dental amalgam

AMALGAMAMALGAM

Dr shabeel pnDr shabeel pnhttp://hi-dentfinishingschool.blogspot.com/

http://apexiondental.com/

DEFINITIONDEFINITION

Dental amalgam is a metal like restorative Dental amalgam is a metal like restorative material composed of a mixture of material composed of a mixture of silver/tin/copper alloy and mercury. silver/tin/copper alloy and mercury.

HISTORYHISTORY

Amalgam has been primary Amalgam has been primary restorative material for more than restorative material for more than 150 yrs.150 yrs.

Initially, amalgam restorations were Initially, amalgam restorations were made by dentists filing silver coins made by dentists filing silver coins and mixing the filings with mercury.and mixing the filings with mercury.

This was made to a putty like mass This was made to a putty like mass that was placed into the defective that was placed into the defective tooth. tooth.

USESUSES

AS CLASS 1,2,5 RESTORATION.AS CLASS 1,2,5 RESTORATION. AS FOUNDATION- IN COMBINATION AS FOUNDATION- IN COMBINATION

WITH RETENTIVE PINS TO RESTORE WITH RETENTIVE PINS TO RESTORE CROWN.CROWN.

FOR MAKING DIES.FOR MAKING DIES. FOR RETROGRADE ROOT CANAL FOR RETROGRADE ROOT CANAL

FILLING.FILLING. AS CARIES CONTROL RESTORATION.AS CARIES CONTROL RESTORATION.

Components of dental Components of dental amalgamamalgam

1)Amalgam alloy1)Amalgam alloy

2)Mercury2)Mercury

CLASSIFICATIONCLASSIFICATION

Classification of dental amalgam Classification of dental amalgam alloysalloys

BASED ON Cu CONTENT

HIGH Cu ALLOYS LOW Cu ALLOYS

> 6% Cu < 6% Cu

ADMIXED

SINGLE COMPOSITION

REGULAR UNICOMPOSITION

BASED ON Zn CONTENT

Zn CONTAINING Zn FREE ALLOY

> 1% Zn < 1% Zn

BASED ON SHAPE OF ALLOY

LATHECUT SPHERICAL ADMIXED

BASED ON NUMBER OF ALLOY METAL

BINARY TERTIARY QUATERNARY

Ag,Sn Ag,Sn,Cu Ag,Sn,Cu,Zn

BASED ON SIZE OF ALLOY

MICROCUT \FINE CUT MACROCUT \COURSE CUT

MANUFATURE OF ALLOY MANUFATURE OF ALLOY POWDERPOWDER

1)LATHECUT ALLOY POWDER1)LATHECUT ALLOY POWDER2)SPHERICAL ALLOY POWDER2)SPHERICAL ALLOY POWDER

COMPARISON OF LATHECUT WITH COMPARISON OF LATHECUT WITH ATOMIZED SPHERICAL POWDERATOMIZED SPHERICAL POWDER

AMALGAM FROM LATHECUT \ ADMIXED AMALGAM FROM LATHECUT \ ADMIXED POWDER,TEND TO RESIST CONDEN-SATION BETTER POWDER,TEND TO RESIST CONDEN-SATION BETTER THAN AMALGAM MADE ENTIRELLY FROM SPHERICAL THAN AMALGAM MADE ENTIRELLY FROM SPHERICAL POWDER.POWDER.

AMALGAM OF SPHERICAL POWDER ARE VERY AMALGAM OF SPHERICAL POWDER ARE VERY PLASTIC-CANNOT RELY ON PRESSURE OF PLASTIC-CANNOT RELY ON PRESSURE OF CONDENSATION TO ESTABLISH PROXIMAL CONDENSATION TO ESTABLISH PROXIMAL CONTOUR.CONTOUR.

SPHERICAL ALLOYS REQUIRE < Hg THAN LATHECUT SPHERICAL ALLOYS REQUIRE < Hg THAN LATHECUT ALLOY DUE TO SMALL SURFACE AREA PER VOLUME .ALLOY DUE TO SMALL SURFACE AREA PER VOLUME .

AMALGAM WITH LOW Hg CONTENT –BETTER AMALGAM WITH LOW Hg CONTENT –BETTER PROPERTIES.PROPERTIES.

COMPOSITIONCOMPOSITION

COMPOSITIONCOMPOSITION

Low Copper:Low Copper:

Silver - 63-70%Silver - 63-70%

Tin - 26-29%Tin - 26-29%

Copper - 2-5%Copper - 2-5%

Zinc – 0-2% Zinc – 0-2%

Admixed:Admixed:

Silver – 40-70%Silver – 40-70%

Tin - 26-30%Tin - 26-30%

Copper-13-30%Copper-13-30%

Zinc - 0-1%Zinc - 0-1%

Unicompositional :Unicompositional :

Silver- 40-60%Silver- 40-60%

Tin - 22-30%Tin - 22-30%

Copper-13-30%Copper-13-30%

Zinc -0%Zinc -0%

FUNCTION OF EACH FUNCTION OF EACH CONSTITUENTCONSTITUENT

SILVER:-SILVER:- MAJOR ELEMENT.MAJOR ELEMENT. WHITENS ALLOY.WHITENS ALLOY. DECREASES CREEP.DECREASES CREEP. INCREASES STRENGTH.INCREASES STRENGTH. INCREASES EXPANSION ON SETTING.INCREASES EXPANSION ON SETTING. INCREASES TARNISHING RESISTANCE IN INCREASES TARNISHING RESISTANCE IN

RESULTING AMALGAM.RESULTING AMALGAM.

TIN:-TIN:- CONTROLS THE REACTION BETWEEN Ag CONTROLS THE REACTION BETWEEN Ag

& Hg.& Hg. REDUCES STRENGH & HARDNESS.REDUCES STRENGH & HARDNESS. REDUCES RESISTANCE TO TARNISH & REDUCES RESISTANCE TO TARNISH &

CORROSION.CORROSION.

COPPER:-COPPER:- INCREASES HARDNESS & STRENGTH.INCREASES HARDNESS & STRENGTH. INCRESES SETTING EXPANSION.INCRESES SETTING EXPANSION.

ZINC:-ZINC:- SMALL AMOUNT –NOT AFFECT SETTING SMALL AMOUNT –NOT AFFECT SETTING

REACTION \ PROPERTIES OF AMALGAM.REACTION \ PROPERTIES OF AMALGAM. ACT AS A SCAVENGER \ DEOXIDISER.ACT AS A SCAVENGER \ DEOXIDISER. WITHOUT Zn ALLOYS ARE MORE BRITTLE WITHOUT Zn ALLOYS ARE MORE BRITTLE

& AMALGAM FORMED LESS PLASTIC.& AMALGAM FORMED LESS PLASTIC. CAUSES DELAYED EXPANSION , IF CAUSES DELAYED EXPANSION , IF

CONTAMINATED WITH MOISTURE DURING CONTAMINATED WITH MOISTURE DURING MANIPULATION.MANIPULATION.

BENEFICIAL EFFECT ON CORROSION & BENEFICIAL EFFECT ON CORROSION & MARGINAL INTEGRATION.MARGINAL INTEGRATION.

PLATINUM:-PLATINUM:- HARDENS THE ALLOY & INCREASES THE HARDENS THE ALLOY & INCREASES THE

RESISTANCE TO CORROSION.RESISTANCE TO CORROSION.

PALLADIUM:-PALLADIUM:- HARDENS THE ALLOY.HARDENS THE ALLOY. WHITENS THE ALLOY.WHITENS THE ALLOY.

PRE AMALGAMATED ALLOYS:-PRE AMALGAMATED ALLOYS:-

SMALL AMOUNT UPTO 3% OF Hg IS ADDED SMALL AMOUNT UPTO 3% OF Hg IS ADDED TO THE ALLOY BY MANUFACTURER.TO THE ALLOY BY MANUFACTURER.

RECENT DEVELOPMENT OF RECENT DEVELOPMENT OF D.AMALGAMD.AMALGAM

Mercury free direct filling amalgam Mercury free direct filling amalgam alloysalloys

Gallium based alloysGallium based alloysLow mercury amalgamsLow mercury amalgams Indium in mercuryIndium in mercury

AMALGAMATIONAMALGAMATION

AMALGAMATION AND AMALGAMATION AND RESULTING MICROSTRUCTURE.RESULTING MICROSTRUCTURE.

DURING TRITURATION Ag & Sn IN THE OUTER DURING TRITURATION Ag & Sn IN THE OUTER PORTION OF THE PARTICLES DISSOLVE INTO Hg . PORTION OF THE PARTICLES DISSOLVE INTO Hg . Hg DIFFUSES INTO ALLOY PARTICLES.Hg DIFFUSES INTO ALLOY PARTICLES.

Hg HAS LIMITED SOLUBILITY FOR Ag (.035WT%) & Hg HAS LIMITED SOLUBILITY FOR Ag (.035WT%) & Sn (.6wt%).Sn (.6wt%).

AMALGAMATION OCCURS WHEN Hg CONTACTS AMALGAMATION OCCURS WHEN Hg CONTACTS THE SURFACE OF Ag-Sn ALLOY PARTICLES.THE SURFACE OF Ag-Sn ALLOY PARTICLES.

WHEN THE SOLUBILITY IN Hg EXEEDED- CRYSTALS WHEN THE SOLUBILITY IN Hg EXEEDED- CRYSTALS OF 2 BINARY METTALIC COMPOUND PRECIPITATE OF 2 BINARY METTALIC COMPOUND PRECIPITATE INTO Hg. THESE ARE BCC Ag2Hg3 & HEXAGONAL INTO Hg. THESE ARE BCC Ag2Hg3 & HEXAGONAL Sn7-8Hg.Sn7-8Hg.

Low copper AlloysLow copper Alloys

AgAg33Sn+Hg > AgSn+Hg > Ag22HgHg33 + Sn + Sn88Hg + AgHg + Ag33Sn Sn

(r) (r(r) (r11) (r) (r22) (unreacted) ) (unreacted)

High Copper AlloysHigh Copper Alloys

(1)(1) Admixed alloysAdmixed alloys

AgAg33Sn + Ag-Cu +Hg>AgSn + Ag-Cu +Hg>Ag22HgHg33 + Sn + Sn88Hg Hg + Ag+ Ag33Sn + AgCuSn + AgCu

LATER,LATER,

SnSn88Hg + AgCu > CuHg + AgCu > Cu66SnSn55 + Ag + Ag22HgHg33

(r(r22) (eutectic) (n) (r) (eutectic) (n) (r11))

Single CompositionSingle Composition

AgSnCu+ Hg > Cu6Sn5 + Ag2Hg3 AgSnCu+ Hg > Cu6Sn5 + Ag2Hg3 +AgSnCu +AgSnCu

PROPERTIES OF SET AMALGAM.PROPERTIES OF SET AMALGAM.

MICROLEAKAGE.MICROLEAKAGE. DIMENSIONAL CHANGES.DIMENSIONAL CHANGES. STRENGTH.STRENGTH. CREEP.CREEP. TARNISH & CORROSION.TARNISH & CORROSION.

MICROLEAKAGE.MICROLEAKAGE.

OCCURS DUE TO PENETRATION OF OCCURS DUE TO PENETRATION OF FLUIDS OR DEBRIS AROUND THE FLUIDS OR DEBRIS AROUND THE MARGINS THAT CAN LEAD TO MARGINS THAT CAN LEAD TO SECONDARY CARIES. AMALGAM HAS SECONDARY CARIES. AMALGAM HAS GOT A SELF SEALING PROPERTY – GOT A SELF SEALING PROPERTY – CORROSION PRODUCT WILL FILL THE CORROSION PRODUCT WILL FILL THE TOOTH RESTORATION INTERFACE & TOOTH RESTORATION INTERFACE & PREVENT MICROLEAKAGE.PREVENT MICROLEAKAGE.

ACCORDING TO ADA SPECIFICATION ,IT ACCORDING TO ADA SPECIFICATION ,IT SHOULD NOT EXPAD OR CONTRACT MORE THAN SHOULD NOT EXPAD OR CONTRACT MORE THAN 20u\cm AT 37 degree celcious BETWEEN 5min 20u\cm AT 37 degree celcious BETWEEN 5min

AND 24hrs AFTER BEGINNING OF TRITURATION.AND 24hrs AFTER BEGINNING OF TRITURATION.

MODERN AMALGAM ALWAYS SHOWS MODERN AMALGAM ALWAYS SHOWS CONTRACTION.CONTRACTION.

OLDER AMALGAM SHOWS EXPANSION.OLDER AMALGAM SHOWS EXPANSION.

DIMENSIONAL CHANGES

CONTRACTION EXPANSION

CONTRACTION.CONTRACTION.

RESULT IN MICROLEAKAGE & SECON RESULT IN MICROLEAKAGE & SECON –DARY CARIES.–DARY CARIES.

FACTORS FAVOURING FACTORS FAVOURING CONTRACTIONCONTRACTION LONGER TRITURATION TIME.LONGER TRITURATION TIME. HIGHER CONDENSATION PRESSURE.HIGHER CONDENSATION PRESSURE. SMALL PARTICLE SIZE.SMALL PARTICLE SIZE. Hg ALLOY RATIO. Hg ALLOY RATIO.

EXPANSION.EXPANSION.

IF A Zn CONTAINING LOW Cu \ HIGH Cu IS IF A Zn CONTAINING LOW Cu \ HIGH Cu IS CONTAMINATED DURING TRITURATION \ CONTAMINATED DURING TRITURATION \ CONDENSATION ,A LARGE EXPANSION TAKE CONDENSATION ,A LARGE EXPANSION TAKE PLACE.IT USUALLY STARTS FROM 3-5 DAYS AND PLACE.IT USUALLY STARTS FROM 3-5 DAYS AND CONTINUE FOR MONTHS CREATING VALUES UPTO CONTINUE FOR MONTHS CREATING VALUES UPTO MORE THAN 400um – DELAYED EXPANSION.MORE THAN 400um – DELAYED EXPANSION.

H2O + Zn ZnO + H2H2O + Zn ZnO + H2 PROTRUSION OF RESTORATION OUT OF CAVITYPROTRUSION OF RESTORATION OUT OF CAVITY INCREASE CREEPINCREASE CREEP INCREASE MICROLEAKAGEINCREASE MICROLEAKAGE PITTED SURFACE OF RESTORATION & CORROSION.PITTED SURFACE OF RESTORATION & CORROSION.

STRENGTH.STRENGTH.

AMALGAM IS SRONGEST IN COMPRE-AMALGAM IS SRONGEST IN COMPRE-SSION & MUCH WEAKER IN TENSION SSION & MUCH WEAKER IN TENSION & SHEAR , THE PREPARD CAVITY & SHEAR , THE PREPARD CAVITY DESIGN SHOULD MAXIMIZE THE DESIGN SHOULD MAXIMIZE THE COMPRESSION FORCES IN SERVICE & COMPRESSION FORCES IN SERVICE & MINIMIZE TENSION \ SHEAR FORCES.MINIMIZE TENSION \ SHEAR FORCES.

CREEP.CREEP.

DEFINED AS A TIME DEPENDENT PLASTIC DEFINED AS A TIME DEPENDENT PLASTIC DEFORMATION UNDER CONSTANT STRESS. DEFORMATION UNDER CONSTANT STRESS.

ACCORDING TO ADA SPECIFICATION NO 1 ACCORDING TO ADA SPECIFICATION NO 1

CREEP SHOULD BE BELOW 3%. CREEP SHOULD BE BELOW 3%.

CREEP OF LOW Cu AMALGAM IS 0.8-8% & CREEP OF LOW Cu AMALGAM IS 0.8-8% & HIGH Cu IS 0.4-1%.HIGH Cu IS 0.4-1%.

MANIPULATIONMANIPULATION

MANIPULATIONMANIPULATION

(1) Selection of materials(1) Selection of materials

(2) Mercury:Alloy ratio(2) Mercury:Alloy ratio

(3) Trituration(3) Trituration

(4) Mulling (4) Mulling

(5) Condensation(5) Condensation

(6) Shaping & finishing(6) Shaping & finishing

SELECTION OF MATERALSSELECTION OF MATERALS

a)a) ALLOYALLOY

b)b) MERCURYMERCURY

c)c) DISPENSORSDISPENSORS

d)d) PRE PROPOTION CAPSULEPRE PROPOTION CAPSULE

MERCURY: ALLOY RATIOMERCURY: ALLOY RATIO

(1)(1) Squeezing clothSqueezing cloth

(2)(2) Increased dryness techniqueIncreased dryness technique

(1)(1) EAMES techniqueEAMES technique

TRITURATIONTRITURATION

(1)Hand mixing(1)Hand mixing

(2)Mechanical(2)Mechanical

MULLINGMULLING

Improve homogenity of mass & get a Improve homogenity of mass & get a single consistent mixsingle consistent mix

CONDENSATIONCONDENSATION

(1)(1) Hand condensationHand condensation

(2)(2) Mech.condensationMech.condensation

SHAPING & FINISHING.SHAPING & FINISHING.

CARVING.CARVING. BURNISHING.BURNISHING. POLISHING.POLISHING.

MERCURY TOXICITYMERCURY TOXICITY..

PRECAUTIONSPRECAUTIONS

VentilationVentilationDisposalDisposalSealed containersSealed containersVaccum cleanersVaccum cleaners

INDICATIONSINDICATIONS

(1)(1) Moderate to Large Class I & Class II Moderate to Large Class I & Class II RestorationsRestorations

(2)(2) Class V RestorationsClass V Restorations

(3)(3) Temporary Caries Control Temporary Caries Control RestorationsRestorations

(4)(4) FoundationsFoundations

CONTRAINDICATIONSCONTRAINDICATIONS

(1)Esthetics(1)Esthetics

(2)Extensive tooth destruction(2)Extensive tooth destruction

(3)Small Class I & II Cavities(3)Small Class I & II Cavities

CAVITY PREPARATIONS

FOR

AMALGAM RESTORATION

What is a Cavity Preparation?What is a Cavity Preparation?

It is a mechanical It is a mechanical alteration of a defective, injured, or alteration of a defective, injured, or diseased tooth to receive a diseased tooth to receive a restorative material that re-restorative material that re-establishes a healthy state for the establishes a healthy state for the tooth, including esthetics corrections tooth, including esthetics corrections where indicated & normal form & where indicated & normal form & function. function.

STEPS IN CAVITY STEPS IN CAVITY PREPARATIONPREPARATION

(1)(1) Initial Cavity preparationInitial Cavity preparation

(2)(2) Final Cavity Preparation Final Cavity Preparation

Initial…Initial…

1.1. Outline form & initial depthOutline form & initial depth

2.2. Primary Resistance formPrimary Resistance form

3.3. Primary Retention formPrimary Retention form

4.4. Convenience form Convenience form

Final…Final…

1.1. Removal of any remaining defective Removal of any remaining defective Enamel or Dentin on Pulpal floorEnamel or Dentin on Pulpal floor

2.2. Pulp protection Pulp protection

3.3. Finishing External WallsFinishing External Walls

4.4. Final Cleaning & Inspection Final Cleaning & Inspection

CLASS ICLASS I

They are restorations on They are restorations on occlusal surfaces of premolars & occlusal surfaces of premolars & molars, occlusal 2/3molars, occlusal 2/3rdrd of facial & of facial & lingual surface of molars & lingual lingual surface of molars & lingual surface of maxillary incisorssurface of maxillary incisors

CLASS IICLASS II

They are reostorations They are reostorations on the proximal surfaces of posterior on the proximal surfaces of posterior teeth- mesio occlusal , disto occlusal, teeth- mesio occlusal , disto occlusal, mesio occluso distalmesio occluso distal

CLASS IIICLASS III

They are restorations They are restorations on the proximal surface of anterior on the proximal surface of anterior teeth that that do not involve incisal teeth that that do not involve incisal angle.angle.

CLASS VCLASS V

They are restorations on They are restorations on gingival 1/3gingival 1/3rdrd of facial & lingual of facial & lingual surface of all teeth.surface of all teeth.

CLASS VI CLASS VI

They are restorations They are restorations on incisal edge of anterior teeth or on incisal edge of anterior teeth or cusp tip region of posterior teeth. cusp tip region of posterior teeth.

FAILURES OF FAILURES OF AMALGAM AMALGAM

RESTORATIONSRESTORATIONS

Signs of failures :Signs of failures :

1.1. Fracture LinesFracture Lines2.2. Marginal DitchingMarginal Ditching3.3. Proximal OverhangsProximal Overhangs4.4. Poor anatomic contoursPoor anatomic contours5.5. Marginal Ridge incompatibilityMarginal Ridge incompatibility6.6. Improper Proximal ContactsImproper Proximal Contacts7.7. Recurrent CariesRecurrent Caries8.8. Poor occlusal ContactsPoor occlusal Contacts9.9. Amalgam BluesAmalgam Blues

Reasons For Failures:Reasons For Failures:

1.1. Improper Case SelectionImproper Case Selection

2.2. Improper Cavity PreparationImproper Cavity Preparation

3.3. Faulty Selection & manipulation of Faulty Selection & manipulation of Amalgam Amalgam

4.4. Errors in Maricing Procedures Errors in Maricing Procedures

5.5. Post Operative FactorsPost Operative Factors

AMALGAM TATOOAMALGAM TATOO

“ “ Accidental implantation of silver Accidental implantation of silver containing compounds into oral mucosal containing compounds into oral mucosal tissue”tissue”

Occur:Occur:1.1. Removal of old amalgamRemoval of old amalgam2.2. Broken Pieces-socket-tooth extractionBroken Pieces-socket-tooth extraction3.3. Particles entering surgical woundParticles entering surgical wound4.4. Amalgam dust in oral fluids- abrasion Amalgam dust in oral fluids- abrasion

areasareas Seen asSeen as – Grayish black pigmentation – Grayish black pigmentation Com. Sites-Com. Sites- Gingiva, buccal mucosa, Gingiva, buccal mucosa,

alveolar mucosaalveolar mucosa

CONCLUSIONCONCLUSION

Class I & II Restorations are still common Class I & II Restorations are still common procedures performed by general Dentists.procedures performed by general Dentists.

Class VI are used infrequentlyClass VI are used infrequently It is important for practitioners to It is important for practitioners to

understand the indications, advantages, understand the indications, advantages, techniques & limitations of these techniques & limitations of these restorations.restorations.

When used correctly & properly selected When used correctly & properly selected cases, these restorations have the cases, these restorations have the potential to serve for many years potential to serve for many years

THANK YOU!!!!