Bleaching of discolored - PowerPoint Presentation

1. Bleaching of discolored toothSIBAR INSTITUTE OF DENTAL SCIENCES,GUNTUR DEPARTMENT OF CONSERVATIVE DENTISTRY AND ENDODONTICSDr. G. ANIL KUMARSENIOR LECTURER

2. ContentsIntroductionTooth discoloration definitionClassification of DiscolourationAetiology of DiscolourationBleaching Mechanism of BleachingBleaching MaterialsBleaching Techniques for Vital and Nonvital teethAdverse Effects of bleaching on ToothConclusion

3. IntroductionDiscoloration of teeth is a cosmetic problems that is often the patient’s primary concern. Although restorative procedures are available, discoloration can often be corrected totally or partially by a more conservative approach i.e. bleaching, which is relatively simple to perform and less expensive.

4. Definition Tooth discoloration is defined as any change in the hue, value or translucency of a tooth due to any cause. (Ingle 6th edition)

5. CLASSIFICATION OF TOOTH DISCOLOURATIONExtrinsic discolourationIntrinsic discolourationCombination of both-Nisha garg

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7. Classification of Extrinsic StainsNathoo’s Classification (chemistry of tooth discoloration) N1 Type (Direct Dental Stain) Coloured material(chromogen) binds to the tooth’s surface and causes discoloration. N2 Type (Direct Dental Stain) Colored material(chromogen) changes color after binding to the tooth. N3 Type (Indirect Dental Stain) Colourless material or a pre-chromogen binds to the tooth and undergoes a chemical reaction to cause a stain.

8. Etiology of Tooth Discolouration The etiology of tooth discolouration may be extrinsic or intrinsic or both. Extrinsic stains:Diet related Bacterial stainsMedicationsHabits

9. Pipe smokingBacterial productsMouth washTobacco stainsMouth wash

10. Extrinsic stains1. Diet: affects multiple teeth appears as yellow or brown stains.Consumption of strong tea or coffee immediately after orange or grape juice is a common cause of external discoloration.Etiology of Tooth Discolouration:

11. 2. Bacterial Stains:Chromogenic bacteria frequently seen in the deciduous or mixed dentition dotted green, or black-brown to orange stain.

12. 3. Medication: Chlorhexidine acts in reducing plaque formation by disturbing the pellicle matrix formation, which attracts more extrinsic stains not readily removed by tooth brushing.

13. 4. Habits: Smoking marijuana may produce characteristic linear, green circumferential rings at the cervical margins. Smoking tobacco causes a yellow-brown discolouration especially on the lingual aspects of the teeth. Chewing tobacco causes a black-brown stain that is most noticeable on the buccal surfaces of the mandibular posterior teeth. Tobacco stainsPipe smoking

14. 5) Gingival HemorrhageChronic gingivitis may induce staining from the breakdown of blood in the gingival sulcus.6) Swimmers calculusYellow- dark brown stain in facial and lingual surfaces of anterior teeth Prolonged exposure to pool water.

15. Etiology of Tooth DiscolourationPRE-ERUPTIVEDisease: Haematological diseasesLiver diseasesDiseases of enamel and dentine (e.g. Amelogenesis/ Dentinogenesis imperfecta)Medication: TetracyclineFluorosis stains (excess F)Enamel hypoplasia (trauma or infection) POST-ERUPTIVETrauma (e.g. pulpal haemorrhagic products) Primary and secondary cariesTooth wearDental restorative materialsAgeing Chemicals AntibioticsIntrinsic stains

16. Enamel hypoplasiaTraumaMild fluorosisSevere flourosis Tetracycline staining Mild tetracycline stainsDentinogenesis imperfectaAmelogenesis imperfectaPulpal heamorrhagic product

17. Types of DiscolorationColour ProducedExtrinsic (Direct stains)Tea, coffee and other foodsCigarettes/cigarsPlaque/poor oral hygieneBrown to blackYellow/brown to blackYellow/brownExtrinsic (Indirect stains)Polyvalent metal salts and cationic antisepticse.g. ChlorhexidineBlack and brownIntrinsic(Metabolic causes)e.g. Congenital erythropoietic porphyria(Inherited causes)e.g. Amelogenesis Imperfectae.g. Dentinogenesis Imperfecta(Iatrogenic causes)TetracyclineMinocyclineFluorosis(Traumatic causes)Pulpal haemorrhage productsRoot resorption(Ageing causes)Purple/brownBrown or blackBlue-brown (opalescent)Banding appearance: classically yellow, brown, blue, black or greyGreyWhite, yellow, grey or blackBrown/Grey blackPink spotYellowInternalizedCariesRestorationsOrange to brownBrown, grey, black

18. INTRINSIC STAINSAlkaptonuria:- Also known as phenylketonuria or ochronosis. recessive genetic disorder resulting in dark brown pigmentation of the permanent teeth. Bleaching - yes

19. Amelogenesis imperfecta:- -Primary and Permanent dentition Hypo maturtion: where the enamel is chipped off from the underlying dentin Hypo calcification: where the thickness of enamel is normal but is soft in consistency and completely abrades soon after eruption dull opaque white to a dark brown. + tooth surfaces are rough and pitted.

20. Hypo plastic: where the enamel is quiet thin, smooth, hard and yellow in appearance, with occasionally pitting. Bleaching – No

21. Dentinogenesis Imperfecta: autosomal dominantSeen in systemic disorder of bone (osteogenesis imperfecta).Teeth: amber-like color due to deposits of minerals in dentinal tubules Bleaching – No

22. Flourosis:optimum concentration of fluoride - 1ppm. 2ppm -noticeable white spots occur in the enamel. 3ppm- patchy brown discolouration of the enamel occurs. Higher concentrations - pitting and anomalies in the enamel formation. The high concentration of fluoride  metabolic alteration in the ameloblasts which results in a defective matrix and improper calcification.

23. FluorosisBleaching: yes(mild cases)SEVERE:Bleaching + bonded composite or porcelain veneersWhite areas if superficialenamel microabrasion

24. Erythroblastosis fetalis:- Rh incompatibility  massive lysis of erythrocytes.The discolouration ranges from brown to greenish-blue. usually “self-treating” and the staining resolves as the child matures.

25. Porphyria:- Metabolic disease. Reddish-brown discolouration of the teeth : Erythrodontia.Common- Primary dentitionTreatment:Bleaching + composite veneers

26. Tetracycline stainingCrosses the placental barrier :affect both primary and permanent dentition. The tetracycline molecule binds to the calcium of the tooth forming tetracycline orthophosphate. The clinical appearance of tetracycline-stained teeth ranges from light yellow to dark grey bands. Darker shades: gingival 1/3rd of the teeth , Lighter shades: incisal 1/3rd of the teeth .

27. Tetracycline stainingSeverity of tooth discolouration - four factorsAge at the time of administration: Anterior primary teeth are susceptible to discoloration by systemic tetracycline from 4 months in utero to 9 months post partum. Anterior permanent teeth are susceptible from 3 months post partum to 8 years. 2. Duration of administration: Severity is directly proportional to the length of time the medication was administered. 3. Dosage: Severity is directly proportional to the administered dosage.4. Type

28. Classification of the tetracycline stainingJordan and Boksman:Primary staining: Light yellow or light grey, slight but uniformly distributed without banding. Secondary staining: Darker or more extensive yellow or grey staining without banding.Tertiary staining: Severe staining characterized by dark grey or blue discoloration, usually with banding.

29. Primary tetracycline stainsSecondary tetracycline stainsTertiary tetracycline stains

30. Minocycline Staining:Minocycline- a semisynthetic derivative of tetracycline -absorbed in gastroinstestinal tract. Minocycline : has the ability to chelate with iron and form insoluble complexes, forming a black discolouration . Minocycline stains: responsive to bleaching.

31. Intrapulpal haemorrhage: Traumatic injury to a tooth,  disruption of coronal blood vessels, haemorrhage and lysis of erythrocytes.Blood disintegration products, iron sulfides permeate dentinal tubules to stain the dentin.The iron sulfides are converted to black ferric sulphide with hydrogen sulphide produced by bacteria  grey staining of the tooth. If the pulp becomes necrotic, the discoloration usually remains. If the pulp survives, the discoloration may resolve and the tooth reverts to its original shade.

32. Dentin hypercalcifiation/calcific metamorphosis: It is the extensive formation of tertiary dentin in the pulp chamber or on canal walls due to traumatic injuries which did not result in pulpal necrosis. Temporary disruption of blood supply + partial destruction of odontoblasts. These are replaced by undifferentiated mesenchymal cells that rapidly form irregular dentin on the walls of the pulp lumen.yellowish or yellow-brown discoloration can be seen.

33. Remnants of pulpal tissues:Pulp fragments remaining in the crown, usually pulp horns, may cause gradual discoloration. Ensure complete removal of pulpal remnants during access opening to prevent discoloration.

34. Intracanal medicaments:Minocycline in triple antibiotic paste. tendency to discolour the dentin gradually.

35. Obturating materials: Incomplete removal of obturating materials and sealer remnants in the pulp chamber, mainly those containing metallic components, often results in dark discoloration. Such discolouration can be prevented by removing all the obturating material to a level just cervical to the gingival margins.

36. Amalgam:Restoration: -Silver alloys : dark coloured metallic components causes dentin to turn dark grey. -Replacing the amalgam restoration with an esthetic restoration corrects the problem. b) Pins and Posts: Discolorations from inappropriately placed pins and posts is caused by a metal seen through the thin tooth structure. In such cases, coverage of the pins with composite resin or removal of the metal and replacement of it with composite restoration is indicated.

37. Composites: Microleakage due to open margins around composite restoration causes staining. Needs to be replaced with a new well sealed restoration.

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39. Internalized discoloration:Internalized discoloration is the incorporation of extrinsic stain within the tooth substance following dental development.The routes by which pigments may become internalized are:1.Developmental defects2. Acquired defectsa) Tooth wear and gingival recessionb) Dental cariesc) Restorative materials

40. BLEACHING Defined as the lightening of the color of a tooth through the application of chemical agent to oxidise the organic pigmentation in the tooth. (Sturdevant) Advantages: Safe procedure Painless No tooth reduction required No anesthesia necessary Least expensive to treatment alternatives

41. BLEACHING Disadvantages:Normal tooth color cannot be restored. prolong treatment plan It is effective in selective casesLead to Cervical resorption of toothBleaching can cause discomfort in children because of their large pulps

42. Chemistry of bleaching:

43. Mechanism of Bleaching -Complete Dental Bleaching by: Ronald E.Goldstein,David A. Garber

44. Mechanism of bleaching of H2O2: H2O2 FREE RADICALS (nascent oxygen,perhydroxyl)Oxidative power breaks up larger macromolecule stains into smaller stain molecules: which reflects less light:Tooth appear lighter Free oxygen opens carbon ring of pigmented molecules converts them into colorless hydroxyl compounds: lighter in color

45. H2O2 Saturation pointAs bleaching proceeds, a point is reached at which only hydrophilic colourless structure exist. This is material’s saturation point.Over bleaching causes:breakdown of carbon backbone of proteins, loss of enamel, tooth brittleness and increased porosityStop Bleaching at or before saturation point to achieve maximum whitening, whereas overbleaching degrades enamel with out further whitening.

46. Dental Bleaching Materials Hydrogen Peroxide Containing Hydrogen Peroxide : various Concentrations Carbamide Peroxide Non Hydrogen Peroxide Materials Sodium Perborate

47. Hydrogen Peroxide It is a clear, colourless and odourless liquid. Higher concentrations of these solutions must be handled with care as they are thermodynamically unstable and may explode .So it should be refrigerated and kept in a dark container.Caustic in nature: chemical burn of soft tissues.It can be used for both intra and extra-coronal bleaching.

48. Hydrogen Peroxide Produces 2 type of Free Radicals (pH Dependant) One Weaker Oxygen free Radical O· One Stronger,more potent Perhydroxyl free Radical HO2· O· HO2·Alkaline pH 9.5- 10.8Acidic pH

49. Acidic pH -Alkaline pH -Ionization of hydrogen peroxide

50. Ionization of Hydrogen Peroxide 2H2O2 Enzymes /Decompn Catalyst 2H2O+ O2Teeth Must be dry and Free of Debris to Prevent Enzymatic Ionization No free radicals are produced and the bleaching is ineffective

51. H2O2 (Hydrogen Peroxide):Mode of Supply:Solution: -30% to 35% solutions are the most commonly used. Gel: -Silicon dioxide gels containing various concentrations of hydrogen peroxide (6 to 38%).Recent: Opalescence extra boost (38% hydrogen peroxide) for quicker results.These gels are also available in preloaded disposable whitening tray (9%hydrogen peroxide): Crest white from Ultradent.30% H2O2: SUPEROXOL

52. Teeth whitening strips:- These are flexible pieces of plastic or polyethylene that have been coated on one side with a thin film of hydrogen peroxide gel (6% to 10%).The idea of the teeth whitening strips was to reduce the thickness of the peroxide gel (0.2mm). It is advised to use these strips for 30 min twice a day.6% gel strips for 14 days & 10% gel strips for 10 days.

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54. Adverse effects of Hydrogen peroxide:Caustic(30%:superoxol-inoffice ):soft tissue burnCervical root resorption after non vital tooth bleaching. Increased postop sensitivity after vital tooth bleaching.High concentration of hydrogen peroxide damage enamel surface integrityBleaching with hydrogen peroxide increase the solubility of glass ionomer and other cements. H2O2 residues in the enamel may inhibit the polymerization of resin based material(composites) and reduce bond strength.

55. Carbamide peroxideIt is a clear, colourless , odourless liquid. Also known as urea hydrogen peroxide, cabramyl peroxide, perhydrol urea,, carbamide urea, urea H2O2 and H2O2 carbamide.MODE OF SUPPLY-The most common mode of supply is in the form of gels, which are supplied in syringes.- It is available in various concentrations ranging from 3 to 45%. -Commercial preparation contain about 10% carbamide peroxide with a mean pH of 5 to 6.5. 10% carbamide peroxide breaks down into urea,ammonia,carbondioxide, and 3.5% hydrogen peroxide. Used for extracoroanl bleaching & Intracoronal bleaching

56. Ionization of Carbamide Peroxide Dispensed in Acidic pH – Extends Shelf LifeUrea produced on ionization tilts pH to Basic –Favours further Production of Perhdroxyl group from H202 Carbamide peroxide used as bleaching agent breaks down into H2O2. 10% carbamide peroxide produces 3.6% H2O2.

57. Sodium PerborateWhite powdered form & they are alkaline.When fresh, it contains about 95% perborate corresponding to 9.9% of the available oxygen. It is stable when dry and decomposes in the presence of acid, warm air or water into: sodium metaborate,hydrogen peroxide releasing nascent oxygen. It is either mixed with water or hydrogen peroxide to form a thick paste and is packed into the pulp chamber in NON-VITAL BLEACHING.

58. Ionization of Sodium Perborate On contact with Water Breaks down to Sodium metaborate and 10% H2O2 Available in 3 forms: monohydrate trihydrate tetrahydrate On contact with H2O2 Breaks down to Sodium metaborate and water releasing oxygen

59. Enzymes-Considerable bleaching efficiency : extrinsic and intrinsic stains.-Obtained either from plants or microorganisms. Laccases: - Act on the molecular oxygen and yield hydrogen peroxide. -They are obtained from fungi. -Effective against intrinsic stains. Oxidases: -Act on the molecular oxygen and yield hydrogen peroxide. -They are obtained from Microorganisms. -Effective against extrinsic stains. Peroxides:-Act on hydrogen peroxide and yield water.- They are obtained from plants or from microorganisms. -Effective against both extrinsic and intrinsic stains.

60. Bleaching TechniquesClassified Broadly as: Vital Tooth bleaching Non vital Tooth bleaching

61. In-office Bleaching/ Power Bleaching Dentist Administered Bleaching Technique Bleaching agent alone (Chemical activated) Heat /Light activated. Dual activated (Light & chemical activated) Laser activated. Dentist Supervised Bleaching (Waiting room bleach/Assisted bleaching technique) At Home Bleaching Dentist supervised Night guard bleaching. Over the Counter products. Combination Techniques Combination of In-office and at home bleaching.Classification of Vital Bleaching

62. Closed chamber Bleaching TechniquesIntracoronal BleachingWalking Bleaching Technique.Modified intracoronal bleaching technique.Thermocatalytic technique.Extracoronal Bleaching Open chamber Bleaching Technique Inside/Outside technique Classification of Non Vital Bleaching

63. BLEACHING TECHNIQUESNisha Garg

64. IN- OFFICE BLEACHING TECHNIQUESDentist Administered Bleaching Utilizes about 25–35% hydrogen peroxideProcedure:Protection of the soft tissues : rubber dam or Opal Dam (Light Cured resin Barrier) Hydrogen peroxide applied and activated by heat or light for around one hour in the dental office Will have 3-5 cycles/session.Light Activation includes: Halogen curing lights, Plasma Arc Lamp, xe–halogen Light, Diode Lasers (both 830 &980 nm) or Metal Halide Light .Advantages: Complete control lies with the dentist and can stop it when the desired shade is achieved.30% H2O2: Superoxol

65. IN- OFFICE BLEACHING TECHNIQUEBleaching agent : Old / New McInnes solution

66. Vital bleachingpreoperativePost operative

67. COMPRESSIVE POWER BLEACHING TECHNIQUE Reported by Miara Advocates Compressing the bleaching gel against the teeth for increased efficacy Rationale:Majority of Free radical ions migrate to the gel surface on decomposition and only a fraction penetrates the enamel. Pressure is applied using polyethylene tray, and tray is secured in place using light cured resin.Pressure enables more permeation of oxidizing ions through the enamel.

68. COMPRESSIVE POWER BLEACHING TECHNIQUE

69. Utilizes 35% Carbamide Peroxide (Releases about 10% H2O2)Introduced by Den – Mat (Quick-Start System) Introduced to : initiate the bleaching in dental clinic and then the patient can continue bleaching at waiting room. 35% carbamide peroxide applied into a custom-made bleaching tray and placed in the patient’s mouth.Excess material removed and patient waits in the waiting room for a period of about 30 minutes 2-3 cycles/ Session.IN- OFFICE BLEACHING TECHNIQUESDentist Supervised Bleaching/WAITING ROOM BLEACH TECHNIQUE

70. IN- OFFICE BLEACHING TECHNIQUEAdvantages Instant ResultsBetter follow up complianceDoes not depend on patient compliance.Do not have any metallic distaste.DisadvantagesProper isolation and Protection mandatoryIncreased Chair side timeExpensivePost Operative Tooth SensitivityGingival Irritation.

71. Home bleaching technique/ Night guardbleaching:Indications:Age-related discolorationsMild generalized stainingMild tetracycline stainingMild fluorosisAcquired superficial stainingstains from smoking tobaccoColor changes related topulpal trauma or necrosisContraindications:Teeth with:Insufficient enamel for bleachingCracks and fracture linesInadequate or defective restorations Large pulp chamberSevere fluorosis and pitting hypoplasia Noncompliant patientsSevere tetracycline staining Sensitivity to heat, cold, or sweets In patients with bulimia nervosa

72. At Home Bleaching/ Night guard Bleaching:Utilizes Low Conc. Carbamide Peroxide (10-20%CP =3.5-6.5% H2O2)Recommendations: 10% Carbamide Peroxide :8 hrs per day & 15–20% Carbamide Peroxide : 3-4 hrs per day Procedure:Application of bleaching gel to the teeth through a custom-fabricated mouth guard worn at night for at least 2 weeksTreatment carried out by the patients themselves, but supervised by dentists during recall visits.

73. ‰. Take the impression and make a stone model‰. Trim the model. Place the stock out resin and cure it‰. Apply separating media‰. Choose the tray sheet material (flexible plastic, ethyl vinyl acetate)‰. Cast the plastic in vacuum tray forming machines‰. Trim and polish the tray.‰. Checking the tray for correct fit, retention, and overextension if any is corrected.‰. Demonstrate the amount of bleaching material to be placed.Thickness of Tray:‰ Standard thickness of tray is 0.035 inch-Thicker tray (0.05 inch) :patients with breaking habitThinner tray (0.02 inch): patients who gagAt home bleaching/Night guard bleaching:Steps of Tray Fabrication:

74. ‰Patient is instructed to brush the teeth before tray application‰ Patient is instructed to place enough bleaching material into the tray to cover the facial surfaces of the teeth.After seating tray in mouth, the extra material is carefully wiped away. Wearing the tray during day time allows replenishment of the gel after 1–2 hrs for maximum concentration. Overnight use causes decrease in loss of material due to decreased salivary flow at night. While removing the tray, patient is asked to remove the tray from second molar region in peeling action. This is done to avoid injury to soft tissues.‰ Patient is instructed to rinse off the bleaching agent and clean the tray‰Duration of treatment depends upon :Discoloration of teeth,Duration of bleaching, Patient compliance, and Time of bleaching‰Patient is recalled for periodic checkups for assessing bleaching process.At home bleaching/Night guard bleachingTreatment Regimen:

75. Bleaching with night guard:Preoperative photographBleaching with night guardPostoperative photograph

76. At home bleaching/Night guard bleachingAdvantagesHigh Degree of Safety Simple and fast for patients to useSelf administration at their convenienceLess Chairside Time Low CostMinimal Adverse Effects.DisadvantagesActive patient compliance is mandatoryLess Colour ChangeExcessive usage may cause POST -OP Sensitivity .Transient Metallic Distaste

77. OVER-THE-COUNTER PRODUCTS: HOME BLEACHING Low Concn. Hydrogen peroxide 3-6% H2O2: Self-applied to the teeth via gum shields, strips, or paint-on product formats.Usually applied twice per day for up to 2 weeks Disadvantages:Safety QuestionableProducts not fully FDA regulated

78. OTC (OVER-THE-COUNTER PRODUCTS):Tooth pastes – AP-24, Rembrandt Mouth rinses – Crest Tooth brushes – Spine brush pro whitening Dental floss – Super smile Teeth whitening strips – Crest Chewing gums – Brits smile, Happy dent Paint on varnish – Vivastyle Brite smile pen

79. OTC(OVER-THE-COUNTER PRODUCTS):Paint on varnish:- -6% carbamide peroxide applied by brush. -Insoluble in saliva and remains on teeth for 20 minutes -Subsequently removed with a tooth brush. Advantages:- Can be applied exactly wherever it is needed. Color change: Noticeable after 7 days

80. OTC(OVER-THE-COUNTER PRODUCTS):Chewing gums:Brite smile, Happy dent Supersmile whitening floss: First floss treated with Calprox to safely whiten between teeth. Removes stubborn stains and odour causing plaque in between teeth.CALPROX: dissolves the protein pellicle, removing stains and plaque.

81. OTC(OVER-THE-COUNTER PRODUCTS):Tooth pastes:- Enzymes :break down of the organic protein components of stains. E.g.Rembrandt whitening : contains Citroxain, derived from Papaya .Janina ultrawhite opal : contains Bromelain, which is derived from Pineapple.

82. OTC(OVER-THE-COUNTER PRODUCTS)Topically applied gel based products:Simply white-18% carbamibe peroxide.Crest night -19% sodium perborateMentadent xtra white -6% hydrogen peroxide

83. OTC(OVER-THE-COUNTER PRODUCTS):Tooth brushes:Powered tooth brushes :remove the extrinsic stains mechanically. Ex: Spin brush pro-whitening.Removes up to 88% of surface stains – tobacco, wine, tea and coffee after 14 days of use. Increased bristle density ; new cup shaped pattern designed to enhance the retention of dentifrice at the brush-tooth interface.

84. ORACURA® Sonic Electric Rechargeable White Power Toothbrush SB200, 40,000 strokes/minSonic White from Cybersonic :Uses the sonic energy + powered toothbrush to whiten teeth quickly and gently. ORACURA® Sonic Electric Rechargeable White Power Toothbrush:40,000 strokes/min Effectively remove plaque in hard-to-reach areasThorough Mouth Clean up With Timer AssistanceSuperior Gum ProtectionTooth brushes:

85. NON VITAL TOOTH BLEACHING

86. NON VITAL TOOTH BLEACHING Closed Chamber Intracoronal Bleaching Walking Bleach Technique: Sodium Perborate + Water or 30% H2O2 (Materials sealed into the Access Cavity ).Thermo catalytic Technique30-35% H2O2 gel placed in the pulp chamberTemperature maintained at 50 to 60°C for 5 minutes with the cool downtime of 5 minutesRecent: Use of Carbamide peroxide Use of low concn of H2O2.Advantages of Non vital bleaching:Predictable, Simple, Quick, CheapConserves Tooth Structure30% H2O2: SuperoxolSpasser:Na perborate + waterNutting & poe:Na perborate + H2O2Yui: Na perborate + 10%Carbamide peroxide

87. BOB SLED TUNNEL(FACIAL VIEW) / Ski slope (proximal view)WALKING BLEACH TECHNIQUE

88. Recommendations for Barrier Placement in Walking bleach technique:Facial View Bob sled TunnelProximal ViewSki Slope

89. Non vital bleachingPREOPERATIVE CLINICAL IMAGE GIC BARRIER PLACEMENT Post operativeAfter composite restoration

90. Walking Bleach TechniqueNew Sodium Perborate + Fresh Superoxol93% effectiveRecommendations:Na Perborate - Avoid Moisture ContaminationH2O2 - Use a fresh solution - Replace supply every 6 months: track dates - Buy a small jar only: 25 mls - Store in brown glass jar with tight lid/seal - Store in the fridge: cool and dark

91. Combined Intra and extracoronal bleaching/INSIDE-OUTSIDE bleaching/OPEN CHAMBER BLEACHINGUtilizes Varying concentrations of Carbamide peroxide Access left open, the material is applied into the pulp chamber directly and retained externally with a home bleaching matrix using Night guard bleaching tray .NON VITAL TOOTH BLEACHING

92. Complications of Intracoronal BleachingExternal Cervical Resorption(ECR)

93. External Cervical Resorption(ECR) Cervical resorption following internal bleaching in non vital tooth was first reported by Harrington and Natkin in 1979.PROPOSED MECHANISMS: FIRST PROPOSED MECHANISM: In order to initiate ECR, the bleaching agent must first reach the periodontal tissues. Defects in cementum at the CEJ present in 10% of teeth.(Rotstein et al) allow hydrogen peroxide to reach the external tooth surface via dentinal tubules during intracoronal bleaching. (Younger patients are at greater risk due to the increased diameter of their dentinal tubules)

94. External Cervical Resorption(ECR)SECOND PROPOSED MECHANISM:Thermocatalytic method requires the application of heat to the bleaching agent Causes widening of dentinal tubules, increasing the diffusion of molecules through the dentine. Lack of a cervical seal increases the diffusion of hydrogen peroxide into the periodontal tissues.Once in contact with the periodontal tissues, hydrogen peroxide denatures dentine, which initiates an inflammatory host immune response. Studies have also shown that the pH at the root surface is reduced to about 6.5 by intracoronal bleaching with hydrogen peroxide and could lead to increased osteoclast activity, possibly causing ECR. However, another theory is that the acidic pH contributes to an etching effect, widening dentinal tubules and allowing greater diffusion of the bleaching agent.

95. PREVENTION OF External Cervical Resorption(ECR):Using lower concentrations of hydrogen peroxide Using carbamide peroxide instead of H2O2Placing restorative cervical seals(using GIC barrier over gutta percha) Using thermocatalysis less frequently.

96. REASONS FOR CARBAMIDE PEROXIDE COULD PREFERRED BLEACHING AGENT INTRACORONALLY:Firstly, it causes an alkaline pH in the tooth, as it breaks down into ammonia, resulting in less etching effect. Secondly, it breaks down to 12% hydrogen peroxide. Lastly, it seems that it diffuses more slowly through dentine, therefore less unreacted hydrogen peroxide reaches the root surface.

97. EAnatomy of CEJ and Dentinal tubule Orientation

98. LASERS IN BLEACHINGBleaching- Argon ,CO2Catalyse oxidation reaction.Mechanism of action: Free radicals of O2: break double valency bonds into simpler ,more stable less pigmented chainsFaster – due to high concentration of active ingredient

99. LASERS IN BLEACHINGAll kinds of stains including tetracycline and non-vital teeth bleaching. Photochemical.Unique alkaline gel – no enamel etching No home bleaching trays Takes one hour Advantages:

100. Argon laser: A true laser is delivered to chemical agent 488nm WL, Blue light. Gel is left on tooth for 3sec- repeat 4-6 times Action is to stimulate the catalyst in the chemical.Adv: No thermal effect, Less dehydration of enamel, Less time(10sec/tooth)

101. Carbon dioxide laser: Invisible infrared light, energy is emitted in the form of heatDirectly interacts with catalyst/peroxide.Disadv: ADA don’t recommend CO2 laser- pulpal irritation and necrosis.

102. Diode laser(power bleaching)True laser produced from a solid state sourceBoth 830 &980 nm can be used It is ultra fast: 3-5 sec to activate the bleaching agent Adv: Produces no heat

103. Adverse effects of bleaching1.Cervical root resorption:High conc of hydrogen peroxide in the presence of heat :increase the cervical root resorption. 2. Crown fracture: use of 30% hydrogen peroxide (intracoronal bleaching) :decrease the microhardness of dentin and enamel and deteriorate the mechanical properties of the dentin.3.Tooth sensitivity: Tooth sensitivity increased in in-office bleach with hydrogen peroxide and heat application.4.Mucosal irritation:High concn of hydrogen peroxide (30%–35%) is destructive to mucus membrane and may lead to burns.

104. Adverse effects of bleaching5.Effect of bleaching agent on enamel surface35% carbamide peroxide produced the roughest enamel surfaces.(Cavalli et al.)6. Effect of bleaching on dental restorative materials:Amalgam:There is a positive correlation between the surface roughness of the amalgam and the acidity of the bleaching agent.Dental ceramics:The surface roughness of alumina-reinforced dental ceramic increased significantly with time of immersion & with the increase in concentration of H2O2 (30%, 35%, 38%).GIC:surface morphology and microhardness of conventional glass ionomer cement were altered after 28-days of 15% Carbamide Peroxide (CP) bleaching.Composite:Observed bleaching-induced color changes of composite resin due to: surface alteration and oxidation of the pigment (15% CP for 28 days)

105. EnzymaticCatalaseperoxidaseNon enzymatic10% Sodium ascorbate 10% alpha tocopherolEthanolVitamin ESodium bicarbonateGreen teaAloevera extractsNeutralizing process of bleaching agents: from antioxidant agentsTo reduce the wait time for post-bleaching bonding procedures: such as for doing composite restorations in same appointment soon after bleaching tooth

106. MICROABRASION:Enamel microabrasion is indicated for the removal of superficial stains and irregularities of the enamel, mainly located in esthetic areas. The technique involves the mechanical rubbing of acidic and abrasive agents on the altered surface.Noninvasive technique.

107. HISTORY FOR MICROABRASION:Croll et al recommended the use of the pumice with 18% hydrochloric acid. Croll later stated that an ideal microabrasive system should include a low acid concentration and abrasive particles in a water-soluble mixture that are applied with a low-rotation handpiece to avoid scattering the compounds, thus making the procedure safer. The author again proposed the use of an extra-fine diamond bur prior to the use of the microabrasive agents to reduce the clinical time needed to perform the procedure.

108. Indications of Microbrasion: Contraindications of Microbrasion: Deeper, opaque stains, such as those resulting from hypoplasia.If the patient presents deficient lip sealing, as the teeth are always exposed to air and dehydrate more easily.White spots in wet conditionStains or defects restricted only to enamelDental flurosisWhite spots in dry connditionLocalized enamel hypoplasiaCorrection of surface irregularitiesPolishing of enamel after orthodontic therapy

109. MICROABRASION:

110. MICROABRASION:Prema compound:10% HCL+silicon carbideOpalustre:6.6%HCL+silicon carbide

111. Technique for Microasbrasion:An ideal microabrasion technique should produce insignificant enamel loss, no damage to pulp or periodontal tissues, and satisfactory and permanent results in a short clinical time.Rubber dam should be applied.Enamel can first be “regularized” with a tapered exra fine-diamond bur to lightly abrade the affected area, referred to as enamel macroreduction to reduce the clinical time. The use of a rubber cup enables precise application of the compound on the enamel surface, which eliminates splattering of the compound and makes the procedure safer, easier, and quicker. The application of microabrasive slurry (acid+abrasive) is done to two or three applications to remove the superficial stains.Afterwards, polishing of the microabraded surface with felt discs. Application of sodium fluoride gels are recommended to promote the remineralization process.

112. CONCLUSIONSuccessful bleaching depends on careful diagnosis and patient selection and extensive treatment planning.

113. REFERENCESBleaching tech in restorative dentistry- Linda GreenwallEndodontics 6 –InglePrincipal and practice Endodontics –TorabenajedComplete dental bleaching- Goldstein,GarberEsthetics –Dale and aschheim.British dental journal –volume 200 no 7 apr 2006IEJ -2003,36,313-329.Vital tooth bleaching in dental practice :1,2,3-dental update,june 2006Color atlas of tooth whitening- FreedmanSturdevant 5th editionFundamentals of opertative dentistry- summitlaura etal- nonvital bleaching: a review of lit and clinical procedure, Joe-34:4,april 008,394Isabel Gimeno 1, Pere Riutord, The whitening effect of enzymatic bleaching on tetracycline:j o u r n a l of de n t i s t ry 3 6 ( 2 0 0 8 ) 79 5 – 80 0

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