Management of Badly Broken Down Teeth II

MANAGEMENTMANAGEMENTMANAGEMENTMANAGEMENTMANAGEMENTMANAGEMENTMANAGEMENTMANAGEMENT OF OF OF OF OF OF OF OF

BADLY BROKEN DOWN BADLY BROKEN DOWN BADLY BROKEN DOWN BADLY BROKEN DOWN BADLY BROKEN DOWN BADLY BROKEN DOWN BADLY BROKEN DOWN BADLY BROKEN DOWN

TEETH (II)TEETH (II)TEETH (II)TEETH (II)TEETH (II)TEETH (II)TEETH (II)TEETH (II)

Dr. Nasrien AteyahDr. Nasrien Ateyah

PINPINPINPINPINPINPINPIN--------RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM

RESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATION

�� DefinedDefined as any restoration requiring the as any restoration requiring the placement of one or more pins in the placement of one or more pins in the dentin to provide adequate resistance and dentin to provide adequate resistance and retention forms.retention forms.

�� UsedUsed→→→→→→→→ whenever adequate resistance and whenever adequate resistance and retention forms retention forms cannot be established cannot be established with slots, locks, or undercuts only.with slots, locks, or undercuts only.

�� It has a It has a greater retentiongreater retention than those using than those using boxer or relying solely on bonding system.boxer or relying solely on bonding system.

PINPINPINPINPINPINPINPIN--------RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM RETAINED AMALGAM

RESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATIONRESTORATION

�� It is indicated for tooth with It is indicated for tooth with

extensive caries or fractures.extensive caries or fractures.

�� Rarely used in anterior teeth Rarely used in anterior teeth

(Bonding Technique)(Bonding Technique)..

�� In class V is rare In class V is rare (horizontal groove (horizontal groove

in the gingival & in the gingival & occlusalocclusal aspect)aspect)..

ADVANTAGEADVANTAGEADVANTAGEADVANTAGEADVANTAGEADVANTAGEADVANTAGEADVANTAGE

�� Conservation of tooth structureConservation of tooth structure

�� Save time vs. cast restorationSave time vs. cast restoration

�� EconomicEconomic

�� Provide Provide ↑↑↑↑↑↑↑↑ resistance & retention formresistance & retention form

DISADVANTAGEDISADVANTAGEDISADVANTAGEDISADVANTAGEDISADVANTAGEDISADVANTAGEDISADVANTAGEDISADVANTAGE

�� Dentinal microfracture or crazingDentinal microfracture or crazing

�� Microleakage around pinMicroleakage around pin

�� ↓↓↓↓↓↓↓↓ strength of amalgamstrength of amalgam

�� Perforation of the pulp or external tooth Perforation of the pulp or external tooth structurestructure

TYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINS

1.1. CementedCemented•• Larger than other pinLarger than other pin

•• Use Zn Ph Use Zn Ph cemcem or Zn or Zn PolycarPolycar cemcem

2.2. Friction Friction –– locked pinslocked pins•• SmallerSmaller

•• Retained by resilience of dentinRetained by resilience of dentin

•• ↑↑↑↑↑↑↑↑ retentive than cemented pinretentive than cemented pin

With time dentin relax With time dentin relax →→→→→→→→ loose pinloose pin

TYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINSTYPE OF PINS

3.3. SelfSelf--threading pin (TMS)threading pin (TMS)

•• Different sizeDifferent size

•• Threads engage dentinThreads engage dentin

•• Depend on elasticity of dentinDepend on elasticity of dentin

•• Most retentive Most retentive (3(3--6 times)6 times)

•• No corrosion No corrosion (gold plated)(gold plated)

•• Create horizontal & vertical stressCreate horizontal & vertical stress

•• Cause dentinal craze lineCause dentinal craze line (size of pin)(size of pin)

MOST CURRENTLY MARKED PINS MOST CURRENTLY MARKED PINS MOST CURRENTLY MARKED PINS MOST CURRENTLY MARKED PINS MOST CURRENTLY MARKED PINS MOST CURRENTLY MARKED PINS MOST CURRENTLY MARKED PINS MOST CURRENTLY MARKED PINS

HAVE:HAVE:HAVE:HAVE:HAVE:HAVE:HAVE:HAVE:

�� Metal thread separatedMetal thread separated

�� Wider dentinal thread Wider dentinal thread →→→→→→→→ retained well in retained well in

dentindentin

�� Shoulder stop Shoulder stop (to prevent putting stress (to prevent putting stress

at the end of pin channel)at the end of pin channel)

TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)

�� RegularRegular 0.031 inch diameter0.031 inch diameter

�� Minim Minim 0.024 inch diameter0.024 inch diameter

�� Minikin Minikin 0.019 inch diameter0.019 inch diameter

�� Minuta Minuta 0.017 inch diameter0.017 inch diameter

TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)TMS PIN (THREAD MATE SYSTEM)

Available inAvailable in

�� Double shear Double shear (two pins in one)(two pins in one)

�� Gold plated, stainless steel or Gold plated, stainless steel or

titanium alloytitanium alloy

�� Inserted manually or with lowInserted manually or with low--speed, speed,

latchlatch--type handpiecetype handpiece

FACTORS AFFECTING THE FACTORS AFFECTING THE FACTORS AFFECTING THE FACTORS AFFECTING THE FACTORS AFFECTING THE FACTORS AFFECTING THE FACTORS AFFECTING THE FACTORS AFFECTING THE

RETENTION OF THE PIN IN DENTIN RETENTION OF THE PIN IN DENTIN RETENTION OF THE PIN IN DENTIN RETENTION OF THE PIN IN DENTIN RETENTION OF THE PIN IN DENTIN RETENTION OF THE PIN IN DENTIN RETENTION OF THE PIN IN DENTIN RETENTION OF THE PIN IN DENTIN

AND AMALGAMAND AMALGAMAND AMALGAMAND AMALGAMAND AMALGAMAND AMALGAMAND AMALGAMAND AMALGAM

Type of pinType of pin

�� SelfSelf--threading threading –– most retentivemost retentive

�� FrictionFriction--locked locked –– intermediateintermediate

�� Cemented Cemented –– leastleast

Surface characteristicsSurface characteristics

�� Number & depth of Number & depth of the elevation on the pinthe elevation on the pin

(serration or thread)(serration or thread)

�� Shape of selfShape of self--threading pin threading pin –– greatest retentiongreatest retention

FACTORS AFFECTING THE RETENTION OF FACTORS AFFECTING THE RETENTION OF FACTORS AFFECTING THE RETENTION OF FACTORS AFFECTING THE RETENTION OF FACTORS AFFECTING THE RETENTION OF FACTORS AFFECTING THE RETENTION OF FACTORS AFFECTING THE RETENTION OF FACTORS AFFECTING THE RETENTION OF

THE PIN IN DENTIN AND AMALGAMTHE PIN IN DENTIN AND AMALGAMTHE PIN IN DENTIN AND AMALGAMTHE PIN IN DENTIN AND AMALGAMTHE PIN IN DENTIN AND AMALGAMTHE PIN IN DENTIN AND AMALGAMTHE PIN IN DENTIN AND AMALGAMTHE PIN IN DENTIN AND AMALGAM

Orientation, number and diameterOrientation, number and diameter

�� NonNon--parallel pin parallel pin -- ↑↑↑↑↑↑↑↑ retentionretention

�� Bending of pin Bending of pin –– not desirablenot desirable

•• Interfere with condensation of amalgamInterfere with condensation of amalgam

•• Weaker pin, fractured dentinWeaker pin, fractured dentin

↑↑↑↑↑↑↑↑ no. of pin no. of pin -- ↑↑↑↑↑↑↑↑ retentionretention

•• ↑↑↑↑↑↑↑↑ crazing & fracturecrazing & fracture

•• ↓↓↓↓↓↓↓↓ amount of dentin availableamount of dentin available

•• ↓↓↓↓↓↓↓↓ amalgam strengthamalgam strength

FACTORS AFFECTING THE RETENTION OF THE PIN FACTORS AFFECTING THE RETENTION OF THE PIN FACTORS AFFECTING THE RETENTION OF THE PIN FACTORS AFFECTING THE RETENTION OF THE PIN FACTORS AFFECTING THE RETENTION OF THE PIN FACTORS AFFECTING THE RETENTION OF THE PIN FACTORS AFFECTING THE RETENTION OF THE PIN FACTORS AFFECTING THE RETENTION OF THE PIN

IN DENTIN AND AMALGAMIN DENTIN AND AMALGAMIN DENTIN AND AMALGAMIN DENTIN AND AMALGAMIN DENTIN AND AMALGAMIN DENTIN AND AMALGAMIN DENTIN AND AMALGAMIN DENTIN AND AMALGAM

↑↑↑↑↑↑↑↑ diameter of pin diameter of pin →↑→↑→↑→↑→↑→↑→↑→↑ retentionretention

�� ↑↑↑↑↑↑↑↑ no. , diameter, depth no. , diameter, depth →→→→→→→→•• Danger of perforation on pulp or Danger of perforation on pulp or

external tooth surfaceexternal tooth surface

•• Interfere with condensation of amalgam Interfere with condensation of amalgam and adaptation to pinsand adaptation to pins

Extension into dentin and amalgamExtension into dentin and amalgam�� Retention is not increase when depth of the pinRetention is not increase when depth of the pin ↑↑↑↑↑↑↑↑

2mm2mm in dentin in dentin →→→→→→→→ fracture of dentinfracture of dentin

�� If If ↑↑↑↑↑↑↑↑ 2mm2mm in amalgamin amalgam→→→→→→→→ fractured amalgamfractured amalgam

PIN PLACEMENT FACTORS AND PIN PLACEMENT FACTORS AND PIN PLACEMENT FACTORS AND PIN PLACEMENT FACTORS AND PIN PLACEMENT FACTORS AND PIN PLACEMENT FACTORS AND PIN PLACEMENT FACTORS AND PIN PLACEMENT FACTORS AND

TECHNIQUESTECHNIQUESTECHNIQUESTECHNIQUESTECHNIQUESTECHNIQUESTECHNIQUESTECHNIQUES

Pin SizePin SizePin SizePin SizePin SizePin SizePin SizePin Size�� Depend on the amount of dentin available and Depend on the amount of dentin available and

amount of retention desired.amount of retention desired.

�� TMS TMS –– pin of choice is Minikin pin of choice is Minikin (0.019 inch)(0.019 inch)

and Minim and Minim (0.024)(0.024)

Minikin Minikin →→→→→→→→ ↓↓↓↓↓↓↓↓ risk of:risk of:�� Dentin crazingDentin crazing

�� Pulpal penetrationPulpal penetration

�� Potential perforationPotential perforation



Number of PinsNumber of PinsNumber of PinsNumber of PinsNumber of PinsNumber of PinsNumber of PinsNumber of PinsSeveral factors must be considered:Several factors must be considered:

�� Amount of tooth structureAmount of tooth structure

�� Amount of dentin available to receive pin Amount of dentin available to receive pin

safelysafely

�� Amount of retention requiredAmount of retention required

�� Size of the pinSize of the pin



Number of PinsNumber of PinsNumber of PinsNumber of PinsNumber of PinsNumber of PinsNumber of PinsNumber of Pins

As a ruleAs a rule →→→→→→→→ one pin/missing axial line angle one pin/missing axial line angle

should be usedshould be used

Excessive number of pinsExcessive number of pins

→→→→→→→→ fracture the toothfracture the tooth

→→→→→→→→ weaken the amalgam restorationweaken the amalgam restoration



LocationLocationLocationLocationLocationLocationLocationLocationSeveral factors aid in determining pinhole Several factors aid in determining pinhole

location:location:

1.1. Knowledge of normal pulp anatomy & Knowledge of normal pulp anatomy &

external tooth contourexternal tooth contour

2.2. Current radiograph of the toothCurrent radiograph of the tooth

3.3. Periodontal probePeriodontal probe

4.4. PatientPatient’’s ages age

SOME CONSIDERATIONS:SOME CONSIDERATIONS:SOME CONSIDERATIONS:SOME CONSIDERATIONS:SOME CONSIDERATIONS:SOME CONSIDERATIONS:SOME CONSIDERATIONS:SOME CONSIDERATIONS:

�� Occlusal clearance should be sufficient to Occlusal clearance should be sufficient to provideprovide 2mm2mm of amalgam over the pin.of amalgam over the pin.

�� Pinhole should be located Pinhole should be located halfway halfway between the pulp and DEJbetween the pulp and DEJ(0.5(0.5--1 mm inside DEJ)1 mm inside DEJ)

�� At least At least 1 mm1 mm of sound dentin around the of sound dentin around the circumference of the pinhole.circumference of the pinhole.

��Such location ensures proper stress Such location ensures proper stress

distribution of distribution of occlusalocclusal forceforce

Pinhole:Pinhole:Pinhole:Pinhole:Pinhole:Pinhole:Pinhole:Pinhole:�� Should be located near the Should be located near the line anglesline angles

of the toothof the tooth

�� Should be Should be parallelparallel to the adjacent to the adjacent external surface of the tooth external surface of the tooth (not closer than 1 (not closer than 1 -- 1.5 mm)1.5 mm)

�� Should be prepared on a Should be prepared on a flat surfaceflat surface

��If three or more pinholes If three or more pinholes

are placed:are placed:

�� Should be located at different Should be located at different vertical vertical levels on the tooth levels on the tooth ((↓↓↓↓↓↓↓↓ stress if pin in same stress if pin in same

horizontal plane)horizontal plane)

�� InterInter--pin distance depend on the size of pin distance depend on the size of the pin to be usedthe pin to be used

�� For MinikinFor Minikin (0.019 inch)(0.019 inch)→→→→→→→→ 3mm3mm

�� For MinimFor Minim (0.024 inch) (0.024 inch) →→→→→→→→ 5 mm5 mm

Maximal interMaximal inter--pin distance results in pin distance results in lower level of stress in dentin.lower level of stress in dentin.

EXTERNAL EXTERNAL EXTERNAL EXTERNAL EXTERNAL EXTERNAL EXTERNAL EXTERNAL PERFORATIONPERFORATIONPERFORATIONPERFORATIONPERFORATIONPERFORATIONPERFORATIONPERFORATION MAY MAY MAY MAY MAY MAY MAY MAY

RESULT FROM PINHOLE PLACEMENTRESULT FROM PINHOLE PLACEMENTRESULT FROM PINHOLE PLACEMENTRESULT FROM PINHOLE PLACEMENTRESULT FROM PINHOLE PLACEMENTRESULT FROM PINHOLE PLACEMENTRESULT FROM PINHOLE PLACEMENTRESULT FROM PINHOLE PLACEMENT

1.1. Over the prominent mesial concavity Over the prominent mesial concavity of the maxillary first premolar.of the maxillary first premolar.

2.2. At the At the midlingualmidlingual and and midfacialmidfacialbifurcations of mandibular bifurcations of mandibular first & second molars.first & second molars.

3.3. At the At the midfacialmidfacial, , midmesialmidmesial, , midmid--distal distal furcationsfurcations of maxillary of maxillary first and second molars.first and second molars.

PULP PULP PENETRATION PENETRATION MAY RESULT MAY RESULT

FROM PIN PLACEMENTFROM PIN PLACEMENT

At mesiofacial corner of:At mesiofacial corner of:

�� Maxillary first molarMaxillary first molar

�� Mandibular first molarMandibular first molar

When possible, location of pinholes on:When possible, location of pinholes on:

�� Distal surface of mandibular, molarsDistal surface of mandibular, molars

�� Lingual surface of maxillary molars Lingual surface of maxillary molars

Should be avoidedShould be avoided

PINHOLE PREPARATION:PINHOLE PREPARATION:PINHOLE PREPARATION:PINHOLE PREPARATION:PINHOLE PREPARATION:PINHOLE PREPARATION:PINHOLE PREPARATION:PINHOLE PREPARATION:

No.No. ¼¼ bur used to prepare a pilot holebur used to prepare a pilot hole

(dimple) (dimple) →→→→→→→→�� To permit more accurate placement To permit more accurate placement of the twist drillof the twist drill

�� Prevent the drill from crawling once Prevent the drill from crawling once it has began to rotateit has began to rotate

�� Optimal depth of the pinhole into theOptimal depth of the pinhole into thedentin isdentin is 2mm 2mm

(Omni(Omni--Depth gauge used)Depth gauge used)


�� The hole should be prepared on The hole should be prepared on flat flat

surface and the drill surface and the drill perpendicular perpendicular to to

it.it.

�� Place flat thinPlace flat thin--bladed hand instrument bladed hand instrument

into the crevice and against the into the crevice and against the

external surface of the toothexternal surface of the tooth

→→→→→→→→ To indicate the proper To indicate the proper

angulations for the drillangulations for the drill


�� Place the drill tip in its proper positionPlace the drill tip in its proper position

�� Hand piece rotating at very Hand piece rotating at very low speedlow speed

�� Apply pressure to the drillApply pressure to the drill

�� Prepare pinhole in one or two movement Prepare pinhole in one or two movement until the depthuntil the depth--limiting portion is reached limiting portion is reached

�� Remove the drill from pinholeRemove the drill from pinhole

Using more thanUsing more than oneone or or two two

movements, tilting the hand movements, tilting the hand

piecepiece →→→→→→→→too large pinholetoo large pinhole

The drill should never stop The drill should never stop

rotatingrotating →→→→→→→→to prevent the drill from to prevent the drill from

breaking while in the pinholebreaking while in the pinhole

PINHOLEPINHOLEPINHOLEPINHOLEPINHOLEPINHOLEPINHOLEPINHOLE PREPARATIONPREPARATIONPREPARATIONPREPARATIONPREPARATIONPREPARATIONPREPARATIONPREPARATION::::::::

��Dull drillDull drill →→→→→→→→

��↑↑↑↑↑↑↑↑ frictional heatfrictional heat

��Cracks in the dentinCracks in the dentin

��To bend the pin To bend the pin →→→→→→→→ TMS bending toolTMS bending tool

INTERNAL STRESS CAUSE BY THE INTERNAL STRESS CAUSE BY THE

PIN PIN ↓↓↓↓↓↓↓↓ BY:BY:

1.1. ↑↑↑↑↑↑↑↑ space between pinsspace between pins

2.2. Channel Channel 2mm2mm deepdeep

3.3. Pins Pins parallelparallel to to occlusalocclusal forceforce

The success of all amalgam restoration depend on The success of all amalgam restoration depend on

→→→→→→→→ stability of the matrixstability of the matrix

Matrix:Matrix:

TofflemireTofflemire

Double matrixDouble matrix

CopperCopper

Auto matrixAuto matrix

FAILURE OF PINFAILURE OF PINFAILURE OF PINFAILURE OF PINFAILURE OF PINFAILURE OF PINFAILURE OF PINFAILURE OF PIN--------RETAINED RESTORATIONRETAINED RESTORATIONRETAINED RESTORATIONRETAINED RESTORATIONRETAINED RESTORATIONRETAINED RESTORATIONRETAINED RESTORATIONRETAINED RESTORATION

Occur at any of five different location:Occur at any of five different location:1.1. Restoration fracture Restoration fracture (failure within rest)(failure within rest)2.2. Pin restoration separation Pin restoration separation (at the interface (at the interface

between the pin and restorative materialbetween the pin and restorative material))3.3. Pin fracture Pin fracture (within the pin)(within the pin)4.4. Pin dentin separation Pin dentin separation (at the interface (at the interface

between the pin and dentinbetween the pin and dentin))5.5. Dentin fracture Dentin fracture (within the dentin)(within the dentin)

Failure is more likely to occur at the Failure is more likely to occur at the pin dentin interfacepin dentin interface

PROBLEMS THAT ARISE DURING PINPROBLEMS THAT ARISE DURING PIN--

RETAINED RESTORATION:RETAINED RESTORATION:

1.1. Broken drills and pinsBroken drills and pins•• Twist drill will break if:Twist drill will break if:

�� Stressed laterallyStressed laterally

�� Allowed to stop rotating before Allowed to stop rotating before removing from the pinholeremoving from the pinhole

�� Dull Dull (20 holes)(20 holes)

•• Pin will breakPin will break

�� During pendingDuring pending

�� Over Over -- screwed in the holescrewed in the hole

Solution:Solution: Leave it in place.Leave it in place.

Do another hole Do another hole 1.5mm 1.5mm from from broken itembroken item



2.2. Loose pinsLoose pins•• Due to:Due to:

�� Loosened while shortened with burLoosened while shortened with bur

�� Pinhole prepared too largePinhole prepared too large

Solution:Solution:•• Remove pin , pinhole prepared with next largest Remove pin , pinhole prepared with next largest

size drill , appropriate pin insertedsize drill , appropriate pin inserted

•• Drill another hole Drill another hole 1.5mm1.5mm from original pinhole, from original pinhole, close the other one with close the other one with

amalgapins amalgapins oror cement the pincement the pin



3.3. Penetration into the pulp and perforation of the Penetration into the pulp and perforation of the external tooth surface:external tooth surface:

•• Either penetration is obvious if there is Either penetration is obvious if there is hemorrhagehemorrhage in the in the pinholepinhole

•• Radiograph can help sometimes.Radiograph can help sometimes.

•• PulpalPulpal penetration treated as a pinpoint exposure penetration treated as a pinpoint exposure →→→→→→→→ Ca OHCa OH and prepare another holeand prepare another hole

•• If patient complains of pain after that If patient complains of pain after that →→→→→→→→endodonticendodontic treatmenttreatment



�� Lateral Perforation:Lateral Perforation:

Occlusal to gingival attachmentOcclusal to gingival attachment

Pin cutPin cut--off flush with the tooth surface.off flush with the tooth surface.

Pin cutPin cut--off and cast restoration extend gingivally.off and cast restoration extend gingivally.

Remove pin , enlarge hole and restored with Remove pin , enlarge hole and restored with amalgam.amalgam.

Apical to gingival attachmentApical to gingival attachment

Surgically remove the bone after Surgically remove the bone after

reflecting the tissue, enlarge reflecting the tissue, enlarge

pinhole, restored with amalgampinhole, restored with amalgam

Crown lengthening and cast Crown lengthening and cast

restoration cover the restoration cover the

perforation.perforation.

Resin Bonded Amalgam Resin Bonded Amalgam

RestorationRestoration

RESIN BONDED AMALGAM RESIN BONDED AMALGAM

RESTORATIONRESTORATION

An amalgam restoration that has been An amalgam restoration that has been

““bondedbonded”” to the existing tooth structure to the existing tooth structure

through the placement of a through the placement of a resin dentin resin dentin

bonding agentbonding agent followed by a viscous resinfollowed by a viscous resin

(or glass ionomer)(or glass ionomer) liner into which the liner into which the

fresh amalgam is condensed while the fresh amalgam is condensed while the

liner is still unset.liner is still unset.

AMALGAM ATTRIBUTESAMALGAM ATTRIBUTES

�� Proven clinical Proven clinical longevitylongevity despite being nondespite being non--

adhesiveadhesive

�� Various Various resistance/retentionresistance/retention forms have forms have

been successful even in large restorationsbeen successful even in large restorations

�� Long Long -- term sealterm seal

AMALGAM DEFICIENCIESAMALGAM DEFICIENCIES

�� Amalgam is not Amalgam is not adhesiveadhesive

�� Restorations are passive and do Restorations are passive and do notnot significantly significantly strengthen remaining toothstrengthen remaining tooth structurestructure

�� Mechanical retention/resistance form is provided Mechanical retention/resistance form is provided at the at the expense of tooth structureexpense of tooth structure

�� MicroleakageMicroleakage is present until corrosion seals the is present until corrosion seals the cavo cavo -- surface interface surface interface

(process is much slower in high(process is much slower in high--copper amalgams)copper amalgams)

ADVANTAGES OF RESIN BONDED ADVANTAGES OF RESIN BONDED

AMALGAMAMALGAM

1.1. Minimize or eliminate Minimize or eliminate microleakagemicroleakage

2.2. Enhance traditional Enhance traditional resistance and resistance and retentionretention methodsmethods

3.3. Increase the Increase the fracture resistancefracture resistance of the of the restored toothrestored tooth

4.4. Permit more Permit more conservativeconservative restorationsrestorations

5.5. Decrease Decrease marginal breakdownmarginal breakdown and and ditchingditching

6.6. Reduced incidence of postoperative tooth Reduced incidence of postoperative tooth sensitivitysensitivity

INDICATIONINDICATIONUsed for:Used for:

Supplementing mechanical resistance feature in Supplementing mechanical resistance feature in

large, complex amalgam restorations large, complex amalgam restorations

especially those replacing cusps.especially those replacing cusps.

When an improved initial seal is needed, such as When an improved initial seal is needed, such as

after after a direct or indirect pulp cappinga direct or indirect pulp capping

procedure in tooth being restored.procedure in tooth being restored.

BONDING MECHANISMBONDING MECHANISM

Dentin Interface Dentin Interface –– micromechanicalmicromechanical(formation of hybrid layer)(formation of hybrid layer)

Amalgam Interface Amalgam Interface –– micromechanicalmicromechanical(interlock between viscous (interlock between viscous

resin and fresh amalgam)resin and fresh amalgam)

Weak LinksWeak Links –– resin/amalgam interface resin/amalgam interface and and resin/dentin interfaceresin/dentin interface

SOME COMMERCIAL SYSTEMSSOME COMMERCIAL SYSTEMS

All bond 2All bond 2 withwith --Resin bonding agentResin bonding agent

--Liner FLiner F

--ResinomerResinomer (BISCO)(BISCO)

Amalgam bondAmalgam bond plus (HPA) (plus (HPA) (ParkellParkell))

Multipurpose resin bonding agentsMultipurpose resin bonding agents

-- OptioOptio--bond (Kerr)bond (Kerr)

-- ScotchbondScotchbondmultipurpose plus (3M)multipurpose plus (3M)

CLINICAL TECHNIQUE FOR RESIN BONDED CLINICAL TECHNIQUE FOR RESIN BONDED

AMALGAM RESTORATIONAMALGAM RESTORATION

Rubber dam isolation is essential for the best clinical Rubber dam isolation is essential for the best clinical

results.results.

Clean preparations and apply Clean preparations and apply

conditioner conditioner (etchant)(etchant) to enamel and to enamel and

dentin following the manufacturersdentin following the manufacturers’’

recommendations. recommendations.

Rinse and dry Rinse and dry lightly.lightly. Do not desiccate Do not desiccate

the tooth.the tooth. This step should be done This step should be done

prior to Matrix band placementprior to Matrix band placement..



Apply dentin primer/sealer following Apply dentin primer/sealer following

manufacturermanufacturer’’s recommendationss recommendations..

Apply the chemicallyApply the chemically--cured resin cured resin

bonding liner manufacturerbonding liner manufacturer’’s s

instructions.instructions.



Condense the amalgam immediately into the Condense the amalgam immediately into the wet linerwet liner before it cure. The resin will have before it cure. The resin will have a tendency to stick to metal condensers a tendency to stick to metal condensers and you may need to wipe them frequently. and you may need to wipe them frequently. You will find the bonding material will You will find the bonding material will oozeooze out at the cavosurface margins and out at the cavosurface margins and some of this excess can be removed before some of this excess can be removed before the material is completely set. Do carving the material is completely set. Do carving as you can at this stage to as you can at this stage to minimizeminimize the the finishing time. finishing time. Try to keep excess resin off Try to keep excess resin off of adjacent tooth structure.of adjacent tooth structure.

CLINICAL TECHNIQUE FOR RESIN BONDED AMALGAM CLINICAL TECHNIQUE FOR RESIN BONDED AMALGAM


Remove the wedge and matrix band carefully. If Remove the wedge and matrix band carefully. If

you have lubricated the band properly, this you have lubricated the band properly, this

step should not present problems.step should not present problems.

Check inter proximal and cervical first. Check inter proximal and cervical first.

Scalpels and sharp chiselsScalpels and sharp chisels will help carve any will help carve any

resin at margins. Resin at Occlusal margins resin at margins. Resin at Occlusal margins

can be carefully removed with rotary finishing can be carefully removed with rotary finishing

burs. Occlusal anatomy can be refined with burs. Occlusal anatomy can be refined with

carverscarvers and rotary instrumentations.and rotary instrumentations.

CLINICAL TECHNIQUE FOR RESIN BONDED AMALGAM CLINICAL TECHNIQUE FOR RESIN BONDED AMALGAM


Remove rubber dam and check and adjust Remove rubber dam and check and adjust occlusions as necessaryocclusions as necessary

DISADVANTAGESDISADVANTAGES

�� Extra steps and expenseExtra steps and expense(both time and materials)(both time and materials)

�� Technique sensitive and messyTechnique sensitive and messy

�� Adhesive may stick to matrix, Adhesive may stick to matrix, instruments and adjacent tooth instruments and adjacent tooth

structurestructure

��Carving more difficultCarving more difficult

�� Finishing usually requires rotary Finishing usually requires rotary instrumentationinstrumentation



1.1. Rubber dam isolation is essential for the best Rubber dam isolation is essential for the best

clinical results.clinical results.

2.2. Current recommendations are to execute Current recommendations are to execute

conventional amalgam preparation following conventional amalgam preparation following

traditional guidelines. It is possible to be traditional guidelines. It is possible to be

somewhat conservative, but you must somewhat conservative, but you must remember remember

thatthat the bulk of the restoration will be dental the bulk of the restoration will be dental

amalgam and that you cannot treat these as amalgam and that you cannot treat these as

preparations for composite resin.preparations for composite resin.



3.3. Clean preparations and apply Clean preparations and apply conditioner conditioner (etchant)(etchant) to enamel and to enamel and dentin following the manufacturersdentin following the manufacturers’’recommendations. recommendations.

Rinse and dry Rinse and dry lightly.lightly. Do not desiccate Do not desiccate the tooth.the tooth. This step should be done This step should be done prior to Matrix band placement.prior to Matrix band placement.



4.4. Carefully lubricateCarefully lubricate (very thin coat of (very thin coat of

Vaseline)Vaseline) matrix band and wedge. Do not matrix band and wedge. Do not

contaminate conditioned tooth surfacecontaminate conditioned tooth surface..



5.5. Apply dentin primer/sealer following Apply dentin primer/sealer following

manufacturermanufacturer’’s recommendationss recommendations..

NOTE: NOTE:

in systems that have a separate dentin bonding agent in systems that have a separate dentin bonding agent

that is placed before the more viscous bonding that is placed before the more viscous bonding

liner is applied, liner is applied,

apply that dentin bonding agent prior to matrix band apply that dentin bonding agent prior to matrix band

placementplacement



6.6. Apply the chemicallyApply the chemically--cured resin bonding liner cured resin bonding liner

manufacturermanufacturer’’s instructions. s instructions.

Current research indicates that the best attachment Current research indicates that the best attachment

between amalgam and liner occurs with the between amalgam and liner occurs with the more more

viscous materialsviscous materials. In addition, it has been suggested . In addition, it has been suggested

that systems that have a that systems that have a fluoride releasefluoride release mechanism mechanism

may be advantageousmay be advantageous

�� The use of The use of adhesive resinsadhesive resins to to

increase the retention,increase the retention,

resistance, and resistance, and

marginal seal of amalgam marginal seal of amalgam

restorations restorations

has gained much popularityhas gained much popularity

�� The use of adhesive resins to increase the The use of adhesive resins to increase the

retentionretention, resistance, and , resistance, and marginal sealmarginal seal of of

amalgam restorations has gained much amalgam restorations has gained much

popularitypopularity

��Several posterior teeth have anatomic Several posterior teeth have anatomic

features that may preclude features that may preclude

safe pinhole placementsafe pinhole placement

•• Fluted & Fureal areas should beFluted & Fureal areas should be

avoided.avoided.

Management of Badly Broken Down Teeth II

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