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Bonding in orthodontics /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

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  • 1. Bonding in OrthdonticsBonding in Orthdontics www.indiandentalacademy.comwww.indiandentalacademy.com INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
  • 2.  HistoryHistory  Advantages ,disavantagesAdvantages ,disavantages  Factors affecting bondingFactors affecting bonding  Bonding procedureBonding procedure  Bonding agentsBonding agents www.indiandentalacademy.comwww.indiandentalacademy.com
  • 3. Based on the investigations of Silverstone,Based on the investigations of Silverstone, acid solutions in concentrations of 20–acid solutions in concentrations of 20– 50% applied for 1–2 minutes was found to50% applied for 1–2 minutes was found to produce the most retentive conditionsproduce the most retentive conditions In 1968 Smith introducedIn 1968 Smith introduced Znpolycarboxylate for bracket bonding.Znpolycarboxylate for bracket bonding. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 4. Buonocore in 1955 introduced the conceptBuonocore in 1955 introduced the concept of acid etching. Pretreatment with 85%of acid etching. Pretreatment with 85% phosphoric acid increased adhesion.phosphoric acid increased adhesion. In 1965 Newman applied direct bonding toIn 1965 Newman applied direct bonding to orthodontics.orthodontics. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 5. Miura et al described an acrylicMiura et al described an acrylic resin(orthomite) using trialkylboraneresin(orthomite) using trialkylborane catalyst for bonding plastic brackets andcatalyst for bonding plastic brackets and for enhanced adhesion in presence offor enhanced adhesion in presence of moisture.moisture. Bowens resin or bisGMA(bisphenolABowens resin or bisGMA(bisphenolA glycidyl dimethacrylate) –designed toglycidyl dimethacrylate) –designed to improve bond strength and improveimprove bond strength and improve dimensional stability by crosslinking.dimensional stability by crosslinking. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 6. AAdvantages of Bondingdvantages of Bonding  Esthetically superiorEsthetically superior  Faster and simplerFaster and simpler  Less discomfort for patientLess discomfort for patient  More precise bracket placementMore precise bracket placement  Improved gingival condition possibleImproved gingival condition possible  Partially erupted teeth can be controlledPartially erupted teeth can be controlled  Mesiodistal enamel reduction possibleMesiodistal enamel reduction possible during treatmentduring treatment www.indiandentalacademy.comwww.indiandentalacademy.com
  • 7. Interprximal areas are accessible forInterprximal areas are accessible for composite buildupscomposite buildups Caries risk under loose bands isCaries risk under loose bands is eliminatedeliminated No band spaces to close at the end ofNo band spaces to close at the end of tratmenttratment  Brackets may be recycled furtherBrackets may be recycled further reducing the costreducing the cost Lingual brackets or invisible braces mayLingual brackets or invisible braces may be used when esthetics is importantbe used when esthetics is important www.indiandentalacademy.comwww.indiandentalacademy.com
  • 8. Disadvantages of BondingDisadvantages of Bonding  Bonded bracket has a weaker attachment than aBonded bracket has a weaker attachment than a cemented bandcemented band  Excess adhesive extending beyond the bracketExcess adhesive extending beyond the bracket base can cause poor oral hygiene ,leading tobase can cause poor oral hygiene ,leading to gingival inflammationgingival inflammation  Protection against interproximal caries of wellProtection against interproximal caries of well contoured cemented bands is absentcontoured cemented bands is absent  Rebonding a loose bracket requires moreRebonding a loose bracket requires more preparation timepreparation time  Debonding is more time consuming thanDebonding is more time consuming than debanding as removal of adhesive is moredebanding as removal of adhesive is more difficult than removal of cementdifficult than removal of cement www.indiandentalacademy.comwww.indiandentalacademy.com
  • 9. Factors affecting BondingFactors affecting Bonding Enamel solubilityEnamel solubility Preeuptive factors: chemical orPreeuptive factors: chemical or histological charecteristics of tooth .histological charecteristics of tooth . Hypocalcification or hypoplasia of aHypocalcification or hypoplasia of a permanent teethpermanent teeth Excessive ingestion of flourideExcessive ingestion of flouride www.indiandentalacademy.comwww.indiandentalacademy.com
  • 10. Posteruptive factotrsPosteruptive factotrs Topical flouridesTopical flourides Presence of plaquePresence of plaque www.indiandentalacademy.comwww.indiandentalacademy.com
  • 11. Conditioning solutionConditioning solution  Phosophoric acid -35 to 50%Phosophoric acid -35 to 50%  Zinc oxide – acts as a buffer and partiallyZinc oxide – acts as a buffer and partially neutralizes the acid.neutralizes the acid.  gels are added to improve the viscosity. Increasedgels are added to improve the viscosity. Increased concentration or viscosity does not ensure betterconcentration or viscosity does not ensure better etching:etching:  Gwinnet and Buonnocore suggested the use ofGwinnet and Buonnocore suggested the use of lower concentration of phosphoric acid .lower concentration of phosphoric acid . www.indiandentalacademy.comwww.indiandentalacademy.com
  • 12. Application of 50% phosphoric acid forApplication of 50% phosphoric acid for 60sec results in formation of monocalcium60sec results in formation of monocalcium phosphate monohydrate ppt that can bephosphate monohydrate ppt that can be rinsed off.rinsed off. Concentration below 27% lead to formationConcentration below 27% lead to formation of dicalcium phosphate which cannot beof dicalcium phosphate which cannot be rinsed offrinsed off www.indiandentalacademy.comwww.indiandentalacademy.com
  • 13. Operator induced complications:Operator induced complications: water contamination via three way syringe.water contamination via three way syringe. Care is taken not to rub the etched enamelCare is taken not to rub the etched enamel with cotton or fingers to avoidwith cotton or fingers to avoid contamination of surface by greasecontamination of surface by grease particles $ perspiration.particles $ perspiration. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 14. Factors influencing bonding to ideallyFactors influencing bonding to ideally etched enameletched enamel Salivary contamination :salivary proteinsSalivary contamination :salivary proteins clog the porosities of etched enamelclog the porosities of etched enamel Water contamination via three wayWater contamination via three way syringe.syringe. Care is taken not to rub the etched enamelCare is taken not to rub the etched enamel with cotton or fingers to avoidwith cotton or fingers to avoid contamination of surface by greasecontamination of surface by grease particles $ perspiration.particles $ perspiration. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 15. Uniform etching at the gingival margin is moreUniform etching at the gingival margin is more difficult :difficult : As sealent approaches marginalAs sealent approaches marginal gingiva,seapage of crevicular fluid acts as agingiva,seapage of crevicular fluid acts as a barrier to the flow of the fluid below the freebarrier to the flow of the fluid below the free gingival margingingival margin Sealant ledge formed at the gingival marginSealant ledge formed at the gingival margin www.indiandentalacademy.comwww.indiandentalacademy.com
  • 16. therefore etching area be restricted to thetherefore etching area be restricted to the center of the clinical crowncenter of the clinical crown to ensure safe marginal seal conditionedto ensure safe marginal seal conditioned area should be larger than bracket & padarea should be larger than bracket & pad area.area. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 17. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 18. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 19. Bonding procedureBonding procedure CleaningCleaning Enamel conditioning and bondingEnamel conditioning and bonding SealingSealing bondingbonding www.indiandentalacademy.comwww.indiandentalacademy.com
  • 20. CleaningCleaning - essential to remove plaque and- essential to remove plaque and organic pellicleorganic pellicle - requires rotary instruments – rubber- requires rotary instruments – rubber cup or a polishing brushcup or a polishing brush -care must be taken to avoid-care must be taken to avoid traumatising gingival margintraumatising gingival margin www.indiandentalacademy.comwww.indiandentalacademy.com
  • 21. For increased patient control cleaningFor increased patient control cleaning should be done before use of moistureshould be done before use of moisture control devicescontrol devices Pumice and water residue is eliminatedPumice and water residue is eliminated www.indiandentalacademy.comwww.indiandentalacademy.com
  • 22. Enamel conditioningEnamel conditioning moisture controlmoisture control :: -- cheek retractorscheek retractors - saliva ejectors- saliva ejectors - cotton or gauze rolls- cotton or gauze rolls - antisialogogues :probathaline, atropine- antisialogogues :probathaline, atropine - dri angles : ot restrict saliva flow from- dri angles : ot restrict saliva flow from parotid glandparotid gland www.indiandentalacademy.comwww.indiandentalacademy.com
  • 23. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 24. Enamel pretreatmentEnamel pretreatment Conditioning solution 35% to 50% isConditioning solution 35% to 50% is applied lightly over the enamel with foamapplied lightly over the enamel with foam pellet , or brush for 60 sec. Surface mustpellet , or brush for 60 sec. Surface must be kept moist by repeated application.be kept moist by repeated application. Etchant is rinsed off using abundant waterEtchant is rinsed off using abundant water sprayspray High speed evacuator used to removeHigh speed evacuator used to remove etchant water sprayetchant water spray www.indiandentalacademy.comwww.indiandentalacademy.com
  • 25.  Teeth are thoroughly dried with air sourceTeeth are thoroughly dried with air source to obtain dull frosty appearanceto obtain dull frosty appearance  Some additional points :Some additional points : - etching entire facial surface with solution is- etching entire facial surface with solution is harmlessharmless - gel gives better control for restricting the etched- gel gives better control for restricting the etched area but requires more thorough rinsingarea but requires more thorough rinsing afterwards.afterwards. -According to Pus routine etching removes 3-10-According to Pus routine etching removes 3-10 micrometer of surface enamelmicrometer of surface enamel www.indiandentalacademy.comwww.indiandentalacademy.com
  • 26. According to Silverstone the etchingAccording to Silverstone the etching patterns were related to five types:patterns were related to five types: Type 1:Type 1: preferential dissolution of thepreferential dissolution of the prism cores resulting in a “honeycomb”prism cores resulting in a “honeycomb” appearance.appearance. Type 2:Type 2: preferential dissolution of thepreferential dissolution of the prism peripheries giving a “cobblestone”prism peripheries giving a “cobblestone” appearance.appearance. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 27. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 28. Type 3:Type 3: a mixture of type 1 and 2 patterns.a mixture of type 1 and 2 patterns. Type 4:Type 4: pitted enamel surfaces as well aspitted enamel surfaces as well as structures which look like unfinishedstructures which look like unfinished puzzles, maps, or network.puzzles, maps, or network. Type 5:Type 5: flat, smooth surfaces.flat, smooth surfaces. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 29. 40% solution40% solution  Occlusal and central sites:Occlusal and central sites: The type 2 etching patternThe type 2 etching pattern with preferentialwith preferential dissolution of the prismdissolution of the prism peripheries predominatesperipheries predominates resulting in aresulting in a “cobblestone” appearance“cobblestone” appearance www.indiandentalacademy.comwww.indiandentalacademy.com
  • 30.  Cervical third :pittedCervical third :pitted enamel surface ,typeenamel surface ,type IV pattrenIV pattren www.indiandentalacademy.comwww.indiandentalacademy.com
  • 31.  Chow and Brown reported that phosphoric acidChow and Brown reported that phosphoric acid concentrations greater than ~27% produceconcentrations greater than ~27% produce monocalcium phosphate monohydrate as amonocalcium phosphate monohydrate as a soluble product, while concentrations less thansoluble product, while concentrations less than ~27% form dicalcium phosphate dihydrate. The~27% form dicalcium phosphate dihydrate. The former product is readily soluble and would beformer product is readily soluble and would be completely washed away in the clinical situation,completely washed away in the clinical situation, whereas the latter product is less soluble.whereas the latter product is less soluble.  Total loss of superficial enamel, which isTotal loss of superficial enamel, which is especially rich in fluoride, is probably smallerespecially rich in fluoride, is probably smaller after etching with 2% or 5% phosphoric acidafter etching with 2% or 5% phosphoric acid than with a 40% solution.than with a 40% solution. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 32. Disadvantages of phosphoric acid:Disadvantages of phosphoric acid: 1.may contribute to decalcification1.may contribute to decalcification 2. development of white spots around the2. development of white spots around the around bonded appliancearound bonded appliance 3.enamel fracture particularly when3.enamel fracture particularly when debonding ceramic bracketsdebonding ceramic brackets www.indiandentalacademy.comwww.indiandentalacademy.com
  • 33.  Softer etching procedures effected mainlySofter etching procedures effected mainly the type 1 pattern with preferentialthe type 1 pattern with preferential dissolution of the prism cores. Type 2dissolution of the prism cores. Type 2 pattern represents an advanced stage ofpattern represents an advanced stage of the etching process possibly caused by athe etching process possibly caused by a breakdown of the fragile prism peripheries.breakdown of the fragile prism peripheries. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 34. The sequence of etching patterns obtainedThe sequence of etching patterns obtained with different acid concentrations gave thewith different acid concentrations gave the impression that the type 2 pattern, i.e.impression that the type 2 pattern, i.e. increased dissolution of the prismincreased dissolution of the prism peripheries, occurred predominantly atperipheries, occurred predominantly at higher acid concentrations (40% andhigher acid concentrations (40% and 20%).20%). www.indiandentalacademy.comwww.indiandentalacademy.com
  • 35. The etching patterns were generallyThe etching patterns were generally similar in the occlusal and central part ofsimilar in the occlusal and central part of the buccal surfaces and frequently differedthe buccal surfaces and frequently differed from the cervical area. Galil and Wrightfrom the cervical area. Galil and Wright reported that type 4 and 5 patternsreported that type 4 and 5 patterns predominated in the cervical regions andpredominated in the cervical regions and types 1, 2, and 3 in the occlusal andtypes 1, 2, and 3 in the occlusal and central regions. .central regions. . www.indiandentalacademy.comwww.indiandentalacademy.com
  • 36. The aprismatic layer is of variableThe aprismatic layer is of variable thickness . The crystallites within the layerthickness . The crystallites within the layer are oriented with their axis almostare oriented with their axis almost perpendicular to the enamel surface. It isperpendicular to the enamel surface. It is present at the cervical third of eamelpresent at the cervical third of eamel www.indiandentalacademy.comwww.indiandentalacademy.com
  • 37. Arakawa reported that the resinArakawa reported that the resin penetration was considerably worse in thepenetration was considerably worse in the cervical region than in the central andcervical region than in the central and occlusal regions.occlusal regions. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 38. Disadvantages of phosphoric acid:Disadvantages of phosphoric acid: 1.may contribute to decalcification1.may contribute to decalcification 2. development of white spots around the2. development of white spots around the around bonded appliancearound bonded appliance 3.enamel fracture particularly when3.enamel fracture particularly when debonding ceramic bracketsdebonding ceramic brackets www.indiandentalacademy.comwww.indiandentalacademy.com
  • 39. Alternative etchants as maleic acid:Alternative etchants as maleic acid: 1.produce clinically reliable bond strength1.produce clinically reliable bond strength 2. reduce depth of enamel dissolution2. reduce depth of enamel dissolution disadvantage of acid etching:disadvantage of acid etching: 1.risk of contamination of moisture and1.risk of contamination of moisture and saliva is increasedsaliva is increased 2.unpleasnt taste of acid2.unpleasnt taste of acid www.indiandentalacademy.comwww.indiandentalacademy.com
  • 40. Selfetching primers donot penetrate theSelfetching primers donot penetrate the enamel surface to the same depth asenamel surface to the same depth as phosphoric acid so conservative treatmentphosphoric acid so conservative treatment possiblepossible [JCO October2005][JCO October2005] www.indiandentalacademy.comwww.indiandentalacademy.com
  • 41. Brajen Unibond is a self etching , lightBrajen Unibond is a self etching , light cured bonding systemcured bonding system Etching pattern similar to that ofEtching pattern similar to that of phosphoric acidphosphoric acid Acid is neutralised by calciumAcid is neutralised by calcium hydrxyapatite of enamel but specialhydrxyapatite of enamel but special compounds are able to penetrate mineralcompounds are able to penetrate mineral component of enamelcomponent of enamel www.indiandentalacademy.comwww.indiandentalacademy.com
  • 42. SEP provides a microretntive bondSEP provides a microretntive bond strength of 22MPastrength of 22MPa Adhesive is designed to release flourideAdhesive is designed to release flouride Good resistance to discolorationGood resistance to discoloration Combines acid etching and priming into aCombines acid etching and priming into a single stepsingle step www.indiandentalacademy.comwww.indiandentalacademy.com
  • 43. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 44. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 45. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 46. SealingSealing Dry the tooth completelyDry the tooth completely Thin layer of sealant painted over theThin layer of sealant painted over the etched surface with a small foam pellet.etched surface with a small foam pellet. Excess sealant may cause bracket drift.Excess sealant may cause bracket drift. Inetrmediate resin is essential for betterInetrmediate resin is essential for better bond strength and pervent microleakage.bond strength and pervent microleakage. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 47. BondingBonding Transfer: reverse action tweezersTransfer: reverse action tweezers Positioning :placement scaler such asPositioning :placement scaler such as RM 349 used to position. This allowsRM 349 used to position. This allows visualisation of the slot w.r.t. ncisal edgevisualisation of the slot w.r.t. ncisal edge and long axisand long axis FittingFitting Removal of excess:scaler or cabide burRemoval of excess:scaler or cabide bur used.used. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 48. BondingBonding www.indiandentalacademy.comwww.indiandentalacademy.com
  • 49. Indirect bondingIndirect bonding Advantage :Advantage : -bracket can be more accurately positioned-bracket can be more accurately positioned -chair side time is reduced-chair side time is reduced ProcedureProcedure www.indiandentalacademy.comwww.indiandentalacademy.com
  • 50. Ideal properties of bonding agentIdeal properties of bonding agent Be nontoxic systemically & to oral tissuesBe nontoxic systemically & to oral tissues Adequte working & setting timeAdequte working & setting time Have moderate viscosityHave moderate viscosity Have sufficient tensile strength &Have sufficient tensile strength & compressive strengthcompressive strength Have ability to wet etched enamelHave ability to wet etched enamel Should resist decomposition in oralShould resist decomposition in oral enviornment.enviornment. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 51. 1955, Buonocore : 30-second application of1955, Buonocore : 30-second application of 85% orthophosphoric acid .85% orthophosphoric acid . In 1962, Bowen :In 1962, Bowen : -bisphenol A-glycidyl dimethacrylate (bis--bisphenol A-glycidyl dimethacrylate (bis- GMA) resin.GMA) resin. -bis-GMA : stronger and more stable than-bis-GMA : stronger and more stable than the acrylic , especially when an inorganicthe acrylic , especially when an inorganic filler material was added.filler material was added. (Volume 1989 Jul (8 - 15): Bond strength comparison(Volume 1989 Jul (8 - 15): Bond strength comparison - Milne, Andreasen, and Jakobsen- Milne, Andreasen, and Jakobsen)) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 52. 1964, Newman :1964, Newman : -bond orthodontic brackets to the teeth-bond orthodontic brackets to the teeth -acid-etch technique and an epoxy-derived-acid-etch technique and an epoxy-derived resin.resin. In 1970, BuonocoreIn 1970, Buonocore - combined the acid-etch technique with a- combined the acid-etch technique with a bis-GMA resinbis-GMA resin - sealing pits and fissures against caries.- sealing pits and fissures against caries. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 53. Weisser (1973) and Silverman andWeisser (1973) and Silverman and associates (1974) : application of directassociates (1974) : application of direct bonded orthodontic bracketsbonded orthodontic brackets  using the acid etch and bis-GMA resinusing the acid etch and bis-GMA resin system.system. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 54. Silverman, Cohen, used aSilverman, Cohen, used a methylmethacrylate and ultraviolet-light-methylmethacrylate and ultraviolet-light- activated unfilled bis-GMA resin.activated unfilled bis-GMA resin.  used chairside as an intermediaryused chairside as an intermediary adhesive between the patient's etchedadhesive between the patient's etched enamel and the preset adhesive on theenamel and the preset adhesive on the bracket base.bracket base. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 55. Resins based composites are moreResins based composites are more viscous than unfilled acrylic resins ,dilutionviscous than unfilled acrylic resins ,dilution by monomers to decrease viscosityby monomers to decrease viscosity &enhance wetting was done.&enhance wetting was done. improved mechanical bonding byimproved mechanical bonding by optimum formation if resin tagsoptimum formation if resin tags www.indiandentalacademy.comwww.indiandentalacademy.com
  • 56. Traditionally: Bis GMA +TEGDMA toTraditionally: Bis GMA +TEGDMA to control viscositycontrol viscosity  these are hydrophobic & worked well asthese are hydrophobic & worked well as long as it was restricted to enamellong as it was restricted to enamel For dentin bonding there should beFor dentin bonding there should be hydrophillic group that bonds dentin & ahydrophillic group that bonds dentin & a hydrophobic group that bonds the resin.hydrophobic group that bonds the resin. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 57. Composite resinsComposite resins Basic compositionBasic composition Resin matrix: BISGMAResin matrix: BISGMA Filler: quartz ,colloidal silicaFiller: quartz ,colloidal silica Coupling agent :organosilanesCoupling agent :organosilanes Inhibitor : hydroquinoneInhibitor : hydroquinone Opacifiers: titanium oxide and aluminiumOpacifiers: titanium oxide and aluminium oxideoxide www.indiandentalacademy.comwww.indiandentalacademy.com
  • 58. Ultraviolet light-cured introduced thirtyUltraviolet light-cured introduced thirty years ago and quickly replaced thoseyears ago and quickly replaced those products that were self-cured.products that were self-cured. Disadvantage :Disadvantage : - radiation hazards- radiation hazards -limited depth of cure.-limited depth of cure.  blue, visible light-cured composite resinblue, visible light-cured composite resin replaced ultraviolet light light cure resins,replaced ultraviolet light light cure resins, visible light has deepervisible light has deeper www.indiandentalacademy.comwww.indiandentalacademy.com
  • 59. Selfcure compositesSelfcure composites Initiator : benzoyl peroxideInitiator : benzoyl peroxide Activator: tertiary amineActivator: tertiary amine www.indiandentalacademy.comwww.indiandentalacademy.com
  • 60. DisadvantagesDisadvantages  The polymerization :starts immediately on mixingThe polymerization :starts immediately on mixing  air bubbles that arise during mixingair bubbles that arise during mixing uneven consistencies in resinsuneven consistencies in resins weakening of the bond strengthweakening of the bond strength (1992 AJO-DO, Volume Apr (350 - 354): Bond strength between light-(1992 AJO-DO, Volume Apr (350 - 354): Bond strength between light- and self-cured resin - Wang and Meng)and self-cured resin - Wang and Meng) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 61. rapid polymerization occurs when therapid polymerization occurs when the visible light spectrum producing avisible light spectrum producing a "command set" of the resin."command set" of the resin.  an unlimited working time is possible withan unlimited working time is possible with the visible light-cured resin, allowing morethe visible light-cured resin, allowing more accuracy and an unlimited number ofaccuracy and an unlimited number of bracket placements with each mix.bracket placements with each mix. ((Volume 1989 Sep (214 - 220): In vitro evaluation ofVolume 1989 Sep (214 - 220): In vitro evaluation of visible light-cured resin system used in bonding -visible light-cured resin system used in bonding - Greenlaw, Way, and Galil)Greenlaw, Way, and Galil)www.indiandentalacademy.comwww.indiandentalacademy.com
  • 62. Light cure resinsLight cure resins single paste system The ketone,single paste system The ketone, camphoroquinone, is sensitive to blue lightcamphoroquinone, is sensitive to blue light at a 470 nm wavelength, which catalyzesat a 470 nm wavelength, which catalyzes the polymerization reaction.the polymerization reaction. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 63. Tensile bond strength of Transbond 60Tensile bond strength of Transbond 60 and 40 stronger than that of Transbond 20and 40 stronger than that of Transbond 20 Bond strength of light-cured resin ofBond strength of light-cured resin of Transbond and self cure resin (except inTransbond and self cure resin (except in instances of 20 seconds or less ofinstances of 20 seconds or less of exposureexposure ((AJOAJO 1992 ,101 350 -354 Comparison of bond strength of light1992 ,101 350 -354 Comparison of bond strength of light cure and selfcure -Wei Nan wangcure and selfcure -Wei Nan wang)) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 64. disadvantagesdisadvantages diffuse penetration of the light for curingdiffuse penetration of the light for curing the resinthe resin incomplete polymerization beneath theincomplete polymerization beneath the surfacesurface limited depth of cure, ranging from 2.0 tolimited depth of cure, ranging from 2.0 to 3.0 mm3.0 mm  doubling the exposure time increased thedoubling the exposure time increased the cured depth by about a third (3.0 to 4.0cured depth by about a third (3.0 to 4.0 mm in depth).mm in depth). www.indiandentalacademy.comwww.indiandentalacademy.com
  • 65. Transbond 60 and 40 have the same bondTransbond 60 and 40 have the same bond strength,strength, adequate time exposure for clinical usageadequate time exposure for clinical usage is 40 seconds to keep minimum operativeis 40 seconds to keep minimum operative timetime www.indiandentalacademy.comwww.indiandentalacademy.com
  • 66. Glass ionomer cement :acid etchingGlass ionomer cement :acid etching not requirednot required Easier to remove from the enamelEasier to remove from the enamel than composites.than composites. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 67. Dentin poses greater obstacles thanDentin poses greater obstacles than enamel :enamel : - it is a living tissue- it is a living tissue - it consists 20% volume of fluid- it consists 20% volume of fluid - tubular fluid adversely affects adhesion- tubular fluid adversely affects adhesion www.indiandentalacademy.comwww.indiandentalacademy.com
  • 68. Glass ionomer cementGlass ionomer cement www.indiandentalacademy.comwww.indiandentalacademy.com
  • 69. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 70. Properties of glass-ionomer liners includes effective bonding to dentin,  release of fluoride,  radio-opacity, low thermal conductivity (Shear bond strength of composite, glass ionomer, and acidic primer adhesive systems Samir E. Bishara AJO 1999 volume 115) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 71.  this product has its own conditioner (20% polyacrylic acid) that removes the smear layer and prepares Carboxyl group of polyacids react with calcium of apatite of enamel and dentin Takes 24 hrs for conventional GICs toTakes 24 hrs for conventional GICs to achieve maximum strengthachieve maximum strength www.indiandentalacademy.comwww.indiandentalacademy.com
  • 72. The results indicated that the resin/phosphoric acid adhesive system (control group) provided the strongest shear bond strength (10.4 ± 2.8 MPa). The glass ionomer adhesive system provided a significantly lower bond strength ( 6.5 ± 1.9 MPa) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 73.  Glass ionomer cement (GIC)  bond chemically to enamel and dentine without etching these surfaces, and  release fluoride ions to the vicinity.  not recommended for bonding orthodontic brackets due to lower bond strength compared to composite resin.  To increase the bond strength, some resins, such as hydroxydimethacrylate and BIS-GMA, are added to GIC. (Shear bond strength of resin reinforced GIC- CHUN,HSI CHUNG AJO DO 1999VOLUME 115) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 74. Resin modified glass ionomerResin modified glass ionomer cementcement COMPOSITIONCOMPOSITION  Fuji Ortho LC powderFuji Ortho LC powder - fluoroalumino-silicate glass- fluoroalumino-silicate glass - polyacrylic acid, water, monomer, and an- polyacrylic acid, water, monomer, and an activator. Theactivator. The -2-hydroxyethyl-methacrylate .-2-hydroxyethyl-methacrylate . -camphorquinone as a photoinitiator.-camphorquinone as a photoinitiator. ((AJODOAJODO 1995,108,231 to 236)1995,108,231 to 236) Elliott Silverstone and MortonElliott Silverstone and Morton CohenCohen)) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 75. Setting reactionSetting reaction -an acid-base reaction-an acid-base reaction - The light irradiation activates free radical- The light irradiation activates free radical polymerization of HEMA to form a polyHEMApolymerization of HEMA to form a polyHEMA matrix that hardens the material.matrix that hardens the material. -self-cure of the resin monomers.-self-cure of the resin monomers. -light initiated reaction : early placement of arch-light initiated reaction : early placement of arch wires,wires, -the acid-base reaction occurs simultaneously and-the acid-base reaction occurs simultaneously and continues for a period of time after the mass hascontinues for a period of time after the mass has been cured by light irradiation.been cured by light irradiation. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 76.  It polyHEMA and the polyacrylic metal salt form aIt polyHEMA and the polyacrylic metal salt form a homogeneous matrix that surrounds the glass particles.homogeneous matrix that surrounds the glass particles. ADVANTAGESADVANTAGES  more comfortable appointments for both the patient andmore comfortable appointments for both the patient and the operator.the operator.  releases fluoridereleases fluoride does not require etching of the enamel,does not require etching of the enamel,  around brackets may well be reduced or eliminated.around brackets may well be reduced or eliminated. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 77. saves valuable chair time with respect tosaves valuable chair time with respect to composite resin bonding :composite resin bonding : - keeping the field dry not required- keeping the field dry not required - etching and priming steps eliminated- etching and priming steps eliminated www.indiandentalacademy.comwww.indiandentalacademy.com
  • 78. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 79. LandmarksLandmarks Acid pretreatment with 85% phosphoric acid Buonocore 1955 bisphenolA-Glycidyl dimethacrylate Bis-GMA Bowen 1962 Cyanoacrylates,polyesters,polyurethanes as ortho adhesives Newman 1965 Direct bonding with epoxy resin G V Newman 1965 Zinc polyacrylate(carboxylate) Mizrahi and smith.1968 www.indiandentalacademy.comwww.indiandentalacademy.com
  • 80. 1st detailed posttreatment evaluation Of direct bonding Zachrisson 1977 U V light cure bonding Silverman 1971 Acrylic resin using tri n borane as catalyst Miura, masuhara 1971 Visible light cure bonding 1979 www.indiandentalacademy.comwww.indiandentalacademy.com
  • 81.  The minimum bond strength required for clinical success is related to the forces of occlusion and not to the forces generated by an orthodontic arch wire. The force generated by an orthodontic arch wire ranges from 15 to 150 gm. Forces produced during mastication are highly variable, with a range up to 50 kg.(40- 120 N)  Thickness of the bonding material between the bracket base and tooth surface is 0.2 to 0.5 mm. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 82. First generation bonding agentFirst generation bonding agent  Experimental bonding systems based on epoxyExperimental bonding systems based on epoxy resins and acrylic resinsresins and acrylic resins  Uses silane coupling agents whichUses silane coupling agents which -bond inorganic filler to the matrix of resin-bond inorganic filler to the matrix of resin -are gamma-methacryloxyprorpyl trimethoxysilane-are gamma-methacryloxyprorpyl trimethoxysilane - represented as M-X.- represented as M-X. -First generation ignored the smear layer-First generation ignored the smear layer www.indiandentalacademy.comwww.indiandentalacademy.com
  • 83.  M is the unsaturated group capable ofM is the unsaturated group capable of copolymerising with unfilled resin.copolymerising with unfilled resin.  X is capable of chemically reacting with siliceousX is capable of chemically reacting with siliceous substratesubstrate  Disadvantage :Disadvantage : 1.high polymerisation shrinkage1.high polymerisation shrinkage 2.different coeffiient of thermal expansion from2.different coeffiient of thermal expansion from enamelenamel 3. Bond strength is 2-3 MPa3. Bond strength is 2-3 MPa www.indiandentalacademy.comwww.indiandentalacademy.com
  • 84. First generation contained NPG-GMAFirst generation contained NPG-GMA An example of NPG-GMA bonding agentAn example of NPG-GMA bonding agent isis S.S. White cervident .S.S. White cervident . www.indiandentalacademy.comwww.indiandentalacademy.com
  • 85. Second generation dental adhesiveSecond generation dental adhesive Polymerisation byPolymerisation by ultraviolet lightultraviolet light  polymerizable phosphates added to BiS-GMApolymerizable phosphates added to BiS-GMA resins promote bonding to calcium called asresins promote bonding to calcium called as phosphate bonding systemphosphate bonding system  In 1978 clearfill bond system F (Kuraray Japan)In 1978 clearfill bond system F (Kuraray Japan) was introduced- first product of secondwas introduced- first product of second generation bonding system(sturdevant).Thisgeneration bonding system(sturdevant).This contained HEMA and Phenyl Pcontained HEMA and Phenyl P www.indiandentalacademy.comwww.indiandentalacademy.com
  • 86. Significant chemical bonding betweenSignificant chemical bonding between adhesive and tooth structure was lackingadhesive and tooth structure was lacking Second generation contained NPG-GMASecond generation contained NPG-GMA (N phenyl glycine glycidyl methacrylate)(N phenyl glycine glycidyl methacrylate) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 87. Mechanism of action :polar interactionMechanism of action :polar interaction between negatively charged phosphatebetween negatively charged phosphate group in resin and positively chargedgroup in resin and positively charged calcium ion in the tooth structurecalcium ion in the tooth structure Disadvantage:Disadvantage: -radiation hazard-radiation hazard - low bond strength- low bond strength -resins devoid of hydrophillic component-resins devoid of hydrophillic component - limited depth of penetration.- limited depth of penetration. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 88. Third generation dental adhesivesThird generation dental adhesives Filled or composite resins addedFilled or composite resins added Based on use of an acid group to react withBased on use of an acid group to react with Ca ions & a methacrylate group toCa ions & a methacrylate group to copolymerise with resin.copolymerise with resin.  these used a conditoning step on dentinthese used a conditoning step on dentin Conditioning agents interact with superficialConditioning agents interact with superficial dentindentin www.indiandentalacademy.comwww.indiandentalacademy.com
  • 89.  Bowen in 1982 developed aBowen in 1982 developed a multistepmultistep adhesive systemadhesive system called as an oxalate bondingcalled as an oxalate bonding system.system.  Used dentin conditioner of 2.5% nitric acidUsed dentin conditioner of 2.5% nitric acid in combination with ferric oxalate.in combination with ferric oxalate.  Bond strength -10.2 to 18.5 MpaBond strength -10.2 to 18.5 Mpa  Bowen later replaced ferric oxalate withBowen later replaced ferric oxalate with aluminium oxalate.Bond strength increased toaluminium oxalate.Bond strength increased to 12.5 +/_ 3.2 Mpa12.5 +/_ 3.2 Mpa www.indiandentalacademy.comwww.indiandentalacademy.com
  • 90. Third generation bonding proceduresThird generation bonding procedures involved following steps:involved following steps: 1 Application of dentin conditioner (type of1 Application of dentin conditioner (type of acid to alter or remove smear layer)acid to alter or remove smear layer) 2.Application of primer2.Application of primer 3.application of adhesive, resin3.application of adhesive, resin Advantage :improved thermal expansionAdvantage :improved thermal expansion qualitiesqualities Removing the flash once it sets is difficultRemoving the flash once it sets is difficult www.indiandentalacademy.comwww.indiandentalacademy.com
  • 91. Develops full strength with in few minutesDevelops full strength with in few minutes Sets rapidlySets rapidly www.indiandentalacademy.comwww.indiandentalacademy.com
  • 92. Fourth generationFourth generation NO MIX TECHNIQUENO MIX TECHNIQUE Excess resin not polymeriseExcess resin not polymerise www.indiandentalacademy.comwww.indiandentalacademy.com
  • 93. It was recognised that phosphoric acidIt was recognised that phosphoric acid could be used to etch both enamel &could be used to etch both enamel & dentin. Previous generations relied ondentin. Previous generations relied on separate etching regimens for enamel &separate etching regimens for enamel & dentin. Thereforedentin. Therefore total etch techniquetotal etch technique was used. This led to decreasedwas used. This led to decreased complexitycomplexity www.indiandentalacademy.comwww.indiandentalacademy.com
  • 94. Fifth generationFifth generation  Used visible light to activate polymerisationUsed visible light to activate polymerisation Micromechanical retention is obtained byMicromechanical retention is obtained by  Penetratoin into partiallly open dentinal tubulesPenetratoin into partiallly open dentinal tubules  Formation of a layer in which hydrophillicFormation of a layer in which hydrophillic monomer penetrate and polymerise to form anmonomer penetrate and polymerise to form an intrepenetrating network with the demineralisedintrepenetrating network with the demineralised collagen fibril network.This leads to good bondcollagen fibril network.This leads to good bond strengthstrength www.indiandentalacademy.comwww.indiandentalacademy.com
  • 95. DisadvantageDisadvantage difficult to get enough visible light todifficult to get enough visible light to bonding material below the base of thebonding material below the base of the bracket to obtain good polymerisation.bracket to obtain good polymerisation. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 96. journal namejournal name www.indiandentalacademy.comwww.indiandentalacademy.com
  • 97. Sixth generation bonding agentSixth generation bonding agent  Self etching primer: etches and primes toothSelf etching primer: etches and primes tooth simultaneuoslysimultaneuosly  Composition: phosphoric acid and methacrylate groupsComposition: phosphoric acid and methacrylate groups  Advantage :Advantage : -reduce number of procedural steps during bonding-reduce number of procedural steps during bonding -Decrease chair side time-Decrease chair side time Product will allow bonding in areas that are difficult toProduct will allow bonding in areas that are difficult to isolate.isolate. Bark Mier : Resin penetrated through enamel surface andBark Mier : Resin penetrated through enamel surface and adequate conditioning was achievedadequate conditioning was achieved www.indiandentalacademy.comwww.indiandentalacademy.com
  • 98. The bonding method involves a pumice prophylaxis, followed by application of the self Etching adhesive for three seconds, a quick blast of air to thin the material, and direct attachment of the bracket to the tooth with a light-cured composite resin. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 99.  Acidic part of the primer dissolves the smear layer and incorporates it into the mixture. Acidic primer solutions also demineralize the dentin and encapsulate the collagen fibers and hydroxyapatite crystals.  This simultaneous conditioning and priming allows penetration of the monomer into the dentin. The adhesive resin component will then diffuse into the primed dentin, which produces a “hybrid layer. (Sameer E. bishara) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 100. Samir E. Bishara.Samir E. Bishara. Shear bond strength of composite, glass ionomer, and acidic primer adhesive systems Am. J . Orthod Dentofacial orthop;1999 :115:24-8 www.indiandentalacademy.comwww.indiandentalacademy.com
  • 101. Combine the conditioning (Phenyl P) and priming (HEMA and dimethacrylate) agents into a single acidic primer solution that can be used on enamel and dentin. Seventy freshly extracted human molars www.indiandentalacademy.comwww.indiandentalacademy.com
  • 102. Group I : polyacrylic acid and GICGroup I : polyacrylic acid and GIC Group II:composite resin adhesive + 37% acid  Group III:same composite resin +acidic primer www.indiandentalacademy.comwww.indiandentalacademy.com
  • 103.  Results : 1. Resin/phosphoric acid adhesive system (control group): shear bond strength ( 10.4 ± 2.8 MPa) 2.GIC adhesivesystem: bond strength ( 6.5 ± 1.9 MPa) 3.acidic primer + orthodontic adhesive: ( 2.8 ± 1.9Mpa www.indiandentalacademy.comwww.indiandentalacademy.com
  • 104. Samir E.Bishara.Samir E.Bishara. Effect of an acidic primer on shear bond strength of orthodontic brackets: Am J Orthod Dentofacial Orthop 1998;114:243-71998;114:243-7 www.indiandentalacademy.comwww.indiandentalacademy.com
  • 105. Group1: 37%phosphoric acid +Group1: 37%phosphoric acid + system1+adhesive (activator liquid +system1+adhesive (activator liquid + adhesive paste placed on bracket)adhesive paste placed on bracket) Group2: 10%maleic acidGroup2: 10%maleic acid +system1+adhesive+system1+adhesive Group3:acidic primer + lightly filledGroup3:acidic primer + lightly filled resins(BisGMA)resins(BisGMA) Group4:acidic primer +highly filled resinsGroup4:acidic primer +highly filled resins www.indiandentalacademy.comwww.indiandentalacademy.com
  • 106. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 107. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 108. RESULTS  acidic primers bonded to orthodontic brackets to the enamel surface can provide clinically acceptable shear bond forces ( 10.4 +/- 4.4 MPa) when used with a highly (77%) filled adhesive.  These debonding forces were comparable to those obtained when the enamel was conditioned with either phosphoric ( 11.8 +/- 4.1 MPa) or maleic ( 10.9 +/- 4.4MPa) acids. With the use of a lightly (10%) filled adhesive (Clearfil Liner Bond 2), the shear bond strength was significantly lower (5.9+/- 5.6 MPa). www.indiandentalacademy.comwww.indiandentalacademy.com
  • 109. Brajen Unibond is a self etching , lightBrajen Unibond is a self etching , light cured bonding systemcured bonding system Etching pattern similar to that ofEtching pattern similar to that of phosphoric acidphosphoric acid Acid is neutralised by calciumAcid is neutralised by calcium hydrxyapatite of enamel but specialhydrxyapatite of enamel but special compounds are able to penetrate mineralcompounds are able to penetrate mineral component of enamelcomponent of enamel www.indiandentalacademy.comwww.indiandentalacademy.com
  • 110. SEP provides a microretntive bondSEP provides a microretntive bond strength of 22MPastrength of 22MPa Adhesive is designed to release flourideAdhesive is designed to release flouride Good resistance to discolorationGood resistance to discoloration Combines acid etching and priming into aCombines acid etching and priming into a single stepsingle step www.indiandentalacademy.comwww.indiandentalacademy.com
  • 111. Seventh Generation bonding agentSeventh Generation bonding agent MIP is hydrophilic because it contains 2- hydroxyethyl methacrylate, polyalkenoate copolymers with carboxylate groups, and ethanol. (Ram Kumar Gandhi .Shear bond strength(Ram Kumar Gandhi .Shear bond strength of stainless steel brackets with moistureof stainless steel brackets with moisture insensitive brackets; AJODO 2001:insensitive brackets; AJODO 2001: 119:251-5)119:251-5) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 112. Concise with its conventional primer had the highest shear bond strength under dry etched enamel surface(14.86 MPa)  Enamel wet with either water or saliva, there was a dramatic and highly significant drop in the bond strength for both the conventional primer and the MIP. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 113. MIP in combination with Transbond XT produced acceptable bond strengths in the presence of a thin film of water or saliva (9.69 MPa and 8.90 MPa) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 114. MIP used with Concise under dry etched enamel surface conditions, the MIP might diffuse into the resin,causing sufficient bond strength without light activation. In contrast, in a wet field, the primer becomes diluted and also no visible light to cure it www.indiandentalacademy.comwww.indiandentalacademy.com
  • 115.  MIP : hydrophilic nature. It is designed to be visible-light cured.  MIP is used with Transbond XT: it can be cured by the visible light that penetrates the resin. Thus, MIP was found to be effective when used with Transbond XT on enamel surfaces contaminated with either water or saliva.  Concise is chemically activated: no mechanism for the hardening of MIP because there is no application of visible light. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 116. Hobson RS, Ledvinka J .The effect ofHobson RS, Ledvinka J .The effect of moisture and blood contamination onmoisture and blood contamination on bond strength of new orthodontic material.bond strength of new orthodontic material. Am.J.Orthod DentofacialAm.J.Orthod Dentofacial orthop2002;122:267-73orthop2002;122:267-73 www.indiandentalacademy.comwww.indiandentalacademy.com
  • 117. Transbond XT with MIP, (Moisture Insensitive Primer,3M/Unitek Dental Products) and Assure (Reliance Orthodontics, Itasca, Ill), a light-cured bis- GMA-type resin. 144 freshly extracted bovine teeth www.indiandentalacademy.comwww.indiandentalacademy.com
  • 118. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 119. Results:Results: highest mean bond strength in groups 1highest mean bond strength in groups 1 and 4and 4 lowest mean bond strength in groups 2&3lowest mean bond strength in groups 2&3 www.indiandentalacademy.comwww.indiandentalacademy.com
  • 120.  Noncontaminated enamel surfaces had the highest bond strengths for both the hydrophilic and hydrophobic materials.  When using a hydrophobic primer, if the etched surface is contaminated with saliva before primer application, it may be necessary to re- etch before proceeding with the bonding procedure. If the contamination occurs after the primer had been placed and cured simple drying and reapplication of primer is necessary to obtain adequate bond strength www.indiandentalacademy.comwww.indiandentalacademy.com
  • 121. CCeramic bracketseramic brackets www.indiandentalacademy.comwww.indiandentalacademy.com
  • 122. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 123.  The esthetic requirements of orthodontic treatment - tooth-colored attachments.  Esthetic brackets - based on polycarbonates and metal-reinforced plastics had been introduced for direct bonding, but they were found clinically inefficient because of their high debonding rates ,lack of strength to resist distortion and breakage,wire slot wear ,discoloration  The ceramic bracket is made of polycrystalline aluminum oxide (Al203) with a specially prepared bonding surface www.indiandentalacademy.comwww.indiandentalacademy.com
  • 124. Bonding ceramic brackets:Bonding ceramic brackets: The ceramic bracket is made of polycrystalline aluminum oxide (Al203) with a specially prepared bonding surface 2 mechanisms;2 mechanisms; Mechanical retention via indentations andMechanical retention via indentations and or undercuts in the bracket base.or undercuts in the bracket base. Chemical bonding using an adhesiveChemical bonding using an adhesive intermediate.intermediate. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 125. Chemically bndedChemically bnded • More recent development. • Glass is added to the aluminium oxide bracket base and treated with silane coupling agent. The silane bonds with glass and has a free end of its molecules that will react with any of acrylic bonding materials • The same mechanism as that used for porcelain crowns and restorations • Produces exceptonal bond strength….But www.indiandentalacademy.comwww.indiandentalacademy.com
  • 126. Can possibly exceed brittle fracture resistance. Stresses of debonding shift from bracket – adhesive interface to enamel- adhesive interface inducing enamel cracks If bracket to adhesive bond is too strong then failure can occur within the enamel within the adhesive or within the ceramic www.indiandentalacademy.comwww.indiandentalacademy.com
  • 127. Bonding materials for ceramics: No-mix or one step bonding materials contraindicated:  They have higher concentrations of amine polymerization accelerator. (Tends to discolour more.) www.indiandentalacademy.comwww.indiandentalacademy.com
  • 128. The newer light cured restorative materials-adhesives of choice. Excellent colour stability Adequate time for bracket placement.  An unfilled acrylic cement gave the highest values of bond strength for both the plastic and the ceramic brackets. A highly filled diacrylate cement gave the highest values of bond strength for the metal brackets. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 129. Ceramic brackets are large , very hardCeramic brackets are large , very hard and do not bend on pressure , extracarefuland do not bend on pressure , extracareful debonding is necessary not to introducedebonding is necessary not to introduce enamel cracksenamel cracks All adhesive outside the bracket isAll adhesive outside the bracket is removed with a bur before bracket isremoved with a bur before bracket is gently lifted off the toothgently lifted off the tooth Also surface of ceramic brackets isAlso surface of ceramic brackets is rougher .thus sttracts more plaquerougher .thus sttracts more plaque www.indiandentalacademy.comwww.indiandentalacademy.com
  • 130. Metal bracketsMetal brackets Rely on mechanical retention for bondingRely on mechanical retention for bonding Perforated bases provide less bondPerforated bases provide less bond strength and are less hygienic than meshstrength and are less hygienic than mesh backed bases as more plaquebacked bases as more plaque accumalates on adhesive resin flowingaccumalates on adhesive resin flowing through holesthrough holes Meshbacked bases should be small andMeshbacked bases should be small and follow gingival contourfollow gingival contourwww.indiandentalacademy.comwww.indiandentalacademy.com
  • 131. Corrosion of metal brackets due to poorCorrosion of metal brackets due to poor bondingbonding through crevice causes black and greenthrough crevice causes black and green stainsstains www.indiandentalacademy.comwww.indiandentalacademy.com
  • 132. Conditioning agents used include:Conditioning agents used include: 1.1. Hydroxymethylmetacrylaye(HEMA)Hydroxymethylmetacrylaye(HEMA) 2.2. solution of maleic acidsolution of maleic acid 3.3. 2% aqueous nitricacid2% aqueous nitricacid - another system consisted of- another system consisted of  aqueous EDTA : as a conditioneraqueous EDTA : as a conditioner  bonding agent: 2% gluteraldehydebonding agent: 2% gluteraldehyde  it reacts with collagen rather the nitric oxideit reacts with collagen rather the nitric oxide www.indiandentalacademy.comwww.indiandentalacademy.com
  • 133. Light cured resins do not set until light ofLight cured resins do not set until light of suitable wavelength and intensity issuitable wavelength and intensity is applied to produce free radicals byapplied to produce free radicals by disruption of double bonds in the alphadisruption of double bonds in the alpha diketone initiator. A wavelength betweendiketone initiator. A wavelength between 460 and 480 nm, within the blue end of the460 and 480 nm, within the blue end of the visible spectrum, is used at an intensityvisible spectrum, is used at an intensity that allows it to pass through the enamelthat allows it to pass through the enamel and produce rapid setting.and produce rapid setting. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 134. BONDING INBONDING IN ORTHODONTICSORTHODONTICS www.indiandentalacademy.comwww.indiandentalacademy.com
  • 135. CONVENTIONAL LIGHTCONVENTIONAL LIGHT CURINGCURING  DISADVANTAGESDISADVANTAGES 1.1. 40 secnds – curing time40 secnds – curing time 2.2. Halogen bulb life -100hrsHalogen bulb life -100hrs 3.3. Increased electricity consumptionIncreased electricity consumption 4.4. Bulky unitBulky unit www.indiandentalacademy.comwww.indiandentalacademy.com
  • 136.  LCU bulb reflectors and filters can degrade overLCU bulb reflectors and filters can degrade over timetime  Large amount of heat is produced duringLarge amount of heat is produced during operating cycles decreasing effectiveness overoperating cycles decreasing effectiveness over time.time.  Ageing LCU produces less effectiveAgeing LCU produces less effective polymerisation and increased premature failurepolymerisation and increased premature failure of restorationof restoration www.indiandentalacademy.comwww.indiandentalacademy.com
  • 137. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 138. PLASMA ARC CURING LIGHTSPLASMA ARC CURING LIGHTS Light source : Xenon bulbLight source : Xenon bulb Mechanism of action :Mechanism of action : www.indiandentalacademy.comwww.indiandentalacademy.com
  • 139. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 140. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 141. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 142. Example: Appolo 95 E from dental medicalExample: Appolo 95 E from dental medical diagnosticsdiagnostics filters high intensity white lightfilters high intensity white light produce blue light (400-500nm)produce blue light (400-500nm) amount several times greateramount several times greater www.indiandentalacademy.comwww.indiandentalacademy.com
  • 143. exposure time -3 secondsexposure time -3 seconds latent period -1.5 secondslatent period -1.5 seconds Disadvantage:Disadvantage:  progress impededprogress impeded  extremely expensiveextremely expensive www.indiandentalacademy.comwww.indiandentalacademy.com
  • 144. W.P. Rock,T.B.Ip. Comparison of threeW.P. Rock,T.B.Ip. Comparison of three light curing units:Journal of Orthodonticslight curing units:Journal of Orthodontics 2004:31;243-2472004:31;243-247 www.indiandentalacademy.comwww.indiandentalacademy.com
  • 145.  Using a plasma light, a 2 seconds exposure toUsing a plasma light, a 2 seconds exposure to adhesive pre-coated (APC) orthodontic bracketsadhesive pre-coated (APC) orthodontic brackets produced a mean bond strength - 9.6 MPaproduced a mean bond strength - 9.6 MPa  Plasma light for 4 seconds produced a meanPlasma light for 4 seconds produced a mean bond strength of 11.19 MPa, equivalent to thebond strength of 11.19 MPa, equivalent to the quartz halogen lights and standard visible lightquartz halogen lights and standard visible light cure at 10 and 20 seconds, respectively.cure at 10 and 20 seconds, respectively. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 146. ARGON LASERSARGON LASERS  Blue light with narrow wavelengthBlue light with narrow wavelength distributiondistribution Example:LaserMed AccueCure300 TMExample:LaserMed AccueCure300 TM Mechanism of action: emitting collimatedMechanism of action: emitting collimated beam of light that can travel distancebeam of light that can travel distance without dispersingwithout dispersing www.indiandentalacademy.comwww.indiandentalacademy.com
  • 147. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 148.  LaserMed light diffuses light into a cone whichLaserMed light diffuses light into a cone which is ideal for orthodontic appliancesis ideal for orthodontic appliances  Audible tone sounds every five secondsAudible tone sounds every five seconds  Advantage: bonding many brackets in a rowAdvantage: bonding many brackets in a row  Light guide made from glass fiberopticLight guide made from glass fiberoptic www.indiandentalacademy.comwww.indiandentalacademy.com
  • 149. LIGHT EMITTING DIODESLIGHT EMITTING DIODES  Mechanism of action:Use junction of semiconductorsMechanism of action:Use junction of semiconductors  Life time : 10000 hoursLife time : 10000 hours  Require no filters to produce blue lightRequire no filters to produce blue light  Resistant to shock and vibrationResistant to shock and vibration  Relatively low power consumptionRelatively low power consumption  Low heat output while on useLow heat output while on use www.indiandentalacademy.comwww.indiandentalacademy.com
  • 150.  fracture resistant chord even when bentfracture resistant chord even when bent or droppedor dropped  light weight and easy to handlelight weight and easy to handle reasonable costreasonable cost  gallium nitride technology replacedgallium nitride technology replaced silicon nitride technology in 1995 whichsilicon nitride technology in 1995 which increased output of lightincreased output of light www.indiandentalacademy.comwww.indiandentalacademy.com
  • 151. www.indiandentalacademy.comwww.indiandentalacademy.com
  • 152. THANK YOUTHANK YOU www.indiandentalacademy.comwww.indiandentalacademy.com For more details please visitFor more details please visit www.indiandentalacademy.comwww.indiandentalacademy.com