BONDING AGENT.pptx

It is an adhesive technique in dentistry involving the acid etching of tooth enamel and/or dentin so as to create tags of resin within the tooth structure that results in mechanical retention of the restorative material.Reliable bonding of resins to enamel and dentin has revolutionized the practice of dentistry. Improvements in dentin bonding materials and techniques are likely to continue. Even as the materials themselves become better and easier to use, however, proper attention to technique and a good understanding of the bonding process remain essential for clinical success.
Current trends in dentistry have rightfully earned the title of age of adhesive dentistry.
1) TERMINOLOGIES�2)INTERATOMIC BOND�3)FACTORS AFFECTING ADHESION�4)MECHANISM OF ADHESION�5)HISTORY�6)ACID ETCHING�7)SMEAR LAYER�8)HYBRID LAYER�9)CONDITIONING OF DENTIN�10)MECHANISM OF DENTIN BONDING�11)WET BONDING VS DRY BONDING�12)PRIMER�13)ADHESIVE�14)CLASSIFICATION�15)GENERATIONS OF DENTIN BONDING AGENT�16)UNIVERSAL ADHESIVES�17) SILICON BONDING AGENT�18) CERAMIC BONDING�19) CONCLUSION

1. BONDING AGENT UNDER THE ABLE GUIDANCE OF:- DR.(PROF) JAYANTA BHATTACHARYA [HOD & PRINCIPAL] DR.(PROF) SAMIRAN DAS DR.(PROF) SOUMITRA GHOSH DR.(PROF) PREETI GOEL DR.SAYAN MAJUMDAR DR. SUBHABRATA ROY PRESENTER: - BAISHALI GHOSH 1 ST YEAR PGT DEPARTMENT OF PROSTHODONTICS, CROWN & BRIDGE

2. 1) TERMINOLOGIES 2)INTERATOMIC BOND 3)FACTORS AFFECTING ADHESION 4)MECHANISM OF ADHESION 5)HISTORY 6)ACID ETCHING 7)SMEAR LAYER 8)HYBRID LAYER 9)CONDITIONING OF DENTIN 10)MECHANISM OF DENTIN BONDING 11)WET BONDING VS DRY BONDING 12)PRIMER 13)ADHESIVE 14)CLASSIFICATION 15)GENERATIONS OF DENTIN BONDING AGENT 16)UNIVERSAL ADHESIVES 17) SILICON BONDING AGENT 18) CERAMIC BONDING 19) CONCLUSION CONTENTS

3. BONDING:- It is an adhesive technique in dentistry involving the acid etching of tooth enamel and/or dentin so as to create tags of resin within the tooth structure that results in mechanical retention of the restorative material.- GPT-9 TERMINOLOGIES BONDING AGENT:- It is a material used to promote adhesion between two different substances, or between a material and natural tooth structures. –GPT-9 ADHESION:- It is the property of remaining in close proximity, as that resulting from the physical attraction of molecules to a substance or molecular attraction existing between the surfaces of bodies in contact. –GPT-9 COHESION:- It is a molecular attraction by which the particles of a body are united throughout their mass. –GPT-9

4. INTERATOMIC BONDS PHILIP’S SCIENCE OF DENTAL MATERIALS, Kenneth J. Anusavice , 12 th edition 4

5. ADHESION - FACTORS AFFECTING ADHESION.

6. SURFACE ENERGY PHILIP’S SCIENCE OF DENTAL MATERIALS, Kenneth J. Anusavice , 12 th edition 6 ADHESIVE:- Any substance that creates close adherence to or on adjoining surfaces. ADHEREND:- A material substrate that is bonded to another material by means of an adhesive.

7. WETTING PHILIP’S SCIENCE OF DENTAL MATERIALS, Kenneth J. Anusavice , 12 th edition 7 PREREQUISITE FOR WETTING:- Clean surface. Low surface tension of adhesives. High surface energy of adherend. To produce adhesion on any targeted surface, the liquid must flow easily over the entire surface and adhere to the solid. This characteristic is known as wetting.

8. CONTACT ANGLE Pres Zhao, Zhilong , Wang, Qihui , Zhao, Jing, Zhao, Bo, Ma, Zhangyu , and Congxiao Zhang. "Adhesion of Teeth." Frontiers in Materials 7 , (2021). PHILIP’S SCIENCE OF DENTAL MATERIALS, Kenneth J. Anusavice , 12 th edition 8 The spreading of liquid corresponds to wetting and depends on three interfacial energies:- (1) The surface energy of the substrate ( γ SV ) (2) The surface energy in of liquid ( γ LV ) (3) The solid-liquid interfacial energy which corresponds to the bonds ( γ SL ) According to YOUNG’S LAW - γ SV= γ LV.cos θ + γ SL (where θ is the contact angle) CONTACT ANGLE = The contact angle is the angle formed at the interface of the adhesive and the adherend. Forces of adhesion(molecular attraction between adhesive and adherend) are stronger than the cohesive forces(molecular attraction of adhesive and adherend within themselves) . Contact angles less than 90 degrees indicate a favorable wetting of the surface. Forces of adhesion(molecular attraction between adhesive and adherend) are weaker than the cohesive forces(molecular attraction of adhesive and adherend within themselves) .

9. Presentation title 9

10. MECHANISM OF ADHESION MECHANICAL ADHESION The interlocking of the adhesive with irregularities on the surface of the substrate or adherend. ADSORPTION ADHESION It occurs due to the chemical interaction between the adhesive and the adherend. Forces may be primary (ionic and covalent) or secondary (hydrogen, dipole interaction). Example= Chemical bonding to the inorganic component (hydroxyapatite) of tooth structure. Pres Zhao, Zhilong , Wang, Qihui , Zhao, Jing, Zhao, Bo, Ma, Zhangyu , and Congxiao Zhang. "Adhesion of Teeth." Frontiers in Materials 7 , (2021). Sturdevant’s Art & Science of Operative Dentistry, page 125. 10 DIFFUSION ADHESION There are two basic criteria for this diffusion: (1) M olecules must be compatible in terms of hydrophobicity and hydrophillicity . (2) Macromolecules must have sufficient mobility. In addition, the molecule diameter and the distance of intermolecular space must be compatible for internal diffusion. Even if the thermodynamic criteria is valid, a 200 Ǻ polymer will not diffuse the membrane of a polymer/protein with intermolecular spaces of 150 Ǻ Example=Polymers from each side of an interface can cross over & react with molecules on the other side. Eventually the interface will disappear and the two parts will become one. ELECTROSTATIC ADHESION The basis of the electrostatic theory of adhesion is the difference in electronegativity of adhering materials. Adhesive force is attributed to the transfer of electrons across the interface creating positive and negative charges that attract one another. An electrical double layer at the interface of a metal with a polymer that is part of the total bonding mechanism

11. HISTORY PHILIP’S SCIENCE OF DENTAL MATERIALS, Kenneth J. Anusavice , 12 th edition 11

12. HISTORIC EVENT OF 1 ST INTRAORAL ADHESION:-  The first meaningful demonstration of intraoral adhesion was reported by Michael Buonocore (1955).  Buonocore etched enamel surfaces with PHOSPHORIC acid, placed an acrylic restorative material on the micromechanically roughened surfaces, and found a great increase in the resin–enamel bond strength (~20 megapascals [MPa]). ACID ETCHING The process of cleaning and roughening a solid surface by exposing it to an acid and thoroughly rinsing the residue to promote micromechanical bonding of an adhesive to the surface. WHY DID PREVIOUS ATTEMPTS OF ADHESION FAILED? Prior to the introduction of enamel acid etching and the use of enamel bonding agents, restorative materials were placed directly on the smear layer of the prepared tooth. It is evident that the apparent bond strength is the cohesive strength (5–10 MPa) of the smear layer, which is not sufficient to withstand the daily mechanical forces experienced in the mouth. As a result, debonding and leakage of oral fluids within the microscopic space between prepared teeth and restorative materials was an ongoing problem. PHILIP’S SCIENCE OF DENTAL MATERIALS, Kenneth J. Anusavice , 12 th edition

13. PHOSPHORIC ACID AS AN ETCHANT Silverstone L, M: Fissure Sealants. Caries Res 1974;8:2-26. Textbook Of Operative Dentistry,4thed,2017, VIKRAM SIKRI, 13 BUONOCORE(1955) Groups in the study:- a) P hosphomolybdate (50%)-oxalic acid(10%) treatment for 30 seconds. b) 85% Phosphoric acid for 30 seconds. Conclusion:- Duration of adhesion of group a treated teeth was found to be 160 hr wheras that of group b was found to be 1070 hr. SILVERSTONE(1974) Groups in the study:- Group a= unbuffered phosphoric acid solutions at concentrations of 20, 30, 40, 50, 60 and 70%. Group b = 50% phosphoric acid buffered with 7% zinc oxide by weight. Group c = 5% and 50% citric acid. Group d = 10% polyacrylic acid. Group e = 5% EDTA The study concluded that unbuffered phosphoric acid concentrations between 30-40% provided enamel surfaces that are most retentive. CURRENT SCENARIO:- 37% phosphoric acid is the most commonly used acid for etching. At concentrations > 50 %  there occurs formation of a layer of MONOCALCIUM PHOSPHATE MONOHYDRATE on etched surface which prevents any further dissolution . Concentrations < 30 %  there forms a precipitate of DICALCIUM PHOSPHATE DIHYDRATE that cannot be easily removed. FORMS OF ETCHANT AVAILABLE:- Gel etchants are preferred because of the ease and control of placement. However, etching pattern with gel and liquid remains the same. Gels are often made by adding colloidal silica or polymer beads to the acid. They are applied to the surface either with a brush or dispensed through a syringe onto the enamel. DURATION OF ETCHING:- The time for etching with 30% to 40% phosphoric acid has been recommended as 15 seconds. Studies with SEM have confirmed that 15 seconds etching provides the same surface roughness as 60 seconds. Similar shear bond strengths for 15 and 60 seconds have been observed. However, enamel which is acid resistant because of a high fluoride content can be etched for 60 seconds.

14. EFFECT OF ETCHANT ON ENAMEL Q) WHY DOES AN UNTREATED ENAMEL FAIL TO PROVIDE A STRONG DURABLE BOND? Reason :- a) Enamel surface have low surface energy that makes it inert. b) Pellicle of saliva covers the untreated enamel that is detrimental to an adhesive bond. c) Preparation of enamel deposits a smear layer over its surface. Presentation title 14 FROSTY APPEARANCE OF ENAMEL DUE TO ETCHING. ACID CONDITIONING/ETCHING AFFECTS THE ENAMEL IN THE FOLLOWING WAYS:-  Removes residual pellicle to expose the inorganic crystallite component of enamel.  Removes approximately 10μm of surface enamel.  Creates a porous layer, the depth of the pores range from 5-50μm.  Increases the wettability and surface area of the enamel substrate.  Raises the surface energy of enamel .

15. ETCHANT PATTERNS OF ENAMEL Textbook Of Operative Dentistry,4thed,2017, VIKRAM SIKRI, Khadry A. Galil, et al Acid Etching Patterns on Buccal Surfaces of Permanent TeethThe American Academy of Pedodontics, August 2019; 1(4): 7-12 15 TYPE 1 Involves the preferential removal of enamel prism cores with prism peripheries remaining relatively intact. Honey comb appearance. TYPE 2 Etching pattern is the reverse of type I, i.e. the peripheries are removed leaving the cores intact . Cobble stone appearance. TYPE 3 Etching pattern is less distinct, and includes areas resembling type I & type II patterns as well as regions in which the etching pattern appears unrelated to prism morphology. This type of etching is generally associated with the presence of prismless enamel. TYPE 4  Pattern displays only a random distribution of depressions with no preferential destruction of either cores or peripheries.  This type of etching pattern is commonly seen in cervical areas and rarely on occlusal . TYPE 5  Etching shows no evidence of prism outline.  The regions of enamel are flat and smooth and lack micro irregularities for penetration of resin.  Such type is seen in high fluoride areas

16. ETCHING PRIMARY TEETH. Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . Pg 40-1 16 CAUSE OF INCREASED DIFFICULTY IN ETCHING PRIMARY TEETH:- In primary teeth the coronal part is covered by a thin enamel layer which is generally less mineralized than permanent enamel. Thicker layer of aprismatic enamel in the primary enamel. ETCHING TIME:-  Etching times ranges from 15 to 30 s provided a detailed etch pattern on primary teeth; however, more clear and deeper porosity obtained after 30 s than after 15 s etching time, resulting in uniform, well performed resin projections.  Nevertheless, the retentive capacity of etched deciduous enamel for 15 s or 60 s was similar, whereas 10 s etching time caused lower bond strength Etched pattern of primary teeth after being treated with 36% phosphoric acid for 30 seconds.

17. LASER ETCHING Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . 17 .

18. AIR ABRASION Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . 18

19. Textbook Of Operative Dentistry,4thed,2017, VIKRAM SIKRI 19 MACROTAGS AND MICROTAGS

20. WHY DOES DENTIN POSE A GREATER CHALLENGE TO BONDING? Sturdevant’s Art & Science of Operative Dentistry, page 121 20

21. PROBLEMS IN DENTIN BONDING Presentation title 21

22. SMEAR LAYER Whenever both enamel and dentin tissues are mechanically cut, especially with a rotary instrument, a layer of adherent grinding debris and organic film known as a smear layer (1-2 µm) is left on their surfaces and prevents strong bonding . Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . Pg 97 22 Depth of Smear Layer= 1-2 µm Depth of Smear Plug= 1-10 µm Tani and Finger [2002] have examined smear layers generated by diamond burs with different grain size and by silicon carbide papers with varying grit numbers. They concluded that the smear layer’s thickness increases with increasing roughness of the diamond bur or SiC paper.

23. Ways to overcome low bond strengths due to the limited strength of the smear layer. 23 SMEAR LAYER REMOVAL PRIOR TO BONDING. USE OF BONDING AGENTS THAT CAN PENETRATE BEYOND THE SMEAR LAYER WHILE INCORPORATING IT Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades .

24. HYBRID LAYER The structure formed in the dental hard tissues by demineralization of the substrate, followed by infiltration of monomers and subsequent polymerization. ( Nakabayashi, 1982) An intermediate layer of resin, collagen, and dentin that is produced by acid etching of dentin and infiltration of resin into the conditioned dentin.( PHILIP’S SCIENCE OF DENTAL MATERIALS, Kenneth J. Anusavice , 12 th edition) Concept of Hybrid layer was introduced by Nobuo Nakabayashi in 1982 Presentation title 24

25. EVOLUTION OF THE CONCEPT OF HYBRID LAYER Nohito Nakahayashi , Ph. D.* Mitsuo Nakamura, Ph. D.' Nohoroir Yasudu . Ph.D. ' Hybrid Layer as a Dentin-Bonding Mechanism. Journal of esthetic dentistry vol 3 number 4 July 1991, pg 223-9 25

26. FORMATION OF HYBRID LAYER Presentation title 26 FORMATION OF HYBRID LAYER IN DENTIN:- THREE CHARACTERISTICS ARE NECESSARY FOR THE FORMATION OF HYBRID LAYER IN DENTIN:- Nohito Nakahayashi, Ph. D.* Mitsuo Nakamura, Ph. D.' Nohoroir Yasudu. Ph.D. ' Hybrid Layer as a Dentin-Bonding Mechanism. Journal of esthetic dentistry vol 3 number 4 July 1991, pg 223-9 PHASES IN FORMATION OF RESIN REINFORCED ZONE:-

27. ZONES OF HYBRID LAYER Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . 27

28. SHAG CARPET APPEARANCE Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . 28

29. TUBULE WALL AND LATERAL TUBULE HYBRIDIZATION Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . 29

30. REVERSE HYBRID LAYER Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . 30

31. CONDITIONING OF DENTIN ACID CONDITIONER CHELATORS Presentation title 31

32. ACID CONDITIONER Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI, Pg 365 32

33. CHELATORS Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI, Pg 366 33

34.  The adhesive molecule is bifunctional, (X) enters into chemical union with the tooth structure (M) co-polymerizes to the resin through the double bond of methacrylate. (R) The spacer group is responsible for making the molecule large enough to keep the methacrylate groups spatially located for optimal chemical reaction with the composite.  Adhesion with dentin can occur either to the inorganic or organic components present on the surface of the tooth.  Ideally, dentin adhesives should be both hydrophilic and hydrophobic. Hydrophilic  so as to be able to displace dentinal fluids and thereby wet the surface, permitting penetration into porosities within the dentin and eventually react with organic or inorganic components. Hydrophobic properties  Required to allow bonding to the composite resin, the matrix of which is hydrophobic in nature. MECHANISM OF DENTIN BONDING Presentation title 34 Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI, Pg 366

35.  Bonding to the inorganic part of dentin occurs through ionic interaction between positive Ca2+ ions on the surface of dentin and negative charges on the group X of the adhesive.  Group X can be a)phosphates b) aminoacids c)dicarboxylates.  Agents that use a phosphate group in their bonding to calcium ions are referred to as phosphate bonding systems and are the most common ones to be employed clinically. The substituent ‘Z’ in the phosphate based adhesives may be chlorine, a hydroxy or a phenyl group. BONDING TO INORGANIC PORTION OF DENTIN Presentation title 35 Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI

36. BONDING TO ORGANIC PORTION OF DENTIN Presentation title 36

37. WET BONDING VS DRY BONDING Presentation title 37

38. WET BONDING Presentation title 38 The use of etch-and-rinse adhesive systems on moist dentin is made possible by incorporation of the organic solvents acetone or ethanol in the primers or adhesives. Because the solvent can displace water from the dentin surface and the moist collagen network, it promotes the infiltration of resin monomers throughout the nanospaces of the dense collagen web. The moist bonding technique has repeatedly proven to enhance the bond strengths of etch-and-rinse adhesives because water preserves the porosity of collagen network available for monomer interdiffusion. DISADVANTAGE:-  White frosty appearance of etched enamel is not visible.  Pooled moisture should not remain on the tooth because excess water can dilute the primer and render it less effective. OVER WETTING PHENOMENA Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI

39. DRY BONDING Presentation title 39 Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI Many clinicians still dry the tooth preparation, to check for the classic etched enamel appearance after rinsing off the etching gel. Because it is very difficult to dry enamel without simultaneously drying dentin, the dentin collagen collapses easily on air drying, resulting in the closure of the micropores. When water is removed, the elastic characteristics of collagen may be lost. While in a wet state, wide gaaps separate the collagen molecules from each other. In a dry state, the molecules are arranged more compactly. This is because extrafibrillar spaces in hydrated type I collagen are filled with water, whereas dried collagen has fewer extrafibrillar spaces open for the penetration of the monomers included in the adhesive systems During air drying, water that occupies the interfibrillar spaces previously filled with hydroxyapatite crystals is lost by evaporation, resulting in a decrease of the volume of the collagen network to about one third of its original volume. Under the scanning electron microscope, the adhesive does not seem to penetrate etched intertubular dentin that has been dried. In dry bonding technique, if water free acetone based primers are used, they do not effectively infiltrate the exposed collagen network because of absence of water, forming the so called ‘HYBRIDOID REGIONS’/’GHOST HYBRID LAYER’

40. PRIMER PHILIPS SCIENCE OF DENTAL MATERIALS, 12 TH EDITION, ANUSAVICE, pg 262-264 40

41. HEMA Gary Alex, DMD Universal Adhesives: The Next Evolution in Adhesive Dentistry? Compendium of continuing education in dentistry January 2015 Volume 36, Number 1, Pg 15-26 41

42. SOLVENT Presentation title 42 PHILIPS SCIENCE OF DENTAL MATERIALS, 12 TH EDITION, ANUSAVICE, pg 265

43. ADHESIVE Presentation title 43 PHILIPS SCIENCE OF DENTAL MATERIALS, 12 TH EDITION, ANUSAVICE, pg 265-6

44. OTHER INGREDIENTS INGREDIENT FUNCTION COMMERCIAL NAME GLUTARALDEHYDE Added as a desensitizer Probond by Dentsply 12-METHACRYLOYLOXYDODECYLPYRIDINIUM BROMIDE, MDPB Antimicrobial Clearfil Protect Bond by Kuraray PARABENE Antimicrobial Adper Prompt-L-Pop by 3M ESPE FLUORIDE To prevent caries Prime & Bond NT by Dentsply Benzalkonium chloride prevent collagen degradation Etch 37, Bisco chlorhexidine prevent collagen degradation Peak LC Bond Resin, Ultradent Products, Presentation title 44 PHILIPS SCIENCE OF DENTAL MATERIALS, 12 TH EDITION, ANUSAVICE, pg 265-6

45. ENAMEL ADHESIVES TYPE MATERIALS Polymerization initiation and application Compositional characteristics MOISTURE ACTIVATED ADHESIVE Smartbond ( Gestenco ) Formulation only initiated through exposure to water Cyanoacrylate. MOISTURE INSENSITIVE ADHESIVE Transbond MIP (3M Unitek ) Primer formulation applied to enamel. Methacrylate-functionalized polyalkenoic acid copolymer. HYDROPHILIC RESIN PASTE FORMULATIONS Assure ( Reliance) Photo-polymerizable paste applied with conventional procedure Hydrophilic copolymer like PEGMA Dental Hard Tissues and Bonding G. Eliades · D.C.Watts · T. Eliades . 45

46. CLASSIFICATION When discussing dentin-bonding agents, it has become customary to describe the generations (first generation, second generation, etc.) of bonding agents that have led sequentially from the earliest, relatively ineffective materials to the current materials, which provide reliable functional bonds. This organization into generations of bonding agents is a somewhat artificial device to mark key advances in materials and techniques along a more-or-less continuous developmental pathway. Hence Anusavice in philips science of dental materials, 12 th edition, put forward a classification for contemporary adhesive systems based rather on their mechanism of adhesion and the number of clinical steps involved. This classification was developed by van Meerbeek et al. (2003). 46

47. CLASSIFICATION BASED ON MODE OF APPLICATION- Ferrari Marco et al in 2007 MODE OF APPLICATION MECHANISM EXAMPLE MODIFY THE SMEAR LAYER  Adhesives modify the retained smear layer and incorporate it into the bonding process.  Penetration of monomers into the smear layer and their subsequent polymerization reinforces the attachment of the smear layer to the underlying dentin and also forms a micromechanical chemical bond to the underlying dentinal surface.  It is however observed that resin is able to penetrate only to a limited extent into the superficial dentin One step Prime and Bond 2.1 Two step Optec Universal Bond COMPLETELY REMOVE THE SMEAR LAYER  It results in complete removal of the smear layer by acidic conditioners that are simultaneously applied to enamel and dentin using the total etch technique.  The action of these agents is principally based on the combined effect of hybridization and resin tag formation. Multiple bottle All-Bond 2 One step Optibond Solo DISSOLVE THE SMEAR LAYER RATHER THAN REMOVE IT.  The process is accomplished in two steps using a self etching primer followed by application of the adhesive resin.  The slightly acidic primers supplied with these systems partially demineralize the smear layer and the underlying dentin surface without removing the dissolved smear layer remanants and unplugging the tubule orifices.  The rationale behind their use is to superficially demineralize dentin and simultaneously penetrate it with monomers, which can be polymerized in-situ. Two step:- Clearfil Liner Bond 2 Scotchbond 2 Syntac 47

48. FIRST GENERATION Sturdevant’s Art & Science of Operative Dentistry,6 TH edition, Harald o Heymann Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 48

49. SECOND GENERATION Most of the second generation bonding agents were:-  Phenyl phosphorous  chloro phosphorous esters of unfilled resins such as BisGMA or HEMA. The bonding mechanism involved improved wetting of the surface and ionic interaction between the phosphate group and calcium of the tooth. Bond strength= 2-7 Mpa DRAWBACKS OF 1 ST AND 2 ND GENERATION BONDING AGENTS:- Lack of adequate bond strength that could overcome contraction stresses during polymerization. Being hydrophobic in nature, close adaptation to the hydrophilic dentin could not be achieved. Biocompatibility was not appropriate. Lack of sufficient knowledge about the presence and nature of smear layer. Moreover, the adhesive was bonded to the smear layer rather than the dentin. As a result the bond achieved was limited by cohesive failure in the smear layer or a break at the smear layer-dentin interface 49 Sturdevant’s Art & Science of Operative Dentistry,6 TH edition, Harald o Heymann Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI

50. Sturdevant’s Art & Science of Operative Dentistry,6 TH edition, Harald o Heymann Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 50

51. THIRD GENERATION 51

52. SYSTEMS OF 3 RD GENERATION Presentation title 52

53. FOURTH GENERATION Sturdevant’s Art & Science of Operative Dentistry,6 TH edition, Harald o Heymann Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 53

54. SYSTEMS OF FOURTH GENERATION ETCHANT= 35% phosphoric acid on dentin and enamel PRIMER=2% NTG GMA (N Tolyglycine – glycidyl methacrylate) and 16% BPDM (biphenyl dimethacrylate ) in ethanol or acetone. ADHESIVE= unfilled resin containing BisGMA and HEMA is applied BOND STRENGTH= 21.4 MPa ALL BOND-2 CONDITIONER= 10% maleic acid PRIMER=an aqueous solution of HEMA and poly alkenoate copolymers. ADHESIVE= BisGMA containing HEMA. BOND STRENGTH= 21.0MPa with wet dentin and 18.0MPa with dry dentin Scotchbond Multipurpose Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 54

55. FIFTH GENERATION Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 55

56. 56 COMMERCIALLY AVAILABLE FIFTH GENERATION BONDING AGENTS

57. SIXTH GENERATION Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 57

58. TYPES OF SIXTH GENERATION These are available in light cure or dual cure product. Self etching primer and resin adhesives are applied in separate layers. Two bottles, Liquid 1 (acidic primer), Liquid 2 (adhesive); acidic primer applied to tooth followed by adhesive Unprepared enamel may require etching with phosphoric acid • Light cured/dual cured formulations • Solvent is water, e.g. Nano Bond, Optibond , Prompt L- PoP Available only in light cure type. The self-etch primer and adhesive is mixed outside and applied . Two bottles, containing acid primer and adhesive; a drop of each liquid is mixed and applied to tooth. Unprepared enamel may require etching with phosphoric acid Light cured formulations Solvent is water, e.g. Xeno III Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 58 TYPE 1 (SELF-ETCHING PRIMER AND ADHESIVE) TYPE 2 (SELF-ETCHING ADHESIVE)

59. SEVENTH GENERATION Available both as light cure and dual cure type. All three components are combined in a single bottle. Seventh generation bonding agents (No mixing, Self-etch adhesive) are slight modification of type II sixth generation bonding agent. The features are: More acidic (pH < 1) Single bottle containing acidic adhesive Unprepared enamel may require etching with phosphoric acid Solvent is water, e.g. G-Bond and i -Bond 59

60. ROLE OF WATER IN SELF ETCH ADHESIVES Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 60

61. EIGHTH GENERATION Himanshu Sood et al DENTIN BONDING AGENTS -A REVIEW European Journal of Molecular & Clinical Medicine ISSN 2515-8260 Volume 9, Issue 8, Autumn 2022 2188-95 61

62. WATER TREE PHENOMENA Tay and Pashley (2003) hypothesized that water trees in dental adhesives along with nanoleakage within the hybrid layer, represent water rich interfacial regions from which the leaching of hydrophilic resin components may occur readily, leading to degradation of resin-dentin bonds Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 62

63. REMNANT WATER THEORY Earlier authors belived that water trees were ‘left out’ water that was incompletely removed from water in dentin adhesives. Water trees were observed at resin dentin interface bonded with ethanol-based adhesives and rarely in acetone-based adhesives. It was further observed that addition of HEMA to water lowered the rate of evaporation of water from the HEMA-water mixture. 63 THIS THEORY DOES NOT ACCOUNT FOR FOLLOWING ASPECTS OF WATER FREE FORMATION. UNEVEN DISTRIBUTION Water trees are never uniformly described. Water trees were seldom seen in the central part of the adhesive layer; rather predominantly present at the surface of the hybrid layer. REVERSE WATER TREE Different shapes and forms of water trees have been observed. Usually water trees originate from the surface of dentin, with their branching pointing upwards into the adhesive. In case of reverse water tree, they appear to originate from water trapped at the interface between the adhesive and the overlying resin composite; they spread downwards with the ‘branches’ pointing towards dentin SECONDARY WATER TREE Water droplets are entrapped and seen as clear holes within the adhesive layer. When observed under silver nitrate tracer, water trees were seen radiating circumferentially from the periphery of these water droplets creating a ‘sunburst’ effect around the droplets. As water trees seldom exist when water containing adhesives are used to bond composite . It is unlikely that water tree formation is caused by water, that is present within the adhesive formulations. Two features which could not be explained are: • From where the water is derived • What triggers the movement of this additional source of water

64. WATER FLUX THEORY 64

65. NANO LEAKAGE & WATER TREE 65

66. FUNCTIONAL IMPLICATIONS OF WATER TREEING Textbook Of Operative Dentistry,4thed, VIMAL K SIKRI 66

67. Clinical factors in dentin bonding. Edward J. Swift, Jr., DMD, MS Bonding systems for restorative materialsa comprehensive review American Academy of Pediatric Dentistry Pediatric Dentistry - 20:2, 1998 67

68. SUCCESS AND FAILURE OF BONDING VIMAL K SIKRI 68

69. UNIVERSAL ADHESIVE ARE UNIVERSAL ADHESIVES REALLY UNIVERSAL? RECENT TREND IN ADHESIVE SYSTEMS. Presentation title 69

70. VERSATILE NATURE OF UNIVERSAL ADHESIVES

71. UNIVERSAL ADHESIVES & THEIR BASIC CHEMISTRIES Gary Alex, DMD Universal Adhesives: The Next Evolution in Adhesive Dentistry? Compendium of continuing education in dentistry January 2015 Volume 36, Number 1, Pg 15-26 71

72. IDEAL REQUIREMENTS OF UNIVERSAL ADHESIVES Gary Alex, DMD Universal Adhesives: The Next Evolution in Adhesive Dentistry? Compendium of continuing education in dentistry January 2015 Volume 36, Number 1, Pg 15-26 72

73. 10-MDP ADHESIVE FUNCTIONAL MONOMER Gary Alex, DMD Universal Adhesives: The Next Evolution in Adhesive Dentistry? Compendium of continuing education in dentistry January 2015 Volume 36, Number 1, Pg 15-26 73

74. The Delicate Balance Between Hydrophilic, Hydrophobic, And Adhesive Functional Monomers Gary Alex, DMD Universal Adhesives: The Next Evolution in Adhesive Dentistry? Compendium of continuing education in dentistry January 2015 Volume 36, Number 1, Pg 15-26 74

75. PUZZLE OF pH Gary Alex, DMD Universal Adhesives: The Next Evolution in Adhesive Dentistry? Compendium of continuing education in dentistry January 2015 Volume 36, Number 1, Pg 15-26 75

76. WAYS TO OPTIMIZE THE PERFORMANCE OF UNIVERSAL ADHESIVE SYSTEM 76 Gary Alex, DMD Universal Adhesives: The Next Evolution in Adhesive Dentistry? Compendium of continuing education in dentistry January 2015 Volume 36, Number 1, Pg 15-26

77. SILANES Presentation title 77

78. SILANE FORMATION Jukka Pekka Matinlinna ∗, Christie Ying Kei Lung∗, James Kit Hon Tsoi Silane adhesion mechanism in dental applications and surface treatments: A review J Dental material September, 2017, pg 1-16 78 STEPS IN SILANE FORMATION   L is an organofunctional group (e.g., methacrylate, acrylate) (CH2)k is a linker (spacer) group that separates the organofunctional group and the Si atom -OR is a hydrolysable alkoxy group (methoxy, ethoxy) SILICA

79. HYDROLYSIS OF SILANE Jukka Pekka Matinlinna ∗, Christie Ying Kei Lung∗, James Kit Hon Tsoi Silane adhesion mechanism in dental applications and surface treatments: A review J Dental material September, 2017, pg 1-16 79

80. COMMERCIALLY AVAILABLE PRODUCTS Jukka Pekka Matinlinna ∗, Christie Ying Kei Lung∗, James Kit Hon Tsoi Silane adhesion mechanism in dental applications and surface treatments: A review J Dental material September, 2017, pg 1-16 80 NAME MANUFACTURER SILANE CONTENT pH SOLVENT USE ESPE RelyX ceramic primer 3M ESPE, St. Paul, MN, USA ‘MPS’, <2 4.6 Ethanol-70-80% Water 20-30% Ceramic primer Laminates Porcelain Pulpdent silane bond enhancer Pulpdent , Watertown, MN, USA MPS, <2 6.3 Ethanol 92% Acetone 7% Porcelain Ultradent silane Ultradent Products, South Jordan, UT,USA MPS <10 5.3 Propan-2-ol <95 Porcelain

81. SILANE ADHESION THERE ARE THE TWO CRITICAL STEPS OF RESIN SUBSTRATE BONDING FORMATION WITH SILANE COUPLING AGENTS:- S ilane and substrate bond formation — activated by acid, Silane is activated by acid to form silanol groups which react with the substrate surface hydroxyl ( OH) groups by a condensation reaction (Si-OH + HO-substrate⇒Si-O-substrate ). R esin and silane bond formation — activated by light curing. The reaction between the organofunctional groups of silane (with a C-C bond), and functional groups of the resin. monomers containing C C bond is induced by the reactive free radicals generated by photo-activation of initiator components in the resin matrix. Jukka Pekka Matinlinna ∗, Christie Ying Kei Lung∗, James Kit Hon Tsoi Silane adhesion mechanism in dental applications and surface treatments: A review J Dental material September, 2017, pg 1-16 81 The strongest adhesion is attained with silica, glass and quartz which form strong siloxane ( Si O Si ) linkages through the condensation with surface hydroxyl groups on the substrate. Mild adhesion is obtained with pure metals and metal alloys by forming Si O M linkages. For gypsum, graphite and carbon black, a negligible concentration of surface hydroxyl groups, OH, makes it difficult to form bonding with silane.

82. APPLICATION Presentation title 82

83. CERAMIC BONDING Presentation title 83

84. MICROMECHANICAL INTERLOCKING OBTAINED BY VARIOUS SURFACE TREATMENT. Presentation title 84

85. ADHESION TO SILICA BASED CERAMICS Presentation title 85

86. ADHESION TO ZIRCONIA BASED CERAMICS Rodrigo Dalla Lana Mattiello , et al A Review of Surface Treatment Methods to Improve the Adhesive Cementation of Zirconia-Based Ceramics,ISRN Biomaterials, Aug 2013 86 SURFACE TREATMENT:- STMs must be correlated to the type of ZrO2. PRIMER SELECTION:-  Universal Adhesive Systems:- In October 2009, Bisco, Inc. introduced a dedicated zirconia primer, Z-Prime™, that utilized a combination of 10-MDP and biphenyl dimethacrylate (BPDM) in its formulation (C. Suh, Bisco, Inc., personal communication). Two years after the introduction of Z-Prime, 3M ESPE introduced the first “universal” adhesive ( Scotchbond Universal), which also utilized 10-MDP in its formulation (J. Fundingsland , 3M ESPE, personal communication).  In glass infiltrtated zirconia, prior application of silane adhesives can also be included. -- Ceramics type STM Y-TZP ZrO2 50–150 𝜇m Al2O3 air-abrasion, with 2.5 bars, 10 mm distance, for 15 seconds. Glass infiltrated ZrO2 Air-abrasion with Si-coating Al2O3 particles ( CoJet or Rocatec system), at 4.5 bars, 10 mm distance for 10 seconds.

87. ALLOY PRIMER Presentation title 87

88. REPAIR OF PORCELAIN FUSED METAL CROWN AND BRIDGES Presentation title 88