Lecture 15 & 16- Endodontic materials and bleaching systems (Slides)

8/3/2019 Lecture 15 & 16- Endodontic materials and bleaching systems (Slides)

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Endodontic materialsEndodontic materialsand bleaching systemsand bleaching systems

Dent 305Dent 305



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EndodonticsEndodontics

►► Is concerned with the morphology, physiology andIs concerned with the morphology, physiology and

pathology of the dental pulp and periradicularpathology of the dental pulp and periradiculartissuetissue

►► Dental materials maybe used to perform pulpDental materials maybe used to perform pulp

capping, intracapping, intra--canal cleaning and obturationcanal cleaning and obturation►► Why do root canal treatment:Why do root canal treatment:

Clean canalsClean canals

Apical seal Apical seal Coronal sealCoronal seal



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Vital pulp capping Vital pulp capping

►►Causes of pulp exposure:Causes of pulp exposure:

CariesCaries During cavity preparationDuring cavity preparation

TraumaTrauma►►Two procedures:Two procedures:

Indirect cappingIndirect capping

Direct cappingDirect cappingReference: Introduction todental materials



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Indirect pulp cappingIndirect pulp capping

►►Criteria for applying this procedure andCriteria for applying this procedure and

ensuring success:ensuring success: No signs of bleeding from the pulpNo signs of bleeding from the pulp

A layer of discolored dentine is left to avoid A layer of discolored dentine is left to avoid

exposing pulpal tissue. Should be caries freeexposing pulpal tissue. Should be caries free

Infection should be removed and not allowedInfection should be removed and not allowed

to return by using antibacterial linerto return by using antibacterial liner A good seal should be attained to prevent A good seal should be attained to prevent

further ingress of bacteriafurther ingress of bacteria

Reference: Introduction todental materials



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Indirect pulp treatment in a permanent molar: case report of 4-year

follow-up. J. Appl. Oral Sci. vol.17 no.1 Bauru Jan./Feb. 2009



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Continue,Continue,

►► Material used forMaterial used for

indirect pulp capping:indirect pulp capping: Calcium hydroxideCalcium hydroxide

(most popular):(most popular):

►►High pHHigh pH►►antibacterialantibacterial

ZincZinc--oxide eugenoloxide eugenol

Bonding agents (acidBonding agents (acidetching near pulp?)etching near pulp?)




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Direct cappingDirect capping

►►Pulp exposure occurred due to cavityPulp exposure occurred due to cavity

preparation not cariespreparation not caries►►Objective:Objective:

Dressing of exposed pulpDressing of exposed pulp WallWall--off bacteriaoff bacteria

Stimulate calcific barrier formation over exposedStimulate calcific barrier formation over exposed

areasareas

Maintain pulp vitalityReference: Introduction todental materialsMaintain pulp vitality



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Direct cappingDirect capping



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Continue,Continue,

►► Pulp capping materials should:Pulp capping materials should:

Be able to induce hard tissue formationBe able to induce hard tissue formation

No adverse effectNo adverse effect Protect pulp from ingress of bacteriaProtect pulp from ingress of bacteria

►► Materials used:Materials used:

Calcium hydroxide (causes a layer of necrosis (1Calcium hydroxide (causes a layer of necrosis (1--1.51.5

mm thick) then calcific layer forms, minerals derivedmm thick) then calcific layer forms, minerals derived

from pulp fluid)from pulp fluid)

Dentine bonding agents: etching? Conflicting resultsDentine bonding agents: etching? Conflicting results

depending on bonding agent type. Homeostasis isdepending on bonding agent type. Homeostasis is

always important (1% Na hypochlorite)always important (1% Na hypochlorite)



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Failure of pulp cappingFailure of pulp capping

►► Chronic inflammationChronic inflammation

of pulpof pulp►► ExtraExtra--pulpal blood clotpulpal blood clot

(prevent contact(prevent contact

between cement andbetween cement andhealthy pulpal tissuehealthy pulpal tissue

►► Restoration failureRestoration failure




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Irrigants and lubricantsIrrigants and lubricants

►► Purpose:Purpose:

DisinfectDisinfect

Remove debrisRemove debris

►► Ideal properties:Ideal properties:

Able to dissolve and disturb debris Able to dissolve and disturb debris Non toxicNon toxic

Low surface tensionLow surface tension

Able to lubricate Able to lubricate Able to sterilize Able to sterilize

Able to remove smear layer Able to remove smear layerReference: Applied dental

materials



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Available irrigants (Table 31.1) Available irrigants (Table 31.1)

Reference: applied dental materialsReference: applied dental materials

►►The best irrigant: sodium hypochlorite 2The best irrigant: sodium hypochlorite 2--

10%10%►►Disadvantage: irritant material if in contactDisadvantage: irritant material if in contact

with living tissuewith living tissue►► Alternative if cannot be used: chlorhexidine Alternative if cannot be used: chlorhexidine

gluconate 0.2%gluconate 0.2%

►►EDTA (ethylene diamine tetra acetic acid):EDTA (ethylene diamine tetra acetic acid):

maybe used as a lubricantmaybe used as a lubricant



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Intracanal medicamentsIntracanal medicaments

►►Paramonochlorophenol (PMCP): no clinicalParamonochlorophenol (PMCP): no clinical

indication for itsindication for its’ ’ use. Acts as a disinfectantuse. Acts as a disinfectant►►NonNon--setting calcium hydroxide: high pH.setting calcium hydroxide: high pH.

Induces closure of apex (in immature teeth)Induces closure of apex (in immature teeth)and arrests root resorptionand arrests root resorption

►►PolyPoly--antimicrobial pasts: mixture of steroids,antimicrobial pasts: mixture of steroids,

tetracycline, sulphonamidetetracycline, sulphonamide

Reference: Applied dental

materials



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Non setting calcium hydroxideNon setting calcium hydroxide



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Obturating materialsObturating materials

►► Historical material:Historical material:

Silver: corrosion, cannot be adapted well, hard toSilver: corrosion, cannot be adapted well, hard toretrieveretrieve

Amalgam: technically hard, retreatment is hard Amalgam: technically hard, retreatment is hard

Medicated pastes: antibacterialMedicated pastes: antibacterial►►Paraformaldehyde based: sets hard, toxicParaformaldehyde based: sets hard, toxic

►► Iodoform based: resorbableIodoform based: resorbable

►► Contemporary material:Contemporary material: Gutta perchaGutta percha

Polyester resinPolyester resin



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Obturating materialsObturating materials

►►Gutta percha (GP)Gutta percha (GP)

►►Composition:Composition: Gutta percha rubberGutta percha rubber

Zinc oxide as a fillerZinc oxide as a filler Metal salts for radiopacityMetal salts for radiopacity

Wax or resin as plasticizerWax or resin as plasticizer

Antioxidants Antioxidants


materials



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Gutta perchaGutta percha

►► Handling characteristics and properties:Handling characteristics and properties: Thermoplastic material softens at 60Thermoplastic material softens at 60--6565°°C and melts atC and melts at

100100°°CC

Oxidizes upon exposure to light and hardensOxidizes upon exposure to light and hardens

Dissolved in chloroformDissolved in chloroform

Maybe disinfected by Na HypochloriteMaybe disinfected by Na Hypochlorite

Solvents such as acetone may cause it to swell then asSolvents such as acetone may cause it to swell then asthe solvent evaporates GP shrinksthe solvent evaporates GP shrinks

No chemical bond with dentineNo chemical bond with dentine



19GP cones for coldpacking



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Application systems Application systems

►► Cold packing (Cold packing (ββ--phase GP)phase GP)::

GP points (cold lateral condensation technique)GP points (cold lateral condensation technique)►► Thermal packing (Thermal packing (άά--phase GP)phase GP)::

Softening a material prior to insertionSoftening a material prior to insertion

Heat application on GP after insertion then condensationHeat application on GP after insertion then condensation

Available systems: Thermafil (plastic carrier), Obtura Available systems: Thermafil (plastic carrier), Obtura

(injection gun)(injection gun)

Heat maybe applied using a rotary instrument,Heat maybe applied using a rotary instrument,clockwise rotation next to GP in canalclockwise rotation next to GP in canal

Reference: Applied dentalmaterials



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Thermafil system

Obtura



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Obturating material continue,Obturating material continue,

►►Polyester resin: based on thermoplasticPolyester resin: based on thermoplastic

synthetic polyester, barium sulphate,synthetic polyester, barium sulphate,bismuth chlorate, bioactive glass (claimed tobismuth chlorate, bioactive glass (claimed to

release calcium and phosphate inducingrelease calcium and phosphate inducing

bone growth). This material is available forbone growth). This material is available for

cold and hot applications.cold and hot applications.


materials



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Root canal sealantsRoot canal sealants

►► Ideal properties:Ideal properties: Easy to useEasy to use

Good sealGood seal Free of air bubbles, homogenous when mixedFree of air bubbles, homogenous when mixed

Flow to thin film thicknessFlow to thin film thickness

InsolubleInsoluble

BiocompatibleBiocompatible

RadiopaqueRadiopaque

slow setting timeslow setting time

►► Function of the sealer:Function of the sealer: To fill spaces between GP pointsTo fill spaces between GP points

Lubricant during obturation and fill irregularities in canalLubricant during obturation and fill irregularities in canal




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SealersSealers

Gap between GP androot dentine

Gutta percha with sealer



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Materials used as sealersMaterials used as sealers

►►Zinc oxide eugenolZinc oxide eugenol

►►ResinsResins►►Calcium hydroxide cements (sealapex)Calcium hydroxide cements (sealapex)

►►Glass ionomer cementsGlass ionomer cements►►Polydimethyl siloxanePolydimethyl siloxane

Zinc oxideZinc oxide eugenoleugenol basedbased



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Zinc oxideZinc oxide--eugenoleugenol--basedbased

cementscements►► Three formulations available:Three formulations available:

Rickets (silver caused discoloration): 15 minute workingRickets (silver caused discoloration): 15 minute workingtime, good flow, but has thick filmtime, good flow, but has thick film

Grossman (contains barium for radiopacity instead of Grossman (contains barium for radiopacity instead of

silver): 1 hour working time, good flow, lower solubilitysilver): 1 hour working time, good flow, lower solubility

Tubliseal (pasteTubliseal (paste--paste system to produce smooth mix):paste system to produce smooth mix):

low film thickness, good flow, 20 minutes working timelow film thickness, good flow, 20 minutes working time



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Calcium hydroxideCalcium hydroxide containingcontaining



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Calcium hydroxideCalcium hydroxide--containingcontaining

cementscements►►2 paste system, base and catalyst2 paste system, base and catalyst

►►Long working timeLong working time►► Antibacterial Antibacterial

►►BiocompatibleBiocompatible►►Can induce hard tissue formationCan induce hard tissue formation

►►Disadvantage: high solubilityDisadvantage: high solubility

Reference: Introduction to

dental materials



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Reference: Applied dentalmaterials + introduction todental materialsResinsResins

►► System available:System available:

Commercial systems:Commercial systems:►► AH plus, 2 paste system: (long working time, better flow & AH plus, 2 paste system: (long working time, better flow &

film thickness, low solubility), based on previous product Ahfilm thickness, low solubility), based on previous product Ah

26 (released formaldehyde)26 (released formaldehyde)

►► ADSEAL Excellent : biocompatibility, Easy to dispense and ADSEAL Excellent : biocompatibility, Easy to dispense andmix, insoluble in tissue fluidsmix, insoluble in tissue fluids

►► Problem: silver content, shrinkage (depends onProblem: silver content, shrinkage (depends onthe product)the product)

►► Newer products maybe silver free with minimalNewer products maybe silver free with minimal

shrinkageshrinkage



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Products availableProducts available





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Polydimethyl siloxanePolydimethyl siloxane

►► Composition:Composition:

Polydimethyl siloxanePolydimethyl siloxane Paraffin oilParaffin oil

Silicon oilSilicon oil

Zirconium dioxideZirconium dioxide►► Advantages: insoluble, dimensionally stable, Advantages: insoluble, dimensionally stable,

biocompatiblebiocompatible

►► Disadvantages: dose not bond o dentine, noDisadvantages: dose not bond o dentine, no

antibacterial abilityantibacterial abilityReference: Introduction to

dental materials

Clinical aspects of root canalClinical aspects of root canal



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Clinical aspects of root canalClinical aspects of root canal

materialsmaterials►►Biocompatibility:Biocompatibility:

GP: highly biocompatibleGP: highly biocompatible ZnO/eugenol: induce inflammation due toZnO/eugenol: induce inflammation due to

eugenoleugenol

Resin systems: once set, low toxicityResin systems: once set, low toxicity

Calcium hydroxide: biocompatible, inducesCalcium hydroxide: biocompatible, induces

cementum formationcementum formation



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Continue,Continue,

►►Sealing properties:Sealing properties:

antibacterial abilitiesantibacterial abilities physical apical sealphysical apical seal

►►Physical properties:Physical properties:

Working timeWorking time

Setting timeSetting time

Film thicknessFilm thickness SolubilitySolubility

Dimensional stabilityDimensional stability

Material for root canal repair andMaterial for root canal repair and



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Material for root canal repair andMaterial for root canal repair and

periperi--radicular surgeryradicular surgery►► MTA: Mineral trioxide aggregate, it is highlyMTA: Mineral trioxide aggregate, it is highly

alkaline, sets when exposed to water. Whenalkaline, sets when exposed to water. When

exposed to water, setting reaction starts, materialexposed to water, setting reaction starts, material

remains plastic for some time which facilitatesremains plastic for some time which facilitates

insertion for repair or root end filling material.insertion for repair or root end filling material.Final setting occurs when the material crystallizesFinal setting occurs when the material crystallizes

to form a hard mass with slight expansionto form a hard mass with slight expansion

►► Characteristics: induces cementogenesis,Characteristics: induces cementogenesis,antimicrobial, biocompatibleantimicrobial, biocompatible




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dP t d t



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Post and core systemsPost and core systems

►►To restore endodontically treatedTo restore endodontically treated--badlybadly

broken don teeth.broken don teeth.►►Post system provides support and retentionPost system provides support and retention

for the coronal restorationfor the coronal restoration

►►Desirable properties:Desirable properties: Maximum retention with minimal preparationMaximum retention with minimal preparation

Aesthetically acceptable Aesthetically acceptable Post is retrievablePost is retrievable

Post can transfer stress to remaining toothPost can transfer stress to remaining tooth

structurestructure Reference: Introduction todental materials



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T f t tT f t t



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Types of post systemsTypes of post systems

►►Prefabricated (core is made from composite,Prefabricated (core is made from composite,

amalgam, GIC, etc.):amalgam, GIC, etc.): Metal postsMetal posts

Fiber reinforced resin postsFiber reinforced resin posts

Ceramic posts: esthetic, strong, tough, rely onCeramic posts: esthetic, strong, tough, rely on

mechanical retentionmechanical retention

►►Cast postsCast posts


P f b i t d tP f b i t d t



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Prefabricated postsPrefabricated posts

►►Metal posts made from stainless steel,Metal posts made from stainless steel,

nickelnickel--chromium, titaniumchromium, titanium►► Variety of designs: Variety of designs:

NoneNone

--threaded parallel sidedthreaded parallel sided

NoneNone--threaded tapered postthreaded tapered post

Threaded tapered postsThreaded tapered posts

►►Requirements needed in a post?Requirements needed in a post?


Fib i f d i tFib i f d i t



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Fiber reinforced resin postFiber reinforced resin post

►►Two types:Two types:

Carbon fiber reinforced (black, unaesthetic)Carbon fiber reinforced (black, unaesthetic) Glass fiber reinforcedGlass fiber reinforced

►►

These posts may allow even stressThese posts may allow even stressdistribution and reduce chance of toothdistribution and reduce chance of tooth

fracture. How?fracture. How?


T th bl hiTeeth bleaching



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Teeth bleachingTeeth bleaching

►►How bleaching works: bleaching agentHow bleaching works: bleaching agent

(hydrogen peroxide or nonperoxide agents)(hydrogen peroxide or nonperoxide agents)penetrate enamel and reach dentine thenpenetrate enamel and reach dentine then

oxidizes pigments and lightens tooth color.oxidizes pigments and lightens tooth color.

This action is enhanced by low intensityThis action is enhanced by low intensityheat or high intensity light.heat or high intensity light.

Reference: Dental materials,clinical applications for dentalhygienists etc.



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BEFORE

CompositionComposition



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CompositionComposition

►►Hydrogen peroxide, carbamide peroxide,Hydrogen peroxide, carbamide peroxide,

urea peroxideurea peroxide►►NonNon--hydrogen peroxide system containing:hydrogen peroxide system containing:

Sodium chlorideSodium chloride

OxygenOxygen

Natrium fluorideNatrium fluoride

►► Additives such as potassium nitrate and Additives such as potassium nitrate and

fluoride to reduce sensitivityfluoride to reduce sensitivity

Types of stainsTypes of stains



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Types of stainsTypes of stains

►►Intrinsic (medication, trauma, diseaseIntrinsic (medication, trauma, disease

conditions during or after toothconditions during or after toothdevelopment)development)

►►Extrinsic: coffee, tea, tobaccoExtrinsic: coffee, tea, tobacco

►►CombinationCombination



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InIn office bleachingoffice bleaching



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InIn--office bleachingoffice bleaching

►►Bleaching of vital teeth:Bleaching of vital teeth:

35% hydrogen peroxide liquid + heat: time35% hydrogen peroxide liquid + heat: timeconsuming for multiple teeth and techniqueconsuming for multiple teeth and technique

sensitivesensitive

Powder and liquid system: hydrogen peroxidePowder and liquid system: hydrogen peroxideliquid + powder containing light/ chemicalliquid + powder containing light/ chemical

activatorsactivators

35% carbamide peroxide gel system: better35% carbamide peroxide gel system: better

control than liquid systemcontrol than liquid system



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Continue,Continue,



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►► Bleaching of nonBleaching of non--vital teeth: staining maybevital teeth: staining maybecaused due to necrotic breakdown products of thecaused due to necrotic breakdown products of the

pulp, or hemoglobin from blood in the pulp.pulp, or hemoglobin from blood in the pulp.

Bleaching is done internally through the access cavityBleaching is done internally through the access cavity

Bleaching solution: 30% hydrogen peroxide on aBleaching solution: 30% hydrogen peroxide on a

saturated cotton pellet in pulp chamber then activatedsaturated cotton pellet in pulp chamber then activated

by a heating instrumentby a heating instrument

Walking bleach: sodium peroxyborate paste or gelWalking bleach: sodium peroxyborate paste or gel

mixed with hydrogen peroxide then placed in accessmixed with hydrogen peroxide then placed in access

cavity.cavity.



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Home bleachingHome bleaching



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►►Chemical used 10Chemical used 10--16% carbamide peroxide16% carbamide peroxide

at a near neutral pH in a viscous gel.at a near neutral pH in a viscous gel.►►Composition:Composition:

Carbamide peroxide: hydrogen peroxide + ureaCarbamide peroxide: hydrogen peroxide + urea

Gel: propylene glycol or glycerinGel: propylene glycol or glycerin

Carbopol: thickenerCarbopol: thickener

Flavoring agentsFlavoring agents




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ContinueContinue



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Continue,Continue,

►►Duration of treatment:Duration of treatment:

30 minutes twice daily30 minutes twice daily

--overnightovernight

2 weeks depending on results2 weeks depending on results

►►OverOver--thethe--counter products:counter products:

Crest white strips worn for 30 minutes twiceCrest white strips worn for 30 minutes twice(5.3% hydrogen peroxide)(5.3% hydrogen peroxide)

Home bleaching products containing preformedHome bleaching products containing preformedtrays or thermoplastic trays heated in watertrays or thermoplastic trays heated in waterthen shaped on the dental arch (10%then shaped on the dental arch (10%carbamide peroxide)carbamide peroxide)



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Before and after bleaching



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Side effects of bleachingSide effects of bleaching



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Side effects of bleachingSide effects of bleaching

SensitivitySensitivity

Irritation of the gingivaIrritation of the gingiva

Soreness of the muscles of mastication from wearingSoreness of the muscles of mastication from wearing

night guards overnightnight guards overnight

Roughness of composite restoration surfacesRoughness of composite restoration surfaces

►► Contraindications for bleaching:Contraindications for bleaching:

Allergy to bleaching agent Allergy to bleaching agent

Patients with very sensitive teethPatients with very sensitive teeth

Patients with multiple composites who do not wish toPatients with multiple composites who do not wish to

replace themreplace them

Restorative considerationsRestorative considerations



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Restorative considerationsRestorative considerations

►►Before bleaching:Before bleaching:

Carious teeth should be restoredCarious teeth should be restored Leaky restorations replacedLeaky restorations replaced

►► After bleaching: After bleaching:

Esthetic restorations may need to be replacedEsthetic restorations may need to be replaced

2 weeks period is needed for teeth color to2 weeks period is needed for teeth color to

stabilize and to replace composites or veneersstabilize and to replace composites or veneers

ReferencesReferences



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ReferencesReferences

►►Introduction to dental materialsIntroduction to dental materials

►► Applied dental materials Applied dental materials►►Dental materials, clinical application forDental materials, clinical application for

dental assistants and hygienistsdental assistants and hygienists

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Lecture 15 & 16- Endodontic materials and bleaching systems (Slides)

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