by

Dr.Anoop.V.Nair, PG,

Dept of Cons & Endodontics

KVG Dental College, Sullia

Contents

• History

• Overview

• Alloy production

• Generations

• Alloy manipulation

• Phases

• Classification

• What is an amalgam failure?

• What types of failure?

• Why failure?

- Alloy

- Dentist

- Patient

• References

• 618-907 AD- Tang dynasty in China, according to GeirBjørklund, an active proponent of mercury free dentistry

• In Germany by Dr. Strockerus in about 1528

• In 1603, German Tobias Kreilius boiled a concoction of copper, acids and mercury which was poured as a hot liquid onto diseased teeth

• In 1819, first dental amalgam was probably introduced inEngland, ‘Bell’s putty’, by Thomas Bell, by mixing metals withmercury at room temperature

• In 1826, Taveau, from France described a silver paste filling material

• 1833 the Crawcour brothers, two Frenchmen, brought amalgam to the

United States

• 1844 it was reported that fifty percent of all dental restorations

placed in upstate New York consisted of amalgam. At that point the

use of dental amalgam was declared to be malpractice, and the

American Society of Dental Surgeons (ASDS), the only US dental

association at the time, forced all of its members to sign a pledge to

abstain from using the mercury fillings. This was the beginning of what

are known as the first dental amalgam war.

• The war ended in 1856 with the rescission of the old association.

• The American Dental Association was founded in its place in 1859, which

has since then strongly defended dental amalgam from allegations of

being too risky from the health standpoint.

• Taft's text was published in 1859, Harris' in 1863. They stated that

beginning in the early 19th century, eleven types of metallic fillings

were used in teeth damaged by dental caries. The simple process of

rolling metal into pellets to be placed into cavities was common. These

pellets were made of some of the aforementioned materials like gold,

lead, platinum, silver and amalgam as well as aluminum.

• Sir Louis Regnart-"Father of Amalgam". He improved on a boiled mineral cement by adding mercury, which greatly reduced the high temperature originally needed to pour the cement onto a tooth.

• 1895-G V Black, a Chicago dentist standardized cavity preparation andamalgam manufacture.

• The ratio of the mercury to the remaining metallic mixture in dentalamalgam has not been always 50:50. It was as high as 66:33 in 1930.

• 1930: ADA spec no 1

• In 1959, Eames introduced minimal mercury technique, with reducedmercury alloy ratio

• Two texts used by American dentists of this time were, "A Practical Treatise

on Operative Dentistry" written by J Taft, and "The Principles and Practice

of Dental Surgery", written by Chapin A Harris.

BEFORE REACTIONBEFORE REACTION AFTER REACTIONAFTER REACTION

AlloyAlloy

MercuryMercuryReactionReactionProductsProducts

AlloyAlloy

AMALGAM = an alloy containing Hg as the major ingredient.

DENTAL AMALGAM = an alloy of Hg with Ag-Sn.

DENTAL AMALGAM ALLOY = a Ag-Sn alloy (to be mixed with Hg).

ALLOY PRODUCTIONMelting / Casting / Comminution IRREGULAR Particles

Melting / Spray Atomization SPHERICAL PARTICLES

“Cast ingots --> filed into powder on a lathe- ComminutionIrregular particles = lathe cut = filings

Particles are polycrystalline

Homogenization heat treatment to remove coring

Annealing heat treatment of filings to relieve cold work

Hot alloy sprayed into cold airParticles spherodize and solidify

Spheres are acid-washedGenerally spheres are Heat Treated

Mercury/Alloy Ratios:

Decreased with time and advent of spherical alloy powders

* Eutectic alloy- is a mixture of chemical compounds or

elements that has a single chemical composition that solidifies at

a lower temperature than any other composition made up of the

same ingredients. This is called eutectic composition and the

temperature at which it solidifies is known as eutectic

temperature.

• Peritectic alloy similar to eutectic alloy, here, a liquid and

solid phase of fixed proportions react at a fixed temperature to

yield a single phase. The solid product forms at the interface

between the two reactants, and forms a diffusion barrier and

causes reactions to proceed much more slowly than eutectic.

• Ternary- a complex formed by interaction of three molecules

Addition of Noble metals- GENERATIONS

(Marzouk)

First generation- GV Black

3 part silver + 1 part tin, peritectic alloy

Alloy product of reaction between the beta-phase of solid solution of tin in

silver with liquid phase of silver & tin. This is defined as gamma phase.

Second generation-

Addition of-

Cu (admixture)- upto 4%, decrease plasticity and increase hardness &

strength of alloy

Zn- traces- deoxidizer or scavenger for alloy, decrease brittleness.

Third generation-

Ag3-Cu eutectic alloy (admixture/blending)

Fourth generation-

Alloying of Cu to silver & tin- upto 29% ternary alloy, most of tin

firmly bonded to Cu.

Fifth generation-

Alloying of silver, copper, tin & indium true quaternary alloy, none of

tin is available to react with mercury.

Sixth generation-

Alloying of palladium (10%), silver (62%) and copper (28%), to form a

eutectic alloy lathe-cut and blended into 1st, 2nd or 3rd gen amalgam-

ratio 1:2 set amalgam, exhibits highest nobility

ALLOY MANIPULATION

Manual Trituration Procedures:

Alloy + Hg mortar + pestle manual mixing

Mechanical Trituration Procedures:

Powdered alloy + Hg capsule + pestle amalgamator

Pelleted alloy + Hg capsule + pestle amalgamator

Powdered alloy + Hg pre-capsulated amalgamator

THE ORGINAL GAMMA PHASE (i.e., Ag3Sn or the alloy

powder) which has not been completely dissolved in mercury.

Mechanically strongest phase, for this reason it should occupy the

maximum available space in the volume of the restoration.

GAMMA-1 Phase (Ag2Hg3) is one of the amalgamation

products that form the matrix. It is the noblest phase i.e., Most

resistant to tarnish & corrosion. Effort, made to make this phase

occupy maximum space in bonding matrix of final product.

GAMMA-2 Phase (Sn7 Hg8)

It is the phase which is the least resistant to tarnish &

corrosion & every effort is made minimize its volume percentage in

the matrix. Most of amalgam failures, due to this phase.

Phases

MERCURY Phase

- Unreacted residual mercury, present in isolated areas within the amalgam mass.

- Mechanically weakest phase & when a certain volume limit exceeds, there

will be drastic drop in the strength & hardness in addition to increase in creep &

flow of restoration.

VOIDS (porous) PHASE

- Due to entrapment of air bubbles, in the process of building the amalgam

restoration, despite any meticulous procedures.

- Such voids act as a nidus not only for internal corrosion, but also leads to stress

concentration & propagation which ultimately leads to early failure of structure

of restoration.

The trace element phase

In which copper & zinc might be found either as separate phases or combined

with Ag, Sn & Hg.

Cu- increase strength, brittleness, hardness and proportional limits of amalgam

Zn- increase deformability, ultimate strengths, resistance to oxidation of final

product.

The INTERPHASES

In terms of the serviceability of final restoration, the most important

components of the mass.

This especially to the interphases between the 3 components namely

gamma, gamma-1 & gamma-2.

In the final restoration, the more continuous they are better is the

bonding between the primary phases. Consequently, the more coherent &

the more resistant to environmental variable the restoration will be.

EPSILON Phase (Cu3Sn)

AgSn alloys are quite brittle & difficult to comminute uniformly unless a

small amount of copper is substituted for silver. This atomic replacement is

limited to about 4-5 wt%, above which Cu3Sn is formed within the limited

range of copper solubility, increased copper content hardens & strengthen

the AgSn alloy.

ETA Phase (Cu6Sn5)

• The crystals are found as meshes of rod crystals at the surfaces of

the alloy particles as well as dispersed in the matrix.

• Meshed ETA crystals on unconsumed alloy particles may

strengthen bonding between the alloy particles & 1 grains.

Crystals dispersed between 1 grains may interlock 1 grains. This

interlocking is believed to improve the amalgam’s resistance to

deformation in high copper alloys.

I. According to the number of alloyed metals

Binary alloys

Only 2 alloys namely silver & tin

Ternary alloys

Along with silver & tin copper was added to increase the

strength of the alloy.

Quaternary alloys

Indium was added to the above which act as a grain refiner.

II. According to the shape of powdered particles

spherical: alloy shape which has smooth surfaced spheres.

Lathe cut: irregular shapes ranging from spindles to shavings.

spheroidal: spherical with irregular spheres

III. According to the powder particle size

micro cut

fine cut

coarse cut

IV. According to the copper content

Low copper alloys, which contain less than 4% of copper

High copper alloys, which contain more than 10% of

copper & has improved physical properties & corrosion resistant.

V. According to whether the powder consists of unmixed or

admixed alloys.

Certain amalgam made of only one alloy, others have one or

more alloys or more alloys (blended) to the basic alloy e.g.;

adding copper to the basic binary silver –tin alloys.

• A failing amalgam filling can be defined as a filling that has been

a contributory cause of secondary injury in the organ of the tooth

i.e, the tooth itself and its surrounding connective tissue.( Knud Dreyer Jorgensen, Amalgams in dentistry, Dental Materials Research: Proceedings of the 50th

Anniversary Symposium, Oct 6-8. 1969 Issue 354, By United States. National Bureau of Standards,

American Dental Association)

• FRACTURE

Marginal fracture

Isthmus fracture

Bulk fracture

Tooth fracture

• SECONDARY CARIES

• POST OPERATIVE SENSITIVITY

• DISLODGEMENT OF RESTORATION

• DISCOLOURATION OF TEETH

• PERIODONTAL DISEASE

• PULPAL DAMAGE

•OCCLUSAL INTERFERENCE

• TARNISH AND CORROSION

•GALVANISM

•AMALGAM TATTOO

•NEGATIVE CONTACT POINT

• FOOD IMPACTION

• ALLOY

• DENTIST

• PATIENT

• Manufacturing defects

• Physical properties of amalgam

Dimensional stability

Strength

Creep

• Contraction/expansion

TIME

D

I

M

E

N

S

I

O C

N H

A A

L N

G

E

S

STAGE 1-

Initial contraction-

absorption of Hg

into alloy powder

STAGE 2-

Expansion, due to

formation & growth

of matrix crystals,

reaches a plateau

with cessation of

matrix formation

STAGE 3-

Limited, delayed

contraction of mass,

absorption of

unreacted Hg

• Factors affecting:

• Constituents- More gamma phase- greater possibility of expansion

- Greater traces of tin, less expansion

• Mercury- More Hg, more prolonged second stage of amalgamation (expansion)

- Greater amount of matrix crystals (gamma, gamma 1 or gamma 2), produces more expansion

• Particle size- smaller size more surface area per unit volume first stage, dissolution occurs rapidly marked contraction second stage also rapid expansion plateau achieved too quickly (before cavity filled)- apparent expansion may not be noticed stage 3 contraction maybe more noticed.

Trituration- more energy used, smaller particles will be made more

mechanical force will be present pushing mercury in between

particles discourage expansion

• More trituration energy, greater distribution of forming matrix

crystals all over mix, preventing outward growth, which creates

expansion of second stage.

• More trituration energy, faster amalgamation proceeds, plateau of

expansion curve occur before completely filling cavity

preparation no apparent expansion, possibly limited contraction

Condensation- more energy used, into condensing amalgam into

cavity preparation, closer original particles of powder are brought

together at expense of expanding matrix crystals.

• Increased condensation energy, also squeezes more Hg out of the

mix less formation of matrix crystals, inducing more contraction.

Particle shape-

• More regular the particle shape is and smoother its surfaces are,

faster and more effectively the mercury can wet the powder

particles.

• Makes faster amalgamation process in all stages, maximum

expansion occurs before filling cavity, with no apparent expansion.

Contamination-

• Moisture- esp affects Zn containing amalgam.

• Water from any source(saliva, blood, respiration etc) + Zn (in

amalgam) ZnO + Hydrogen gases

• Takes place- 24-72 hours after amalgam insertion.

• Hydrogen gases, accumulate, exert pressure- upto 2000 PSI.

• Protrusion of entire restoration outside cavity, increased

microleakage space around restoration, restoration perforation,

blister formation on restoration surface, increased flow & creep,

pulpal pressure pain, delayed expansion- 400 µ/cm3

• Clinical significance

• Zn containing alloys

• Moisture contamination

• 3-5 days till months:

400µ/cm3

• Early hour strength (C.S.)

• Strength after setting (C.S.)

• Tensile strength

Amalgam 1 hr 7 days T.S.

Low Cu 145 343 60

Admix 137 431 48

Single comp

262 510 64

• Temperature

• Trituration

• Mercury content

• Condensation

• Porosity

• Particle shape & size

• Inteparticle distance

• Dispersion

• Gamma-2 phase

• Corrosion

Temperature-

• Amalgam loses 15% strength when temp elevated from room to

mouth

• Loses 50% strength when temperature elevated to 60% (hot

coffee, soups)

Trituration-

• More energy used, more continuous interphases between matrix

crystals & original particles, more evenly distributed matrix crystals

over mix more coherent mass greater strength

• If trituration, continued after complete matrix crystals formation,

excess energy will crack crystals & interphases drop in strength

of amalgam

Mercury- weakest phase, liquid room temp., cannot resist any slip or

dislocation within amalgam caused by external loading

• Residual mercury- increase in Hg content from 53%- 55%, causes

drop in compressive strength, more than 50%

Condensation-

• More energy used, less residual mercury, higher relative

percentage of strong original particles in restoration.

• More continuous interphase between original particles & forming

matrix

• More even distribution of gamma1 or gamma 1-gamma 2 matrix

crystals more consistent strength throughout restoration mass

*condensation of an amalgam mass after formation of matrix

crystals does not diminish strength as trituration does, because there

is more resistance to crystal displacement during condensation than

trituration.

Porosity-

• Important to minimize the number & size of pores

• Keep them away from critical areas of the restoration

• Pores facilitate stress concentration, propagation of cracks,

corrosion and fatigue failures of amalgam structures

• Porosity of 1% reduces amalgam strength as 10% excessive

mercury

• Results from the fact that different phases of amalgam do not

completely wet each other simultaneously during amalgam

fabrication

• Under-trituration, under condensation, irregular shaped particles of

alloy powder, miscalculated diameter varieties of powder particles

to occupy available spaces, insertion of too large increments into

cavity preparation, delayed insertion after trituration or a

generally non-wetting, non-plastic mass of amalgam.

Particle size & shape-

• Alloy particles, more regular & smooth- more wettable

• Will react & combine more efficiently

• Resultant, less interrupted interphases create a more coherent and strong

mass

• Smaller the diameter of the original particles, greater will be the strength

of the set amalgam.

Compressive strength-

• 1 day specimen- substantial increase in strength, average particle

diameter 12 or less microns

• 1 week specimen- substantial increase when average particle diameter

16 or less microns

Tensile strength-

• 1 day specimen- marked increase in strength when average particle

diameter 18 microns or less

• 1 week specimen- same increase when average particle diameter 12

microns or less

Interparticle distance-

• Closer original particles of alloy are- stronger end product will be

• When average interparticle distance is 38 microns or less,

noticeable increase in compressive strength in 24 hr sample

• 1 week sample- 32 microns or less

• Tensile strength- 28 microns or less, marked increase in 24 hr

specimen

• 39 microns or less, marked increase in one week specimen

Dispersion-

• A solid state dispersion within amalgam mass of another phase,

with one which has a different shape & dimension than original

phases, can distort original space lattices, precipitating

interferences with slip increasing amalgam strength

• Eg:- addition of Cu or addition of Ag-Cu eutectic or Ag-Cu-

Palladium near-eutectic alloys

• Net result- greatly enhanced strength

Gamma 2 phase

• Mechanically, second Weakest phase

• Corrosion ability

• Reduction or prevention of its formation- increase strength of

amalgam, especially age strength

Corrosion

• Decreasing corrosion activity within an amalgam restoration will

protect the adhesive integrity between the multiple phases, thus

preventing the strength from deteriorating.

Flow Creep

Measured during setting of amalgam Measured after amalgam sets

Reflects change in dimension of amalgam

after load

Reflects constant change in dimension

under either static or dynamic loading

Incremental deformation

Markedly pronounced after

EQUICOHESIVE temperature

More energy used to condense, less the

creep, mercury increase will increase

creep

Dispersion or elimination of gamma-2 can

reduce creep

Lesser the creep, better will be the

marginal integrity & longevity of the

restoration

• ‘It is mainly the operator who causes the amalgam restoration to

be a success or failure’

• The choice between spherical, spheroidal or lathe-cut alloy

particles can be related to the type of patient population the

dentist is involved with.

• Spherical particle alloy- quick strength attainment

- Require fast operator

- exhibit more flow

- deformation with time

• Choice between zinc containing & zinc free-

Zinc containing- problems in presence of moisture

Zinc free- less plastic, less workable, more susceptible to oxidation, so

should be used in cases only where elimination of moisture is

impossible, eg:- root apices, subgingival lesions

Marzouk, 1st edition

Proportioning of alloy & mercury

Choose between

*consider manufacturer’s recommendation which is based on metallurgical condition, thermal

treatment, powder particle specification

High mercury technique (increasing

dryness technique)

Minimum mercury/ Eame’s

technique/1:1

Initial amalgam mix contains a little

more Hg than needed for the powder

(52-53%), producing a very plastic mix

Initial amalgam mix contains equal

amounts of mercury and powder alloy

Necessary to continue squeezing the

mercury out of the mix increments being

introduced to build up the restoration, so

that each increment will be drier than

the previous one

Necessary to squeeze mercury out of the

mix during the incremental build-up of

the restoration.

50% or less mercury only will be in the

final restoration, with obvious

advantages

• Restorations to be retained with multiple auxillary means of

retention (pins, internal boxes, grooves)- need wetting or plastic

consistency of amalgam increasing dryness technique

• A very large restoration which needs more than one mix

increasing dryness technique

• Proportioning is done by weight and not by volume- volume is

misleading because of trapped air and voids in mass

• Choice between pre-weighed, pre-proportioned alloy mercury

capsules or weight proportioning oneself in the office

• Do not leave previous mixes

remnants in the capsule, as this

will get incorporated into a new

mix without proper binding or

plasticity, weakening the final

product.

• Scratches in the capsules may

trap mercury or traces of old

mixes, compromising quality of

amalgam product.

• Cracks in the capsules that leak

mercury will pollute the office

and reduce mercury in the mix,

sometimes with undesirable

effects

• Improper case selection

• Improper selection of alloy and mercury

• Improper Cavity preparation

• Improper manipulation of alloy

• Improper Pulp protection

• Improper Matrix adaptation

• Contamination

• Extensive loss of tooth structure and

undermined enamel.

• Poor retention and resistance form

• Areas of high masticatory loads

• Parafunctional habits

• Extensive/open contacts

• Improper outline form

• Cavity outline in stress bearing areas

• Improper resistance form

• Improper retention form

• Improper convenience form

• Inadequate occlusal extension- include pits & fissures

• Inadequate extension of the proximal box- if proximal box walls

are not adequately extended into embrasures they are not

amenable to cleaning secondary caries

• Overextension of cavity preparation walls- 1/4th the intercuspal

distance facio-lingual width

• If cavity preparation extends to half the intercuspal distance,

capping of cusps should be considered, if cavity preparation

extends to 2/3rd, cusp capping becomes mandatory.

• Minimum thickness in cusp capping should be 2mm over functional

cusps and 1.5mm over non-functional cusps.

Minimum depth of 1.5mm to provide bulk

Flat pulpal floor

Butt joints in regions where occlusal stresses encountered

Round off axio pulpal line angle

Failure to diverge mesial & distal walls of occlusal cavity

preparation

Retentive devices should be prepared entirely in dentin without

undermining enamel

Incomplete removal of carious tooth structure

correct

Insufficient

gingivally

Insufficient

occlusally

correctexcessive

• Matrix should be stable after it has been applied-

if unstable, distorted restoration, gross marginal

excesses

• Cervical excess can irritate peridontium

• Unstable matrix- proper condensation cannot be

carried out soft amalgam filled with voids

shape

surface

size• If large cavity, demands working time

exceeds 3-4 mins, use multiple mixes

• Elimination of Hg by excessive

squeezing, may reduce strength

• Very small plugger holes- punch holes in

amalgam

• Very large plugger holes- may not

condense amalgam in corners

• Light tapping- to remove Hg to surface,

adequate condensation pressure

Mechanical

condensation

Lathe cut alloys Spherical alloys

• Over- carving-

• Will reduce thickness of amalgam & increase chances of fracture.

• Under-carving

• Failure due to improper pulp protection

• Failure due to contamination

• Failure due to improper instructions

• Oral hygiene

• Excessive stress

• Malposed occlusion

• Galvanism

• Parafunctional habits

• Failure to follow instructions

•Electrochemical

•Chemical

•Mercury level

• Surface texture

•Galvanic action

•Moisture contamination

By-products are tin-oxide, copper-oxide,

silver sulfides

• Improper cavity preparation and finishing

• Excess mercury

•Creep

•Corrosion

If varnish not applied, continuous leakage around restoration

occurs, may cause postoperative sensitivity and amalgam blues due

to penetration of corrosion products into dentinal tubules.

Newer

modifications

RESIN COATED AMALGAM

• To overcome the limitation of microleakage with amalgams, a

coating of unfilled resin over the restoration margins and the

adjacent enamel, after etching the enamel, has been tried.

Although the resin may eventually wear away, it delays

microleakage until corrosion products begin to fill the tooth

restoration interface.

• Mertz-fairhurst and others evaluated bonded and sealed

composite restorations placed directly over frank cavitated

lesions extending into dentin versus sealed conservative

amalgam restorations and conventional unsealed amalgam

restorations. The results indicate that both types of sealed

restorations exhibited superior clinical performance and

longevity compared with unsealed amalgam restorations over a

period of 10 years

FLUORIDATED AMALGAM

• Fluoride, being cariostatic, has been included in amalgam to deal with

the problem of recurrent caries associated with amalgam restorations.

The problem with this method is that the fluoride is not delivered long

enough to provide maximum benefit.

• Several studies investigated fluoride levels released from amalgam.

These studies concluded that a fluoride containing amalgam may release

fluoride for several weeks after insertion of the material in mouth.

• As an increase of up to 10–20-fold in the fluoride content of whole

saliva could be measured, the fluoride release from this amalgam seems

to be considerable during the first week.

• An anticariogenic action of fluoride amalgam could be explained by its

ability to deposit fluoride in the hard tissues around the fillings and to

increase the fluoride content of plaque and saliva, subsequently

affecting remineralization. In this way, fluoride from amalgam could have

a favorable effect not only on caries around the filling but on any initial

enamel demineralization. The fluoride amalgam thus serves as a “slow

release device”.

BONDED AMALGAM

• Conventional amalgam is an obturating material as it merely fills the

space of prepared cavity, and thus, does not restore the fracture

resistance of the tooth, which was lost during cavity preparations. In

addition, the provision for adequate resistance and retention form for

amalgams may require removal of healthy tooth structure. Further, since

amalgam does not bond to tooth structure, microleakage immediately

after insertion is inevitable. So, to overcome these disadvantages of

amalgam, adhesive systems that reliably bond to enamel and dentin have

been introduced.

• Amalgam bond is based on a dentinal bonding system developed in

Japan by Nakabayashi and co-workers. The bond strengths recorded in

studies have varied, approximately 12–15 MPa, and seem to be

routinely achievable. Using a spherical amalgam in one study of bonded

amalgam, Summitt and colleagues reported mean bond strength of 27

MPa. The authors believed that this higher bond strength was achieved

because the bonding material was refrigerated until immediately before

its use.

• Bond strengths achieved with admixed alloys tend to be slightly

lower than those with spherical alloys. One study compared post-

insertion sensitivity of teeth with bonded amalgams to that of teeth

with pin-retained amalgams. After 6 months, teeth with bonded

amalgams were less sensitive than teeth with pin-retained

amalgams. This difference in sensitivity was not present 1 year after

insertion. This is possibly because of corrosion products in

nonbonded amalgam restorations filling the interface, and thus,

decreasing microleakage and sensitivity.

• If bonding proves successful over the long term, method of

mechanical retention can be eliminated, thus reducing the potential

for further damage to tooth structure that occurs with pin placement

or use of amalgapins. If mechanical retention is not needed, cavity

design can allow more sound tooth structure to be preserved.

CONSOLIDATED SILVER ALLOY SYSTEM

• One amalgam substitute being tested is a consolidated silver alloy

system developed at the National Institute of Standards and

Technology.

• It uses a fluoroboric acid solution to keep the surface of the silver

alloy particles clean.

• The alloy, in a spherical form, is condensed into a prepared cavity

in a manner similar to that for placing compacted gold. One

problem associated with the insertion of this material is that the

alloy strain hardens, so it is difficult to compact it adequately to

eliminate internal voids and to achieve good adaptation to the

cavity without using excessive force.

FUTURE OF DENTAL AMALGAM

• The prediction that amalgam would not last until the end of the

20th century was wrong.

• Its unaesthetic appearance, its inability to bond tooth, concerns

about the mercury and versatility of other materials have not

not led to the elimination of this inexpensive and durable

material. As other materials and techniques improve, the use of

amalgam will likely continue to diminish, and it will eventually

disappear from the scene.

• Yet, amalgam continues to be the best bargain in the

restorative armamentarium because of its durability and

technique insensitivity. Amalgam will probably disappear

eventually, but its disappearance will be brought about by a

better and more aesthetic material, rather than by concerns

over health hazards. When it does disappear, it will have

served dentistry and patients well for more than 200 years.

References

• Dental Materials Research: Proceedings of the 50th Anniversary Symposium,

Oct 6-8. 1969 Issue 354, By United States. National Bureau of Standards,

American Dental Association

• Dental amalgam: An update

Ramesh Bharti, Kulvinder Kaur Wadhwani, Aseem Prakash Tikku, and Anil Chandra

J Conserv Dent. 2010 Oct-Dec; 13(4): 204–208

• Textbook of dental materials by Sharmila Hussain

• Dental materials: Prep manual for under graduates by Patil

• Sturdevant’s Art and Science of Operative Dentistry

• Operative dentistry- modern theory and practice- Marzouk, Simonton, Gross- 1st

edition

• Essentials of Operative Dentistry- Anand Sherwood

• Textbook of operative dentistry- Vimal K Sikri

• Skinner’s Science of Dental Materials- 9th edition

• Pictures- various sources from the internet

•Thank you