This document provides an overview of dental amalgam, including its: - Classification based on composition and particle shape - Generations and typical compositions - Properties including strength, creep, corrosion resistance - Toxicity and mercury levels - Manipulation techniques for mixing, condensing, and finishing amalgam restorations - Status and concerns about mercury levels from dental offices

1. Prepared by Dr Boris saha
Supervisor : Prof Ashok kumar
Co supervisor : Dr Shariq Alam

2. Overview
 Introduction
 Classification
 Generations
 Composition
 Variants
 Effects of components
 Properties
 Toxicity
 Manipulation
 Status past n present

3. INTRODUCTION

4.  Amalgam –
 Dental amalgam is a metal like restorative
material composed of mixture of Ag/Sn/Cu alloy
and mercury
 Almost 80% of dental restorations.
 Reasons:
 Ease of use
 Self sealing ability
 High compressive strength
 Excellent wear resistance
 Dentist friendly technique
 Low cost than composite restoration

5. CLASSIFICATION

6.  According to presence or
absence of Zinc
 Zinc-containing alloys:
More than 0.01% Zn.
 Zinc-free alloys:
Less than 0.01% Zn.
 According to Copper
content
 Low Copper alloys
(2-4% Cu)
 High copper alloys
(13-30% Cu)
 Admixed alloy
(LowCu + Ag-Cu eutectic)
 Unicompositional alloy
 According to number of
metals in the alloy
 Binary : Ag; Sn
 Ternary : Ag; Sn; Cu
 Quarternary : Ag;
Sn;Cu;In
 According to the shape
and size of alloy particles
 Spherical (Smooth shaped
spheres)
 Spheroidal (Irregular shaped
spheres)
 Lathe-cut (Irregular shavings
or filings)
 Micro-cut
 Fine-cut
 Coarse cut

7. Generations of amalgam.

8.  1st generation amalgam alloys
G.V.Black's formulation of 3parts Ag and 1 part sSn.
peritectic alloy
 2nd generation amalgam alloys
 Addition of 4% Cu (to ↓ plasticity and ↑strength) and
upto 1% Zn (scavenger and ↓ brittleness)
 3rd generation amalgam alloys
 1st gen + Ag-Cu eutectic spherical alloy.

9.  4th generation amalgam alloys
 Ternary alloys - Alloying of Cu upto 29%toAg and Sn
to form Ag2CuSn.
 5th generation amalgam alloys
 Quarternary alloys - Ag, Sn, Cu, and Indium
 6th generation amalgam alloys
 Ag-Cu-Pd eutectic alloy (62%, 28%, and 10%
respectively) is added in a ratio of 1:2 to low Cu alloy.
This has the highest nobility.

10. COMPOSITIONOF AMALGAM ALLOY

11. Silver 68-72%
Tin 26-28%
Copper 02-04%
Zinc 00-02%
Low copper alloy
Silver 71.9%
Copper 28.1%
or
Silver 62%
Copper 28%
Palladium 10%
Admix alloy:
1/3 lathe cut Eutectic alloy
†2/3 low Cu alloy

12. Silver 40-60%
Tin 27-30%
Copper 13-30%
Silver 40-60%
Tin 22-35%
Copper 13-30%
Indium 5%
Ternary alloys Quarternary
alloys

13. Other alloys
 Hybrid alloys: Spherical particles of a ternary
Ag-Sn-Cu alloy with lathe-cut particles
containing Ag3Sn or Ag-Sn-Cu.
 Fluoridated amalgam alloys: Fluoride is added
for anticariogenicity.
 Pre amalgamated alloys: Mercury used is less
than 3%. Alloy particles are coated with
mercury so that they become self
condensable.
 Noble metal amalgam alloys: Contain Au and/or
Pd for good corrosion resistance.

14. SILVER COPPER TIN
Increases Strength Increases Strength Decreases Strength
Increases Expansion Increases Expansion Decreases Expansion
Decreases Flow Decreases Flow Increases Flow
Decreases Setting time Decreases Setting time Decreases Setting time
Increases Corrosion
resistance
Increases Corrosion
resistance
Decreases Corrosion
resistance
Decreases Plasticity Increases Plasticity
Increases Hardness
Increases Brittleness

15. ZINC INDIUM GOLD
Increases Strength Increases Strength Increases Strength
Increases Expansion Increases Expansion
Increases Corrosion
resistance
Increases Flow Increases Flow
Increases Setting time Increases Setting time MERCURY
Decreases Corrosion
resistance
Amalgamation more
difficult
Decreases setting
time
Increases Plasticity Deoxidiser Decreases delayed
expansionDecreases Hardness
Decreases Brittleness
Scavenger

16. Amalgam Properties values
Compressive
Strength (MPa)
%
Creep
Tensile
Strength
(24 hrs) (MPa)
Amalgam Type 1 hr 7 days
Low Copper1 145 343 2.0 60
Admixture2 137 431 0.4 48
Single
Composition3
262 510 0.13 64

17. PROPERTIES

18.  Dimensional Change
 Strength
 Creep
 Resistance to corrosion
 Biological properties

19. Dimensional change
Three stages of setting reaction:
initial contraction, then expansion and finally
limited delayed contraction.
Factors causing expansion: Expansion >> 4%
 More gamma phase and tin
 More Hg
 Larger particle size
 More energy of trituration
 Lesser condensation forces
 Moisture contamination for Zn alloys

20. Dimensional change
Most high-copper amalgams undergo a net
contraction.
 contraction : Contraction < than 50µ/cm
 type of alloy
spherical alloys have more
contraction due to lesser mercury
 condensation technique
greater condensation = higher contraction
 trituration time
overtrituration causes higher contraction

21. Strength
 Develops slowly
 1 hr: 40 to 60% of maximum
 24 hrs: 90% of maximum
 Spherical alloys strengthen faster
require less mercury
 Higher compressive vs. tensile strength
 Weak in thin sections
 unsupported edges fracture.
 Minimum thickness required 1 to 1.5 mm.

22. Strength
Factors decreasing strength:
 Temperature increase
 Excess mercury and porosity
Factors Increasing strength:
 More trituration and condensation energy.
 Regular size, shape of particle and dispersion.
 More ϒ and ϒ1 phase and lesser ϒ2.

23. Creep
Slow deformation of amalgam placed under a constant load leads
to marginal breakdown - load less than that necessary to produce
fracture.
Factors :
 Gamma 2 dramatically affects creep rate.
allows gamma-1 grains to slide
 Excess mercury and temperature rise increase it.
 Over/under trituration increases it.
 Dispersion can reduce it.
 Increased condensation force reduces it.

24. Creep
 High-copper amalgams have creep resistance
 prevention of gamma-2 phase
 requires >12% Cu total
 Single composition spherical
 eta (Cu6Sn5) embedded in gamma-1 grains
interlock
 Admixture
 eta (Cu6Sn5) aroundAg-Cu particles
improves bonding to gamma 1

25. Electrochemical corrosion
occurs whenever
chemically different sites
act as anode & cathode
It requires the site to be
connected by an electrical
circuit in the presence of an
electrolyte eg saliva
The anode corrodes ,
producing soluble and
insoluble corrosion reaction
products
MECHANISM OF ELECTRO CHEMICAL CORROSION

26. Corrosion
 Reduces strength
 Seals margins
 low copper
 6 months
 SnO2, SnCl
 gamma-2 phase
 high copper
 6 - 24 months
 SnO2 , SnCl, CuCl
 eta-phase (Cu6Sn5)

27. Biological properties
 The pulp needs to be protected from
amalgam due to its chemical, thermal,
electrical and physical nature.
 Mercury can discolor dentinal tubules,
damage odontoblasts.
 There should be an optimum barrier of ≥2mm
between pulp and amalgam.

28. Hypersensitivity
 Type IV or cell-mediated immune response
 Contact dermatitis
 Lichenoid lesions adjacent to
amalgam
 Most reactions subside
amalgam removal usually not necessary
 True allergy is rare
 < 1%

29. TOXICITY

30. Biologic Activity of Mercury
 Binds to protein sulfhydryl groups
 loses structure and function
 No carcinogenicity
 Teratogenicity

32. Symptoms of Toxicity
 Acute high-level
exposure
 hypersalivation
 cough
 dyspnea
 bronchitis
 Pneumonia
 vomiting
 gastroenteritis
 Chronic low-level
exposure
 depression
 irritability
 weakness
 tremor
 insomnia
 renal failure
 memory loss

33. Amalgam Waste
 Mercury is a naturally occurring metal
 Half of environmental mercury comes from
human activity----< 1% dentistry.
52%
34%
13% <1%
Fuel Combustion
Waste Combustion
Manufacturers
Dentistry

34. Dental Hygeine mercury
Recommendation
 Education to all persons involved in handling
the amalgam
 Using a mercury spill kit
 Reacting unused elemental Hg with Ag to
form scrap amalgam
 Not throwing Hg to garbage or SINK
 Use hi-volume evacuation when finishing or
removing amalgam

35.  Floor coverings should be nonabsorbent , seamless & easy
to clean
 Work in well ventilated spaces
 Use an amalgammator with enclosed arm
 Cleanup spilled mercury , dont use house hold vaccum
cleaner
 Remove prof clothing b4 leaving the workplace
 Regularly check the dental operatory atm. Dosimeter & Hg
vapor analyzer may be used
 Current limit for Hg vapor is 50µg/m3 in an 8hr work shift
ovr a 40hr work week

36. MANIPULATION

37. Alloy selection
 Alloy should be ADA/FDA certified.
 Metallurgical modifications determine working
and setting time as well as strength.
 Spherical particle are good for early strength but
requires a fast operator and are not good for
inaccesible contours.
 Non zinc alloys should be used only in conditions
of impossible isolation.
 Best mechanical properties are exhibited by
HCU alloys.

38. Difference in manipulation:
LATHE CUT
 Require more mercury
(50%)
 Require more
condensation force
 Overtrituration
increases strength
 Undertrituration
decreases creep
 Require smaller
condenser points
 Less ease in carving
and burnishing
SPHERICAL
 Require less mercury
(42%)
 Require less
condensation force
 Overtrituration
decreases strength
 Undertrituration
increases creep
 Require broader
condenser points
 Smooth surface during
carving & burnishing

39. Mercury selection
 Should have less than 0.02% of non-
volatile residue.

40. Proportioning
Proportioning should be done by wt. if possible.
 Mercury Alloy ratio
 Lathe cut alloys 1:1 or Eames ratio (50% Hg)
 Spherical alloys 40.0% Hg
 High copper alloys 43.0% Hg
 Low copper alloys 53.7% Hg
Alternatives of dispensing:
 Automatic mechanical dispensers
 Preweighed pellets
 Preproportioned capsules

41. Techniques
i. High Hg or increasing dryness technique
useful for large and complex restorations.
ii. Minimal mercury or Eame’s technique
beneficial to minimise Hg content.

42. Trituration
Trituration is the process by which mercury
is allowed to react with the alloy powder .
This procedure allows the rubbing of the
surface oxide on amalgam particles ,
exposing an active surface to react with
mercury .
 Hand trituration
 Mechanical trituration

43. Amalgamator (Triturator)
 Speeds vary upward
from 3000 rpm
 Times vary from 5–20
seconds
 Mix powder and liquid
components to achieve
a pliable mass
 Reaction begins after
components are mixed

44. Trituration
 Mixing time
 refer to manufacturer
recommendations
 Overtrituration
 “hot” mix
 sticks to capsule
 decreases working / setting time
 slight increase in setting contraction
 Undertrituration
 grainy, crumbly mix

45. Effect of over-trituration and
under-trituration
 Working time decreases with over- trituration.
 Setting contraction increases with over- trituration.
 Compressive and tensile strengths increase with over-
trituration of lath cut alloys;
 however they decrease with over- and under-
trituration of spherical alloys.
 Creep increases with over- trituration.

47. Mulling
 It’s a continuation of trituration to form a
coherent mass easy to manage.
 The mix is rubbed between fingers in a dry
rubber dam for 2 to 5 sec.
 For capsule it is done in the amalgamator for
2 to 3 sec after removing the pestle.

48. Condensation
 lathe-cut alloys
 small condensers
 high force
 spherical alloys
 large condensers
 less sensitive to amount of force
 vertical / lateral with vibratory motion
 admixture alloys
 intermediate handling between lathe-cut and spherical

49. Condensation
 Usually only 3 to 3.5 minutes is available for
condensation.
 After that the mix should be discarded.
 At least force required for adequate
condensation. : 3 to 4 lbs. For this pressure,
force at the tip of the condenser point of 2
mm diameter is around 600 -800 psi.
 Types- hand and mechanical or pneumatic.

50. Burnishing
 Pre-carve
 removes excess mercury
 improves margin adaptation
 Done with large burnisher
 Post-carve
 improves smoothness
 Done with smaller burnisher
 Inaccessible areas should be done by
beavertail
 Done from amalgam to tooth surface.

51. Carving
 Aims to reproduce physiologic contours.
 Done with sharp instruments.
 Strokes given from tooth to amalgam or
laterally along tooth surface.

52. Early Finishing
 After initial set
 prophy cup with pumice
 provides initial smoothness to restorations
 recommended for spherical amalgams

53. Finishing and polishing
Done usually after 24 hrs.
FINISHING: abrasive stones, rubber cups, or
rotary brushes.
POLISHING: with extrafine silex, slurry of chalk,
SnO, ZnO, or pumice-wet mix in a paste form
to avoid heat generation.

54. Factors for success
 Osborne and Gale evaluated 196 amalgam
restorations 13–14 years after insertion.
 They found that cavity width was the single
most significant factor for clinical survival.
 Wider restorations showed greater marginal
fracture and a higher rate of replacement than
narrow restorations.
 Reasons include reduced occlusal stress on the
margins and preservation of tooth strength.

55. SUBSTITUTES
1. CONSOLIDATED SILVER ALLOY SYSTEM.
 It uses a fluoroboric acid solution to keep the
surface of the silver alloy particles clean.
 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.

56. 2. GALLIUM ALLOYS
 1956, Smith and Caul and Smith and co-workers
claimed gallium as an alternate to mercury.
 Mixing gallium with either nickel or copper and
tin produced a pliable, condensable mass.
 Physical, mechanical properties suitable for a
restorative material.
 Early moisture sensitivity, excessive expansion.
 Toxic corrosion products accumulate on surface.

57. 3. MODIFIED COMPOSITES
 Packable composites
 Nanocomposites
 Fiber reinforced composites
 Lab processed inlay, onlay or crown
4. All ceram restorations
5. Metal alloys
6. GIC modifications

58. STATUS OF AMALGAM
PAST AND PRESENT

59. Story begins ......
 Amalgam -- First used by Chinese.There is a mention of
silver mercury paste by Sukung (659AD) in the Chinese
medic
 1578-lshitichen used 100 parts if Hg, 45 parts ofAg and 100
parts of Sn
 LiuWen-Thai (1508) and Li Shih-Chen (1578) discussed its
formulation; 100 parts of mercury to 45 parts of silver and
900 parts of tin, trituration of these ingredients produced a
paste said to be as solid as silver

60.  Introduced in 1800’s in France alloy of
bismuth, lead, tin and mercury plasticized at
100ºC poured directly into cavity
 1819, Bell advocated the use of a room
temperature mixed amalgam as a restorative
material, in England
 1826, M.Traveau is credited with advocating
the first form of amalgam paste , in France.

61.  1833 Crawcour brothers introduced amalgam to
US > powdered silver coins mixed with mercury
expanded on setting
 1895 To overcome expansion problems G.V.
Black developed a formula for modern amalgam
alloy > 67% silver, 27% tin, 5% copper, 1% zinc
 Black’s formula was well accepted and not much
changed for nearly sixty years.(1890-1963)
 1946 - Skinner, added copper to the amalgam
alloy composition in a small amount.This served
to increase strength and decrease flow.

62.  Traditional or conventional amalgam alloys
predominated from 1900 to 1970.
 1960’s - conventional low-copper lathe-cut alloy
was introduced
 1962 - A spherical particle dental alloy was
introduced, by Demaree andTaylor
 The work of Innes andYoudeis (1963) has led to
the development of high copper alloys.>Had
longer working time, less dimensional change,
easy to finish, set faster, low residual mercury,
low creep & higher early strength

63.  Added spherical silver copper eutectic
alloy(71.9wt% Ag and 28.1wt%Cu)particles to
lathe cut low copper amalgam alloy particles.
These alloys are called admixed alloys
 1971 – Johnson designed a spherical particle
alloy having the composition 64% Ag, 26% Sn
and 10% cu by weight, and exhibiting no
Sn8Hg after amalgamation.
 1973 - first single composition spherical alloy
namedTytin (Kerr) a ternary system
(silver/tin/copper) was discovered by Kamal
Asgar of the University of Michigan

64.  1980’s alloys similar to Dispersalloy andTytin
was introduced

65. Social consideration
 The first dental society, the American Society
of Dental Surgeons (ASDS), was founded in
1840 on the basis of the physician-surgeons
taking a stance against the use of amalgam
which it regarded as being unethical due to
the recognised toxic effects of mercury.

66. Amalgam WARS
 1st amalgam war : American society of dental surgeons
condemmed the use of all filling materials other than gold as
toxic , therby igniting the 1st amalgam war
 2nd amalgam war : In mid 1920 a german dentist named alfred
stock started the so called 2nd amalgam war . He claimed to
have evidence showing mercury from dental amalgam leads to
serious toxicity
 3rd amalgam war (1970-1990) began primarily through seminars
, writing & videotapes if Dr HA huggins from colorado springs .
Pressure from mounting clinical evidence forced the ADA to
finally publicly concede that mercury vapour does escape from
the amalgam filling into the patient’s mouth

67. The derogatory term 'quack'
(from quecksilber, the German word
for mercury) was originally coined by
the physicians to refer to the
tradesmen who used amalgam fillings.

68. The Rise
 The American Dental Association (ADA),
founded in 1859 actively promoted the use of
amalgam, for which it currently owns the
patents (U.S. Patents 4018600 and 4078921).
 In 1877, J. Foster Flagg, managed to change the
attitude toward dental amalgams. He published
the results of his laboratory tests and 5-year
clinical observation of new alloys with 60% of
silver and 40% of tin as major constituents in
1881 and thus predated by some 15 years the
work of G.V. Black.

69.  S.S.White manufactured the first
commercial alloy rich in silver,True Dentalloy
(1900), in which gold was replaced by copper.

70. Anti-Amalgamists
 Dentists specialize in treating purported mercury
toxicity--becomes a marketing tool
Hal Huggins
 publications, videotapes
and seminars
 removal of amalgam cures
 Leukemia
 Hodgkins’disease
 Multiple Sclerosis

72. The debate goes on
 The debate over the safety and efficacy of
amalgam has raged since time immemorial BUT
Amalgam has served the dental profession for
more than 165 years.
 Incidents of true allergy to mercury have been
rare and attempts to link its usage with diseases
like multiple sclerosis and Alzheimer’s disease
have not been significantly proven, although
there may be some association between
amalgam restorations and oral lichenoid lesions.

73.  Recently however, its popularity has diminished
somewhat due to aesthetics, environmental
pollution, health, and the availability of
improved, reliable, composite materials .
 In particular, concerns about the toxicity of
mercury have made its use increasingly
controversial.

74. Countries banning amalgam
 As of 2008, the use of dental amalgam has been banned
in Norway, Sweden and Finland, Denmark and some other
developed countries and a committee of the US Food and
Drug Administration (FDA) has refused to ratify assertions
of safety.

75.  In May 2011, the 47 nations of the
Parliamentary Assembly of the Council of
Europe passed a resolution calling for all
member nations to start "restricting or
prohibiting the use of amalgams as dental
fillings".

76. United States
 In US, three Californian cities have banned
amalgam.
 And many others are phasing down

77. RESEARCHES….
 In 2004, the Life Sciences Research Office
analyzed studies related to dental amalgam
published after 1996. Concluding that mean
urinary mercury concentration was the most
reliable estimate of mercury exposure

78.  However,WHO states mercury levels in
biomarkers such as urine, blood, or hair do not
represent levels in critical organs and tissues.
 Additionally, Gattineni et al. found that mercury
levels do not correlate with the number or
severity of symptoms. It concluded that there
was not enough evidence to support or refute
many of the other claims such as increased risk
of autoimmune disorders, but stated that the
broad and nonspecific illness attributed to dental
amalgam is not supported by the data.

79.  Scientists agree that dental amalgam fillings
leach mercury into the mouth, but studies
vary widely in the amount and whether such
amount presents significant health risks.
 Estimations run from 1-3 micrograms (µg)
per day (FDA) up to 27 µg/day (Patterson).
 The effects of that amount of exposure is also
disputed.

80. ANIMAL STUDIES
 Research on monkeys has shown that mercury
released from dental amalgam restorations is
absorbed and accumulates in various organs such as
the kidney, brain, lung, liver, gastro-intestinal tract,
the exocrine glands.
 It was also found to have crossed the placental barrier
in pregnant ratsand shown to cross the
gastrointestinal mucosa when amalgam particles are
swallowed after amalgam insertion or after removal
of old amalgam fillings.

81. HEALTH RISKS
 Review published in 2005 by the Freiburg
University Institute for Environmental Medicine
found that
 "mercury from dental amalgam may lead
to nephrotoxicity, neurobehavioural
changes, autoimmunity, oxidative stress, autism,
skin and mucosa alterations or non-specific
symptoms and complaints", that "Alzheimer's
disease or multiple sclerosis has also been linked to
low-dose mercury exposure", and that "removal of
dental amalgam leads to permanent improvement
of various chronic complaints in a relevant number
of patients in various trials."

82. Maths Berlin 2002 study concludes:
 mercury is a multipotent toxin with effects on several levels of the
biochemical dynamics of the cell, amalgam must be considered to
be an unsuitable material for dental restoration.
 This is especially true since fully adequate and less toxic
alternatives are available.
 With reference to the risk of inhibiting influence on the growing
brain, it is not compatible with science and well-tried experience
to use amalgam fillings in children and fertile women.
 Every doctor and dentist should, where patients are suffering
from unclear pathological states and autoimmune diseases,
consider whether side-effects from mercury released from amalgam
may be one contributory cause of the symptoms.

83. Occupational Exposure
 UK published in the Occupational and
Environmental Medicine Journalconcluded that
dentists had on average 4 times the urinary
mercury excretion levels of 180 people in a
control group. Dentists were significantly more
likely than control subjects to have had disorders
of the kidney or memory disturbance.
 Urine testing is unreliable for showing lifetime
mercury accumulation rather than recent
exposure.

84. Environmental hazard
 TheWHO reports that mercury from
amalgam and laboratory devices accounts for
53% of total mercury emissions, and that one-
third of the mercury in the sewage system
comes from dental amalgam flushed down the
drain.
 Mercury is an environmental toxin and
theWorld Health Organization, OSHA,
and NIOSH have established specific
occupational exposure limits.

85. Environmental hazard
 The Association of Metropolitan Sewerage
Agencies (AMSA) studied seven major waste-
water treatment plants and found that dental
uses were "by far" the greatest contributors of
mercury load, on average contributing 40%,
over 3 times the next greatest contributor

86. ADA
 The ADA has asserted that dental amalgam is safe
since its foundation in 1859.
 In its advisory opinion to Rule 5.A. of the ADA Code of
Ethics, it has also held that, "the removal of amalgam
restorations from the non-allergic patient for the
alleged purpose of removing toxic substances from
the body, when such treatment is performed solely at
the recommendation or suggestion of the dentist, is
improper and unethical".

87.  "A dentist who is found guilty of violating the ADA
Code of Ethics can be sentenced, censured,
suspended, or expelled from the ADA" and the "ADA
forbids its dentists from suggesting mercury
removal under threat of license suspension“
 Perhaps louder than its words are the actions of the
ADA which has deleted reassuring statements
about the safety of amalgam from its website.
 The Center for Disease Control (CDC) has also
deleted an entire webpage refuting amalgam as a
cause of illness.

88. Conclusion of ADA report
 no health consequences from exposure to such
low levels of mercury released from amalgam
restorations have been demonstrated.
 there currently appears to be no justification for
discontinuing the use of dental amalgam.

89. FDI World Dental Federation
Use of Dental Amalgam
Intergovernmental Negotiating Committee 2
January 24, 2011
China, Japan
Dr. Peter Cooney
Chair, Public Health Section, FDI
Chief Dental Officer, Canada

90. FDI :Use of Dental Amalgam –
Country Example: Canada
Extensive Review led to 1996 Health Canada
Recommendations*. Now on product labels.
• Avoid in baby teeth of children if possible.
• If possible, avoid in pregnant women and people
with impaired kidney function.
• Use safe handling practices and provide
information to patients.

91. FDI Resolution – Brazil,
September 2010
FDI voice of the dental profession resolved that,
Amalgam is a safe and highly effective restorative
material.
To maintain and protect global public health, a phase
down of amalgam will be only appropriate when an
alternative and suitable restorative material is
available.

92. FDI Conclusions
 Mercury from dental amalgam is a very small
component of the environmental problem
 Amalgam use has continued in Canada and in 10
years we have seen a large reduction in use.
 Results of blood/urine testing on Canadians
shows very low mercury exposure levels.
 Increased emphasis on prevention and clear
guidelines for mercury use can safeguard the
health of the public.

93. WHO
GENEVA , Oct. 11, 2011
 TheWorld Health Organization released its
long-awaited 2009 meeting report on the
"Future Use of Materials for Dental
Restorations"
PR Newswire (http://s.tt/1bMlK)

94. WHO Report
According to the report:
 "Mercury is one of the ten chemicals of major
public health concern thatWHO prioritizes.
 Dental amalgam is a significant source of
exposure… National, regional and global
actions, both immediate and long-term, are
needed to reduce or eliminate releases of
mercury and its compounds to the environment.

95.  WHO is committed to work with the health sector and national,
regional and global health partners to:
 reduce mercury exposure;
 eliminate the use of mercury wherever possible;
 promote the development of alternatives to the use of mercury;
 lead the profession in the negotiations of the development of
the legally binding instrument on mercury.
PR Newswire (http://s.tt/1bMlK)

96.  For primary (baby) teeth, theWHO report states
that, "The report makes clear that alternatives
are here today worldwide for children, who are
the ones most vulnerable to amalgam's
neurotoxic effects," "For example, (ART) is
especially suitable for children."

97. CONCLUSION
 Removal of existing amalgam fillings should not be
undertaken unless there are medical reasons for
doing so.The reason is that the risk of complications
from the removal may exceed the risk of side-effects
from the amalgam. (ADA)
 "For medical reasons, amalgam should be eliminated
in dental care as soon as possible.This will confer
gains in three respects:The prevalence of side-effects
from patients’ mercury exposure will decline;
occupational exposure to mercury can cease in dental
care; and one of our largest sources of mercury in the
environment can be eliminated."

98. THANK YOU