logging in or signing up Principle of bonding Bandar part 1 dr.bandarw Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 369 Category: Science & Tech.. License: All Rights Reserved Like it (1) Dislike it (0) Added: December 02, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... By: dasmd (17 month(s) ago) thank u.... Saving..... Post Reply Close Saving..... Edit Comment Close By: sunyoungkim (18 month(s) ago) could you kindly send this file to me? sykim.dds@gmail.com Saving..... Post Reply Close Saving..... Edit Comment Close By: drzohaib (29 month(s) ago) kindly send me dis presentation in dis email drzohaib@hotmail.com Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Slide 1: Bandar Al-Abdulwahhab Department of Operative Dentistry Riyadh Colleges of Dentistry and Pharmacy Principle of Adhesion Introduction : Introduction Definitions : The word of adhesion is derived from Latin word : Adhaerere = to stick to. Adhesion(bonding): Unlike molecules are attracted e.g. A-B Cohesion: Same kind of molecules are attracted e.g. B-B Introduction : Introduction Adhesive: Material or film added to produce the adhesion B Adherend/substrate: Material to which adhesive is applied A Slide 4: Adhesive Interface 1 ADHESION ENAMEL, DENTIN Liner, Base, Cement Dental Amalgam Implant < Inlay, Onlay, or Crown < All-Ceramic Inlay, Onlay, or Crown < Veneers, Maryland Bridges < Orthodontic Brackets Question : Question Adhesion failure v.s. cohesion failure Introduction : Introduction Adhesive strength: is the measure of the load-bearing capacity of the adhesive (MPa). Durability: The time period during which the bond remains effective. Slide 8: Four theories of adhesion Phenomena (MADE): 1. Mechanical Adhesion : Macro-mechanical and Micro-mechanical interlocking. Adsorption Adhesion : All kinds of chemical bonds: (Primary: ionic and covalent) or (Secondary: Hydrogen and Van der Waals) Diffusion Adhesion : interlocking between mobile molecules (e.g. adhesion of two polymers). Electrostatic Adhesion. Bonding of resins to tooth structures is a result of four mechanisms: Mechanical Adhesion (90%) / Adsorption Adhesion / Diffusion Adhesion or a combination of all mechanisms Slide 9: Four theories of adhesion Phenomena : 1. Mechanical Adhesion: - Macro-mechanical interlocking : screws, undercuts. - Micro-mechanical interlocking : pores in the surface of the substrate. Slide 10: Requirements for good adhesion/bonding 1-Materials must be in contact: Attraction is negligible when the surface molecules are separated more than 0.7 nm (0.0007 µm). Why is it difficult to force two solid surfaces to adhere? Because the rough surfaces at the atomic or molecular scale will keep the major area of the surfaces apart. Slide 11: Use of a fluid that flows into these irregularities provides contact over a greater part of the surface of the solid. Slide 12: Requirements for good adhesion/bonding 2- Wetting of the Material surface must occur: The tendency for the liquid to spread (wettability) increases as the contact angle decreases. Low contact angle High contact angle The angle formed by the adhesive with the adherend at their interface Contact angle Contact angle is used to determine how well an adhesive can wet the surface of an adherend. Slide 13: Wetting ability is influenced by: Surface energy and surface tension: The energy at the surface of a solid is greater than that of its interior because the outermost atoms are not equally attracted in all directions. The increase in energy per unit area of surface is referred to as the surface energy (solid) or surface tension (liquid). J/m2 Cleanliness of the surface :(water contamination, oxide film) surface energy of the adherend. Question : Question High- surface energy solids and low-surface tension liquids: (good or bad) Wetting? (high or low) Contact angle? Good wetting Low contact angle Slide 15: Steps in Forming Good Adhesion (1) Clean adherend (2) Good wetting (3) Intimate adaptation (4) Bonding (5) Good curing Slide 16: 18-35 MPa (typically 20 MPa) 10-12 MPa (typically 10 MPa) 40-80 MPa (typically 60 MPa) 40-80 MPa (typically 60 MPa) BOND STRENGTH TESTING What are good bond strengths? 0.1 mm² Mature Enamel: : Mature Enamel: Composition: Primarily inorganic content-hydroxyapatite - : (95 to 98 by wt%) and (86% by vol.). Organic material: (1% wt. and 2% vol.). Water (4%wt and 12%vol.). Organic 2% Water 12% Inorganic 86% By volume Inorganic 95% By Weight Water 4% Organic 1% Water Water 4% Organic 1% Mature Enamel: : Mature Enamel: Homogeneous in structure ( irrespective to depth or location), except to outer surface (prismless). Hydroxyapatite has high surface energy. Natural surface of enamel is smooth and the microscopic unit called the rod or prism, end in keyhole pattern. Slide 19: By volume Mature Dentin : Composition: Inorganic content-hydroxyapatite - : (70% by wt%) and (50% by vol.). Organic material: (18% wt. and 25% vol.), mainly Collagen Type I filled with water. Water (12%wt and 25%vol.). Organic 25% Inorganic 50% Water 25% Slide 20: Mature Dentin : Peritubular dentin Intertubular dentin Dentinal fluid Odontoblastic process Slide 21: Mature Dentin : Composition Pattern: - Peritubular dentin: surrounds tubule and hypermineralized. - Intertubular dentin: between tubules, less mineralized and contain collagen. - Odontoblastic process. - Dentinal fluid. Any Question : Any Question You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Principle of bonding Bandar part 1 dr.bandarw Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 369 Category: Science & Tech.. License: All Rights Reserved Like it (1) Dislike it (0) Added: December 02, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... By: dasmd (17 month(s) ago) thank u.... Saving..... Post Reply Close Saving..... Edit Comment Close By: sunyoungkim (18 month(s) ago) could you kindly send this file to me? sykim.dds@gmail.com Saving..... Post Reply Close Saving..... Edit Comment Close By: drzohaib (29 month(s) ago) kindly send me dis presentation in dis email drzohaib@hotmail.com Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Slide 1: Bandar Al-Abdulwahhab Department of Operative Dentistry Riyadh Colleges of Dentistry and Pharmacy Principle of Adhesion Introduction : Introduction Definitions : The word of adhesion is derived from Latin word : Adhaerere = to stick to. Adhesion(bonding): Unlike molecules are attracted e.g. A-B Cohesion: Same kind of molecules are attracted e.g. B-B Introduction : Introduction Adhesive: Material or film added to produce the adhesion B Adherend/substrate: Material to which adhesive is applied A Slide 4: Adhesive Interface 1 ADHESION ENAMEL, DENTIN Liner, Base, Cement Dental Amalgam Implant < Inlay, Onlay, or Crown < All-Ceramic Inlay, Onlay, or Crown < Veneers, Maryland Bridges < Orthodontic Brackets Question : Question Adhesion failure v.s. cohesion failure Introduction : Introduction Adhesive strength: is the measure of the load-bearing capacity of the adhesive (MPa). Durability: The time period during which the bond remains effective. Slide 8: Four theories of adhesion Phenomena (MADE): 1. Mechanical Adhesion : Macro-mechanical and Micro-mechanical interlocking. Adsorption Adhesion : All kinds of chemical bonds: (Primary: ionic and covalent) or (Secondary: Hydrogen and Van der Waals) Diffusion Adhesion : interlocking between mobile molecules (e.g. adhesion of two polymers). Electrostatic Adhesion. Bonding of resins to tooth structures is a result of four mechanisms: Mechanical Adhesion (90%) / Adsorption Adhesion / Diffusion Adhesion or a combination of all mechanisms Slide 9: Four theories of adhesion Phenomena : 1. Mechanical Adhesion: - Macro-mechanical interlocking : screws, undercuts. - Micro-mechanical interlocking : pores in the surface of the substrate. Slide 10: Requirements for good adhesion/bonding 1-Materials must be in contact: Attraction is negligible when the surface molecules are separated more than 0.7 nm (0.0007 µm). Why is it difficult to force two solid surfaces to adhere? Because the rough surfaces at the atomic or molecular scale will keep the major area of the surfaces apart. Slide 11: Use of a fluid that flows into these irregularities provides contact over a greater part of the surface of the solid. Slide 12: Requirements for good adhesion/bonding 2- Wetting of the Material surface must occur: The tendency for the liquid to spread (wettability) increases as the contact angle decreases. Low contact angle High contact angle The angle formed by the adhesive with the adherend at their interface Contact angle Contact angle is used to determine how well an adhesive can wet the surface of an adherend. Slide 13: Wetting ability is influenced by: Surface energy and surface tension: The energy at the surface of a solid is greater than that of its interior because the outermost atoms are not equally attracted in all directions. The increase in energy per unit area of surface is referred to as the surface energy (solid) or surface tension (liquid). J/m2 Cleanliness of the surface :(water contamination, oxide film) surface energy of the adherend. Question : Question High- surface energy solids and low-surface tension liquids: (good or bad) Wetting? (high or low) Contact angle? Good wetting Low contact angle Slide 15: Steps in Forming Good Adhesion (1) Clean adherend (2) Good wetting (3) Intimate adaptation (4) Bonding (5) Good curing Slide 16: 18-35 MPa (typically 20 MPa) 10-12 MPa (typically 10 MPa) 40-80 MPa (typically 60 MPa) 40-80 MPa (typically 60 MPa) BOND STRENGTH TESTING What are good bond strengths? 0.1 mm² Mature Enamel: : Mature Enamel: Composition: Primarily inorganic content-hydroxyapatite - : (95 to 98 by wt%) and (86% by vol.). Organic material: (1% wt. and 2% vol.). Water (4%wt and 12%vol.). Organic 2% Water 12% Inorganic 86% By volume Inorganic 95% By Weight Water 4% Organic 1% Water Water 4% Organic 1% Mature Enamel: : Mature Enamel: Homogeneous in structure ( irrespective to depth or location), except to outer surface (prismless). Hydroxyapatite has high surface energy. Natural surface of enamel is smooth and the microscopic unit called the rod or prism, end in keyhole pattern. Slide 19: By volume Mature Dentin : Composition: Inorganic content-hydroxyapatite - : (70% by wt%) and (50% by vol.). Organic material: (18% wt. and 25% vol.), mainly Collagen Type I filled with water. Water (12%wt and 25%vol.). Organic 25% Inorganic 50% Water 25% Slide 20: Mature Dentin : Peritubular dentin Intertubular dentin Dentinal fluid Odontoblastic process Slide 21: Mature Dentin : Composition Pattern: - Peritubular dentin: surrounds tubule and hypermineralized. - Intertubular dentin: between tubules, less mineralized and contain collagen. - Odontoblastic process. - Dentinal fluid. Any Question : Any Question