Bleaching internal (part two)

Oxalic acid - 1877Oxalic acid - 1877

Hydrogen Peroxide (HHydrogen Peroxide (H220022) - 1884 ) - 1884

Electric current - 1895Electric current - 1895

Ultraviolet light - 1911Ultraviolet light - 1911

Intracoronal heat - 1913Intracoronal heat - 1913

Superoxol + electric light rays - 1918Superoxol + electric light rays - 1918

Superoxol + Sodium Perborate - 1924Superoxol + Sodium Perborate - 1924

Sodium Perborate and Water - 1959Sodium Perborate and Water - 1959

Bleaching Materials and MethodsBleaching Materials and Methods

C.H. Abbott

Oxalic acid - 1877Oxalic acid - 1877

Hydrogen Peroxide (HHydrogen Peroxide (H220022) - 1884 ) - 1884

Electric current - 1895Electric current - 1895

Ultraviolet light - 1911Ultraviolet light - 1911

Intracoronal heat - 1913Intracoronal heat - 1913

Superoxol + electric light rays - 1918Superoxol + electric light rays - 1918

Superoxol + Sodium Perborate - 1924Superoxol + Sodium Perborate - 1924

Sodium Perborate and Water - 1959Sodium Perborate and Water - 1959

““Walking bleach” - 1963Walking bleach” - 1963

Bleaching Materials and MethodsBleaching Materials and Methods

C.H. Abbott

Internal Bleaching - ChemistryInternal Bleaching - Chemistry

““Walking Bleach” TechniqueWalking Bleach” Technique

Hydrogen peroxide - HHydrogen peroxide - H22OO22

Superoxol - 35% HSuperoxol - 35% H22OO22

Sodium Perborate - 2NaBoSodium Perborate - 2NaBo22[OH][OH]22[nH[nH22O]O]

Hydrogen Peroxide - HHydrogen Peroxide - H22OO22

An oxidising agent:An oxidising agent: Produces perhydroxyl and oxygen “free radicals”Produces perhydroxyl and oxygen “free radicals”

Highly unstable and very reactiveHighly unstable and very reactive

Goldstein & Garber 1995


An oxidising agent:An oxidising agent: Produces perhydroxyl and oxygen “free radicals”Produces perhydroxyl and oxygen “free radicals”

Highly unstable and very reactiveHighly unstable and very reactive

Weakly acidic in pure Weakly acidic in pure aqueous form:aqueous form:

Produces more free Produces more free oxygen radicals oxygen radicals

Weaker bleaching Weaker bleaching agent than the agent than the perhydroxyl radicalperhydroxyl radical


BUT at alkaline pH:BUT at alkaline pH: Greater bleaching Greater bleaching

effect as more effect as more perhydroxyl free perhydroxyl free radical is releasedradical is released


pH: 9.5 – 10.8


Sodium Perborate Sodium Perborate - - 2NaBo2NaBo22[OH][OH]22[nH[nH22O]O]

When contact with water:When contact with water: Breaks down to produce HBreaks down to produce H22OO2 2 - Approx. 10%- Approx. 10%

Attin et al IEJ 2003

Sodium Perborate Sodium Perborate - - 2NaBo2NaBo22[OH][OH]22[nH[nH22O]O]

When contact with water:When contact with water: Breaks down to produce HBreaks down to produce H22OO2 2 - Approx. 10%- Approx. 10%

Has alkaline pH of 10.0Has alkaline pH of 10.0 Increases the effectiveness of bleaching if Increases the effectiveness of bleaching if

used with H used with H22OO22

Bleaching - an oxidation-reduction reactionBleaching - an oxidation-reduction reaction

Agent must diffuse through the dentineAgent must diffuse through the dentine




Free radicals attack organic moleculesFree radicals attack organic molecules

Break unsaturated bonds to create Break unsaturated bonds to create

simpler moleculessimpler molecules




Free radicals attack organic moleculesFree radicals attack organic molecules

Break unsaturated bonds to create simpler Break unsaturated bonds to create simpler

moleculesmolecules Less absorption energy Less absorption energy

Less light reflectedLess light reflected

Produces a whitening effectProduces a whitening effect


Has a “saturation point” Lightening effect slows

dramatically

Breaks down proteins & carbon-containing molecules

Increases brittleness and porosity

If continued - converts dentine & enamel to CO2 and H2O

ESSENTIAL to Know When to Stop !!!



An An in vitroin vitro comparison of comparison of

different bleaching agents in different bleaching agents in

the discoloured tooththe discoloured tooth

Ho S, Goerig AC.Ho S, Goerig AC.

J Endod J Endod 1989; 15: 106 1989; 15: 106

Ho & Goerig - 1989Ho & Goerig - 1989

New Na PerborateNew Na Perborate ++ Fresh SuperoxolFresh Superoxol

New Na PerborateNew Na Perborate ++ 1-year old Superoxol1-year old Superoxol

New Na PerborateNew Na Perborate ++ WaterWater

Old Na PerborateOld Na Perborate ++ WaterWater

New Na PerborateNew Na Perborate + + Fresh SuperoxolFresh Superoxol 93% effective93% effective

New Na PerborateNew Na Perborate ++ 1-year old Superoxol1-year old Superoxol 73% effective73% effective

New Na PerborateNew Na Perborate ++ WaterWater 53% effective53% effective

Old Na PerborateOld Na Perborate ++ WaterWater 53% effective53% effective


New Na PerborateNew Na Perborate ++ Fresh Superoxol Fresh Superoxol 93% effective93% effective

New Na PerborateNew Na Perborate + 1-year old Superoxol + 1-year old Superoxol 73% effective73% effective

New Na PerborateNew Na Perborate + Water + Water 53% effective53% effective

Old Na Perborate + WaterOld Na Perborate + Water 53% effective53% effective


New Na PerborateNew Na Perborate ++ Fresh Superoxol Fresh Superoxol 93% effective93% effective


Recommendations:Recommendations: Na PerborateNa Perborate - avoid moisture contamination- avoid moisture contamination

HH22OO22 - Use a fresh solution- Use a fresh solution

- Replace supply every 6 months: track dates- Replace supply every 6 months: track dates

- Buy a small jar only: 25 mls- Buy a small jar only: 25 mls

- Store in brown glass jar with tight lid/seal- Store in brown glass jar with tight lid/seal

- Store in the fridge: cool and dark- Store in the fridge: cool and dark

HH22OO22 - Effects on Tooth Structure - Effects on Tooth Structure


Titley Titley et alet al - - J EndodJ Endod 1988; 14: 69-74 1988; 14: 69-74 HH22OO2 2 produces a precipitate on the produces a precipitate on the enamelenamel surface surface Acid etch first + then HAcid etch first + then H22OO22

More precipitate and a more porous enamel More precipitate and a more porous enamel surfacesurface


Titley Titley et alet al - - J EndodJ Endod 1988; 14: 69-74 1988; 14: 69-74 HH22OO2 2 produces a precipitate on the produces a precipitate on the enamelenamel surface surface Acid etch first + then HAcid etch first + then H22OO22

More precipitate and a more porous enamel More precipitate and a more porous enamel surfacesurface

Titley Titley et alet al - - EDTEDT 1988; 4: 32-6 1988; 4: 32-6 HH22OO2 2 leaves an amorphous precipitate on leaves an amorphous precipitate on dentinedentine Acid etch first + then HAcid etch first + then H22OO22

Less precipitate and more tubules openLess precipitate and more tubules open

Adibfar Adibfar et alet al - - J EndodJ Endod 1992; 18; 488-91 1992; 18; 488-91

Peroxide is Peroxide is absorbedabsorbed by both enamel and by both enamel and dentine during bleachingdentine during bleaching

Leaches out if left in water for a long timeLeaches out if left in water for a long time

Can not remove just by rinsingCan not remove just by rinsing


HH22OO22 - Effects on Bonding Materials - Effects on Bonding Materials

Titley Titley et alet al - - EDTEDT 1989; 5: 132-8 1989; 5: 132-8

Highly significant reduction in bond strength Highly significant reduction in bond strength of of GICGIC to to dentinedentine after treatment with H after treatment with H22OO22


Titley Titley et alet al - - EDTEDT 1989; 5: 132-8 1989; 5: 132-8

Highly significant reduction in bond strength Highly significant reduction in bond strength of of GICGIC to to dentinedentine after treatment with H after treatment with H22OO22

Titley Titley et alet al - - J Dent ResJ Dent Res 1988; 67: 1523-8 1988; 67: 1523-8

Highly significant reduction in bond strength Highly significant reduction in bond strength of of compositecomposite to to enamelenamel treated with H treated with H22OO22

Torneck Torneck et alet al - - EDTEDT 1990; 6: 97-103 1990; 6: 97-103 No measurable adhesion of No measurable adhesion of compositecomposite to to

dentinedentine treated with H treated with H22OO22

A highly significant difference in bond A highly significant difference in bond strength of composite resin to untreated strength of composite resin to untreated dentinedentine


Torneck Torneck et alet al - - EDTEDT 1990; 6: 97-103 1990; 6: 97-103 No measurable adhesion of No measurable adhesion of compositecomposite to to

dentinedentine treated with H treated with H22OO22

A highly significant difference in bond A highly significant difference in bond strength of composite resin to untreated strength of composite resin to untreated dentinedentine

Bond failure was cohesive Bond failure was cohesive ANDAND adhesive adhesive

Suggests HSuggests H22OO22 affects setting of bonding affects setting of bonding resin AND its adhesion to filled resinresin AND its adhesion to filled resin


Torneck Torneck et alet al - - J EndodJ Endod 1991; 17: 156-60 1991; 17: 156-60

Water immersion for 7 daysWater immersion for 7 days

Eliminated the reduction in bond strength Eliminated the reduction in bond strength for composite to peroxide treated enamelfor composite to peroxide treated enamel




Eliminated the reduction in bond strength for Eliminated the reduction in bond strength for composite to peroxide treated enamelcomposite to peroxide treated enamel

Significantly higher bond strength for Significantly higher bond strength for peroxide-treated enamel compared to saline-peroxide-treated enamel compared to saline-treated enameltreated enamel

Possibly due to improved surface conditioning or Possibly due to improved surface conditioning or cleansing action by cleansing action by the peroxidethe peroxide




Eliminated the reduction in bond strength for Eliminated the reduction in bond strength for composite to peroxide treated enamelcomposite to peroxide treated enamel

Significantly higher bond strength for peroxide-Significantly higher bond strength for peroxide-treated enamel compared to saline-treated enameltreated enamel compared to saline-treated enamel

Possibly due to improved surface conditioning or Possibly due to improved surface conditioning or cleansing action by cleansing action by the peroxidethe peroxide

Saliva may have similar effect to water, but possibly Saliva may have similar effect to water, but possibly slowerslower


Clinical RecommendationsClinical Recommendations

After internal bleaching:After internal bleaching:

Delay restoration of the access cavity Delay restoration of the access cavity and replacement of other restorationsand replacement of other restorations



Delay restoration of the access cavity Delay restoration of the access cavity and replacement of other restorationsand replacement of other restorations

For a minimum of 14 daysFor a minimum of 14 days Fill the entire access cavity with Cavit Fill the entire access cavity with Cavit

(with NO cotton pellet) for this time(with NO cotton pellet) for this time



Delay restoration of the access cavity and Delay restoration of the access cavity and replacement of other restorationsreplacement of other restorations

For a minimum of 14 daysFor a minimum of 14 days Fill the entire access cavity with Cavit (with NO Fill the entire access cavity with Cavit (with NO

cotton pellet) for this timecotton pellet) for this time

After external bleaching:After external bleaching:

Delay all restorations for at least 14 daysDelay all restorations for at least 14 days

Disadvantages of BleachingDisadvantages of Bleaching

Caustic solutionsCaustic solutions

Can change the structure of tooth substanceCan change the structure of tooth substance

Not always permanentNot always permanent

External cervical invasive resorption (ECIR)External cervical invasive resorption (ECIR) Reports of an associationReports of an association But not provenBut not proven

External Cervical Invasive ResorptionExternal Cervical Invasive Resorption

Harrington & Natkin 1979Harrington & Natkin 1979 Reported 7 cases with ECIRReported 7 cases with ECIR


Harrington & Natkin 1979Harrington & Natkin 1979 Reported 7 cases with ECIRReported 7 cases with ECIR

Lado Lado et alet al 1983 1983 - 1 case- 1 case

Montgomery 1984 Montgomery 1984 - 1 case- 1 case

Cvek & Lindvall 1985 Cvek & Lindvall 1985 - 11 cases- 11 cases

Friedman Friedman et alet al 1988 1988

4 cases out of 58 4 cases out of 58 7% 7%


Total 36 cases reported 1979 – 2003Total 36 cases reported 1979 – 2003 But how many teeth have been bleached ??But how many teeth have been bleached ??



Probably millions!!Probably millions!!



Probably millions!!Probably millions!!

Clinical studies: Total 701 teeth Clinical studies: Total 701 teeth

8 cases of ECIR (1.1%)8 cases of ECIR (1.1%) Slightly higher than the Slightly higher than the

population estimate ofpopulation estimate of0.02% - Heithersay 19990.02% - Heithersay 1999

Possible Factors / MechanismsPossible Factors / Mechanisms

TraumaTrauma Base over RCF Base over RCF Level of RCF removedLevel of RCF removed Heat used in bleachingHeat used in bleaching Chemical burn from OChemical burn from O22 and and HH22OO2 2

Cause coagulation and inflammationCause coagulation and inflammation May lead to necrosis of p.d.l.May lead to necrosis of p.d.l.

Cementum defectCementum defect


Total 36 cases reported Total 36 cases reported

10 teeth10 teeth No details reported of the bleaching processNo details reported of the bleaching process

The other 26:The other 26: None had cervical seal / base over RCFNone had cervical seal / base over RCF





All had HAll had H22OO22

24 also had Na Perborate24 also had Na Perborate






24 also had Na Perborate24 also had Na Perborate 22 used heat22 used heat






24 also had Na Perborate24 also had Na Perborate 22 used heat22 used heat 10 had history of trauma10 had history of trauma

Others - no detail givenOthers - no detail given

Cervical root resorption Cervical root resorption following bleaching of following bleaching of

endodontically treated teethendodontically treated teeth

Madison S, Walton R.Madison S, Walton R.

J EndodJ Endod 1990; 16: 570-4 1990; 16: 570-4

Madison & Walton - 1990Madison & Walton - 1990

45 teeth in dogs45 teeth in dogs

Bleached twice 1 week apartBleached twice 1 week apart

Reviewed histologically after 1 yearReviewed histologically after 1 year

Factors associated with ECIR:Factors associated with ECIR:

30% H30% H22OO22 plus heat plus heat

Dentine thicknessDentine thickness

Madison & Walton - 1990Madison & Walton - 1990

NOT associated with ECIR:NOT associated with ECIR: Walking bleach techniqueWalking bleach technique Internal etchingInternal etching

HH22OO2 2 and Na Perborateand Na Perborate

Na Perborate inhibits macrophages

Macrophages stimulate clastic cells

Jiménez-Rubio & Segura - JoE 1998

Possible Factors / MechanismsPossible Factors / Mechanisms

TraumaTrauma Base over RCF Base over RCF Level of RCF removedLevel of RCF removed Heat used in bleachingHeat used in bleaching Chemical burn from OChemical burn from O22 and and HH22OO2 2

Cause coagulation and inflammationCause coagulation and inflammation May lead to necrosis of p.d.l.May lead to necrosis of p.d.l.

Cementum defectCementum defect

5 - 10% of all teeth30% of upper incisors

30% of teeth 60 - 65% of teeth

Geoffrey HeithersayGeoffrey Heithersay

Heithersay Heithersay et al - ADJ et al - ADJ 19941994

204 teeth reviewed for up to 19 years after 204 teeth reviewed for up to 19 years after internal bleachinginternal bleaching

4 teeth (1.9%) had ECIR4 teeth (1.9%) had ECIR All had luxation injuriesAll had luxation injuries

Concluded:Concluded: ““There is a very low, although positive, risk of There is a very low, although positive, risk of

ECIR after bleaching – ECIR after bleaching – especially if there has especially if there has been a history of trauma to the tooth”been a history of trauma to the tooth”

Heithersay Heithersay - Quintessence Int - Quintessence Int 19991999

257 teeth with ECIR257 teeth with ECIR 0.02% of the population0.02% of the population

Assessed for “potential predisposing Assessed for “potential predisposing factors”factors”

Sole factorsSole factors Multiple factorsMultiple factors


Potential predisposing factorsPotential predisposing factors Orthodontics: 24.1%Orthodontics: 24.1%

4.3% with other factors4.3% with other factors

No identifiable factor: 16.4%No identifiable factor: 16.4%

Trauma 15.1%Trauma 15.1% 10.6% with other factors10.6% with other factors

Restoration in tooth: 14.1%Restoration in tooth: 14.1%


Potential predisposing factorsPotential predisposing factors Orthodontics: 24.1%Orthodontics: 24.1%

4.3% with other factors4.3% with other factors

No identifiable factor: 16.4%No identifiable factor: 16.4%

Trauma 15.1%Trauma 15.1% 10.6% with other factors10.6% with other factors

Restoration in tooth: 14.1%Restoration in tooth: 14.1%

Internal bleaching: 3.9%Internal bleaching: 3.9% 9.7% with other factors9.7% with other factors

Concluded:Concluded: ““There is a very low, although positive, risk There is a very low, although positive, risk

of ECIR after bleaching ….of ECIR after bleaching ….

… … especially in association with other especially in association with other potential predisposing factors such as potential predisposing factors such as trauma and orthodontic treatment”trauma and orthodontic treatment”


Cervical canal leakage Cervical canal leakage

after internal bleaching after internal bleaching

proceduresprocedures

Smith JJ, Cunningham CJ, Smith JJ, Cunningham CJ, Montgomery S.Montgomery S.

J EndodJ Endod 1992; 18: 476-81 1992; 18: 476-81

No Cavit

Cavit base

Interprox. CEJ Labial CEJ 1mm apical Interprox. CEJ Labial CEJ 1mm apical to labial CEJ to labial CEJ

Conclusions - SmithConclusions - Smith et al et al 19921992

2mm Cavit base was sufficient to 2mm Cavit base was sufficient to dentinal penetration of the dyedentinal penetration of the dye

Cavit should be placed slightly Cavit should be placed slightly coronal to labial CEJcoronal to labial CEJ

Cemental defects – greater dye Cemental defects – greater dye penetration in areas of defectspenetration in areas of defects

An An in vitroin vitro comparison of bleaching comparison of bleaching agents on the crowns and roots of agents on the crowns and roots of

discoloured teethdiscoloured teeth

Warren MA, Wong M, Ingram TA.Warren MA, Wong M, Ingram TA.

J EndodJ Endod 1990; 16: 463-7 1990; 16: 463-7

Warren Warren et al et al - 1990- 1990

IRM base at CEJ or 2mm below CEJ IRM base at CEJ or 2mm below CEJ No difference in bleaching resultNo difference in bleaching result

Warren Warren et al et al - 1990- 1990

IRM base at CEJ or 2mm below CEJ IRM base at CEJ or 2mm below CEJ No difference in bleaching resultNo difference in bleaching result

BUT - also bleached some of the tooth rootBUT - also bleached some of the tooth root Effectiveness of IRM “seal” against liquid Effectiveness of IRM “seal” against liquid

penetration is very questionablepenetration is very questionable

RECOMMENDED to cover root RECOMMENDED to cover root

canal filling with 2mm Cavit canal filling with 2mm Cavit

before bleachingbefore bleaching

Why not GIC ???Why not GIC ???

Very difficult to place without getting on Very difficult to place without getting on labial dentine wall of access cavitylabial dentine wall of access cavity

Very difficult to remove if on labial wallVery difficult to remove if on labial wall

Why not GIC ???Why not GIC ???

Very difficult to place without getting on Very difficult to place without getting on labial dentine wall of access cavitylabial dentine wall of access cavity

Very difficult to remove if on labial wallVery difficult to remove if on labial wall

GIC’s not proven to prevent moisture GIC’s not proven to prevent moisture penetration through dentinepenetration through dentine

RECOMMENDED to cover root RECOMMENDED to cover root

canal filling with 2mm Cavit canal filling with 2mm Cavit

before bleachingbefore bleaching

Bleaching internal (part two)

Health & Medicine

Transcript of Bleaching internal (part two)