding to enamel and dentin. Developments in bonding agents and composite materials as well as increased focus on aesthetics have boosted adhesive dentistry.
2. Bonding techniques minimize removal of tooth structure, manage sensitivity, reduce microleakage, and expand aesthetic options. Conditioning enamel with phosphoric acid increases surface area for bonding through resin tags.
3. Dentin requires both acid conditioning to remove the smear layer and expose collagen and priming to promote resin infiltration into demineralized dentin. Maintaining a moist environment is important for optimal dentin bonding.
This document discusses dentin bonding agents. It begins with an introduction to adhesive dentistry and the importance of bonding to enamel and dentin. It then covers the basic concepts of adhesion, mechanisms of dental adhesion, and factors that affect bonding. The document discusses the evolution of dentin bonding agents through multiple generations as the technology advanced. It provides details on the components of dentin bonding agents including etchants, primers, and adhesives. In summary, this document provides a comprehensive overview of dentin bonding agents and the principles behind adhesive dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This document provides an overview of dental ceramics. It discusses the history, structure, composition, properties, classification, and fabrication of dental ceramics. The key points are: Dental ceramics can be crystalline or non-crystalline. Common components include feldspar, silica, alumina, and color pigments. Ceramics are classified based on firing temperature, microstructure, and indications. Metal-ceramic systems involve a cast metal framework with ceramic layers bonded to it. The fabrication process involves building and firing layers of ceramic powder to form the final restoration.
Composite resin is a combination of two or more chemically different materials that results in properties superior to the individual components. It consists of a resin matrix and filler materials. Over time, developments have included the introduction of silane coupling agents, light-cured composites, microfilled composites, and nanofilled composites. Composites are classified based on properties such as filler size and distribution, polymerization method, presentation, consistency, and intended use. Proper use of composites for dental restorations requires understanding of factors like smile design, tooth color, shape, and position.
This document discusses root canal curvatures and methods for determining their degree. It begins with an introduction on the importance of understanding root canal anatomy for successful endodontic treatment. It then covers causes of canal curvatures, various classification systems, and techniques for assessing curvature using periapical radiographs, cone-beam computed tomography, and angular measurement methods. The relationship between curvature degree and ledge formation risk is also addressed, as are canal characteristics often invisible on routine radiographs. The document concludes by emphasizing the challenges of treating severely curved canals and the need for accurate preoperative assessment and proper instrumentation.
The document provides a historical perspective and current status of dental bonding agents. It discusses how bonding agents have evolved over generations from early calcium ion-based first generation agents with low bond strengths to today's multi-step etch-and-rinse and single-step self-etch adhesives. Current adhesives can achieve bond strengths of 20-50 MPa to enamel and 13-80 MPa to dentin. While newer single-step adhesives offer simplicity, their long-term performance is still being evaluated compared to multi-step systems. Proper technique remains important for clinical success with any bonding agent.
Biodentine is a new tricalcium silicate-based restorative cement that can be used as a dentin substitute with superior physical and biological properties compared to MTA. It sets faster than MTA due to the addition of calcium chloride as an accelerator. Upon setting, Biodentine releases calcium ions that stimulate reparative dentin formation and pulp healing. Studies show Biodentine forms a stronger bond to dentin and achieves higher mechanical strengths than MTA, making it suitable for various restorative, endodontic and pulp capping procedures.
The document discusses various techniques and materials for posterior composite restorations, including the use of liners to reduce marginal leakage and polymerization shrinkage stress. It also covers advances in dental adhesives that incorporate solvents and nanoparticles to improve bonding to dentin. Proper layering of composites incrementally is recommended to minimize shrinkage and debonding at restoration interfaces.
Dental waxes are used to create patterns for dental restorations and appliances, with the main types being pattern waxes like inlay wax for dental restorations, processing waxes for tasks like boxing impressions, and impression waxes for corrections or bite registration. Inlay wax is a common pattern wax that comes in different types for direct or indirect use and has properties like thermal expansion and potential for distortion that make it suitable for creating wax patterns.
Endodontic sealers a summary and a quick review Rami Al-Saedi
a slideshow presentation lectured and presented in Al-Sadr Specialized dental center in the continuing dental learning weekly lectures.
Rusafa medical institute- Baghdad- Iraq
lecturer: Dr. Rami Ahmed Jumaah (BDS)
Supervisor: Dr. Iman J. Ahmed (BDS: MSc)
Composite Resin Luting cements (2nd edition) presentation powerpoint
A type of dental cement
Used for cementation of indirect restorations & brackets
A summary of five textbooks
This document provides guidelines for preparing metal-ceramic crown restorations. It describes the indications and contraindications for metal-ceramic crowns as well as their advantages and disadvantages. The preparation involves placing depth grooves, reducing the incisal/occlusal, labial/buccal, and axial surfaces, and finishing the margins. The preparation aims to provide at least 1-2mm of tooth reduction, maintain a continuous 90 degree shoulder, eliminate unsupported enamel, and avoid undercuts.
MTA is a biocompatible material composed mainly of Portland cement with bismuth oxide added. It has a high pH and seals well against tooth structures. MTA has applications in pulp capping, pulpotomies, apexification, repair of root perforations, and as a root-end filling material. Its advantages include biocompatibility, ability to set in the presence of moisture and blood, and promotion of hard tissue formation.
Gingival finish lines in fixed prosthodonticsNAMITHA ANAND
This document discusses different finish line designs used in fixed prosthodontics. It defines a finish line as the junction between prepared and unprepared tooth structure. Common finish line locations are subgingival, equigingival, and supragingival. Common designs include chamfer, shoulder, bevelled shoulder, and knife edge. A chamfer is the preferred design as it provides greater angulation than knife edge but less width than shoulder. Placement depends on factors like esthetics, plaque control, and periodontal health. Subgingival margins are not recommended but may be used when esthetics require. Equigingival placement at the gingival crest is optimal when possible.
Introduction to biomechanics
Biomechanical properties of enamel
Biomechanical properties of dentin
Force resisting structures in enamel
Force resisting properties of dentin
Functional aspects related to forces acting on restorations
Type of tooth contacts
Functional cusps
Non Functional cusps
Areas of stress concentration in anterior teeth
Areas of stress concentrations in posterior teeth
Weak areas in teeth
MECHANICAL PROPERTIES OF RESTORATIVE MATERIALS
Concept of stress and strain
Modulus of Elasticity and Proportional limit
Yeild strength and Ultimate strength
Hardness and Fracture toughness
Time dependent properties- creep
BIOMECHANICAL UNIT
STRESS DISTRIBUTION IN RESTORED TEETH
This document provides information on root canal obturation materials. It defines obturation as the three dimensional filling of the entire root canal system as close to the cementodentinal junction as possible. The objectives and ideal requirements of root canal filling materials are described. Materials are classified and various materials used for filling root canals are discussed, including gutta percha, resilon, silver points, and various cements. The properties, advantages, and disadvantages of gutta percha are summarized. Recent advances in materials like medicated gutta percha and resilon are also outlined.
There have been several changes since inception in the field of dental ceramics. Need for newer materials with improved aesthetics, flexural strength and optical properties made it necessary for introduction of advanced technology in fabrication of dental ceramics.
This document provides information about various luting cements used in dentistry. It focuses on zinc phosphate cement, discussing its composition, setting reaction, properties and applications. The key points are:
1. Zinc phosphate cement is the oldest luting agent and consists of a powder made primarily of zinc oxide and a liquid of phosphoric acid. The acid reacts with zinc oxide to form zinc phosphate during setting.
2. It has a working time of 1.5-2 minutes and setting time of 2.5-8 minutes. Its compressive strength is 104MPa and it bonds mechanically rather than chemically.
3. Zinc phosphate cement is used for cementing permanent restorations
Indian Dental Academy: will be one of the most relevant and exciting
training center with best faculty and flexible training programs
for dental professionals who wish to advance in their dental
practice,Offers certified courses in Dental
implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic
Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
This document discusses casting alloys used in dentistry. It begins with a brief history of casting alloys and their evolution since the 1900s. It then covers the key properties casting alloys must have including biocompatibility, corrosion resistance, hardness, castability and bonding to ceramics. The document classifies casting alloys and discusses commonly used types such as gold alloys, silver-palladium alloys, cobalt-chrome alloys and titanium alloys. It provides details on the composition and characteristics of different alloy groups.
The document discusses the principles and evolution of adhesive dentistry. It explains that adhesive dentistry aims to create adhesion between tooth structure and restorative materials. Historically, acid etching of enamel by Buonocore in 1955 improved adhesion of acrylic resin to enamel and marked the beginning of adhesive dentistry. The document covers topics such as the principles of adhesion, mechanisms of adhesion, factors affecting adhesion, dentin bonding systems, classification of bonding agents, and challenges in adhesion.
This document provides an overview of dental adhesion and dentin bonding. It discusses the basic concepts and requirements of adhesion, applications of adhesive restorative techniques, enamel and dentin adhesion mechanisms, and challenges in dentin bonding. It also summarizes the generations of dentin bonding agents from the beginning in the 1950s to current techniques, noting limitations and improvements over time in bonding strength and stability of the bond. The goal has been to develop adhesive systems that can effectively bond to tooth structure, withstand stresses from polymerization, and resist degradation in the oral cavity.
Composite resin is a combination of two or more chemically different materials that results in properties superior to the individual components. It consists of a resin matrix and filler materials. Over time, developments have included the introduction of silane coupling agents, light-cured composites, microfilled composites, and nanofilled composites. Composites are classified based on properties such as filler size and distribution, polymerization method, presentation, consistency, and intended use. Proper use of composites for dental restorations requires understanding of factors like smile design, tooth color, shape, and position.
This document discusses root canal curvatures and methods for determining their degree. It begins with an introduction on the importance of understanding root canal anatomy for successful endodontic treatment. It then covers causes of canal curvatures, various classification systems, and techniques for assessing curvature using periapical radiographs, cone-beam computed tomography, and angular measurement methods. The relationship between curvature degree and ledge formation risk is also addressed, as are canal characteristics often invisible on routine radiographs. The document concludes by emphasizing the challenges of treating severely curved canals and the need for accurate preoperative assessment and proper instrumentation.
The document provides a historical perspective and current status of dental bonding agents. It discusses how bonding agents have evolved over generations from early calcium ion-based first generation agents with low bond strengths to today's multi-step etch-and-rinse and single-step self-etch adhesives. Current adhesives can achieve bond strengths of 20-50 MPa to enamel and 13-80 MPa to dentin. While newer single-step adhesives offer simplicity, their long-term performance is still being evaluated compared to multi-step systems. Proper technique remains important for clinical success with any bonding agent.
Biodentine is a new tricalcium silicate-based restorative cement that can be used as a dentin substitute with superior physical and biological properties compared to MTA. It sets faster than MTA due to the addition of calcium chloride as an accelerator. Upon setting, Biodentine releases calcium ions that stimulate reparative dentin formation and pulp healing. Studies show Biodentine forms a stronger bond to dentin and achieves higher mechanical strengths than MTA, making it suitable for various restorative, endodontic and pulp capping procedures.
The document discusses various techniques and materials for posterior composite restorations, including the use of liners to reduce marginal leakage and polymerization shrinkage stress. It also covers advances in dental adhesives that incorporate solvents and nanoparticles to improve bonding to dentin. Proper layering of composites incrementally is recommended to minimize shrinkage and debonding at restoration interfaces.
Dental waxes are used to create patterns for dental restorations and appliances, with the main types being pattern waxes like inlay wax for dental restorations, processing waxes for tasks like boxing impressions, and impression waxes for corrections or bite registration. Inlay wax is a common pattern wax that comes in different types for direct or indirect use and has properties like thermal expansion and potential for distortion that make it suitable for creating wax patterns.
Endodontic sealers a summary and a quick review Rami Al-Saedi
a slideshow presentation lectured and presented in Al-Sadr Specialized dental center in the continuing dental learning weekly lectures.
Rusafa medical institute- Baghdad- Iraq
lecturer: Dr. Rami Ahmed Jumaah (BDS)
Supervisor: Dr. Iman J. Ahmed (BDS: MSc)
Composite Resin Luting cements (2nd edition) presentation powerpoint
A type of dental cement
Used for cementation of indirect restorations & brackets
A summary of five textbooks
This document provides guidelines for preparing metal-ceramic crown restorations. It describes the indications and contraindications for metal-ceramic crowns as well as their advantages and disadvantages. The preparation involves placing depth grooves, reducing the incisal/occlusal, labial/buccal, and axial surfaces, and finishing the margins. The preparation aims to provide at least 1-2mm of tooth reduction, maintain a continuous 90 degree shoulder, eliminate unsupported enamel, and avoid undercuts.
MTA is a biocompatible material composed mainly of Portland cement with bismuth oxide added. It has a high pH and seals well against tooth structures. MTA has applications in pulp capping, pulpotomies, apexification, repair of root perforations, and as a root-end filling material. Its advantages include biocompatibility, ability to set in the presence of moisture and blood, and promotion of hard tissue formation.
Gingival finish lines in fixed prosthodonticsNAMITHA ANAND
This document discusses different finish line designs used in fixed prosthodontics. It defines a finish line as the junction between prepared and unprepared tooth structure. Common finish line locations are subgingival, equigingival, and supragingival. Common designs include chamfer, shoulder, bevelled shoulder, and knife edge. A chamfer is the preferred design as it provides greater angulation than knife edge but less width than shoulder. Placement depends on factors like esthetics, plaque control, and periodontal health. Subgingival margins are not recommended but may be used when esthetics require. Equigingival placement at the gingival crest is optimal when possible.
Introduction to biomechanics
Biomechanical properties of enamel
Biomechanical properties of dentin
Force resisting structures in enamel
Force resisting properties of dentin
Functional aspects related to forces acting on restorations
Type of tooth contacts
Functional cusps
Non Functional cusps
Areas of stress concentration in anterior teeth
Areas of stress concentrations in posterior teeth
Weak areas in teeth
MECHANICAL PROPERTIES OF RESTORATIVE MATERIALS
Concept of stress and strain
Modulus of Elasticity and Proportional limit
Yeild strength and Ultimate strength
Hardness and Fracture toughness
Time dependent properties- creep
BIOMECHANICAL UNIT
STRESS DISTRIBUTION IN RESTORED TEETH
This document provides information on root canal obturation materials. It defines obturation as the three dimensional filling of the entire root canal system as close to the cementodentinal junction as possible. The objectives and ideal requirements of root canal filling materials are described. Materials are classified and various materials used for filling root canals are discussed, including gutta percha, resilon, silver points, and various cements. The properties, advantages, and disadvantages of gutta percha are summarized. Recent advances in materials like medicated gutta percha and resilon are also outlined.
There have been several changes since inception in the field of dental ceramics. Need for newer materials with improved aesthetics, flexural strength and optical properties made it necessary for introduction of advanced technology in fabrication of dental ceramics.
This document provides information about various luting cements used in dentistry. It focuses on zinc phosphate cement, discussing its composition, setting reaction, properties and applications. The key points are:
1. Zinc phosphate cement is the oldest luting agent and consists of a powder made primarily of zinc oxide and a liquid of phosphoric acid. The acid reacts with zinc oxide to form zinc phosphate during setting.
2. It has a working time of 1.5-2 minutes and setting time of 2.5-8 minutes. Its compressive strength is 104MPa and it bonds mechanically rather than chemically.
3. Zinc phosphate cement is used for cementing permanent restorations
Indian Dental Academy: will be one of the most relevant and exciting
training center with best faculty and flexible training programs
for dental professionals who wish to advance in their dental
practice,Offers certified courses in Dental
implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic
Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
This document discusses casting alloys used in dentistry. It begins with a brief history of casting alloys and their evolution since the 1900s. It then covers the key properties casting alloys must have including biocompatibility, corrosion resistance, hardness, castability and bonding to ceramics. The document classifies casting alloys and discusses commonly used types such as gold alloys, silver-palladium alloys, cobalt-chrome alloys and titanium alloys. It provides details on the composition and characteristics of different alloy groups.
The document discusses the principles and evolution of adhesive dentistry. It explains that adhesive dentistry aims to create adhesion between tooth structure and restorative materials. Historically, acid etching of enamel by Buonocore in 1955 improved adhesion of acrylic resin to enamel and marked the beginning of adhesive dentistry. The document covers topics such as the principles of adhesion, mechanisms of adhesion, factors affecting adhesion, dentin bonding systems, classification of bonding agents, and challenges in adhesion.
This document provides an overview of dental adhesion and dentin bonding. It discusses the basic concepts and requirements of adhesion, applications of adhesive restorative techniques, enamel and dentin adhesion mechanisms, and challenges in dentin bonding. It also summarizes the generations of dentin bonding agents from the beginning in the 1950s to current techniques, noting limitations and improvements over time in bonding strength and stability of the bond. The goal has been to develop adhesive systems that can effectively bond to tooth structure, withstand stresses from polymerization, and resist degradation in the oral cavity.
This document discusses bonding in dental adhesion. It begins with a brief history of bonding agents, dating back to the 1950s. It then covers principles of adhesion, bonding to enamel and dentin. For enamel, it describes the composition and etching process. Etching creates microporosities that allow resin tags to mechanically bond to enamel. For dentin, bonding is more complex due to its heterogeneous nature. The document classifies different generations of bonding agents and their approaches to dentin bonding.
This document discusses adhesion and bonding in dentistry. It provides background on the history of adhesion, definitions of key terms, and the principles of adhesion. Specifically, it describes how adhesion is achieved through mechanical interlocking and various adhesion mechanisms for bonding dental materials to tooth structures like enamel and dentin. It discusses the role of surface properties, bonding agents, and clinical factors that influence adhesion. Methods for bonding various restorative materials like glass ionomers, amalgam, and ceramics are also covered.
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.
Fundamental concepts of enamel and dentin adhesionRicha Singh
1. The document discusses the fundamental concepts of enamel and dentin adhesion, including the mechanisms of adhesion and classifications of dental adhesives.
2. It describes Buonocore's acid etch technique for bonding to enamel and the challenges of bonding to dentin, such as its structure, the smear layer, and stresses at the resin-dentin interface.
3. Current strategies for resin-dentin bonding are discussed, including etch-and-rinse adhesives and self-etch adhesives. Etch-and-rinse adhesives involve removing the smear layer with acid before bonding, while self-etch adhesives combine etching and priming into one step.
The document discusses the history and development of dental bonding systems. It describes the key differences between first, second, and third generation bonding agents. First generation agents from the 1960s produced weak bonds of 2-3 MPa and had high failure rates. Second generation agents from the 1970s-1980s left the smear layer intact and achieved bonds of 4.5-6 MPa. Third generation "total-etch" systems from the 1990s removed the smear layer prior to bonding and produced stronger bonds of 16-26 MPa approaching that of enamel. The three-step approach of conditioning, priming, and applying adhesive resin was developed to strongly bond to both enamel and dentin.
The document reviews the principles of adhesion, discussing the mechanisms of adhesion, requirements for good adhesion, factors that affect adhesion, adhesive materials, bonding systems, and success and failure of adhesives. It provides details on the composition of enamel and dentin, the smear layer, and classifications of different generations of dental bonding systems with examples of commercial products.
This document provides information on bonding in operative dentistry and enamel and dentin adhesion. It discusses the history and development of dental bonding agents from the 1950s to present. Key topics covered include the mechanism of adhesion, factors affecting adhesion to enamel and dentin, wet versus dry adhesion techniques, challenges with bonding, and the requirements for an ideal bonding agent. The document also defines important terms, discusses the components and removal of the smear layer, and compares adhesion to enamel versus dentin.
Dentin bonding has progressed through several generations of adhesives to improve bond strength and reduce technique sensitivity. The 8th generation features all-in-one bottle adhesives containing nanosized fillers that increase resin penetration and bond strength while maintaining simplicity of use. Water-based adhesives are primarily self-etching systems suitable for porous substrates, while acetone/ethanol systems require separate acid-etching but maintain a drier surface. Fluoride-releasing adhesives can strengthen bonds through acid-resistant zone formation while protecting against recurrent decay.
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.
This document discusses factors that affect bonding to intraradicular dentin in endodontics. It covers differences between coronal and radicular dentin, how instrumentation can create a smear layer, and how various endodontic materials and procedures like irrigation, bleaching, and retreatment can impact bonding. Root canal anatomy and the inability to control moisture present unique challenges for achieving effective adhesion. Resin-based sealers and core filling materials that utilize adhesive technology are also discussed as ways to potentially improve bonding and sealing of root canals.
This document discusses adhesion and surface phenomena in dentistry. It defines adhesion as the attachment between two dissimilar substances and describes the components of an adhesive junction. Adhesion can occur through mechanical, chemical, or physical bonding. The document outlines factors that affect adhesion such as surface energy, surface tension, wettability and contact angle. It also lists criteria for successful bonding and discusses the importance of adhesion for dental procedures like bonding restorations and sealing pits/fissures. Specific techniques for bonding to enamel and dentin are covered, including acid etching of enamel and the use of etchants, primers and bonding agents to create a hybrid layer for dentin bonding.
Adhesion in dentistry involves bonding dental materials such as composites to tooth structure. There are two main types of adhesion - chemical and micromechanical. Chemical adhesion involves bonding between tooth and material molecules while micromechanical adhesion uses surface irregularities created by etching to mechanically interlock the material. Factors like surface energy and cleanliness influence adhesion. Conditioning times for enamel and dentin can affect bond strength, with some studies finding extended times increase strength for dentin but not enamel. High quality adhesion improves restoration retention and resistance to leakage and fracture.
The document summarizes a literature review on adhesive cementation techniques for indirect composite resin restorations. It discusses the history and types of dental adhesive systems, including etch-and-rinse, self-etch, and self-adhesive systems. Tooth preparation for indirect composites is described, emphasizing immediate dentin sealing, rounded internal angles, and butt joint margins. The authors conclude that indirect composite techniques can achieve acceptable long-term survival and esthetics if the correct adhesive cementation protocols are followed, requiring knowledge of adhesive principles and adherence to the clinical protocol.
This document discusses dentin bonding agents. It provides background on adhesion and the challenges of bonding to dentin compared to enamel. Key points discussed include:
- Conditioning of dentin is needed to remove the smear layer and expose collagen fibers. This can be done chemically using acids or chelators.
- Primers are then used which contain both hydrophilic and hydrophobic monomers. They displace water from the moist collagen network and allow resin infiltration.
- The concept of "wet bonding" was introduced, in which acid-etched dentin is kept moist during bonding to maintain the expanded collagen network for resin penetration.
Presentation- yahia (1) adhesion in dentistry.pptxmahmoudyahia31
This document discusses dental adhesion, including the principles, mechanisms, classifications, and factors affecting the durability of adhesion. It covers topics such as the etch and rinse approach, self-etch approach, glass ionomer approach, and factors related to dentin, adhesives, micromechanics of the interface, water sorption, and the role of saliva in bond degradation. The classifications of dental adhesives include generational, scientific, clinical application steps, and smear layer handling mechanisms.
Dentin bonding agents are resinous materials used to bond dental composites to dentin by forming a hybrid layer. They were introduced to reduce the need for extensive tooth preparation. A dentin bonding agent consists of a conditioner/etchant, primer, and adhesive. It bonds to dentin by partially demineralizing it with acid and forming resin microtags within the dentin. Dentin bonding agents have various clinical applications including bonding composites, veneers, and orthodontic appliances to teeth.
The document discusses the hybrid layer, which is the zone where adhesive resin micromechanically interlocks with demineralized dentin. It provides a brief history of the hybrid layer concept and covers topics like the goals of hybridization, formation of the hybrid layer, etching effects, zones within the hybrid layer, and degradation of the hybrid layer over time. The summary focuses on the key aspects and does not include specifics or examples from the document.
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
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3. CONTENTS
Introduction Terminologies
Adhesion- Theories
•Requirements
•Clinical factors affecting
adhesion
Enamel-
Composition and
structure
Adhesion to enamel
Dentin- Composition
and structure of
dentin
Adhesion to dentin
Mechanism of
bonding to dentin
Generations of
dentin bonding
agents
Classification of
dentin bonding
agents
Challenges-bonding
procedure
RECENT ADVANCES Conclusion References
3
4. INTRODUCTION
• Today we are in the age of the adhesive
dentistry. Traditional mechanical methods of
retaining restorative materials have been
replaced, to a large extent, by tooth
conserving adhesive methods.
• The concepts of large preparations and
extension and prevention, proposed by
Black, have gradually been replaced by
smaller preparations and more conservative
techniques.
• One major problem in restorative dentistry is
the lack of proper union between the
restorative material and the tooth surface.
The process of inventions over a period of4
5. BONDING IN DENTISTRY HAS
IMPROVED STABILIZATION AND
RETENTION OF RESTORATION
,ELIMINATED EXCESSIVE REMOVAL
OF SOUND TOOTH STRUCTURE
AND THE RESTORATIONS ARE
BETTER ABLE TO TRANSMIT AND
DISTRIBUTE FUNCTIONAL
STRESSES ACROSS THE BONDING
INTERFACE.
5
6. HISTORY
6
▸1949: Dr Hagger (De Trey/Amalgamated Dental Company)Sevriton Cavity Seal
▸1954: M Buonocore- Acid Etching
▸1968: Buonocore, Matsui and Gwinnet (Published report ) ‘Prism like Tags’
▸1960: Pit & fissure Sealants/ Composite introduced
▸1982: Nakabayashi : Hybrid layer formation
▸Fusayama: Total Etch sysytem
▸1992: Wet Bonding technique by Kanca
▸1990: 3 step Total Etch adhesive system
▸2000: SEA’s were developed
▸2011: Adhesion Decalcifictaion Concept by Van Meerberk et al
▸2011: Universal Adhesives developed
8. IDEAL REQUIREMENTS OF DENTIN BONDING
AGENTS
• Provide high bond strength to dentin that should be present
immediately after placement and that should be permanent.
• Provide bond strength to dentin similar to that of enamel.
• Show biocompatibility to dental tissue including the pulp.
• Minimize microleakage at the margins of the restorations.
• Prevent recurrent caries and marginal staining
• Be easy to use and minimally technique sensitive.
• Possess a good shelf life.
• Be compatible with a wide range of resins.
• In addition it should be non toxic and non sensitizing to the
operators or patients.
• Bonding agents should seal the tooth surfaces from oral fluids.
8
9. ADHESIVE DENTISTRY
INDICATIONS
•Restore carious area
•Fractured tooth structure
•Correction of unesthetic shapes,
shades, positions- Close diastema,
add length, mask discoloration
•Bond ceramic restorations,
crowns, FPD, orthodontic brackets
•Treat dentinal hypersensitivity
•Repair fractured restorations
•Core built up foundations
9
10. TERMINOLOGIES
• DENTIN BONDING AGENT: The dentin
bonding agents are di or multifunctional
organic molecules that contain reactive
groups which interact with dentin and
the monomer of the restorative resin.
• INDIAN DENTAL ACADEMY
• Adhesion: is the force or the intermolecular
attraction that exists between molecules of
two unlike substances when placed in
intimate contact with each other
• Adhesive: The material that when applied
to surfaces of substances, can join them
together, resist separation & transmit loads
across the bond. i.e., Material that join
• ( Handbook of adhesion)
• Adherend: The surface / substrate that is
adhered to is termed the Adherend. 10
11. WORD ADHESION IS DERIVED FROM THE LATIN WORD
ADHAERERE TO STICK
Attachment of one substance to another.
Forces or energies between atoms or molecules, at an interface that
hold two phases together
The substance added to produce the adhesion is known as ‘Adhesive’
and the material to which applied known as ‘Adherend’
11
12. DEFINITION
• “The mechanism that bonds two materials in
intimate contact across an interface” -
Davidson (1996).
• “ The state in which two surfaces are held
together by interfacial forces which may consist
of valence forces or interlocking forces or both.”
(The American Society for Testing and Materials)
12
15. MechanicalTheory:
•Solidified
adhesive
interlocks
micromechanic
ally with the
roughness and
irregularities of
the surface of
the adherend.
AdsorptionTheory:
• All kinds of
chemical
bonds
between the
adhesive and
adherend,
including
primary (ionic
and covalent)
and secondary
(hydrogen
bond, dipole
interaction)
valence forces.
DiffusionTheory:
• Adhesion is
the result of
bonding
between
mobile
molecules.
Polymers from
each side of an
interface can
cross over and
react with
molecules on
other side.
Eventually, the
interface will
disappear and
the two parts
will become
ElectrostaticTheory:
•Electrical
double layer
forms at the
interface
between a
metal and a
polymer
making a
certain, yet
obscure,
contribution
to the bond
strength
15
16. SURFACE
ENERGY
• “The increase in energy per unit area
of surface is referred to as the surface
energy or surface tension.”
(science of dental materials,
Anusavice)
• For adhesion to exist, the surfaces
must be attracted to one another at
their interface.
• The energy at the surface of a solid is
greater than that of its interior.
• The surface atoms of a solid tend to
form bonds to other atoms in close
proximity to the surface and reduce
the surface energy. This attraction
across the interface between unlike
molecules is called adhesion.
16
17. • When primary bonding is
involved, the adhesion is
termed chemisorption.
• In this a chemical bond is
formed in between the
adhesive and the adherend.
Eg., oxide film formed on the
surface of a metal.
• The surface energy and the
adhesive qualities of a given
solid can be reduced by any
surface impurity, such as
adsorbed gas, an oxide, or
human secretions.
17
18. The greater
the surface
energy, the
greater the
capacity for
adhesion.
Surface
energy of
the adhesive
should
always be
lower than
the surface
energy of
enamel of
dentin
Concerned
to dental
structures,
enamel
which
contains
primarily
hydroxyapat
ite – has
high surface
free energy. 18
19. WETTING :
• WETTING is the measure of the energy of
interaction of the materials.
• It is difficult to force two solid surfaces to
adhere. Regardless of how smooth these
surfaces may appear, they are likely to be
extremely rough when viewed on an atomic /
microscopic scale.
• The attraction is generally negligible when the
surface molecules of substrates are separated
by distance > 0.7 nm.
• One method of overcoming this difficulty is
to use a fluid that flows into these
irregularities to provide contact over a greater
19
20. • The liquid must flow easily over
the entire surface and adhere to
solid. This characteristic is
known as wetting.
• If the liquid does not wet the
surface of the adherend,
adhesion between the liquid
and adherend will be negligible
or non existent.
20
21. CONTACT ANGLE :
• The extent to which an adhesive
wets the surface of an adherend
may be determined by measuring
the contact angle between the
adhesive and the adherend.
• The contact angle is the angle
formed by the adhesive with the
adherend at their interface.
21
θ
22. • Thus, smaller the contact angle
between the adhesive and an
adherend, the better the ability of
the adhesive to fill in irregularities
on the surface of the adhered.
• Complete wetting occurs at a
contact angle of 0o and no wetting
occurs at an angel of 180o.
• If the molecules of the adhesive are
attracted to the molecules of the
adherend as much as or more than
they are to themselves, the liquid
adhesive will spread completely
over the surface of the solid, and
no angle will be formed.
22
23. THEREFORE AN ADHESIVE WITH LOW VISCOSITY,
LOW SURFACE TENSION AND LOW CONTACT
ANGLE IS PREFERRED
23
24. B) MOISTURE CONTAMINATION
FROM HAND PIECES :
• Water leakage from aerotor hand-
piece / air water syringes is an
unrecognized problem in most
situations.
• The source of leakage could be due to:
• 1) Lack of drying devices on air lines
leading from the compressor, allowing
wet air to be carried out to the syringe /
hand pieces.
• 2) Due to leakage of plumbing lines /
due to the condensation of water in
24
25. C) OIL CONTAMINATION FROM
HAND PIECES / AIR WATER
SYRINGES :
• Oil contamination from airline occurs due
to lack of maintenance of air compressors.
This can be prevented by using effective oil
filters.
• Oil and water contamination are the most
potential and significant factors present in
tooth adhesion, because their presence is
relatively unknown and the result is
unexpected.
• Bonding to dentin is compromised but the
influence on adhesion to etched enamel is
25
26. SURFACE ROUGHNESS OF TOOTH
STRUCTURE :
• Increase in surface area created by
surface roughness may explain slightly
better bonds to dentin.
• It is possible that mechanical retention
may be increased slightly by
microscopic roughness produced on
dentin and enamel by rotary cutting
instruments.
26
27. e) Mechanical Undercuts in Tooth preparation
The mechanical undercuts are placed in the tooth structure
to hold the restorative material from bodily displacement
from the preparation.
They also may resist some microscopic movement of the
restorative material caused by thermal / polymerization
influences.
This is further augmented with the current generation dentin
bonding agents (CLIM 1990).
27
28. f) Fluoride Content of Tooth
Increased fluoride content of enamel has shown
to resist acid etching. Clinicians generally need
double the time to etch this enamel.
Fluoride presence in dentin appears to influence
bonding of adhesive agents negatively (Nystrom
Holtan and Douglas 1990).
28
29. g.) Location and Size of Dentinal Tubules :
Dentinal canals at the external surface of roots or near the
dentino-enamel junction have small diameters.
Dentinal canals which are closer to the dentinal pulp are
larger.
Old dentin has smaller dentinal canals, while new dentin has
larger dentinal canals (Pashley 1990).
29
30. h) Presence of Plaque, Calculus, Extrinsic Stains / Debris :
• Plaque present on the tooth surface prevents etching with 37%
phosphoric acid. Penetration of plaque by the less aggressive
acids used in dentin bonding agents is not possible and so will
result in a clinical adhesive failure.
• Tooth surface stains and dental calculus if not removed will not
permit bonding.
Hence before any bonding procedure the surfaces should be
thoroughly cleaned with scalers, abrasive prophylactic pastes using
rubber cusp or with abrasive rotary instruments.
30
31. i) Presence of Bases / Liners on Prepared Teeth :
Varnishes and resin liners affect the bonding of
the subsequently placed restorative material to the
tooth surface.
When Composite resins are placed over glass
ionomer liner, it is seen that the bond of resin to the
tooth is less than bond of the glass ionomer to the
tooth.
31
32. j) Tooth Dehydration :
Overdrying the dentinal surfaces will cause
collapse of exposed collagen. Such collapse may
prevent resin infiltration and impair bonding. So drying
only until the obvious shine of moisture is lost is
necessary.
32
34. TOOTH AS A SUBSTRATE FOR BONDING
Etching Bonding
34
Enamel
▸Composed of hard Crystalline –HAp with strong
intermolecular forces
▸High surface energy
▸Water
▸Organic material
35. • In the oral environment, an organic pellicle covers the enamel surface
creating a chemically complex surface with low reactivity. This results
in poor bonding to enamel surface. Here the critical surface tension
is approximately 28 dynes/cm.
• The cutting of enamel surface during cavity preparation removes this
organic biofilm but does not increase the enamel surface energy.
• Whereas etching (40%) increases the critical surface energy to 72
dynes/cm. The creation bonding area and surface roughness make
bonding of hydrophobic resin possible.
• Enamel is more homogeneous in structure, composition irrespective
of its depth and location, unlike dentin.
35
36. ACID ETCHING
EFFECTS
Removes the residual pellicle to expose the inorganic
crystalline component
Creates a porous layer 5 to 10 um in depth
Increase the wettability & surface area
Raises the free surface energy ----72 dynes/ cm 36
37. • Bonding to enamel depends primarily on resin tags becoming
interlocked within enamel surface irregularities
• Acid etching transform smooth enamel into rough surface .
• So when resin based material is applied to irregular etched
enamel ,resin penentrates into surface aided by capillary
action.
• Monomers polymerise and material becomes interlocked with
enamel surface
37
38. THE EFFECT OF ACID ETCHING ON ENAMEL DEPENDS ON SEVERAL
PARAMETERS :
• Kind of acid used
• Acid concentration
• Etching time
• Form of etchant – gel /semi gel / acquired solution gel is preferably – better control.
• Way in which wetting is activated (rubbing / irritating and or repeated application of fresh acid).
• Whether enamel is instrumented before etching.
• The rinsing time
• The chemical composition and condition of enamel.
• Whether enamel is on primary or permanent teeth. Primary teeth – prismless enamel and therefore
require longer etching time.
• Whether enamel is fluoridated, demineralised or stained.
• Etchant should always be applied in dabbing action. It should not be applied in rubbing action,
because rubbing action may fracture the thinned enamel rods thereby reducing the depths of the
created valleys and irregularities and obliterating what is left of them with fractured enamel pieces.
38
39. CONDITIONING ENAMEL :
The enamel bonding technique, known as acid-etch
technique was introduced by Buonocore in 1955.
• Enamel etching transforms the smooth enamel surface
into an irregular surface with a high surface free energy
of about 72 dynes/cm, more than twice that of
unetched enamel.
(Jendresen & Glantz.Microtopography and clinical adhesiveness of
an acid etched tooth surface-an invivo study) 39
40. 40
Type I : Predominant dissolution of prism
core and peripheries left intact – most
common.
Three etching patterns have been described
;
(Silverstone LM. Variation in pattern of
etching of human dental enamel examined
by SEM. Caries Res 1975)
HONEYCOMB APPEARANCE
41. Type II : Predominant dissolution of prism peripheries.
41
Cobblestone appearance
42. Type III : No prism structure is evident/combination
Mostly seen by action of strong chelating agents, but it is also
seen with acids. There is no one specific pattern seen here.
Different patterns may be due to difference in chemical
composition and crystalline orientation. Variation may be seen
from site to site or tooth to tooth.
42
Includes areas resembling Type I & II patterns-
presence of prism less enamel
43. ACID ETCHANTS
• Includes acids like
• Citric acid, tannic acid, maleic acid, polyacrylic acid.
• Most commonly used however is Phosphoric acid – 37% 15-20 secs.
• NEW CONCEPT OF ETCHING :
Combined action of different etchants i.e. phosphoric acid on enamel
and EDTA (24% pH 7) on dentin may be a better alternative than
etching the entire cavity with single etchant.
43
44. PHOSPHORIC ACID
• Most commonly used etchant.
• Concentration – 30%-40%
37% phosphoric acid with etching time not less than 15 seconds and washing
time of 5-10 seconds Most receptive enamel surface for bonding.
(Gwinnett AJ and
Summitt JB)
• Calcium dissolution and etching depth increase as the concentration of H3PO4
increases until a concentration of 40% and at higher than this it will start
showing reverse effect. 44
45. • At concentration 50% phosphoric acid There occurs a
formation of monocalcium phosphate monohydrate on the
etched surface which can be rinsed off.
• At concentration less than 27% There forms a precipitate of
dicalcium phosphate dihydrate that can not be easily removed.
(Chow & Brown)
• Etching time also has been reduced from traditional 60 seconds
to 15 seconds and it has demonstrated equivalent bonding
effectiveness.
45
46. • Rinsing is important to remove dissolved CaPO4 from the
etched surface, which otherwise might impair infiltration of
monomers into the etched enamel microporosities.
• Flat surfaces -1 to 3 sec
• Complex preparation forms – 5 to 10 sec
(Summitt,Chan,Dutton.Effect of air/water rinse v/s water only
and of five rinse times to resin to etched enamel shear bond
strength. )
46
47. • Phosphoric acid is often made thicker with →
Silica thickening agents which increase ph
Polymer beads which lower ph
• Aqueous preparation and polymer gelled acids have lower pH and thus etches
deeper.
(Perdigao et al 1996)
• In acidic gels - silica particles, precipitate on the surface of etched dentin which
decreases permeability
• Shear bond strength of composite to phospohoric acid-etched enamel usually
exceed 20MPa
• Such bond strength provide adequate retention for a broad variety of procedures
and prevent leakage around enamel margins of restorations.
47
48. • The use of ethanol to remove residual water from the etched
pattern has been reported to enhance the ability of resin
monomers to penetrate the surface irregularities (Gwinett
1992, Qusit V, Quist J 1985).
• Modern primers frequently contain drying agents such as
ethanol / acetone, with a similar effect.
48
49. ALTERNATIVE ENAMEL ETCHANTS :
As phosphoric acid ( H3PO4) is said to be more aggressive, other
alternatives have been suggested like ;
• EDTA
• Pyruvic acid 10%
• Sulphuric acid 2%
• nitric acid – 2.5% concentration.
Organic Acids :
• 10% Citric acid
• Maleic acid 10%
• Oxalic acid: 1.6% - 3.5% 49
50. • Ethylene diamine tetraacetic acid (EDTA) – is a strong
decalcifying agent, promotes only low bond strength to
enamel, probably EDTA does not etch preferentially.
• Pyruvic acid : 10% buffered with glycine to a pH of about
2.2, promotes high bond strengths to enamel, but has been
found to be impractical because of its instability.
• Sulphuric acid : 2% used for 30 seconds has shown to be as
effective as H3PO4 whereas high H2SO4 concentration
produce heavy crystal deposits which interfere with bonding
and cannot be washed away easily.
50
51. • With the introduction of total-etch systems, in which enamel and
dentin are etched simultaneously, weaker acids are applied to
enamel.
• With this total etch concept, the term etching is often referred to as
conditioning. Etchant is referred to as conditioning agent.
• The concentration and length of application of the conditioning
agents are adapted to provide a microporous etch pattern in enamel
and causing extreme demineralization of the dentinal surface.
51
52. • SEP which serve simultaneously as conditioner and primer.
• The rationale behind these acid monomer solution is the
formation of continuum between tooth surface and adhesive
material by simultaneous demineralization and penetration of
enamel surface with the acidic monomers that can be
polymerized in situ.
52
53. • MAIJER and D.C. SMITH have proposed a new method of
bonding that involves crystal growth of enamel surface.
• The system consists of treating a clean tooth surface with a
50% solution of polyacrylic acid containing sulfate ions (SO4-
ions).
• The liberated Ca ions will react with these sulfate ions
forming CaSO4. 2H2O in 1 or 2 minutes.
• As these crystals nucleate within the tooth and grow
outwardly in a spherulic habit, with irregular surfaces they
are similar to an etched enamel with loss of tooth substrate.
53
55. • Lasers have been used for enamel / dentin preparation prior to the
restorative material placement.
• Laser etching is a process of continuous vaporization and micro
explosion due to vaporization of water trapped within the
hydroxyapatite matrix.
• In general, more material is removed by the micro explosion of
entrapped water than by direct vaporization of the HA crystals.
The amount of surface roughening is dependent upon the type
and wavelength of the laser.
• CO2 and Nd:YAG proved most effective lasers for etching.
However, studies have shown that changes in surface morphology
and bond strength after laser etching are quite similar to acid
etching.
• KCP Technique : Kinetic cavity preparation – here both enamel and
55
57. Air Abrasive Technology
• In 1992 U.S. Food and Drug Administration granted
clearance to air abrasive cavity preparation system.
• Here, a high speed stream of purified Aluminium Oxide
particles (0.5 um) propelled by air-pressure.
• It can prepare enamel and dentin for bonding, similar to
chemical etching.
• Lawrell et al, observed that bond strength to air-abrasive
treated enamel surfaces similar to the values obtained
with acid etching.
57
59. ENAMEL BONDING AGENTS
• Consists of BIS-GMA or UDMA resins with dilutent like TEGDMA.
• They flow easily into the microporosities of enamel.
• In the last few years these bonding agents here been replaced by same
adhesives that are used on dentin -advantage of simultaneously bonding to
both enamel and dentin.
• Bonding of resin to Enamel is mainly of Micromechanical type where Resin
Tags gets interlocked with Enamel Tags or surface 59
60. RESIN TAGS
• Enamel Bonding depends on resin tags becoming interlocked with surface
irregularities created by etching
MACRO TAGS : (interprismatic)
• Formed circularly between enamel rod peripheries.
• Most macro tags are only 2-5microns in length
60
61. MICROTAGS : (intraprismatic)
• Formed at the cores of enamel prisms
• A much finer network of thousands of smaller tags
from across the end of each rod where individual
hydroxyapatite crystals have been dissolved, leaving
crypts outlined by residual organic material
• Length is 2-10 microns
Micro tags contribute most because of their larger
number and greater surface area.
61
62. • Regarding bonding to enamel, the rapid volatilization of the solvent
allows for the complete interdiffusion of the adhesive system through the
extension of the conditioning.
• It is not an easy procedure to keep dentin moist and dry only the
enamel.
• Hydrophilic primers work very well when enamel is dry.
• The presence of residual moisture and organic solvents interferes
negatively in the complete polymerization of monomers
• Is important after the application to properly dry with air spray of a triple
syringe
• Also, it has been theorized that the stability of bonding to enamel is also
compromised with time because of the formation o f adhesive layers
similar to semipermeable membranes.
62
63. • Viscosity of the Adhesive System
Some adhesives have inorganic filler particles to increase their
film thickness and cohesive strength (filler loading ranges
between 8.5% and 25% weight).
This seems to be related to the high viscosity of these
adhesives, which makes it difficult to penetrate in interprismatic
areas as deeply as unfilled adhesives.
It has been reported that highly viscous sealants have greater
difficulty penetrating enamel as much as the conditioning depth.
63
64. • Cleaning Enamel
A relevant factor in bonding to enamel is the
cleaning of the substrate to be bonded.
This cleaning must be accomplished before etching
using cotton pellets soaked in agents such as
chlorhexidine gluconate and benzalkonium chloride.
• Use of air/water spray of a triple syringe in easy
access locations .
• Floss and gauze are recommended for proximal
surfaces. Prophylactic pastes are useful on
noninstrumented enamel surfaces. 64
65. Dentin adhesion
65
To achieve adequate wetting on this low surface energy, dentin
is conditioned to various treatments to increase the surface free
energy and thereby help in bonding.
Adhesion to dentine remain difficult.adhesive materials can
interact with dentin in different ways-mechanical,chemical,or
both.
Dentin adhesion relies primarily on the penetration of adhesive
monomers into the network of collagen fibers left exposed by
acidic etching.
66. CLINICAL FACTORS IN DENTIN
ADHESION
1. Structure of dentin
2. Smear layer
3. Stresses at the resin denin interface—C factor,COTE
4. Type of composite
5. Biocompatibility
6. Microleakage
7. Nanoleakage 66
67. Smear Layer
When the tooth surface is instrumented with rotary and manual
instrument during cavity preparations, cutting debris is smeared over the
enamel and dentinal surfaces forming what is termed as smear layer.
Definition :
Any debris, calcific in nature, produced by reduction or
instrumentation of dentin, enamel or cementum or as a ‘contaminant’ that
precludes the interaction with the underlying pure tooth tissue.
(J prosth. Dent.1989)
• The thickness of the smear layer has been reported to vary from 0.5 – 2
m.
• Thickness of smear plug : 1-10 m
67
68. • Smear layer is reported to reduce dentinal permeability by
86%.(Pashley 1982)
• Although smear layer occludes the dentinal tubules with the
formation of smear plugs, the smear layer is porous and
penetrated by submicron channels, which allows a small amount
of dentinal fluid to pass through.
• Factors determining of composition of smear layer
1. Type of cutting/abrading instrument used
2. Type and method of chemicals/disinfectants employed
68
69. SMEAR LAYER TREATMENT
• NO TREATMENT- Resin would infiltrate through the entire
thickness of smear layer and even bond to underlying matrix or
penetrate into tubules Eg. Scotch bond and prisma bond.
• REMOVAL AND REPLACEMENT OF SMEAR LAYER- Removal of
smear layer by acid etching and replacement with another
mediation agent. Here replaces smear layers with oxalate
crystals which are deposited in dentinal tubules.
69
70. • Dissolution of the smear layer- This dissolved smear layer plays
an vital role in chemical attachment of dentin bonding agent to
dentin. Eg. Scotchbond-2.
• Removal of smear layer by acid etching- Acid etching agents are
used to remove smear layer and develops attachment directly to
intact dentin (through primers).
• Modification of smear layer : Modification of smear layer allows
interaction of dentin bonding agent with the smear layer.
Eg. Bonding agent – Prisma 2, XR Bond, All bond.
70
71. MICROLEAKAGE
• Microleakage is defined as the passage of bacteria and their toxins
between restoration margin and the tooth preparation walls.
• MOA: an adhesive restoration might not bond sufficiently to etched
dentin to prevent gap formation at margins.
• The occurrence of gap at the resin – dentin interface may not cause
immeadiate debonding of the restoration. However ,if a dentin
adhesive system does not adhere intimately to the dentin substrate,
to the interfacial gap eventually develops, and bacteria are able to
penetrate through this gap.
71
72. NANOLEAKAGE
• The term Nanoleakage has been used to describe small
porosities in the hybrid layer or at the transmission between the
hybrid layer and the mineralized dentin that allow the
penetration of miniscule particle of a silver nitrate dye.
• If the bond fails at the interface between two substrates is
referred to as adhesive failure.
• cohesive failure, if occurs in one of the substrates, but not at the
interface.
• But the mode of failure is often mixed. 72
73. • DENTINAL PERMEABILITY
• It refers to the ease with which a substance can move into or
across a diffusion barrier.
• Variation in permeability affects the bonding mechanism of
dentin.
73
• MAINLY OF 2 TYPES-
74. INTERTUBULAR PERMEABILITY
• Diffusion of monomer into demineralized intertubular dentin,
the dentin between the tubules.
• Intertubular dentin must be demineralized to expose the
collagen fibrils of the dentinal matrix and to create diffusion
pathways for monomer into these long, continuous,
interconnected, narrow channels, or pores.
74
75. INTRATUBULAR PERMEABILITY
• The movement of fluid within dentinal tubules
• Responsible for dentinal sensitivity
• Formation of resin tags
75
76. e) Internal and External Dentinal Wetness :
The dentinal permeability and consequently, the
internal dentinal wetness depend on several factors,
• diameter and length of the tubule,
• the viscosity of dentinal fluid
• the molecular size of substances dissolved in it,
• the pressure gradient,
• the surface area available for diffusion,
• the patency of the tubules, and
• the rate of removal of substances by pulpal circulation. 76
77. Two factors that determine the wetting behaviour & penetration are
1. polarity
2. solubility
• Occlusal dentin is more permeable over the pulp horns than at the
centre of the occlusal surface, proximal dentins more permeable
than occlusal dentin, and coronal dentin is more permeable than
root dentin.
• High dentinal permeability allows bacteria and their toxin to easily
penetrate dentinal tubules to the pulp, if the tubules are not
hermetically sealed.
77
78. • Early DBA failed primarily because their hydrophobic resins were not
capable of sufficiently wetting the hydrophilic substrate.
• In addition, bond strengths of several adhesive systems were shown
to decrease as the depth of the preparation increased, because
dentinal wetness was greater.
• No significant differBond strengths of more recent adhesive systems
that remove the smear layer appear to be less affected by
differences in dentinal depth, probably because of their increased
hydrophilicity which provides better bonding to the wet dentinal
surface.
• ences in bond strengths is observed between deep and superficial
dentin when smear layer is left intact.
78
82. CONDITIONING OF DENTIN
• It can be defined as any chemical alteration of the dentinal
surface by acids or less commonly a calcium chelator (EDTA)
with the objective to remove the smear layer and simultaneously
demineralize the dentinal surface.
• Etching of enamel and dentin together for 15sec called as Total
etch or Unietch is the most successful way of managing smear
layer.
• It was introduced by Fusayama et al in 1979 and is now
commonly practiced.
• Acid- 35-37% phosphoric acid.
82
83. • Removes smear layer and smear plugs
• Demineralizes intertubular dentin
- upto a depth of 1-5µ
- Exposes longitudinally / obliquely oriented collagen
fibres
- Interfibrillar spaces – 15 –20nm (nanochannels)
• Demineralizes peritubular dentin.
- Opens tubule orifices in a typical funnel shape
configuration
- Exposes a circularly oriented collagen fibril
arrangement.
• Decreases free surface energy 83
84. • In superficial dentin the surface of dentin changes from one in which
only 1% of surface area is porous before etching to a condition in
which 13.4% of the surface area consisting of water filling tubules
that can serve for infiltration of monomer
• Also demineralizes 3- 7 microns of superficial dentin.
• Exposes a micro-porous collagen scaffold which is permeable to
resin.
• Surface free energy of etched dentin-
44.8 dynes/cm
84
86. PRIMERS
• These are monomers dissolved in solvents such as
water, acetone or alcohol , applied to the etched or
conditioned dentin substrate but are not rinsed off.
• After conditioning maintainence of a moist dentinal
surface is essential to optimal bonding with modern
hydrophilic adhesive system.
• Desiccation of the conditioned dentin can cause
collapse of the unsupported collagen web preventing
infiltration of the resin.
86
87. • Primer monomers are amphiphilic i.e. they contain hydrophilic groups
(eg. –OH, -COOH) for better compatibility of the resin monomers with
the moist dentin, and hydrophobic methacrylate groups for the co-
polymerization with the bonding resin.
• Organic solvents aid in displacing water,
Expanding
Or re-expanding the collagen fiber network
• Promoting the infiltration of the monomer
Into the sub-micron sized spaces within the collagen fiber network
• The objective of this step is to transform the hydrophilic dentin
surface into a hydrophobic and spongy state. 87
88. POSSIBLE EXPLANATIONS FOR THE MAJOR SHRINKAGE OF
DEMINERALIZED DENTINAL MESHWORK WHEN IT IS AIR-DRIED
• DEMINERALIZED COLLAGEN FIBRIL NETWORK IS FLOATING / SUSPENDED IN
WATER.
• EACH FIBRIL IS SEPARATED FROM THE OTHER BY WATER FILLED SPACE, WHICH
OCCUPIES THE SPACE THAT WAS PREVIOUSLY OCCUPIED BY APATITE
CRYSTALLITES.
• As the water supported collagen network is air-dried, the amount of
water separating the fibrils disappears as the water evaporates and the
collagen fibrils come closer together in all three dimensions.
• This results in a passive collapse of the collagen network. 88
91. • This results in a loss of space between the fibrils.
The addition of water rapidly reverses these events
causing passive re-expansion of the collapsed
collagen network.
• If water or an aqueous primer is added to dried
dentin -The water reverses all of these events; water
molecules will bind with collagen peptide using
hydrogen bond
91
93. Acetone Acetone Water Acetone Ethanol Ethanol Ethanol Water Water
ABC Enhanced (Chemeleon) AQ Bond (Sun Medical) All Bond 2 (BISCO) Excite (Vivadent) Gluma Comfort Bond (Kulzer) Amalgam bond Plus (Parkell)
EG Bond (Sun Medical) Reactmer (Shofu) Optibond Solo Plus (Kerr) Optibond FL (Kerr) ART Bond (Coltene)
Gluma One Bond (Kulzer) Tenure Quick (Den-Mat) Pq1 (Ultra dent) Permaquik (Ultra dent) Clearfil SE Bond (Kuraray)
One Step (BISCO) Quadrant Unibond (Cavex) Denthesive II (Kulzer)
Permagen (Ultra dent) Scotch bond 1 (3M) EBS (ESPE)
Prime & Bond NT (Dentsply) Syntac sprint (Vivadent) Fuji Bond LC (GC)
Solid Bond (Kulzer) Single Bond (3M) One – Coat Bond (Coltene)
Solist (DMG) Prompt L-Pop 1,2 (ESPE)
Stae (SDI) Scotch Bond Multi-Purpose (3M)
Tenure Quick F (Den Mat) Syntac Single Comp (Vivadent)
93
Current adhesives are categorized following the type of solvent of the primer or combined primer / adhesive resin.
94. MOIST BONDING– KANCA TECHNIQUE :
• In order to avoid the collapse of the collagen network, a moist (wet)
bonding procedure has been proposed in which the primer is applied to the
moist or even wet dentin where the peri-fibrillar spaces are kept open with
water (Kanca 1992).
• Surface moisture is an important factor in optimal bonding.
• Moist bonding is only essential for particular bonding systems with a low
water content of primer such as All Bond 2.
• The primer of All Bond 2 contains acetone as solvent with only 5% of water.
• In contrast primers with water content of 20% or more (eg. Optibond FL,
Scotch bond Multipurpose) are able to re-expand the collapsed collagen
due to their intrinsic rewetting capacity.
94
95. • On enamel, a dry condition is theoretically preferred
• On dentin, certain amount of moisture is needed to avoid collapse
of the exposed collagen fibers.
• Acid etched dentin shrinks 65% vol.
• Stiffness of mineralized dentin is about 19,000 MPa
Stiffness of acid etched dentin matrix is about 1 Mpa.
• The resulting layer of imperfect bonding is known as HYBRIDOID
REGION.
• Residual water is left in the acid etched dentin, then bond strength
could be doubled. (Kanca )
95
98. 98
WET BONDING (KANCA & GWINETT) 1990
Once etched dentin should be left moist
Primer (Acetone) vaporizes the water-leaving the space for resin topenetrate
Optimal wetting of exposed collagen achieving high bond strength
Wet bonding Technique – Kanca & Gwinett 1990
▸How wet or dry the dentin should be……
Substrate should be neither too Wet or too dry
Excess water should be blotted with a dry sponge/ tissue paper
99. Dry Bonding
• refers to the bonding in which the acid
etched dentin is dry and uses the adhesive
systems that provide water based primers.
These rehydrate and re expand the collagen
fibers , allowing the resin to infiltrate.
99
100. • Ideally, water should form a uniform layer without pooling (overwet) & without dry
areas (overdried).
• Air drying with an air syringe after rinsing off the ecthing gel – not recommended
cannot form uniform layer of water on the surface.
WATER BASED PRIMERS:
• The first approach to creating a hybrid layer in wet dentin is the use of water-soluble
primers containing HEMA.
• Examples Scotch bond 2 and Scotch bond Multi-purpose.
• After application of the water HEMA mixture, the surface is air dried to evaporate the
water. As the water concentration falls, the HEMA concentration rises, until
theoretically, there should be near zero water and 100% HEMA on the surface.
• CONSEQUENCES OF APPLYING ACETONE BASED PRIMERS TO OVER-WET DENTIN
DESCRIBED BY TAY ET AL (1994) USING ALL BOND 2, BISCO.
• SMALL GLOBULES ARE FORMED WITHIN DENTINAL TUBULES.
100
101. • When the first one or two layers of primer were applied i.e. in the
tubules filled with dentinal fluid there was too much water
available to dilute the acetone with the result that the monomer
came out of the solution.
• As more globules formed, they accumulated on walls of the
tubules, reducing the permeability of the tubules, permitting
successive primer applications to dehydrate the tubules enough to
form normal resin tags.
101
103. HYBRID LAYER:
Dentin hybrid layer is a
• “TRANSITIONAL ZONE OF RESIN
REINFORCED DENTIN SANDWICHED
BETWEEN CURED RESIN AND THE
UNALTERED DENTINAL SUBSTRATE”
(nakabayashi 1982)
• hybrid layer is the resin infiltrated
surface layer of collagen fibers in
demineralized dentin.
The synonyms are:
• “Adhesion interface”,
• “resin-dentin inter-diffusion zone”,
• Inter penetration zone.
103
106. SHAG CARPET APPEARANCE:
• Appears when dentin surface after being acid etched is actively
scrubbed with an acidic primer solution.
• Mechanism of action:
The combined mechanical and chemical action of rubbing the acid
etched dentin with an acidic primer dissolves additional mineral salts
while fluffing and separating the entangled collagen at the surface.
TUBULE WALL HYBRIDIZATION:
• Extension of the hybrid layer into tubule wall area.
• Hermetically sealing the pulpodentinal complex against microleakage
• Especially protective when bond fails at top or bottom of the hybrid layer
• The resin tags keep tubules sealed as they break off at the level of hybrid
layer. This is attributed to tubule wall hybridization which ensures a
leakage free seal of tubules.
106
107. GHOST HYBRID LAYER:
• This layer is formed due to incorporation of air bubbles at the substrate
adhesive interface.
REVERSE HYBRID LAYER:
• The acid etched surface of dentin is further subjected to treatment with
NaOCl. This results in dissolution of the collagen fibrils that are exposed.
• Here the hybrid layer is surrounded by more of inorganic material
unlike the normal hybrid layer where the collagen fibers are encapsulated
by resin, and so this layer thus formed is termed reversed hybrid layer.
Reverse hybrid layers form when dentin-bonding agent comes in contact
with the pulp.
• Gentle drying of the dentin surface, has been shown to result in
INCOMPLETE INTERTUBULAR RESIN INFILTRATION.
• Incomplete resin penetration due to collagen collapse has been observed
as the formation of a hybridoid layer/zone.
107
108. 108
WATER TREES’– TAY & PASHLEY
▸Water can pass from dentin around resin tags& form water
filled channels that project from the hybrid layer into the
overlying adhesives
• Water absorption character of HEMA, water is prone to
permeate into the dental resin composite completely
through the dental adhesive materials by forming water
blisters and “Water trees”. Thus leading to Nanoleakage
problem and failure of dental restorations.
Bidirectional water current
115. FIRST GENERATION
• In 1956, Buonocore and colleagues demonstrated that
use of a glycerophosphoric acid dimethacrylate (NPG-
GMA) containing resin would bond to acid-etched dentin.
• This bond was believed to be due to the interaction of this
bifunctional resin molecule with the calcium ions of
hydroxyapatite.
• immersion in water would greatly reduce this bond.
• The bond strengths of these early systems were only 1 to
3 MPa . The clinical results with these systems were poor.
115
116. SECOND GENERATION
• Introduced in the late 1970s
• Attempted to bond chemically to either the inorganic or organic
components of dentin.
• They contain phosphate group, amino acid group,isocyanate group or
carboxylic acid group to effect the bond to the calcium or collagen of
dentin.
• Clinical applications did not succeed due to their lack of hydrolytic
stability; also they primarily bonded to smear layer and not to underlying
dentin.
• Bond strength :5 to 6 MPa
• Eg: Clear fil Bond system, Scotch bond, bond lite, prisma 116
117. THIRD GENERATION
• 1979 –fusayama-total etch concept
• Deal with smear layer as well as the dentinal fluid
• They employed 2 approach
1. Modification of smear layer to improve properties
2. Removal of smear layer with out disturbing smear plug that occlude dentinal tubule
ie, required either removal,modification or dissolution of smear layer
• Idea was to avoid aggressive etching of dentin , beacause of concerns that acid etching of
dentin can cause pulpal inflammation.
• In this they used mild acids like 2% nitric acid, 2.5% maleic acid with HEMA ,10% phosphoric
acid etc..
• Bond strength : 3 -8 MPa
Eg: clearfil new bond , scotch bond 2, Tenure, gluma, C&B meta bond
117
118. FOURTH GENERATION
• Total etch concept/Moist bonding
• 1982 Nakabayashi- Hybrid layer
Enamel & dentin both simultaneously etch with 37% phosphoric
acid for 15 sec.
Tooth washed & gently dried to leave the dentin surface moist , so
as to prevent collapse of exposed collagen network.
Primer applied, final step involves application of adhesive resin
Bond strength : 7 -24 MPa
• Eg: Compobond LCM, Scotch bond MPa
118
120. FIFTH GENERATION
• To simplify the clinical procedure by reducing the bonding
steps and thus, the working time, a better system was
needed. Also, clinicians needed a better way to prevent
collagen collapse of demineralized dentin.
• Totally removes smear layer
• based on Total etch concept.
• Eg: single bond(3M), one step , Exite,gluma comfort bond
,opti bond solo (kerr)
120
122. • The fifth generation consists of two different types of adhesive materials:
the so-called "one-bottle systems" and the “self-etching primer”
bonding systems.
• One-bottle systems. To facilitate clinical use, "one-bottle" systems
combined the primer and adhesives into one solution to be applied after
etching enamel and dentin simultaneously (the total-etch wet-bonding
technique) with 35 to 37 percent phosphoric acid for 15 to 20 seconds.
These bonding systems create a mechanical interlocking with etched
dentin by means of resin tags, adhesive lateral branches and hybrid layer
formation and show high bond-strength values both to the etched
enamel and dentin.
• Self-etching primer. Watanabe and Nakabayashi developed a self-
etching primer that was an aqueous solution of 20 percent phenyl-P in
30 percent HEMA for bonding to enamel and dentin simultaneously.
• The combination of etching and priming steps reduce the working time,
eliminate the washing out of the acidic gel and also eliminate the risk of
122
123. SIXTH GENERATION
• These bonding systems are characterized by the possibility to
achieve a proper bond to enamel and dentin using only one solution.
• These materials should really be a one-step bonding system.
Unfortunately, the first evaluations of these new systems showed a
sufficient bond to conditioned dentin while the bond with enamel was
less effective.
• Primer and etchant are combined in one step( self etching primers)
• Mainly two type; 1-SEP , 2 -SEA
• Eg: Prompt L-Pop, Clearfil SE bond, Liner bond
123
128. 128
Addition of nano fillers help in the penetration of resin monomers and hybrid layer
thickness .
It improves mechanical properties of bonding system.
146. CONCLUSION
• Various advances in bonding agents have
eliminated the need for sacrificing sound tooth
structure for establishing retention form.
• Understanding the composition of the tooth and
components, mechanism of bonding agents help to
overcome difficulties and aid in mastering the
bonding technique for success of restorative
procedures.
146
147. REFERENCES
Sturdevant’s Art and science of operative dentistry, 5th edition
Phillips science of dental materials
Fundamentals of operative dentistry , summitt
Text book of OperativeDentistry. Nisha Garg, IVEdition JPpublications
Materials used in Dentistry. S. Mahalakshmi 2nd Edition, Wolters Kluwer
Text book of Dental Materials.Arvind Shenoy.Elsevier
Textbook of OperativeDentistry. Vimal Sikri
Classification of review of dental adhesive systems:from the IV generation to the universal type,E
.Sofan,Annali et al
147