Amalgam
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About This Presentation
technical considerations of amalgam
Slide Content
Technical considerations of
Silver Amalgam
1
PRESENTED BY,
VISHNUJA V R NAIR
1
ST
YEAR MDS
DEPT OF CONSERVATIVE
DENTISTRY AND ENDODONTICS
Silver Amalgam
1
PRESENTED BY,
VISHNUJA V R NAIR
1
ST
YEAR MDS
DEPT OF CONSERVATIVE
DENTISTRY AND ENDODONTICS
CONTENTS
INTRODUCTION
CLASSIFICATION
COMPONENTS OF AMALGAM
BASIC SETTING REACTION
GENERAL CONSIDERATIONS FOR
AMALGAM RESTORATIONS
MANIPULATION
o SELECTION OF ALLOY
o PROPORTIONING
o TRITURITION
o CONDENSATION
o BURNISHING
o CARVING
oFINISHING
oPOLISHING
INDICATIONS AND
CONTRAINDICATIONS
ADVANTAGES AND DISADVANTAGES
MODIFICATION OF AMALGAM
MERCURY MANAGEMENT
CLINICAL LONGEVITY OF AMALGAM
REVIEW OF LITERATURE
CONCLUSION
REFERENCES
2
INTRODUCTION
CLASSIFICATION
COMPONENTS OF AMALGAM
BASIC SETTING REACTION
GENERAL CONSIDERATIONS FOR
AMALGAM RESTORATIONS
MANIPULATION
o SELECTION OF ALLOY
o PROPORTIONING
o TRITURITION
o CONDENSATION
o BURNISHING
o CARVING
oFINISHING
oPOLISHING
INDICATIONS AND
CONTRAINDICATIONS
ADVANTAGES AND DISADVANTAGES
MODIFICATION OF AMALGAM
MERCURY MANAGEMENT
CLINICAL LONGEVITY OF AMALGAM
REVIEW OF LITERATURE
CONCLUSION
REFERENCES
2
3
INTRODUCTION
ANSI/ADASpecificationNo.1
Amalgamisoneoftheoldestofallmaterialsusedforrestoringacarious
lesion.
Dentalamalgamisanalloymadebymixingmercurywithsilver-tinalloy
towhichvaryingamountofcopperandsmallamountofzincare
added.
LouisRegnart(1818)-Fatherofamalgam.
INTRODUCTION
ANSI/ADASpecificationNo.1
Amalgamisoneoftheoldestofallmaterialsusedforrestoringacarious
lesion.
Dentalamalgamisanalloymadebymixingmercurywithsilver-tinalloy
towhichvaryingamountofcopperandsmallamountofzincare
added.
LouisRegnart(1818)-Fatherofamalgam.
CLASSIFICATION
1.AccordingtotheNumberof
alloyedmetals
•Binaryalloy(Eg:Ag,Sn)
•Ternaryalloy(Eg:Ag,Sn,Cu)
•Quaternaryalloy(Eg:Ag,Sn,
Cu,In)
2.AccordingtoShapeof
powderedparticles
•Spherical
•Spheroidal
•Lathe cut
4
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
1.AccordingtotheNumberof
alloyedmetals
•Binaryalloy(Eg:Ag,Sn)
•Ternaryalloy(Eg:Ag,Sn,Cu)
•Quaternaryalloy(Eg:Ag,Sn,
Cu,In)
2.AccordingtoShapeof
powderedparticles
•Spherical
•Spheroidal
•Lathe cut
4
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
3.Accordingtopowderparticle
Size
•Microcut
•Finecut
•Coarsecut
5.Accordingtopresenceor
absenceofZinc
•ZincfreeLessthan.01%
•ZinccontainingMorethan
0.01%
4.AccordingtoCoppercontents:
•LowCopperLessthan6%
•HighCopperMorethan6%
6.Accordingtowhetherpowder
containsunmixedoradmixed
alloys
•Dispersed/blended/Admixedalloys
•Unicompositional/single
compositional
5
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
Size
•Microcut
•Finecut
•Coarsecut
5.Accordingtopresenceor
absenceofZinc
•ZincfreeLessthan.01%
•ZinccontainingMorethan
0.01%
4.AccordingtoCoppercontents:
•LowCopperLessthan6%
•HighCopperMorethan6%
6.Accordingtowhetherpowder
containsunmixedoradmixed
alloys
•Dispersed/blended/Admixedalloys
•Unicompositional/single
compositional
5
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
TYPES OF DENTAL AMALGAM ALLOYS
Low copper alloy
High copper alloy
a) Admixed b)Uni-compositional
Low Cu alloy (5% or less)
High Cualloy (13%-30%)
High compressivestrength
Better marginaladaptation
Lowcreep(0.1%-1%)
Least stable and corrosive
High creep (1-8%)
6Roberson T, HeymannHO, Swift Jr EJ. Sturdevant'sart and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
Low copper alloy
High copper alloy
a) Admixed b)Uni-compositional
Low Cu alloy (5% or less)
High Cualloy (13%-30%)
High compressivestrength
Better marginaladaptation
Lowcreep(0.1%-1%)
Least stable and corrosive
High creep (1-8%)
6Roberson T, HeymannHO, Swift Jr EJ. Sturdevant'sart and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
Elements Increases Decreases
Silver (Ag) Whitens the alloy, Strength, Setting
expansion, Resistance to tarnish.
Flow and Creep
Tin (Su) Creep, Rate of Amalgamation, corrosion ,
contraction
Strength, Hardness, speed
of setting
Copper (Cu) Strength, Hardness,
Setting expansion, tarnish
Creep
Zinc (Zn) Act as a plasticizer, Delayed expansion,
corrosion.
Brittleness,
COMPONENTS OF ALLOY POWDER
7
Materials used in dentistry-S.Mahalaxmi
Silver (Ag) Whitens the alloy, Strength, Setting
expansion, Resistance to tarnish.
Flow and Creep
Tin (Su) Creep, Rate of Amalgamation, corrosion ,
contraction
Strength, Hardness, speed
of setting
Copper (Cu) Strength, Hardness,
Setting expansion, tarnish
Creep
Zinc (Zn) Act as a plasticizer, Delayed expansion,
corrosion.
Brittleness,
COMPONENTS OF ALLOY POWDER
7
Materials used in dentistry-S.Mahalaxmi
THE BASIC SETTING REACTION OF AMALGAM
Alloy Particles for Amalgam + Mercury Dental Amalgam + Nonreacted Alloy Powder
Particles
•gphase(Ag3Sn):strongestphasewhichoccupiesthemaximumavailablespace
inthevolumeofrestoration.
•g1phase(Ag2Hg3):noblestphase,mostresistanttotarnishandcorrosion.
•g2phase(Sn7–8Hg):weakestphase,morepronetocorrosionandcreep.
8
Materials used in dentistry-S.Mahalaxmi
LOW COPPER ALLOYS
Alloy Particles for Amalgam + Mercury Dental Amalgam + Nonreacted Alloy Powder
Particles
•gphase(Ag3Sn):strongestphasewhichoccupiesthemaximumavailablespace
inthevolumeofrestoration.
•g1phase(Ag2Hg3):noblestphase,mostresistanttotarnishandcorrosion.
•g2phase(Sn7–8Hg):weakestphase,morepronetocorrosionandcreep.
8
Materials used in dentistry-S.Mahalaxmi
LOW COPPER ALLOYS
9
Ag3sn + AgCu+ Hg Ag2Hg3 + Sn8Hg + Ag3Sn + AgCu
Sn8Hg + AgCu Cu6Sn5 + Ag2Hg3 + Ag3Sn
Initial Reaction
Final Reaction
HIGH COPPER ADMIXED ALLOY
HIGH COPPER UNICOMPOSITIONAL
Ag3sn + Cu3Sn + Hg Cu6Sn5+ Ag2Hg3
Epsilon reduces creep,andprevent formation of gamma2 phase
Eta phase strengths the bond between alloy particles and gamma1 phase. It increases resistance to deformation
and resistance to tarnish and corrosion
Craig’s restorative dental materials 12
th
edition
Ag3sn + AgCu+ Hg Ag2Hg3 + Sn8Hg + Ag3Sn + AgCu
Sn8Hg + AgCu Cu6Sn5 + Ag2Hg3 + Ag3Sn
Initial Reaction
Final Reaction
HIGH COPPER ADMIXED ALLOY
HIGH COPPER UNICOMPOSITIONAL
Ag3sn + Cu3Sn + Hg Cu6Sn5+ Ag2Hg3
Epsilon reduces creep,andprevent formation of gamma2 phase
Eta phase strengths the bond between alloy particles and gamma1 phase. It increases resistance to deformation
and resistance to tarnish and corrosion
Craig’s restorative dental materials 12
th
edition
GENERAL CONSIDERATIONFOR AMALGAM
RESTORATION
•Amalgamiseffectiveasadirectrestorativematerialbecauseofitseasyinsertionintoa
toothpreparationand,whenhardened,itsabilitytorestorethetoothtoproperformand
function.
•Therequiredtoothpreparationformmustallowtheamalgamto
1.Possessauniformspecifiedminimumthicknessforstrength(sothatitwillnotlex
andfractureunderload)
2.Producea90-degreeamalgamangle(butt-jointformformaximumedgethickness)at
themargin,bemechanicallyretainedinthetooth.
3.Amalgamrestorationsinitiallyleakandthereforerequirestepstoprotectfrompulpal
sensitivityuntilself-sealingisabletooccur.
10
Sturdevant Operative Dentistry 7th Edition
RESTORATION
•Amalgamiseffectiveasadirectrestorativematerialbecauseofitseasyinsertionintoa
toothpreparationand,whenhardened,itsabilitytorestorethetoothtoproperformand
function.
•Therequiredtoothpreparationformmustallowtheamalgamto
1.Possessauniformspecifiedminimumthicknessforstrength(sothatitwillnotlex
andfractureunderload)
2.Producea90-degreeamalgamangle(butt-jointformformaximumedgethickness)at
themargin,bemechanicallyretainedinthetooth.
3.Amalgamrestorationsinitiallyleakandthereforerequirestepstoprotectfrompulpal
sensitivityuntilself-sealingisabletooccur.
10
Sturdevant Operative Dentistry 7th Edition
Technical consideration of Amalgam Restoration
Selection ofalloy
Proportioning
Trituration
Mulling
Matricing
Condensation
Carving
Burnishing
Finishing and polishing
12
Sturdevant Operative Dentistry 7th Edition
Selection ofalloy
Proportioning
Trituration
Mulling
Matricing
Condensation
Carving
Burnishing
Finishing and polishing
12
Sturdevant Operative Dentistry 7th Edition
SELECTION OFALLOY
Shape of
alloy
Size of
alloy
Composition of
alloy
13
Sturdevant Operative Dentistry 7th Edition
Sincelowcopperandzinccontaining
alloyshavethedisadvantagesofg2
phaseandhygroscopicexpansion,
theyarenotusednowadays.
Thehighcopperalloysareusedin
morethan90%ofthecases,the
majorityofwhicharethespherical
singlecompositionaloradmixed
types,duetotheirhighearly
strength,lowcreep,bettermarginal
adaptation,andgoodresistanceto
corrosion.
Shape of
alloy
Size of
alloy
Composition of
alloy
13
Sturdevant Operative Dentistry 7th Edition
Sincelowcopperandzinccontaining
alloyshavethedisadvantagesofg2
phaseandhygroscopicexpansion,
theyarenotusednowadays.
Thehighcopperalloysareusedin
morethan90%ofthecases,the
majorityofwhicharethespherical
singlecompositionaloradmixed
types,duetotheirhighearly
strength,lowcreep,bettermarginal
adaptation,andgoodresistanceto
corrosion.
oSmallertheparticlesize,higheristhestrength,lesserexpansion,moreeasilyadopted
intothecavitywallsandmoreeasilypolished.
oOnlyfinerparticle-sizedlowcopperlathe-cutalloyscanbeusedbecauseofimproved
surfacefinishduringcarvingandfinishing,enhancedclinicalconvenience,suchasthe
easeofdispensingfrommechanicalpropositioningdevices.
oMoreover,lathe-cutalloysrequirealmost50%ormoremercurytoobtainadequate
plasticityduringtrituration;hence,itsuseisnotrecommended.
oSincesphericalalloysaresmootherandconsistofvarioussizesofspheres(2–3mm)
thatallowcompactpackingoftheparticleswithalowareatovolumeratio,they
generallyrequirelessmercury(about42%)fortrituration.
14
Materials used in dentistry-S.Mahalaxmi
intothecavitywallsandmoreeasilypolished.
oOnlyfinerparticle-sizedlowcopperlathe-cutalloyscanbeusedbecauseofimproved
surfacefinishduringcarvingandfinishing,enhancedclinicalconvenience,suchasthe
easeofdispensingfrommechanicalpropositioningdevices.
oMoreover,lathe-cutalloysrequirealmost50%ormoremercurytoobtainadequate
plasticityduringtrituration;hence,itsuseisnotrecommended.
oSincesphericalalloysaresmootherandconsistofvarioussizesofspheres(2–3mm)
thatallowcompactpackingoftheparticleswithalowareatovolumeratio,they
generallyrequirelessmercury(about42%)fortrituration.
14
Materials used in dentistry-S.Mahalaxmi
•The lathe-cut and spherical alloys react differently to condensation
forces. Due to their shape, spherical alloys cannot offer much
resistance to the condensation pressure and require much
less force than lathe-cut alloys during condensation.
•Another criterion depends on the presence or absence of zinc. If
an alloy containing more than 0.01% zinc is used, it exhibits
excessive corrosion and expansion if moisture contamination
occurs.
•The alloy that does not contain zinc will be less plastic, less
workable, and more susceptible to oxidation.
15
Materials used in dentistry-S.Mahalaxmi
forces. Due to their shape, spherical alloys cannot offer much
resistance to the condensation pressure and require much
less force than lathe-cut alloys during condensation.
•Another criterion depends on the presence or absence of zinc. If
an alloy containing more than 0.01% zinc is used, it exhibits
excessive corrosion and expansion if moisture contamination
occurs.
•The alloy that does not contain zinc will be less plastic, less
workable, and more susceptible to oxidation.
15
Materials used in dentistry-S.Mahalaxmi
16
SHAPE OF ALLOY
Sphericalalloysarepreferredbecauseit:
Givesbetterfinish,marginaladaptation
Goodstrength
Requireslesscondensationforces
Requireslessmercury(42%concofHg)duetolowsurfacearea
comparedtolathecutwhichrequires50%ormoreHg.
HighCopperalloyispreferredoverlowCoppersince:
-Lesscreepduetoabsenceofgamma2phaseandbettercorrosion
resistance.
Sturdevant Operative Dentistry 7th Edition
SHAPE OF ALLOY
Sphericalalloysarepreferredbecauseit:
Givesbetterfinish,marginaladaptation
Goodstrength
Requireslesscondensationforces
Requireslessmercury(42%concofHg)duetolowsurfacearea
comparedtolathecutwhichrequires50%ormoreHg.
HighCopperalloyispreferredoverlowCoppersince:
-Lesscreepduetoabsenceofgamma2phaseandbettercorrosion
resistance.
Sturdevant Operative Dentistry 7th Edition
TYPE OF ALLOY FEATURES
Spherical alloy Tend to flow into andadapt themselves
more readily into internal cavity
walls.(class I cavity)
Admixed alloy Does not flow ahead of the condenser,
gets adapted itself to the angles and
corners within the confines of the
matrix and developing a positive
contact with the adjacent tooth.
(class I and II cavity)
17
Materials used in dentistry-S.Mahalaxmi
Spherical alloy Tend to flow into andadapt themselves
more readily into internal cavity
walls.(class I cavity)
Admixed alloy Does not flow ahead of the condenser,
gets adapted itself to the angles and
corners within the confines of the
matrix and developing a positive
contact with the adjacent tooth.
(class I and II cavity)
17
Materials used in dentistry-S.Mahalaxmi
Alloy powder & mercury
Disposable capsules with pre proportioned alloy powder &
mercury
Preweighted pellets or tablets & mercury in sachets.
Self activating Capsules.
MODE OFSUPPLY
18
Materials used in dentistry-S.Mahalaxmi
Disposable capsules with pre proportioned alloy powder &
mercury
Preweighted pellets or tablets & mercury in sachets.
Self activating Capsules.
MODE OFSUPPLY
18
Materials used in dentistry-S.Mahalaxmi
PROPORTIONING
Manipulation
AlloyComposition
Particle Size and Shape
Heat Treatment
CondensationTechnique
19
Sturdevant Operative Dentistry 7th Edition
Manipulation
AlloyComposition
Particle Size and Shape
Heat Treatment
CondensationTechnique
19
Sturdevant Operative Dentistry 7th Edition
20
PROPORTIONING OF ALLOY TO MERCURY
Therearedifferentwaysofproportioning:
Weighing and triturating: this is ideal but time consuming
Volume dispensing:
Widely used-however it is difficult to dispense any powder
accurately by volume
Pre-weighed capsules of alloy powder and Mercury separated by a membrane:
Disposable capsules containing pre-proportioned amounts of mercury and alloy are
widely used. Just before the mix is triturated, the membrane is ruptured by compression
of the capsule.
Phillip’s Science of Dental Materials 11
th
edition
PROPORTIONING OF ALLOY TO MERCURY
Therearedifferentwaysofproportioning:
Weighing and triturating: this is ideal but time consuming
Volume dispensing:
Widely used-however it is difficult to dispense any powder
accurately by volume
Pre-weighed capsules of alloy powder and Mercury separated by a membrane:
Disposable capsules containing pre-proportioned amounts of mercury and alloy are
widely used. Just before the mix is triturated, the membrane is ruptured by compression
of the capsule.
Phillip’s Science of Dental Materials 11
th
edition
DISPOSABLECAPSULES
-Disposablecapsules
contain preproportioned
alloyparticles andmercury
separatedby a membrane.
Before use themembrane
isrupturedby compressing
thecapsule
21
Materials used in dentistry-S.Mahalaxmi
-Disposablecapsules
contain preproportioned
alloyparticles andmercury
separatedby a membrane.
Before use themembrane
isrupturedby compressing
thecapsule
21
Materials used in dentistry-S.Mahalaxmi
22
Somealloysarenowavailableinself-activatingcapsules,whichautomaticallyreleasethe
mercuryintothealloychamberduringthefirstfewoscillationsoftheamalgamator.
Size:Capsulescontaining400,600,800or1200mgofthealloyand
appropriateamountofHgaccordingtothesizeofthecavity.
Phillip’s Science of Dental Materials 11
th
edition
Somealloysarenowavailableinself-activatingcapsules,whichautomaticallyreleasethe
mercuryintothealloychamberduringthefirstfewoscillationsoftheamalgamator.
Size:Capsulescontaining400,600,800or1200mgofthealloyand
appropriateamountofHgaccordingtothesizeofthecavity.
Phillip’s Science of Dental Materials 11
th
edition
MERCURY / ALLOY RATIO
For conventional mercury added systems 2 techniques were used for mercury
reduction:
a)By squeezing or wringing the mixed amalgam in a squeeze cloth before insertion
into the prepared cavity.
b) Mercury rich amalgam was worked to the top during condensation of each
increment, and this excess was removed as the amalgam mix was built up to form a
restoration.
23
Marzouk
For conventional mercury added systems 2 techniques were used for mercury
reduction:
a)By squeezing or wringing the mixed amalgam in a squeeze cloth before insertion
into the prepared cavity.
b) Mercury rich amalgam was worked to the top during condensation of each
increment, and this excess was removed as the amalgam mix was built up to form a
restoration.
23
Marzouk
MINIMAL MERCURY TECHNIQUE
EAMESTECHNIQUE
(1959)
RECOMMENDED HG/ALLOY RATIO
1:1
25
Themostobviousmethodforreducingthemercurycontentoftherestorationistoreducethe
originalmercury/alloyratio.Thepresentdayalloysaredesignatedformanipulationwith
reducedmercury/alloyratiosjustenoughtogetacoherentplasticmass.
Marzouk
EAMESTECHNIQUE
(1959)
RECOMMENDED HG/ALLOY RATIO
1:1
25
Themostobviousmethodforreducingthemercurycontentoftherestorationistoreducethe
originalmercury/alloyratio.Thepresentdayalloysaredesignatedformanipulationwith
reducedmercury/alloyratiosjustenoughtogetacoherentplasticmass.
Marzouk
26
TRITURITION
Marzouk
•The purpose of trituration is to mix the amalgam alloy intimately with mercury so
as to wet the surface of the powder particles to allow the reaction between
liquid mercury and silver alloy.
•There is always an oxide layer of the alloy surface that hinders diffusion of mercury
into the alloy.
•This film must be disrupted so that a clean surface of alloy can make intimate
contact with the mercury. The oxide layer is removed by abrasionwhen the alloy
particles and mercury are triturated.
TRITURITION
Marzouk
•The purpose of trituration is to mix the amalgam alloy intimately with mercury so
as to wet the surface of the powder particles to allow the reaction between
liquid mercury and silver alloy.
•There is always an oxide layer of the alloy surface that hinders diffusion of mercury
into the alloy.
•This film must be disrupted so that a clean surface of alloy can make intimate
contact with the mercury. The oxide layer is removed by abrasionwhen the alloy
particles and mercury are triturated.
To achieve a
workable mass of
amalgam within a
minimum time.
To remove
oxides from the
powder particle
surface,
facilitating direct
contact between
the particles and
the mercury
To pulverize pellets
into particles that can
be easily attacked by
the mercury.
OBJECTIVES OFTRITURATION
Marzouk
27
workable mass of
amalgam within a
minimum time.
To remove
oxides from the
powder particle
surface,
facilitating direct
contact between
the particles and
the mercury
To pulverize pellets
into particles that can
be easily attacked by
the mercury.
OBJECTIVES OFTRITURATION
Marzouk
27
To reduce particle
size so as to increase
the surface area of the
alloy particles per
unit volume, leading
to a faster and more
complete
amalgamation.
To keep the gamma1
matrix crystals as
minimal as possible
yet evenly distributed
throughout the mass
for proper binding
and consistent
adequate strength
To dissolve the
particles or part of
the particles of the
powder in mercury,
which is a
prerequisite for the
formation of the
matrix crystals
Marzouk
28
size so as to increase
the surface area of the
alloy particles per
unit volume, leading
to a faster and more
complete
amalgamation.
To keep the gamma1
matrix crystals as
minimal as possible
yet evenly distributed
throughout the mass
for proper binding
and consistent
adequate strength
To dissolve the
particles or part of
the particles of the
powder in mercury,
which is a
prerequisite for the
formation of the
matrix crystals
Marzouk
28
29
HAND MIXING BY THE MORTAR AND PESTLE METHOD
In this a glass mortar of parabolic shape and a pestle is used.
The time of mixing is 30-40secwith a force of 800-900 gm being applied.
The mixed mass should be homogeneous, smooth, should not stick to walls of mortar and
pestle and should form a lump.
Factors affecting it include:
•Pressure exerted on the mix
•Number of revolutions per minute
•Inclination of the pestle relative to the mortar
•Surface roughness of both mortar and pestle
HAND MIXING BY THE MORTAR AND PESTLE METHOD
In this a glass mortar of parabolic shape and a pestle is used.
The time of mixing is 30-40secwith a force of 800-900 gm being applied.
The mixed mass should be homogeneous, smooth, should not stick to walls of mortar and
pestle and should form a lump.
Factors affecting it include:
•Pressure exerted on the mix
•Number of revolutions per minute
•Inclination of the pestle relative to the mortar
•Surface roughness of both mortar and pestle
MECHANICAL TRITURATION
oTriturationof amalgam alloy and Mercuryisdone withamechanical mixing device
calledAMALGAMATOR -Time ranges from 3 to 30 seconds.
30
oThis saves time, standardizes the procedure, produces an even mix, and is
advantageous for use with a low Mercury: Alloy ratio.
oTriturationof amalgam alloy and Mercuryisdone withamechanical mixing device
calledAMALGAMATOR -Time ranges from 3 to 30 seconds.
30
oThis saves time, standardizes the procedure, produces an even mix, and is
advantageous for use with a low Mercury: Alloy ratio.
31
oThemainmixingmechanismofamechanicaltrituratorisareciprocatingarmthat
holdsthecapsuleunderaprotectivehood.Thepurposeofthehoodistoconfine
mercurythatmightescapeintotheroomortopreventacapsulefrombeing
accidentallyejectedfromthetrituratorduringtrituration.
oAmoderntrituratorisoftenmicroprocessorcontrolledandcontainspresettrituration
programsforanumberofmaterials.Acylindricalmetalorplasticpistonofsmaller
diameterthanthecapsuleisinsertedintothecapsule,andthisservesasthepestle.
Sphericalalloysoftendonotneedapestle.
oAtrituratorshouldbeusedatthespeedrecommendedbythealloymanufacturer.
oSelf-activatingcapsulesareusuallyverysensitivetotriturationspeed.
Phillip’s Science of Dental Materials 11
th
edition
oThemainmixingmechanismofamechanicaltrituratorisareciprocatingarmthat
holdsthecapsuleunderaprotectivehood.Thepurposeofthehoodistoconfine
mercurythatmightescapeintotheroomortopreventacapsulefrombeing
accidentallyejectedfromthetrituratorduringtrituration.
oAmoderntrituratorisoftenmicroprocessorcontrolledandcontainspresettrituration
programsforanumberofmaterials.Acylindricalmetalorplasticpistonofsmaller
diameterthanthecapsuleisinsertedintothecapsule,andthisservesasthepestle.
Sphericalalloysoftendonotneedapestle.
oAtrituratorshouldbeusedatthespeedrecommendedbythealloymanufacturer.
oSelf-activatingcapsulesareusuallyverysensitivetotriturationspeed.
Phillip’s Science of Dental Materials 11
th
edition
32
ADVANTAGES
1.Uniformandreproduciblemixcanbeattained.
2.Minimaltriturationtimeisrequired.
3.AgreaterAlloy:Mercuryratioisusedforpreparingthemixastheyareproportionedbythe
manufacturer.
4.Atmosphericmercurycontaminationisreduced.
Phillip’s Science of Dental Materials 11
th
edition
ADVANTAGES
1.Uniformandreproduciblemixcanbeattained.
2.Minimaltriturationtimeisrequired.
3.AgreaterAlloy:Mercuryratioisusedforpreparingthemixastheyareproportionedbythe
manufacturer.
4.Atmosphericmercurycontaminationisreduced.
Phillip’s Science of Dental Materials 11
th
edition
Foragivenmercury/alloyratio,increasedtriturationtimeand/orspeedshortensthe
workingandsettingtimes.
Low,mediumandhighspeedamalgamatorsoperateatabout3200-4400cyclesper
minute.
Coherencetime:
Itisdefinedastheminimummixingtimerequiredforanamalgamtoformasinglecoherent
pellet.
Ithasbeenfoundthatthecompressivestrength,dimensionalchangeandcreepare
optimizedifthemixingiscarriedoutforatimeof5timesthecoherencetime.
33
workingandsettingtimes.
Low,mediumandhighspeedamalgamatorsoperateatabout3200-4400cyclesper
minute.
Coherencetime:
Itisdefinedastheminimummixingtimerequiredforanamalgamtoformasinglecoherent
pellet.
Ithasbeenfoundthatthecompressivestrength,dimensionalchangeandcreepare
optimizedifthemixingiscarriedoutforatimeof5timesthecoherencetime.
33
COMPRESSIVE STRENGTH OF AMALGAM TRITURATED BY A
HIGH-SPEED AMALGAMATOR AND BY AN ULTRAHIGH -SPEED
MIXER
•Fourfrequentlyuseddentalamalgamalloyswereselectedforthisstudy.Eachofthealloys
wastrituratedinahigh-speedamalgamatorandinaultrahigh-speedmixerwithandwithout
apestleinthecapsule.Thecompressivestrengthofthesetrituratedamalgamwascompared.
•Alloystrituratedinthehigh-speedamalgamatorsatisfactorilyattainedtheirmaximum
crushingstrengthswhenmixedaccordingtoeachmanufacturer'sinstructionsforthatalloy.
•Atmostofthetimestested,alloystrituratedwiththeultrahigh-speedmixerwiththepestle
inthecapsulereachedslightlyhighercompressivestrengthsthanthosemixedintheusual
high-speedamalgamator.
•Itisconcludedthattheultrahigh-speedmixerisaninstrumentcapableofproducing
satisfactorytriturationofthealloysstudiedwhencompressivestrengthsareusedasthe
criterion.
34
Osborne JW, Ferguson GW, Sorensen SE, Gale EN. Compressive strength of amalgam triturated by a high-speed amalgamator and by an ultrahigh-speed mixer. The Journal of prosthetic dentistry. 1968 Jun 1;19(6):598-604.
HIGH-SPEED AMALGAMATOR AND BY AN ULTRAHIGH -SPEED
MIXER
•Fourfrequentlyuseddentalamalgamalloyswereselectedforthisstudy.Eachofthealloys
wastrituratedinahigh-speedamalgamatorandinaultrahigh-speedmixerwithandwithout
apestleinthecapsule.Thecompressivestrengthofthesetrituratedamalgamwascompared.
•Alloystrituratedinthehigh-speedamalgamatorsatisfactorilyattainedtheirmaximum
crushingstrengthswhenmixedaccordingtoeachmanufacturer'sinstructionsforthatalloy.
•Atmostofthetimestested,alloystrituratedwiththeultrahigh-speedmixerwiththepestle
inthecapsulereachedslightlyhighercompressivestrengthsthanthosemixedintheusual
high-speedamalgamator.
•Itisconcludedthattheultrahigh-speedmixerisaninstrumentcapableofproducing
satisfactorytriturationofthealloysstudiedwhencompressivestrengthsareusedasthe
criterion.
34
Osborne JW, Ferguson GW, Sorensen SE, Gale EN. Compressive strength of amalgam triturated by a high-speed amalgamator and by an ultrahigh-speed mixer. The Journal of prosthetic dentistry. 1968 Jun 1;19(6):598-604.
35
POTENTIAL HEALTH AND ENVIRONMENTAL ISSUES OF MERCURY -
CONTAMINATED AMALGAMATORS
Theauthorsassessedusedamalgamatorsandevaluatedthepotentialmercuryvaporhealth
risk,usingestablishedOccupationalSafetyandHealthmethodsandAmericanConferenceof
GovernmentalIndustrialHygienistsstandards.
Tenofthe11amalgamatorsassessedhadmeasurablemercuryvaporlevels.Four
amalgamatorswerefoundtohaveinternalstaticmercuryvaporlevelsaboveOccupational
SafetyandHealthAdministrationceilinglimitthresholds.
Conclusion:Amalgamatorsmaybecontaminatedinternallywithmetallicmercury.Although
theauthorsdetectedmercuryvaporfromtheseunitsduringaggressive,simulatedclinicaluse,
dilutionfactorscombinedwithroomairexchangewerefoundtokeephealthrisksbelow
establishedfederalsafetythresholds.
Roberts HW, Leonard D, Osborne J. Potential health and environmental issues of mercury-contaminated amalgamators. The Journal ofthe American Dental Association. 2001 Jan 1;132(1):58-64.
POTENTIAL HEALTH AND ENVIRONMENTAL ISSUES OF MERCURY -
CONTAMINATED AMALGAMATORS
Theauthorsassessedusedamalgamatorsandevaluatedthepotentialmercuryvaporhealth
risk,usingestablishedOccupationalSafetyandHealthmethodsandAmericanConferenceof
GovernmentalIndustrialHygienistsstandards.
Tenofthe11amalgamatorsassessedhadmeasurablemercuryvaporlevels.Four
amalgamatorswerefoundtohaveinternalstaticmercuryvaporlevelsaboveOccupational
SafetyandHealthAdministrationceilinglimitthresholds.
Conclusion:Amalgamatorsmaybecontaminatedinternallywithmetallicmercury.Although
theauthorsdetectedmercuryvaporfromtheseunitsduringaggressive,simulatedclinicaluse,
dilutionfactorscombinedwithroomairexchangewerefoundtokeephealthrisksbelow
establishedfederalsafetythresholds.
Roberts HW, Leonard D, Osborne J. Potential health and environmental issues of mercury-contaminated amalgamators. The Journal ofthe American Dental Association. 2001 Jan 1;132(1):58-64.
36
MULLING
Mullingisacontinuationoftrituration.
Improvethehomogeneityofthemass
Toassureaconsistentmix.Itcanbeaccomplishedintwoways:
1.Themixisenvelopedinadrypieceofrubberdamandvigorouslyrubbedbetweenthe
firstfingerandthumb;orthethumbofonehandandpalmofanotherhand.The
processshouldnotexceed2to5seconds.
2.Aftertriturationthepestlecanberemovedfromthecapsule,andthemixtrituratedin
thepestle-freecapsuleforadditional2to3seconds.Thiswillalsoassurecleaningof
thecapsulewallsofremnantsoftheamalgammix,therebydeliveringthemixinone
single,coherent,andconsistentmass.
MULLING
Mullingisacontinuationoftrituration.
Improvethehomogeneityofthemass
Toassureaconsistentmix.Itcanbeaccomplishedintwoways:
1.Themixisenvelopedinadrypieceofrubberdamandvigorouslyrubbedbetweenthe
firstfingerandthumb;orthethumbofonehandandpalmofanotherhand.The
processshouldnotexceed2to5seconds.
2.Aftertriturationthepestlecanberemovedfromthecapsule,andthemixtrituratedin
thepestle-freecapsuleforadditional2to3seconds.Thiswillalsoassurecleaningof
thecapsulewallsofremnantsoftheamalgammix,therebydeliveringthemixinone
single,coherent,andconsistentmass.
CONSISTENCY OFMIX
37
Undertriturated Normal Overtriturated
Philips, Text book of dental materials , 12
TH
Edition
Rough & grainy mix,
difficult to manipulate
Rough surface after carving,
less resistance to tarnish &
corrosion
Compressive & tensile
strength reduced
Mix will harden too rapidly
& excess mercury will be left
in the restoration
•Has maximum strength.
•Appears shiny and has a
smooth surface and
consistency.
•Smooth carved surface
will retain its luster long
after polishing.
•Separates as single mass
from capsule.
•Mix will be soupy,
difficult to remove from
capsule, too plastic to
manipulate
•Working time decreased
•Creep is increased
•Increased contraction of
amalgam
37
Undertriturated Normal Overtriturated
Philips, Text book of dental materials , 12
TH
Edition
Rough & grainy mix,
difficult to manipulate
Rough surface after carving,
less resistance to tarnish &
corrosion
Compressive & tensile
strength reduced
Mix will harden too rapidly
& excess mercury will be left
in the restoration
•Has maximum strength.
•Appears shiny and has a
smooth surface and
consistency.
•Smooth carved surface
will retain its luster long
after polishing.
•Separates as single mass
from capsule.
•Mix will be soupy,
difficult to remove from
capsule, too plastic to
manipulate
•Working time decreased
•Creep is increased
•Increased contraction of
amalgam
CONDENSATION
38
Phillip’s Science of Dental Materials
11
th
edition
oThegoalofcondensationistocompactthealloyintothepreparedcavitysothatthe
greatestpossibledensityisattained,withsufficientmercurypresenttoensurecontinuity
ofthematrixphase(Ag2Hg3)betweentheremainingalloyparticles.
oThisresultsfromareductionofexcessmercuryandporositywithinthesetamalgam.
oAfterthemixtureismade,theincrementsofalloyshouldbecarriedto,andinsertedin,the
preparedcavitybymeansofinstrumentssuchassmallforcepsoranamalgamcarrier
designedforthispurpose.
38
Phillip’s Science of Dental Materials
11
th
edition
oThegoalofcondensationistocompactthealloyintothepreparedcavitysothatthe
greatestpossibledensityisattained,withsufficientmercurypresenttoensurecontinuity
ofthematrixphase(Ag2Hg3)betweentheremainingalloyparticles.
oThisresultsfromareductionofexcessmercuryandporositywithinthesetamalgam.
oAfterthemixtureismade,theincrementsofalloyshouldbecarriedto,andinsertedin,the
preparedcavitybymeansofinstrumentssuchassmallforcepsoranamalgamcarrier
designedforthispurpose.
OBJECTIVES
To reduce the
number of voids
To remove unreacted Hg out
of increments during
building up restoration
To adapt the plastic
amalgam mix to cavity
walls and margins.
39
To reduce the
number of voids
To remove unreacted Hg out
of increments during
building up restoration
To adapt the plastic
amalgam mix to cavity
walls and margins.
39
40
oAwell-condensedamalgamrestorationcanbeachievedonlyifthemixturehasaproper
consistency.
oAdry,grainymixlacksauniformdistributionofmercuryandplasticity,asdescribed
previously,andamixthatishardandhottothetouchhasprobablybeenmixedtoolong.In
eithercase,anewmixshouldbeprepared.
oThelongerthetimethatelapsesbetweenmixingandcondensation,theweakertheamalgam
willbe.Condensationofpartiallysetmaterialfracturesandbreaksupthematrixthathas
alreadyformed.
oInaddition,whenthealloyhaslostacertainamountofplasticity,itisdifficulttocondense
withoutproducinginternalvoidsandlayering.
oAwell-condensedamalgamrestorationcanbeachievedonlyifthemixturehasaproper
consistency.
oAdry,grainymixlacksauniformdistributionofmercuryandplasticity,asdescribed
previously,andamixthatishardandhottothetouchhasprobablybeenmixedtoolong.In
eithercase,anewmixshouldbeprepared.
oThelongerthetimethatelapsesbetweenmixingandcondensation,theweakertheamalgam
willbe.Condensationofpartiallysetmaterialfracturesandbreaksupthematrixthathas
alreadyformed.
oInaddition,whenthealloyhaslostacertainamountofplasticity,itisdifficulttocondense
withoutproducinginternalvoidsandlayering.
41
Effectofelapsedtimebetweentriturationandcondensationonthestrengthofthe
hardenedamalgam.Thegreatertheelapsedtime,theloweristhestrength
Effectofelapsedtimebetweentriturationandcondensationonthestrengthofthe
hardenedamalgam.Thegreatertheelapsedtime,theloweristhestrength
42
HAND CONDENSATION
Oncetheincrementofamalgamisinsertedintothecavity,itshouldimmediatelybe
condensedwithsufficientpressuretoremovevoidsandtoadaptthematerialtothewalls.
Theinitialcondensershouldbesmallenoughtocondenseamalgamintothelineangles.
Whenthefirstportionhasbeencondensed,thesuccessiveportionsofthedivided
amalgamareaddedafterfirstsqueezingtheexcessmercuryaway.
Successiveportionsrequiremoreforcetosqueezeawaymercury,becausemorefree
mercuryisreactingwiththealloyparticles.
Phillip’s Science of Dental Materials 11
th
edition
HAND CONDENSATION
Oncetheincrementofamalgamisinsertedintothecavity,itshouldimmediatelybe
condensedwithsufficientpressuretoremovevoidsandtoadaptthematerialtothewalls.
Theinitialcondensershouldbesmallenoughtocondenseamalgamintothelineangles.
Whenthefirstportionhasbeencondensed,thesuccessiveportionsofthedivided
amalgamareaddedafterfirstsqueezingtheexcessmercuryaway.
Successiveportionsrequiremoreforcetosqueezeawaymercury,becausemorefree
mercuryisreactingwiththealloyparticles.
Phillip’s Science of Dental Materials 11
th
edition
43
Condensationisusuallystartedatthecenterandthenthecondenserpointis
steppedlittlebylittletowardsthecavitywalls.
Careshouldbetakenwhencondensingwithhand
instrumentstousepointsthatareshapedapproximatelyto
theoutlineoftheareabeingrestored.
Spheroiding’ofamalgamattheinternallineangles
whichresultifinadequatelydesignedinstrumentsare
used
Condensationisusuallystartedatthecenterandthenthecondenserpointis
steppedlittlebylittletowardsthecavitywalls.
Careshouldbetakenwhencondensingwithhand
instrumentstousepointsthatareshapedapproximatelyto
theoutlineoftheareabeingrestored.
Spheroiding’ofamalgamattheinternallineangles
whichresultifinadequatelydesignedinstrumentsare
used
44
Aftercondensationofanincrement,thesurfaceshouldbeshinyinappearance.This
indicatesthatthereissufficientmercurypresentatthesurfacetodiffuseintothenext
incrementsothateachincrement,asitisadded,bondstotheprecedingone.
Thisisdoneuntilthecavityisoverfilledbyaround1mm.Anymercuryrichmaterialat
thesurface,isremovedwhentherestorationiscarved.
Ifthecavityislargerandextratimeisrequiredforcondensation,anothermixshouldbe
madejustbeforetheoriginalonelosesitsplasticity.
Phillip’s Science of Dental Materials 11
th
edition
Aftercondensationofanincrement,thesurfaceshouldbeshinyinappearance.This
indicatesthatthereissufficientmercurypresentatthesurfacetodiffuseintothenext
incrementsothateachincrement,asitisadded,bondstotheprecedingone.
Thisisdoneuntilthecavityisoverfilledbyaround1mm.Anymercuryrichmaterialat
thesurface,isremovedwhentherestorationiscarved.
Ifthecavityislargerandextratimeisrequiredforcondensation,anothermixshouldbe
madejustbeforetheoriginalonelosesitsplasticity.
Phillip’s Science of Dental Materials 11
th
edition
45
•After completely filling the cavity, an over dried amalgam mix is condensed
heavily over the restoration using the largest condensers possible for the involved
tooth. This mix is called the blotting mix.
This serves to :
•Blot excess mercury from the critical marginal and surface area of the
restoration and
•To adapt amalgam more intimately to the cavosurfaceanatomy.
•After completely filling the cavity, an over dried amalgam mix is condensed
heavily over the restoration using the largest condensers possible for the involved
tooth. This mix is called the blotting mix.
This serves to :
•Blot excess mercury from the critical marginal and surface area of the
restoration and
•To adapt amalgam more intimately to the cavosurfaceanatomy.
•A small condenser(0.8mm) is used at the initial stages of condensation to
pack into retentive grooves and cavo surface margins.
•Medium sized condensers should be used to pack the bulk of the restoration.
•Large size is used for the last portion of the occlusal surface.
46
pack into retentive grooves and cavo surface margins.
•Medium sized condensers should be used to pack the bulk of the restoration.
•Large size is used for the last portion of the occlusal surface.
46
MECHANICAL CONDENSORS
ULTRASONIC CONDENSORS
•Not recommended because of increased mercury
levels in dental office.
•Use rapid vibration
•Used where high condensation forces
are required.
47
ULTRASONIC CONDENSORS
•Not recommended because of increased mercury
levels in dental office.
•Use rapid vibration
•Used where high condensation forces
are required.
47
48
Mechanical Condensation:
-Condensation of the amalgam is performed by an automatic device.
-Useful for irregular shaped alloys when high force is used.
-two types: Mallet type and vibrating type.
Advantages are:
a) less energy is needed than for hand condensation.
b) operation may cause less fatigue to the dentist.
Dentatus amalgam condenser (vibrating type)
Mechanical Condensation:
-Condensation of the amalgam is performed by an automatic device.
-Useful for irregular shaped alloys when high force is used.
-two types: Mallet type and vibrating type.
Advantages are:
a) less energy is needed than for hand condensation.
b) operation may cause less fatigue to the dentist.
Dentatus amalgam condenser (vibrating type)
CONDENSATION PRESSURE
oTheareaofthecondensertipandtheforceexertedonitbythe
operatorgovernthecondensationpressure(forceperunitarea).When
agivenforceisapplied,thesmallerthecondenser,thegreateristhe
pressureexertedontheamalgam.
oIfthecondenserpointistoolarge,theoperatorcannotgenerate
sufficientpressuretocondensetheamalgamadequatelyandforceit
intoretentiveareas.
oStudieshaveshownthatforceintherangeof13.3-17.8N(3-4lb)representthe
averageforceemployed.
49
Phillip’s Science of Dental Materials 11
th
edition
oTheareaofthecondensertipandtheforceexertedonitbythe
operatorgovernthecondensationpressure(forceperunitarea).When
agivenforceisapplied,thesmallerthecondenser,thegreateristhe
pressureexertedontheamalgam.
oIfthecondenserpointistoolarge,theoperatorcannotgenerate
sufficientpressuretocondensetheamalgamadequatelyandforceit
intoretentiveareas.
oStudieshaveshownthatforceintherangeof13.3-17.8N(3-4lb)representthe
averageforceemployed.
49
Phillip’s Science of Dental Materials 11
th
edition
THE INFLUENCE OF PRECONDENSATION MERCURY CONTENT
AND MULLING ON THE TRANSVERSE STRENGTH OF
AMALGAMS CONDENSED AFTER A DELAY
•Thepurposeofthisstudywastoinvestigatetheinfluenceofchanginginitialmercury
contentonthefinalstrengthofamalgamsandtheeffectoftransversestrengthofmulling
theamalgamwhenthecondensationwasdelayedforfiveminutes.
•Thefiveminutesdelayofthecondensationreducedthestrengthoftheamalgamsby1to
42%dependingonthebrandofalloyandinitalmercurycontent.Increasingtheinital
mercurycontentreducedtheeffectofthedelayonthefinalstrength.Themullingofthe
amalgammixalsodecreasedtheeffectofthedelay.
•Itwasconcludedthatamoderateexcessofinitialmercurygivesthedentistalonger
condensingtimethusallowinghimtoperformthecondensingprocedurewithcare.
50
Forsten L. The Influence of Precondensation Mercury Content and Mulling on the Transverse Strength of Amalgams Condensed After aDelay. Acta Odontologica Scandinavica. 1972 Jan 1;30(4):453-61.
AND MULLING ON THE TRANSVERSE STRENGTH OF
AMALGAMS CONDENSED AFTER A DELAY
•Thepurposeofthisstudywastoinvestigatetheinfluenceofchanginginitialmercury
contentonthefinalstrengthofamalgamsandtheeffectoftransversestrengthofmulling
theamalgamwhenthecondensationwasdelayedforfiveminutes.
•Thefiveminutesdelayofthecondensationreducedthestrengthoftheamalgamsby1to
42%dependingonthebrandofalloyandinitalmercurycontent.Increasingtheinital
mercurycontentreducedtheeffectofthedelayonthefinalstrength.Themullingofthe
amalgammixalsodecreasedtheeffectofthedelay.
•Itwasconcludedthatamoderateexcessofinitialmercurygivesthedentistalonger
condensingtimethusallowinghimtoperformthecondensingprocedurewithcare.
50
Forsten L. The Influence of Precondensation Mercury Content and Mulling on the Transverse Strength of Amalgams Condensed After aDelay. Acta Odontologica Scandinavica. 1972 Jan 1;30(4):453-61.
PRE CARVEBURNISHING
51
Materials used in dentistry –S Mahalaxmi
oBurnishingisdefinedastheplasticdeformationofasurfacedueto
rubbing/slidingcontactwithanotherobject.Indentalrestorations,burnishingis
donetoimprovethesurfacecharacteristicsofarestoration.
oImmediatelyaftercondensation,alarge,roundburnisherisusedinlightstrokes
fromtherestorationtowardthecavosurfacemargin.Thisisknownaspre-
carveburnishing.Itisconsideredtobeacontinuationofthecondensation
procedure.Beavertailburnisherisusedininaccessibleareassuchasproximal
surfacesoftherestoration.
51
Materials used in dentistry –S Mahalaxmi
oBurnishingisdefinedastheplasticdeformationofasurfacedueto
rubbing/slidingcontactwithanotherobject.Indentalrestorations,burnishingis
donetoimprovethesurfacecharacteristicsofarestoration.
oImmediatelyaftercondensation,alarge,roundburnisherisusedinlightstrokes
fromtherestorationtowardthecavosurfacemargin.Thisisknownaspre-
carveburnishing.Itisconsideredtobeacontinuationofthecondensation
procedure.Beavertailburnisherisusedininaccessibleareassuchasproximal
surfacesoftherestoration.
52
THE OBJECTIVES OF PRE-CARVE BURNISHING
1.Toimprovethemarginaladaptationoftheamalgam
2.Tofurtherreducethesizeandnumberofvoidspresentonthesurfaceofthe
restoration
3.Tobringanyfurtherexcessmercurytothesurface,whichcanberemovedduring
carving
4.Toconditiontheamalgamsurfacetothecarvingprocedure
Materials used in dentistry –S Mahalaxmi
THE OBJECTIVES OF PRE-CARVE BURNISHING
1.Toimprovethemarginaladaptationoftheamalgam
2.Tofurtherreducethesizeandnumberofvoidspresentonthesurfaceofthe
restoration
3.Tobringanyfurtherexcessmercurytothesurface,whichcanberemovedduring
carving
4.Toconditiontheamalgamsurfacetothecarvingprocedure
Materials used in dentistry –S Mahalaxmi
53
oAftertheamalgamhasbeencondensedintothepreparedcavity,itiscarvedto
reproducethepropertoothanatomy.
oTheobjectiveofcarvingistosimulatetheanatomyratherthantoreproduceextremely
finedetails.Ifthecarvingistoodeep,thebulkofamalgammaybecometoothinandit
mayfractureunderdirectocclusalloading.
CARVING
oAftertheamalgamhasbeencondensedintothepreparedcavity,itiscarvedto
reproducethepropertoothanatomy.
oTheobjectiveofcarvingistosimulatetheanatomyratherthantoreproduceextremely
finedetails.Ifthecarvingistoodeep,thebulkofamalgammaybecometoothinandit
mayfractureunderdirectocclusalloading.
CARVING
To produce a restoration with no underhangs, ie., all
marginal details of the cavity preparation are completely
covered with amalgam.
To produce a restoration with the proper physiological
contours.
.
To produce a restoration with functional, non
interfering Occlusal anatomy.
54
To produce a restoration with minimal flash
Silver Amalgam in Clinical Practice: by I.D.Gainsford
OBJECTIVES
marginal details of the cavity preparation are completely
covered with amalgam.
To produce a restoration with the proper physiological
contours.
.
To produce a restoration with functional, non
interfering Occlusal anatomy.
54
To produce a restoration with minimal flash
Silver Amalgam in Clinical Practice: by I.D.Gainsford
OBJECTIVES
57
To produce a restoration with adequate, compatible
marginal ridges.
Toproducearestorationwiththepropersize,location,
extentandinterrelationshipofcontactareas.
.
To produce a restoration not interfering in any way
with the integrity of the periodontium, enhancing its
health and amenable for plaque control.
Toproducearestorationwithphysiological
compatibleembrasures.
Silver Amalgam in Clinical Practice: by I.D.Gainsford
To produce a restoration with adequate, compatible
marginal ridges.
Toproducearestorationwiththepropersize,location,
extentandinterrelationshipofcontactareas.
.
To produce a restoration not interfering in any way
with the integrity of the periodontium, enhancing its
health and amenable for plaque control.
Toproducearestorationwithphysiological
compatibleembrasures.
Silver Amalgam in Clinical Practice: by I.D.Gainsford
58
A scraping or ringing sound should be heard when it is carved(amalgam cry).
After carving, the outline of the amalgam margin should reflect the contour and location of the
prepared cavosurface margin.
An amalgam restoration that is more than minimally overcarved (a submarginal defect >
0.2mm) should be replaced.
Silver Amalgam in Clinical Practice: by I.D.Gainsford
A scraping or ringing sound should be heard when it is carved(amalgam cry).
After carving, the outline of the amalgam margin should reflect the contour and location of the
prepared cavosurface margin.
An amalgam restoration that is more than minimally overcarved (a submarginal defect >
0.2mm) should be replaced.
Silver Amalgam in Clinical Practice: by I.D.Gainsford
To remove scratches and
irregularities on the amalgam surface
POST CARVEBURNISHING
60
Final smoothening can be concluded by rubbing the surface
with a moist cotton pellet or by lightly smoothing the surface
with a rubber polishing cup and an extremely fine polishing
or prophylaxis paste
Burnishing of the occlusal anatomy can be
accomplished with a ball burnisher with gentle
strokes from the amalgam to the tooth surface.
Aftercarvingiscompletedthesurfaceoftherestorationshouldbesmoothened.Thismaybe
accomplishedbyburnishingthesurfaceandmarginsoftherestorationlightlytoproducea
smoothandsatinappearance.
irregularities on the amalgam surface
POST CARVEBURNISHING
60
Final smoothening can be concluded by rubbing the surface
with a moist cotton pellet or by lightly smoothing the surface
with a rubber polishing cup and an extremely fine polishing
or prophylaxis paste
Burnishing of the occlusal anatomy can be
accomplished with a ball burnisher with gentle
strokes from the amalgam to the tooth surface.
Aftercarvingiscompletedthesurfaceoftherestorationshouldbesmoothened.Thismaybe
accomplishedbyburnishingthesurfaceandmarginsoftherestorationlightlytoproducea
smoothandsatinappearance.
61
•Clinical data on performance of restorations support the desirability of burnishing the fast
setting, high-copper systems. Burnishing slow-setting alloys can damage the margins of
the restoration.
Unduepressureshouldnotbeexertedinburnishingandheatgenerationshouldbe
avoided.Temperaturesabove60°C(140°F)causeasignificantreleaseofmercury.
•Clinical data on performance of restorations support the desirability of burnishing the fast
setting, high-copper systems. Burnishing slow-setting alloys can damage the margins of
the restoration.
Unduepressureshouldnotbeexertedinburnishingandheatgenerationshouldbe
avoided.Temperaturesabove60°C(140°F)causeasignificantreleaseofmercury.
oRegardlessofalloy,triturationmethodorcondensationtechnique,thecarvedsurfaceof
thefillingisrough,orcoveredwithscratches,pits,andirregularities,whichcanresultin
concentrationcellcorrosionovertime.
oThesmoothsurfaceontherestorationsisproducedbythefinalfinishingprocedure.
oThefinalfinishingoftherestorationshouldbedelayeduntiltheamalgamdevelops
sufficientstrengthtoresistthepressureofpolishing.
oGenerally,therecommendationistowaitforatleast24horuntilthenextappointment.
62
thefillingisrough,orcoveredwithscratches,pits,andirregularities,whichcanresultin
concentrationcellcorrosionovertime.
oThesmoothsurfaceontherestorationsisproducedbythefinalfinishingprocedure.
oThefinalfinishingoftherestorationshouldbedelayeduntiltheamalgamdevelops
sufficientstrengthtoresistthepressureofpolishing.
oGenerally,therecommendationistowaitforatleast24horuntilthenextappointment.
62
63
Influence of burnishing on amalgam adaptation to cavity walls
CONCLUSIONS
Bycomparingthetwoimages,itcanbeseenthattheburnishedamalgamhasbetter
adaptationthantheunburnishedamalgam.Thisstudyindicatedthatburnishingduring
condensationimprovesamalgamadaptation.
High-copperalloysprovidedbetteradaptationthantheconventionalfinecutalloy.
Sphericalhigh-copperalloytestedbetterthanconventionalhigh-copperalloy.
Threealloyswereusedinthestudy(NewTrueDentalloy,aconventionalfinecutalloy,
Novaloy,aconventionalhigh-copperalloyandSybraloy,asphericalhigh-copperalloy).
Thealloywastrituratedfor10secondsinamechanicalamalgamatorwiththeuseofa
plasticcapsuleandmetalpestle.
Theamalgamcondensationwasmadebytwomethods:withburnishingandwithout
burnishing.BlackandwhitephotographsofeachspecimenatamagnificationofX500
weremade
Lovadino JR, Ruhnke LA, Consani S. Influence of burnishing on amalgam adaptation to cavity walls. J Prosthet Dent. 1987 Sep 1;58(3):284.
Influence of burnishing on amalgam adaptation to cavity walls
CONCLUSIONS
Bycomparingthetwoimages,itcanbeseenthattheburnishedamalgamhasbetter
adaptationthantheunburnishedamalgam.Thisstudyindicatedthatburnishingduring
condensationimprovesamalgamadaptation.
High-copperalloysprovidedbetteradaptationthantheconventionalfinecutalloy.
Sphericalhigh-copperalloytestedbetterthanconventionalhigh-copperalloy.
Threealloyswereusedinthestudy(NewTrueDentalloy,aconventionalfinecutalloy,
Novaloy,aconventionalhigh-copperalloyandSybraloy,asphericalhigh-copperalloy).
Thealloywastrituratedfor10secondsinamechanicalamalgamatorwiththeuseofa
plasticcapsuleandmetalpestle.
Theamalgamcondensationwasmadebytwomethods:withburnishingandwithout
burnishing.BlackandwhitephotographsofeachspecimenatamagnificationofX500
weremade
Lovadino JR, Ruhnke LA, Consani S. Influence of burnishing on amalgam adaptation to cavity walls. J Prosthet Dent. 1987 Sep 1;58(3):284.
64
FINISHING AND POLISHING
Finishing:Removesthesurfaceirregularities
Polishing:Theprocessthatremovesthescratches&irregularitiesfromthesurfaceofthe
restorationleavingasmooth,highlyglazedsurfacethatiscorrosionresistant.
Finishingandpolishingarenecessaryto:
1.Completethecarving
2.Refinetheanatomy,contoursandmarginalintegrity.
3.Enhancethesurfacetextureoftherestoration.
Finalfinishingisdonetoremovesuperficialscratches,pits&irregularities.Thisinturn
minimizescorrosion&preventsadherenceofplaque.
FINISHING AND POLISHING
Finishing:Removesthesurfaceirregularities
Polishing:Theprocessthatremovesthescratches&irregularitiesfromthesurfaceofthe
restorationleavingasmooth,highlyglazedsurfacethatiscorrosionresistant.
Finishingandpolishingarenecessaryto:
1.Completethecarving
2.Refinetheanatomy,contoursandmarginalintegrity.
3.Enhancethesurfacetextureoftherestoration.
Finalfinishingisdonetoremovesuperficialscratches,pits&irregularities.Thisinturn
minimizescorrosion&preventsadherenceofplaque.
Removal of gross overhangs and
flashes
FinishingBurs
Removal of unwanted shiny
contacts
•Finer finishing
burs and disc
Removal of Superficial
scratches and irregularities
Finer Rubber
cups
FINISHING
65
flashes
FinishingBurs
Removal of unwanted shiny
contacts
•Finer finishing
burs and disc
Removal of Superficial
scratches and irregularities
Finer Rubber
cups
FINISHING
65
Finishing strips for
proximal surfaces
POLISHING
•Rubber cup
with flour of
pumice
66
proximal surfaces
POLISHING
•Rubber cup
with flour of
pumice
66
67
•Theareamaybefurthersmoothenedusinglightpressurewithasuitablyshaped
roundfinishingbur.Thisburremovesthescratchesfromthegreenorwhite
stone.
•Polishingisinitiatedwithcoarseabrasiverubberpointatslowspeedandan
airwaterspray.
•Finalpolishingmaybeaccomplishedbyusingarubbercupwithaflourof
pumiceortinoxidefollowedbyahighlusteragentlikeprecipitatedchalk.
•Additionalfinishingandpolishingproceduresarenotattemptedwithin24
hoursofinsertionbecausecrystallizationisincomplete.
•Theareamaybefurthersmoothenedusinglightpressurewithasuitablyshaped
roundfinishingbur.Thisburremovesthescratchesfromthegreenorwhite
stone.
•Polishingisinitiatedwithcoarseabrasiverubberpointatslowspeedandan
airwaterspray.
•Finalpolishingmaybeaccomplishedbyusingarubbercupwithaflourof
pumiceortinoxidefollowedbyahighlusteragentlikeprecipitatedchalk.
•Additionalfinishingandpolishingproceduresarenotattemptedwithin24
hoursofinsertionbecausecrystallizationisincomplete.
ADVANTAGES
Ease of handling
High compressive strength
Excellent wear resistance
Favourablelong term clinical results
Optimal dimensional changes
Sealing ability improves with age by
formation of corrosion products at tooth
amalgam interface.
Relatively not technique sensitive
DISADVANTAGES
Non esthetic
Less conservative in removal of tooth
structure
More difficult tooth preparation
Initial marginal leakage
Does not bond to the tooth structure
Amalgam is a good thermal conductor-thus
base is required.
Less tensile strength
Galvanic currents produced in certain cases.
68
ADVANTAGES AND DISADVANTAGES OF
SILVER AMALGAM
Ease of handling
High compressive strength
Excellent wear resistance
Favourablelong term clinical results
Optimal dimensional changes
Sealing ability improves with age by
formation of corrosion products at tooth
amalgam interface.
Relatively not technique sensitive
DISADVANTAGES
Non esthetic
Less conservative in removal of tooth
structure
More difficult tooth preparation
Initial marginal leakage
Does not bond to the tooth structure
Amalgam is a good thermal conductor-thus
base is required.
Less tensile strength
Galvanic currents produced in certain cases.
68
ADVANTAGES AND DISADVANTAGES OF
SILVER AMALGAM
INDICATIONS AND CONTRAINDICATIONS
OF AMALGAM RESTORATIONS
INDICATIONS
1.ForpermanentlyrestoringclassI,
II,andVrestorations(where
estheticsisnotaconcern)
2.Corebuild-upmaterial
3.Complexamalgamrestorations
4.Forpreparationofdyes
5.Asaretrogradefillingmaterial
(notusednowadays)
6.Postendodonticaccessfilling
CONTRAINDICATIONS
1.Anterior teeth where aesthetics is
prime concern
2.Aesthetically prominent areas of
posterior teeth.
3.Small to Moderate class I and II
restoration that can be well isolated.
4.Small class IV defects.
69
OF AMALGAM RESTORATIONS
INDICATIONS
1.ForpermanentlyrestoringclassI,
II,andVrestorations(where
estheticsisnotaconcern)
2.Corebuild-upmaterial
3.Complexamalgamrestorations
4.Forpreparationofdyes
5.Asaretrogradefillingmaterial
(notusednowadays)
6.Postendodonticaccessfilling
CONTRAINDICATIONS
1.Anterior teeth where aesthetics is
prime concern
2.Aesthetically prominent areas of
posterior teeth.
3.Small to Moderate class I and II
restoration that can be well isolated.
4.Small class IV defects.
69
70
MERCURY MANAGEMENT
CrucialthatthealloyingreactionofmercurywiththeAg-Snalloyiscomplete.after
completiononlyextremelyminutelevelsofmercurycanbereleased.
MackertetalandMandelscientificallyrefutedtheproblemscausedbymercury
hypersensitivity.Itisamildreactionandnotlifethreatening.
In1991,theNationalinstituteofhealth-Nationalinstitutefordentalresearch,theFDA
andseveralscientistsandcliniciansconcludedthattherewasnobasisforclaimsthat
amalgamwasasignificanthealthhazard.
MERCURY MANAGEMENT
CrucialthatthealloyingreactionofmercurywiththeAg-Snalloyiscomplete.after
completiononlyextremelyminutelevelsofmercurycanbereleased.
MackertetalandMandelscientificallyrefutedtheproblemscausedbymercury
hypersensitivity.Itisamildreactionandnotlifethreatening.
In1991,theNationalinstituteofhealth-Nationalinstitutefordentalresearch,theFDA
andseveralscientistsandcliniciansconcludedthattherewasnobasisforclaimsthat
amalgamwasasignificanthealthhazard.
71
Historically the source of mercury contamination was spillage of liquid mercury as it
was dispensed in bottles which was transferred to dispensers and then to individual
capsules for mixing.
Mishandling at any stage could result in splashing of mercury and its scattering
widely as small droplets.
Current use of encapsulated amalgam has eliminated most chances of spillage.
The critical time is when the metallic mercury is in the vapors form, it can be inhaled
and absorbed through the alveoli in the lungs at 80% efficiency. Thus inhalation is
the major route of entry in the human body.
Historically the source of mercury contamination was spillage of liquid mercury as it
was dispensed in bottles which was transferred to dispensers and then to individual
capsules for mixing.
Mishandling at any stage could result in splashing of mercury and its scattering
widely as small droplets.
Current use of encapsulated amalgam has eliminated most chances of spillage.
The critical time is when the metallic mercury is in the vapors form, it can be inhaled
and absorbed through the alveoli in the lungs at 80% efficiency. Thus inhalation is
the major route of entry in the human body.
72
MERCURY THERMOMETER POTRAYING DIFFERENT LEVELS OF MERCURY TOXICITY –
ASSESSED BY URINARY MERCURY CONCENTRATION
(as micrograms of mercury per gram of creatinine)
Materials used in dentistry S.Mahalaxmi
MERCURY THERMOMETER POTRAYING DIFFERENT LEVELS OF MERCURY TOXICITY –
ASSESSED BY URINARY MERCURY CONCENTRATION
(as micrograms of mercury per gram of creatinine)
Materials used in dentistry S.Mahalaxmi
73
Mercurialism (Hydragyrism):
Ifexposedtoabovethresholdvaluesofmercuryvapourforalongtime,thismaybe
seen.Featuresinclude:
Drowsiness,headache,lossofconcentration,tremorsinhands,lips,tongue,kidney
failure,stomatitis,gingivitisandincreasedsalivation,ulcerationsandeven
looseningofteeth.(Shaefer)
Amalgamillness–termgiventothecondition,usuallyselfreported,thatis
attributedpatientstomercuryvapourintakefromtheirexistingamalgam
restorations.
symptoms-fatigue,difficultyinconcentrating,muscularpainandimmunologic
disorders.
Bates MN. Dental amalgam fillings: An under-investigated source of mercury exposure. 2019.
Mercurialism (Hydragyrism):
Ifexposedtoabovethresholdvaluesofmercuryvapourforalongtime,thismaybe
seen.Featuresinclude:
Drowsiness,headache,lossofconcentration,tremorsinhands,lips,tongue,kidney
failure,stomatitis,gingivitisandincreasedsalivation,ulcerationsandeven
looseningofteeth.(Shaefer)
Amalgamillness–termgiventothecondition,usuallyselfreported,thatis
attributedpatientstomercuryvapourintakefromtheirexistingamalgam
restorations.
symptoms-fatigue,difficultyinconcentrating,muscularpainandimmunologic
disorders.
Bates MN. Dental amalgam fillings: An under-investigated source of mercury exposure. 2019.
74
In the dental office, the sources of mercury exposure related to amalgam include:
(1)Amalgam raw materials being stored for use
(2)Mixed but unhardened amalgam during trituration, insertion and intraoral hardening.
(3)Amalgam scrap that has insufficient alloy to consume the mercury present completely.
(4)Amalgam undergoing finishing and polishing operations.
(5)Amalgam restorations being removed.
In the dental office, the sources of mercury exposure related to amalgam include:
(1)Amalgam raw materials being stored for use
(2)Mixed but unhardened amalgam during trituration, insertion and intraoral hardening.
(3)Amalgam scrap that has insufficient alloy to consume the mercury present completely.
(4)Amalgam undergoing finishing and polishing operations.
(5)Amalgam restorations being removed.
75
Duringtriturition,smalllocalspillsarebestcollectedwithavacuumaspirator.
Whensmalldropletsofmercuryrichmaterialcontaminatethefloorcoverings,the
onlypracticalapproachtodecontaminatetheareaistoreplacethecoverings.There
isnoeffectivetreatmentforremovingliquidmercuryfromcarpeting.
Mouthmasksdonotfiltermercuryvapourfromair.Routineexposuresaremonitored
withexposurebadges(dosimeters).
Duringintraoralcondensationsomemercuryvapourisreleased.Tocontrolthisa
rubberdamandhighvolumeevacuationshouldbeused.
Duringtriturition,smalllocalspillsarebestcollectedwithavacuumaspirator.
Whensmalldropletsofmercuryrichmaterialcontaminatethefloorcoverings,the
onlypracticalapproachtodecontaminatetheareaistoreplacethecoverings.There
isnoeffectivetreatmentforremovingliquidmercuryfromcarpeting.
Mouthmasksdonotfiltermercuryvapourfromair.Routineexposuresaremonitored
withexposurebadges(dosimeters).
Duringintraoralcondensationsomemercuryvapourisreleased.Tocontrolthisa
rubberdamandhighvolumeevacuationshouldbeused.
76
Scrap amalgam from condensation procedures should be collected and stored under
water, glycerin or spent x-ray filter(source of sulfide and silver ions for it to react and
form a solid product) in a tightly capped jar.
Melting of the Ag-Hg phase also occurs during amalgam removal since the surface
temperature increases several hundred degrees when the high speed bur contacts the tooth
structure. Thus mercury is vaporized. Rubber dam, high volume evacuation and water
cooling is used to control the situation.
Scrap amalgam from condensation procedures should be collected and stored under
water, glycerin or spent x-ray filter(source of sulfide and silver ions for it to react and
form a solid product) in a tightly capped jar.
Melting of the Ag-Hg phase also occurs during amalgam removal since the surface
temperature increases several hundred degrees when the high speed bur contacts the tooth
structure. Thus mercury is vaporized. Rubber dam, high volume evacuation and water
cooling is used to control the situation.
77
ADA RECOMMENDATIONS FOR DENTAL MERCURY HYGEINE
1)Train all personnel regarding mercury handling and hazards.
2)Make them aware of the potential sources of mercury vapourin the operatory.
3)Work in well ventilated spaces with an exhaust.
4)Monitor the dental operatory atmosphere for mercury vapour. Current limit for mercury
vapouris 50 microgram/m3 in any 8 hrwork shift over a 40 hrweek.
5)Floor covering should be non absorbent, seamless and easy to clean.
6)Use precapsulatedalloys.
7)Use amalgamator with completely enclosed arm.
8)Avoid skin contact with mercury or freshly prepared amalgam.
9)Re-cap single use capsules after use if possible.
Sturdevant; 5
th
Edition
ADA RECOMMENDATIONS FOR DENTAL MERCURY HYGEINE
1)Train all personnel regarding mercury handling and hazards.
2)Make them aware of the potential sources of mercury vapourin the operatory.
3)Work in well ventilated spaces with an exhaust.
4)Monitor the dental operatory atmosphere for mercury vapour. Current limit for mercury
vapouris 50 microgram/m3 in any 8 hrwork shift over a 40 hrweek.
5)Floor covering should be non absorbent, seamless and easy to clean.
6)Use precapsulatedalloys.
7)Use amalgamator with completely enclosed arm.
8)Avoid skin contact with mercury or freshly prepared amalgam.
9)Re-cap single use capsules after use if possible.
Sturdevant; 5
th
Edition
78
10) Use high volume evacuation while finishing or removing amalgam.
11) Salvage and store all scrap amalgam.
12) Dispose amalgam scrap and mercury contaminated items as per applicable
regulations.
13) Clean up spilled mercury using trap bottles, tape or freshly mixed amalgam.
14) Remove professional clothing before leaving the workplace.
Sturdevant; 5
th
Edition
10) Use high volume evacuation while finishing or removing amalgam.
11) Salvage and store all scrap amalgam.
12) Dispose amalgam scrap and mercury contaminated items as per applicable
regulations.
13) Clean up spilled mercury using trap bottles, tape or freshly mixed amalgam.
14) Remove professional clothing before leaving the workplace.
Sturdevant; 5
th
Edition
CLINICAL LONGEVITY
79
Corbin SB, Kohn WG. The benefits and risks of dental amalgam: current findings reviewed. Journal of the American Dental Association (1939). 1994 Apr 1;125(4):381-8.
79
Corbin SB, Kohn WG. The benefits and risks of dental amalgam: current findings reviewed. Journal of the American Dental Association (1939). 1994 Apr 1;125(4):381-8.
80
CLINICAL LONGEVITY
Silver amalgam continues to be the most widely used permanent restorative
material for posterior teeth. However, the clinical success of amalgam
restoration depends upon the proper cavity design and correct manipulation of
the alloy.
Itisdeterminedbymonitoringmanyrestorationsthroughalongitudinalclinical
researchstudyoracrosssectionalclinicalstudy.
Clinicalfailureisthepointatwhichtherestorationwasnolongerserviceableorat
whichtimetherestorationposesothersevererisksifitisnotreplaced.
TheaveragereplacementageofconventionallowCopperamalgaminclinicalpractice
is5-8yrs.HighCuamalgamshaveahighestsurvivalrateof85%.
Advances in operative dentistry; by –Narin, Jean
CLINICAL LONGEVITY
Silver amalgam continues to be the most widely used permanent restorative
material for posterior teeth. However, the clinical success of amalgam
restoration depends upon the proper cavity design and correct manipulation of
the alloy.
Itisdeterminedbymonitoringmanyrestorationsthroughalongitudinalclinical
researchstudyoracrosssectionalclinicalstudy.
Clinicalfailureisthepointatwhichtherestorationwasnolongerserviceableorat
whichtimetherestorationposesothersevererisksifitisnotreplaced.
TheaveragereplacementageofconventionallowCopperamalgaminclinicalpractice
is5-8yrs.HighCuamalgamshaveahighestsurvivalrateof85%.
Advances in operative dentistry; by –Narin, Jean
81
Amalgam restoration related failures include:
1.Bulk fracture of the restoration.
2.Corossion and excessive marginal fracture.
3.Sensitivity or pain.
4.Secondary caries.
5.Fracture of tooth structure forming the restorative tooth preparation wall.
•Annual failure rates range between 0% to 7% for Non gamma-2 and gamma-2
containing alloys with observation periods of upto20 years.
•Clinical diagnosis of secondary caries was recorded to be the main reason for
the failure of amalgam restorations.
Advances in operative dentistry; by –Narin, Jean
Amalgam restoration related failures include:
1.Bulk fracture of the restoration.
2.Corossion and excessive marginal fracture.
3.Sensitivity or pain.
4.Secondary caries.
5.Fracture of tooth structure forming the restorative tooth preparation wall.
•Annual failure rates range between 0% to 7% for Non gamma-2 and gamma-2
containing alloys with observation periods of upto20 years.
•Clinical diagnosis of secondary caries was recorded to be the main reason for
the failure of amalgam restorations.
Advances in operative dentistry; by –Narin, Jean
82
REPAIR
Afailingamalgamrestorationshouldberepairedratherthanreplaced.Everytimean
amalgamrestorationisreplaced,thecavityoutlineisincreasedbyatleast0.5mm
leadingtolargerrestorationandweakertooth.
Forrepairing,newamalgamiscondensedtothealreadyfailingmaterial.Thebond
betweentheoldandnewamalgamisthemainsourceofstructuralweaknessofthe
repairedrestoration.
Factorssuchascontaminationwithsalivaandoxidizationofthefracturedsurfaceof
theoldamalgamrestorationpreventaneffectivebondbetweentheoldandnew
amalgam.
JorgensenandSaito(1968)wereabletoobtainanincreasedbondstrengthbyrubbing
thesurfaceoftheoldrestorationwiththecondenserinthepresenceofmercury.
However,thistechniqueisnotreliableunderoralconditions.
JessupJP,VandewalleKS,HermeschCB,BuikemaDJ.Effectsofsurfacetreatmentsonamalgamrepair.Operativedentistry.1998Jan1;23:15-20.
REPAIR
Afailingamalgamrestorationshouldberepairedratherthanreplaced.Everytimean
amalgamrestorationisreplaced,thecavityoutlineisincreasedbyatleast0.5mm
leadingtolargerrestorationandweakertooth.
Forrepairing,newamalgamiscondensedtothealreadyfailingmaterial.Thebond
betweentheoldandnewamalgamisthemainsourceofstructuralweaknessofthe
repairedrestoration.
Factorssuchascontaminationwithsalivaandoxidizationofthefracturedsurfaceof
theoldamalgamrestorationpreventaneffectivebondbetweentheoldandnew
amalgam.
JorgensenandSaito(1968)wereabletoobtainanincreasedbondstrengthbyrubbing
thesurfaceoftheoldrestorationwiththecondenserinthepresenceofmercury.
However,thistechniqueisnotreliableunderoralconditions.
JessupJP,VandewalleKS,HermeschCB,BuikemaDJ.Effectsofsurfacetreatmentsonamalgamrepair.Operativedentistry.1998Jan1;23:15-20.
Amalgam Repair: Quantitative Evaluation of Amalgam-resin and
Resin-tooth Interfaces with Different Surface Treatments
Çehreli SB, Arhun N, Celik C.
•Repairingdefectiveamalgamrestorationswithresincompositeoffersaminimally
invasivesolutioncomparedtoreplacement;etch&rinseadhesivesystemsaresuggested
toreducemicroleakage.
•Thisinvitrostudyevaluatedtheeffectofdifferentadhesivesystemsandsurface
treatmentsontheintegrityofamalgam-resinandresin-toothinterfaceafterpartial
removalofpre-existingamalgam.
•AllBond3andXPbond(etch&rinse)producedthebestresultsateachsection.Allthe
materialsexhibitedmoremicroleakageattheamalgaminterfacethanthetoothinterface.
Surfacefinishingwithdifferentbursdidnotstatisticallyaffectmicroleakage.
•Conclusion:Intermsofmicroleakagereduction,etch&rinseadhesivesmaybepreferred
overself-etchadhesivesforamalgamrepair.
CehreliSB, ArhunN, CelikC. Amalgam repair: quantitative evaluation of amalgam-resin and resin-tooth interfaces with different surface treatments. Operative dentistry. 2010 May;35(3):337-44.
83
Resin-tooth Interfaces with Different Surface Treatments
Çehreli SB, Arhun N, Celik C.
•Repairingdefectiveamalgamrestorationswithresincompositeoffersaminimally
invasivesolutioncomparedtoreplacement;etch&rinseadhesivesystemsaresuggested
toreducemicroleakage.
•Thisinvitrostudyevaluatedtheeffectofdifferentadhesivesystemsandsurface
treatmentsontheintegrityofamalgam-resinandresin-toothinterfaceafterpartial
removalofpre-existingamalgam.
•AllBond3andXPbond(etch&rinse)producedthebestresultsateachsection.Allthe
materialsexhibitedmoremicroleakageattheamalgaminterfacethanthetoothinterface.
Surfacefinishingwithdifferentbursdidnotstatisticallyaffectmicroleakage.
•Conclusion:Intermsofmicroleakagereduction,etch&rinseadhesivesmaybepreferred
overself-etchadhesivesforamalgamrepair.
CehreliSB, ArhunN, CelikC. Amalgam repair: quantitative evaluation of amalgam-resin and resin-tooth interfaces with different surface treatments. Operative dentistry. 2010 May;35(3):337-44.
83
MODIFICATIONS OF AMAGAM
84
84
Gallium Alloys
•Introduced by Putt Kammerin1928
•Galliumalloyshavebeendevelopedasanattempttoreplacemercuryinamalgam.
Indiumand/ortinareincorporatedtogalliumtoproduceanalloywhichisliquidat
roomtemperature.Thisalloycanbemixedandcondensedsimilartosilver
amalgam.
Eg-GalliumAlloyGF
-Gallium Alloy GF II
-Galloy
85
ALLOY LIQUID
Silver (Ag) –60% Gallium (Ga) -62%
Tin (Sn) -25% Indium (In) -25%
Copper (Cu) -13% Tin (Sn) -13%
Palladium ( Pd) -2%
Bharti R, Wadhwani KK, Tikku AP, Chandra A. Dental amalgam: An update. Journal of conservative dentistry: JCD. 2010 Oct;13(4):204.
•Introduced by Putt Kammerin1928
•Galliumalloyshavebeendevelopedasanattempttoreplacemercuryinamalgam.
Indiumand/ortinareincorporatedtogalliumtoproduceanalloywhichisliquidat
roomtemperature.Thisalloycanbemixedandcondensedsimilartosilver
amalgam.
Eg-GalliumAlloyGF
-Gallium Alloy GF II
-Galloy
85
ALLOY LIQUID
Silver (Ag) –60% Gallium (Ga) -62%
Tin (Sn) -25% Indium (In) -25%
Copper (Cu) -13% Tin (Sn) -13%
Palladium ( Pd) -2%
Bharti R, Wadhwani KK, Tikku AP, Chandra A. Dental amalgam: An update. Journal of conservative dentistry: JCD. 2010 Oct;13(4):204.
PROPERTIES:
Compressive strength: 350 MPa
(High Copper silver alloy –370 MPa )
Creep-0.09+0.03%
(High Copper silver alloy –0.04 + 0.13%)
Tensile strength is higher.
Manipulation of these alloys are difficult. Since these alloys are sticky, their condensation
into the cavity is time consuming.
86
Compressive strength: 350 MPa
(High Copper silver alloy –370 MPa )
Creep-0.09+0.03%
(High Copper silver alloy –0.04 + 0.13%)
Tensile strength is higher.
Manipulation of these alloys are difficult. Since these alloys are sticky, their condensation
into the cavity is time consuming.
86
Drawbacks
Corrosion of gallium alloy is high.
Surface roughness, marginal discoloration and fracture were reported.
Setting expansion is very high.
(hydrophobic resin coating has to be applied above and below the
restoration)
Technique sensitive.
Expensive.
87
Corrosion of gallium alloy is high.
Surface roughness, marginal discoloration and fracture were reported.
Setting expansion is very high.
(hydrophobic resin coating has to be applied above and below the
restoration)
Technique sensitive.
Expensive.
87
A comparison of the mechanical properties of a gallium-
based alloy with a spherical high-copper amalgam
Theaimofthepresentstudywastoinvestigatehowthemechanicalpropertiesof
apalladiumfreegallium-basedalloy(Galloy)comparewithaleadingsphericalhigh-
copperAmalgam(Tytin).
Conclusion:Thesignificantreductioninthe1hmeancompressivefracturestrengthand
hardnessidentifiedforGalloycomparedwithTytinpossiblyindicateaslowersetting
reactioninthegallium-basedalloy.
Manualcondensationofthegallium-basedalloyproducedspecimenswithinferior
mechanicalpropertiespossiblyduetotheincreasedlikelihoodofintroducingvoidswithin
thetestspecimens.Previousreportsindicatingpoorcorrosionresistanceandmoisture
sensitivityofgallium-basedalloys.
88
ShainiFJ, Fleming GJ, Shortall AC, Marquis PM. A comparison of the mechanical properties of a gallium-based alloy with a spherical high-copper amalgam. Dental Materials. 2001 Mar 1;17(2):142-8.
based alloy with a spherical high-copper amalgam
Theaimofthepresentstudywastoinvestigatehowthemechanicalpropertiesof
apalladiumfreegallium-basedalloy(Galloy)comparewithaleadingsphericalhigh-
copperAmalgam(Tytin).
Conclusion:Thesignificantreductioninthe1hmeancompressivefracturestrengthand
hardnessidentifiedforGalloycomparedwithTytinpossiblyindicateaslowersetting
reactioninthegallium-basedalloy.
Manualcondensationofthegallium-basedalloyproducedspecimenswithinferior
mechanicalpropertiespossiblyduetotheincreasedlikelihoodofintroducingvoidswithin
thetestspecimens.Previousreportsindicatingpoorcorrosionresistanceandmoisture
sensitivityofgallium-basedalloys.
88
ShainiFJ, Fleming GJ, Shortall AC, Marquis PM. A comparison of the mechanical properties of a gallium-based alloy with a spherical high-copper amalgam. Dental Materials. 2001 Mar 1;17(2):142-8.
FLUORIDE CONTAINING AMALGAM
Secondarycariesisoneofthemostimportantcauseoffailureinamalgamrestoration.
Theadditionoffluoridetoamalgamwasthereforeattractivewaytostimulatethe
anticariogenicpropertiesofsilicatecement.
8%Stannousfluoride
SomestudiesalsousedStannousfluorideascavitylinerbelowtheamalgam
restorations.
89
Bharti R, Wadhwani KK, Tikku AP, Chandra A. Dental amalgam: An update. Journal of conservative dentistry: JCD. 2010 Oct;13(4):204.
Secondarycariesisoneofthemostimportantcauseoffailureinamalgamrestoration.
Theadditionoffluoridetoamalgamwasthereforeattractivewaytostimulatethe
anticariogenicpropertiesofsilicatecement.
8%Stannousfluoride
SomestudiesalsousedStannousfluorideascavitylinerbelowtheamalgam
restorations.
89
Bharti R, Wadhwani KK, Tikku AP, Chandra A. Dental amalgam: An update. Journal of conservative dentistry: JCD. 2010 Oct;13(4):204.
Results / Advantages :
Studies showed that there was reduced solubility of enamel adjacent to fluoride
containing amalgam.
One study has shown that there was lower incidence of secondary caries around the
fluoride containing amalgam restoration.
Exact mechanism played in fluoride uptake in the fluoride containing amalgam
restoration is unknown.
Disadvantages :
Invitro studies have shown that there is reduction in mechanical properties such as
compressive strength and corrosion resistance when stannous fluoride is added to the
amalgam.
Burke FM, Ray NJ, McConnell RJ. Fluoride‐containing restorative materials. International dental journal. 2006 Feb;56(1):33-43.
90
Studies showed that there was reduced solubility of enamel adjacent to fluoride
containing amalgam.
One study has shown that there was lower incidence of secondary caries around the
fluoride containing amalgam restoration.
Exact mechanism played in fluoride uptake in the fluoride containing amalgam
restoration is unknown.
Disadvantages :
Invitro studies have shown that there is reduction in mechanical properties such as
compressive strength and corrosion resistance when stannous fluoride is added to the
amalgam.
Burke FM, Ray NJ, McConnell RJ. Fluoride‐containing restorative materials. International dental journal. 2006 Feb;56(1):33-43.
90
INDIUM
Indium was incorporated into the amalgam structure to minimize the vaporization of
mercury from the amalgam surface.
Powell et al in 1989 first reported that the addition of pure indium powder to a high
copper amalgam alloy decreases mercury vaporization.
Properties :
decreases surface tension
reduces amount of mercury necessary
reduces creep and marginal breakdown
increases strength
91
Powell LV, Johnson GH, Bales DJ. Effect of admixed indium on mercury vapor release from dental amalgam. Journal of dental research. 1989 Aug;68(8):1231-3.
Indium was incorporated into the amalgam structure to minimize the vaporization of
mercury from the amalgam surface.
Powell et al in 1989 first reported that the addition of pure indium powder to a high
copper amalgam alloy decreases mercury vaporization.
Properties :
decreases surface tension
reduces amount of mercury necessary
reduces creep and marginal breakdown
increases strength
91
Powell LV, Johnson GH, Bales DJ. Effect of admixed indium on mercury vapor release from dental amalgam. Journal of dental research. 1989 Aug;68(8):1231-3.
Advantages:
Total reduction in the amount of mercury present.
More efficient oxidation of the surface of mercury releasing phase.
It is good wetting agent and adapts well to tooth surface.
higher in compressive strength by 16%, lower in creep by 40% (0.17%) and has a
lower dimensional change on setting.
92
Total reduction in the amount of mercury present.
More efficient oxidation of the surface of mercury releasing phase.
It is good wetting agent and adapts well to tooth surface.
higher in compressive strength by 16%, lower in creep by 40% (0.17%) and has a
lower dimensional change on setting.
92
BONDED AMALGAM RESTORATIONS
To overcome one of the major disadvantage of silver (it does not adhere properly to
cavity walls) adhesive systems were designed to bond amalgam to enamel and dentin.
It also improves its adhesion, inability to strengthen remaining tooth structure and the
need for removal of healthy tooth structure for gaining retention.
The most commonly used amalgam adhesives are based on the 4 -META system.
Various Agents are
Amalgam Bond , All Bond 2, Optibond 2 ,Panavia ,Clearfil Linear Bond 2, Scothbond MP.
93
Mahler DB, Engle JH, Simms LE, Terkla LG. One-year clinical evaluation of bonded amalgam restorations. The Journal of the American Dental Association. 1996 Mar 1;127(3):345-9.
To overcome one of the major disadvantage of silver (it does not adhere properly to
cavity walls) adhesive systems were designed to bond amalgam to enamel and dentin.
It also improves its adhesion, inability to strengthen remaining tooth structure and the
need for removal of healthy tooth structure for gaining retention.
The most commonly used amalgam adhesives are based on the 4 -META system.
Various Agents are
Amalgam Bond , All Bond 2, Optibond 2 ,Panavia ,Clearfil Linear Bond 2, Scothbond MP.
93
Mahler DB, Engle JH, Simms LE, Terkla LG. One-year clinical evaluation of bonded amalgam restorations. The Journal of the American Dental Association. 1996 Mar 1;127(3):345-9.
INDICATIONS
Conservative preparations , reinforcement of remaining tooth structure, improvement of
marginal seal.
Boned amalgam restorations are specially indicated for extensively carious posterior.
Bonded amalgam restorations may be used as a temporary restoration, which later
can be reduced to a core under a cast crown.
Can be used as amalgam sealants.
94
Conservative preparations , reinforcement of remaining tooth structure, improvement of
marginal seal.
Boned amalgam restorations are specially indicated for extensively carious posterior.
Bonded amalgam restorations may be used as a temporary restoration, which later
can be reduced to a core under a cast crown.
Can be used as amalgam sealants.
94
ADVANTAGE DIS ADVANTAGE
More conservative
Reinforces tooth structure
Decreases the incidence of
marginal fracture
Provides a bond at the tooth
restoration interface
Cost effective
Technique sensitive
Clinical performance are not
documented
No sustained effects of
amalgam bonding when
subjected to thermocycling
Hydrolytic stability of the
bond is questionable
95
More conservative
Reinforces tooth structure
Decreases the incidence of
marginal fracture
Provides a bond at the tooth
restoration interface
Cost effective
Technique sensitive
Clinical performance are not
documented
No sustained effects of
amalgam bonding when
subjected to thermocycling
Hydrolytic stability of the
bond is questionable
95
CONSOLIDATED SILVER ALLOY SYSTEMS
Oneamalgamsubstitutebeingtestedisaconsolidatedsilveralloysystemdevelopedat
theNationalInstituteofStandardsandTechnology(Eichmilleretal.,1998).
Itusesafluoroboricacidsolutiontokeepthesurfaceofthesilveralloyparticlesclean.
Thealloy,inasphericalform,iscondensedintoapreparedcavityinamannersimilarto
thatforplacingcompactedgold.
Oneproblemassociatedwiththeinsertionofthismaterialisthatthealloystrain
hardens,soitisdifficulttocompactitadequatelytoeliminateinternalvoidsandto
achievegoodadaptationtothecavitywithoutusingexcessiveforce(Berryetal.,1998).
96Monomers M. RECENT ADVANCES AND MODIFICATIONS OF DENTAL RESTORATIVE MATERIALS -A REVIEW.
Oneamalgamsubstitutebeingtestedisaconsolidatedsilveralloysystemdevelopedat
theNationalInstituteofStandardsandTechnology(Eichmilleretal.,1998).
Itusesafluoroboricacidsolutiontokeepthesurfaceofthesilveralloyparticlesclean.
Thealloy,inasphericalform,iscondensedintoapreparedcavityinamannersimilarto
thatforplacingcompactedgold.
Oneproblemassociatedwiththeinsertionofthismaterialisthatthealloystrain
hardens,soitisdifficulttocompactitadequatelytoeliminateinternalvoidsandto
achievegoodadaptationtothecavitywithoutusingexcessiveforce(Berryetal.,1998).
96Monomers M. RECENT ADVANCES AND MODIFICATIONS OF DENTAL RESTORATIVE MATERIALS -A REVIEW.
RESIN COATED AMALGAM
Toovercomethelimitationofmicroleakagewithamalgams,acoatingofunfilledresinover
therestorationmarginsandtheadjacentenamel,afteretchingtheenamel,hasbeentried.
Althoughtheresinmayeventuallywearaway,itdelaysmicroleakageuntilcorrosion
productsbegintofillthetoothrestorationinterface.
Mertz-fairhurstandothersevaluatedbondedandsealedcompositerestorationsplaced
directlyoverfrankcavitatedlesionsextendingintodentinversussealedconservative
amalgamrestorationsandconventionalunsealedamalgamrestorations.Theresultsindicate
thatbothtypesofsealedrestorationsexhibitedsuperiorclinicalperformanceandlongevity
comparedwithunsealedamalgamrestorationsoveraperiodof10years.
97
Bharti R, Wadhwani KK, Tikku AP, Chandra A. Dental amalgam: An update. Journal of conservative dentistry: JCD. 2010 Oct;13(4):204.
Toovercomethelimitationofmicroleakagewithamalgams,acoatingofunfilledresinover
therestorationmarginsandtheadjacentenamel,afteretchingtheenamel,hasbeentried.
Althoughtheresinmayeventuallywearaway,itdelaysmicroleakageuntilcorrosion
productsbegintofillthetoothrestorationinterface.
Mertz-fairhurstandothersevaluatedbondedandsealedcompositerestorationsplaced
directlyoverfrankcavitatedlesionsextendingintodentinversussealedconservative
amalgamrestorationsandconventionalunsealedamalgamrestorations.Theresultsindicate
thatbothtypesofsealedrestorationsexhibitedsuperiorclinicalperformanceandlongevity
comparedwithunsealedamalgamrestorationsoveraperiodof10years.
97
Bharti R, Wadhwani KK, Tikku AP, Chandra A. Dental amalgam: An update. Journal of conservative dentistry: JCD. 2010 Oct;13(4):204.
REVIEW OF LITERATURE
98
98
99
Bernando M, Luis H, Martin MD, et al: Survival and reasons for failure of amalgam versus composite restorations placed in a randomized clinical trial. J Am Dent Assoc 138:775–783, 2007.
Thesurvivalrateoftheamalgamrestorationswas94.4percent;thatofcomposite
restorationswas85.5percent.
Annualfailureratesrangedfrom0.16to2.83percentforamalgamrestorationsandfrom
0.94to9.43percentforcompositerestorations.Secondarycarieswasthemainreasonfor
failureinbothmaterials.Riskofsecondarycarieswas3.5timesgreaterinthecomposite
group.
Amalgamrestorationsperformedbetterthandidcompositerestorations.Thedifferencein
performancewasaccentuatedinlargerestorationsandinthosewithmorethanthreesurfaces
involved.
ClinicalImplications.Useofamalgamappearstobepreferabletouseofcompositesin
multi-surfacerestorationsoflargeposteriorteethiflongevityistheprimarycriterionin
materialselection.
Bernando M, Luis H, Martin MD, et al: Survival and reasons for failure of amalgam versus composite restorations placed in a randomized clinical trial. J Am Dent Assoc 138:775–783, 2007.
Thesurvivalrateoftheamalgamrestorationswas94.4percent;thatofcomposite
restorationswas85.5percent.
Annualfailureratesrangedfrom0.16to2.83percentforamalgamrestorationsandfrom
0.94to9.43percentforcompositerestorations.Secondarycarieswasthemainreasonfor
failureinbothmaterials.Riskofsecondarycarieswas3.5timesgreaterinthecomposite
group.
Amalgamrestorationsperformedbetterthandidcompositerestorations.Thedifferencein
performancewasaccentuatedinlargerestorationsandinthosewithmorethanthreesurfaces
involved.
ClinicalImplications.Useofamalgamappearstobepreferabletouseofcompositesin
multi-surfacerestorationsoflargeposteriorteethiflongevityistheprimarycriterionin
materialselection.
Amalgamrestorationsdonotchemicallybondtothecavitywalls,butallowmicroleakage
whichisgraduallyreducedbycorrosionproducts.
Highcopperamalgamcorrodesmoreslowlythanconventionalamalgamandan
intermediarysealersuchasacavityvarnishisneeded.
Corrosionisalsodependentonindividualvariationsofthechemicalcomponentsoforal
fluids.
Theabilityoftheamalgamtoresistcorrosionaffectstheprogressofpotentialsecondary
cariesattherestorationmargin.
Ben‐AmarA,CardashHS,JudesH.Thesealingofthetooth/amalgaminterfacebycorrosionproducts.JournalofOralRehabilitation.1995Feb;22(2):101-4.
100
whichisgraduallyreducedbycorrosionproducts.
Highcopperamalgamcorrodesmoreslowlythanconventionalamalgamandan
intermediarysealersuchasacavityvarnishisneeded.
Corrosionisalsodependentonindividualvariationsofthechemicalcomponentsoforal
fluids.
Theabilityoftheamalgamtoresistcorrosionaffectstheprogressofpotentialsecondary
cariesattherestorationmargin.
Ben‐AmarA,CardashHS,JudesH.Thesealingofthetooth/amalgaminterfacebycorrosionproducts.JournalofOralRehabilitation.1995Feb;22(2):101-4.
100
101
CONCLUSION
Dentalamalgamremainsapredictable,cost-effective,andsafemeansforthe
restorationofposterior(andsomeanterior)teeththataremissingvarious
amountsoftoothstructure.
Althoughtheuseofdentalamalgamsisonthedeclineinmany
countries,thebasisofanyrestorationistheunderstandingofthe
underlyingmaterialscience.Thedentisthastoweightheadvantages
overthedisadvantagesofanymaterialtoanalyzeanddecidehowbest
touseit.Thisholdsgoodforsilveramalgammaterialandrestorations
aswell.
CONCLUSION
Dentalamalgamremainsapredictable,cost-effective,andsafemeansforthe
restorationofposterior(andsomeanterior)teeththataremissingvarious
amountsoftoothstructure.
Althoughtheuseofdentalamalgamsisonthedeclineinmany
countries,thebasisofanyrestorationistheunderstandingofthe
underlyingmaterialscience.Thedentisthastoweightheadvantages
overthedisadvantagesofanymaterialtoanalyzeanddecidehowbest
touseit.Thisholdsgoodforsilveramalgammaterialandrestorations
aswell.
REFERENCE
•Sturdevant'sart & science of operative dentistry book.
•Marzouk Operative Dentistry, Modern Theory And Practice.
•Craig's Restorative Dental Materials 13th Edition
•Anusavice-K.J. Phillip’s Science Of Dental Materials –13
thEdition
•Science Of Dental Materials And Clinical Application-V ShamaBhat And B T Nandish-2
nd
Edition
•Materials Used In Dentistry: S. Mahalaxmi –1
stEdition
•Graham BP. Advances in Operative Dentisty: Contemporary Clinical Practice. New York
State Dental Journal. 2002 Feb 1;68(2):60.
•Mahler DB: he high-copper dental amalgam alloys. J Dent Res 76:537–541, 1997. 17.
•SuchatlampongC, GotoS, Ogura H: Early compressive strength and phase-formation of
dental amalgam. Dent Mater 14:143–151, 1995.
•Burke FM, Ray NJ, McConnell RJ. Fluoride‐containing restorative materials. International
dental journal. 2006 Feb;56(1):33-43.
102
•Sturdevant'sart & science of operative dentistry book.
•Marzouk Operative Dentistry, Modern Theory And Practice.
•Craig's Restorative Dental Materials 13th Edition
•Anusavice-K.J. Phillip’s Science Of Dental Materials –13
thEdition
•Science Of Dental Materials And Clinical Application-V ShamaBhat And B T Nandish-2
nd
Edition
•Materials Used In Dentistry: S. Mahalaxmi –1
stEdition
•Graham BP. Advances in Operative Dentisty: Contemporary Clinical Practice. New York
State Dental Journal. 2002 Feb 1;68(2):60.
•Mahler DB: he high-copper dental amalgam alloys. J Dent Res 76:537–541, 1997. 17.
•SuchatlampongC, GotoS, Ogura H: Early compressive strength and phase-formation of
dental amalgam. Dent Mater 14:143–151, 1995.
•Burke FM, Ray NJ, McConnell RJ. Fluoride‐containing restorative materials. International
dental journal. 2006 Feb;56(1):33-43.
102
•BhattacharyaA,VaidyaS,TomerAK,RainaA.GICatIt’sbest–Areviewonceramic
reinforcedGIC.InternationalJournalofAppliedDentalSciences.2017;3(4):405-8.
•BernandoM,LuisH,MartinMD,etal:Survivalandreasonsforfailureofamalgamversus
compositerestorationsplacedinarandomizedclinicaltrial.JAmDentAssoc138:775–783,
2007.
•CorbinSB,KohnWG.Thebenefitsandrisksofdentalamalgam:currentfindingsreviewed.
JournaloftheAmericanDentalAssociation(1939).1994Apr1;125(4):381-8.
•JessupJP,VandewalleKS,HermeschCB,BuikemaDJ.Effectsofsurfacetreatmentson
amalgamrepair.Operativedentistry.1998Jan1;23:15-20.
•ÇehreliSB,ArhunN,CelikC.Amalgamrepair:quantitativeevaluationofamalgam-resinand
resin-toothinterfaceswithdifferentsurfacetreatments.Operativedentistry.2010
May;35(3):337-44.
•Ben‐AmarA,CardashHS,JudesH.Thesealingofthetooth/amalgaminterfacebycorrosion
products.JournalofOralRehabilitation.1995Feb;22(2):101-4.
•MahlerDB,EngleJH,SimmsLE,TerklaLG.One-yearclinicalevaluationofbonded
amalgamrestorations.TheJournaloftheAmericanDentalAssociation.1996Mar
1;127(3):345-9.
103
reinforcedGIC.InternationalJournalofAppliedDentalSciences.2017;3(4):405-8.
•BernandoM,LuisH,MartinMD,etal:Survivalandreasonsforfailureofamalgamversus
compositerestorationsplacedinarandomizedclinicaltrial.JAmDentAssoc138:775–783,
2007.
•CorbinSB,KohnWG.Thebenefitsandrisksofdentalamalgam:currentfindingsreviewed.
JournaloftheAmericanDentalAssociation(1939).1994Apr1;125(4):381-8.
•JessupJP,VandewalleKS,HermeschCB,BuikemaDJ.Effectsofsurfacetreatmentson
amalgamrepair.Operativedentistry.1998Jan1;23:15-20.
•ÇehreliSB,ArhunN,CelikC.Amalgamrepair:quantitativeevaluationofamalgam-resinand
resin-toothinterfaceswithdifferentsurfacetreatments.Operativedentistry.2010
May;35(3):337-44.
•Ben‐AmarA,CardashHS,JudesH.Thesealingofthetooth/amalgaminterfacebycorrosion
products.JournalofOralRehabilitation.1995Feb;22(2):101-4.
•MahlerDB,EngleJH,SimmsLE,TerklaLG.One-yearclinicalevaluationofbonded
amalgamrestorations.TheJournaloftheAmericanDentalAssociation.1996Mar
1;127(3):345-9.
103
THANK YOU
104
104
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