1. POSTGRADUATE DEPARTMENT OF CONSERVATIVE
DENTISTRY AND ENDODONTICS
SEMINAR TOPIC:-
DENTAL AMALGAMPAST,PRESENT & FUTURE-II
(TECHNICAL CONSIDERATIONS, PRESENT SCENARIO & FUTURE)
Presented by- Ashish Choudhary
Pg student
UNDER GUIDANCE OF :-
Prof. Dr Riyaz Farooq (HOD)
Dr Aamir Rashid (lecturer)
Dr Fayaz Ahmed (lecturer)
1
2. Contents
Introduction
History of amalgam
Amalgam wars
Classification
Components of amalgam
Basic setting reaction
Manufacture of alloy powder
Properties of amalgam
Manipulation of amalgam
Recent advances in amalgam
Side effects of mercury
Durability of amalgam
Future of amalgam
Conclusion
2
5. Selection of alloy
involves a number of factors, including
setting time, particle size & shape &
composition, particularly as it relates to the
elimination of the γ2 phase & the presence
or absence of zinc
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
More than 90% of the dental amalgams currently placed
are high copper alloys including spherical & admixed types
5
Phillip’s Science of Dental Materials;11th ed
6. Selection of alloy mainly aims at
High one hour strength
Minimum dimensional change
Lowest creep value
Good condensing property
High corrosion resistance
Good polishing and finishing abilities
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
6
8. Mercury/alloy ratio
• Earlier excess mercury was used to
achieve smooth & plastic amalgam
mix
• This excess Hg was removed from the
amalgam by:1. Squeezing the excess Hg out by
using squeeze cloth before insertion
of increments in the prepared cavity
2. Increasing dryness technique
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
8
Phillip’s Science of Dental Materials;11th ed
9. Eames minimal mercury technique
Recommended ratio→ 1:1→ 50%
Hg
Lathe cut alloys =50%
Spherical alloys = 42%
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
produce a workable mass
9
Phillip’s Science of Dental Materials;11th ed
10. • VARIOUS METHODS –
PROPORTIONING
PREWEIGHED TABLET : specific weight of powder
with appropriate Hg is dispensed into mixing
capsule
• proportion– by wt – not by volume
• %Hg can be adjusted from 48-55%.
DISPENSERS : accommodate 2 containers
• 1- having Hg;
• 2 – powder.
• specific volume of powder & Hg - dispensed Into
capsule.
• proportion– by volume – not by wt
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
10
Phillip’s Science of Dental Materials;11th ed
11. • DISPOSABLE CAPSULES
• SELF ACTIVATING CAPSULES
• Reusable capsules
• Preamalgamated alloys
11
Sturdevant’s Art & Science of Operative Dentistry;5th ed
12. SIZE OF MIX
Capsules containing 400, 600 or 800mg of
alloy and the appropriate Hg are available
Colour coded for easy identification of
capsules.
•
•
•
•
400mg - single mix.
600mg – single mix.
800mg – double mix
1200mg – for amalgam
core
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
14
CRAIG’s Restorative Dental Materials;12th ed
14. TRITURATION
• Defined as process of grinding powder,
esp. within a liquid. In dentistry, the
term is used to describe the process of
mixing the amalgam alloy particles with
mercury in an amalgamator (as given in
Phillip’s , 11th edn)
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
16
Phillip’s Science of Dental Materials;11th ed
15. • Objective:-to wet all the surfaces of the alloy particles
with Hg
-for proper wetting, the alloy surface should be
clean
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
-rubbing of the particles mechanically removes
the oxide film coating on alloy particles
17
Phillip’s Science of Dental Materials;11th ed
16. • Trituration is achieved either by :
A) Hand mixing
B) Mechanical mixing
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
18
Phillip’s Science of Dental Materials;11th ed
17. v
HAND TRITURATION
MORTAR
PESTLE
Roughened inner
surface, maintained
by carborundum
paste
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
glass rod with a
round end
19
Phillip’s Science of Dental Materials;11th ed
18. • The 3 factors to obtain a well mixed
amalgam mass are:
1. Number of rotations
2. Speed of rotation
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
3. Magnitude of pressure placed on the
pestle. Typically a 25-45 seconds period is
sufficient
20
Phillip’s Science of Dental Materials;11th ed
19. Mechanical trituration
• Trituration of alloy & Hg is done with a
mechanical mixing device called an
“amalgamator or triturator”
• The disposable capsule serves as a
mortar
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
• a cylindrical metal or plastic piston is
placed in the capsule which serve as a
pestle
21
Phillip’s Science of Dental Materials;11th ed
20. AMALGAMATORS FOR MECHANICAL
TRITURATION
SPEED
TIME
The speed used is recommended by the manufacturer. High
ENERGY = Speed higher
copper alloys require x Time mixing speeds
The capsule is inserted b/w the armscapsule oscillate at
When amalgamatorsarms automaticthe on speed of
the
The put on, the have holding timer &3800,top - 40- 4400
low speed 32 -3400cycles/min, medium - 37high
22
machines device triturating the amalgam
high speed, thus
control
21. • Using a parameter called coherence time
(tc), defined as the minimum mixing time
required for an amalgam to form a single
coherent pellet, it has been found that
the compressive strength, dimensional
change & creep are optimized if mixing is
carried out for a time of 5tc.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
23
Phillip’s Science of Dental Materials;11th ed
22. MIXING TIME
--spherical alloys usually
require less amalgamation
time than lathe cut alloys
--a large mix requires
slightly longer mixing time
than a smaller one
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
24
Phillip’s Science of Dental Materials;11th ed
23. • Advantages of mechanical
trituration:
1.Shorter mixing time
2.More standardized procedure
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
3.Require less mercury when compared
to hand mixing technique
25
Phillip’s Science of Dental Materials;11th ed
25. Undertriturated mix
is rough & grainy
may crumble
mix hardens too rapidly
excess mercury will remain
gives a rough surface after carving
tarnish & corrosion may occur
less strength
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
27
Phillip’s Science of Dental Materials;11th ed
26. NORMAL MIX
shiny surface
smooth & soft consistency
warm, when removed from the
capsule
best compressive & tensile strength
increased resistance to tarnish &
corrosion
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
28
Phillip’s Science of Dental Materials;11th ed
27. Overtriturated mix
Soupy mix
difficult to remove from the capsule
too plastic to manipulate
decreased working time
higher contraction of amalgam
strength of lathecut alloys is
increased, whereas it is reduced in
high copper alloys
increased creep
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
29
Phillip’s Science of Dental Materials;11th ed
28. MULLING
• Continuation of trituration
• Hand mulling
Dry piece of rubber dam or glove
Rubbed between the first finger and thumb
2 to 5 seconds.
• Mechanical mulling
mix is retriturated in an pestle free capsule
for an addtional 2-3 sec
• Advantages
Coherent, consistent and homogenous mix
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
30
30. CONDENSATION
• The amalgam is placed in the cavity after
trituration & the packed (condensed) using
suitable instruments
• Goal of condensation-is to compact
the alloy into the prepared cavity so that the
greatest possible density is achieved, with
sufficient Hg to ensure complete continuity
of the matrix phase(Ag2Hg3) b/w the
remaining alloy particles
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
32
Phillip’s Science of Dental Materials;11th ed
31. Aims of condensation
1. to secure adaptation of the amalgam to
the walls and the margins
2. to get compactness and homogeneity of
the amalgam in the restoration with
minimal voids
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
3. Remove the excess mercury
33
Phillip’s Science of Dental Materials;11th ed
32. Modes of condensation
Manual condensation
Mechanical condensation
Pneumatic
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Electrical
34
33. Condensers
Are instruments with serrated tips of
different shapes & sizes
The shapes are oval, crescent, trapezoidal,
triangular, circular or square
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Condenser type is selected as per the area &
shape of the cavity
Smaller the condenser, greater is the
pressure exerted on the amalgam
35
Phillip’s Science of Dental Materials;11th ed
34. Condensation technique
• The field of operation should be kept
absolutely dry during condensation
The amalgam should be carried to the cavity
with amalgam carrier incrementally
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Immediate condensation done after each increment
with sufficient pressure (3-4 pounds) in vertical and
horizontal direction starting with smaller condenser
36
Phillip’s Science of Dental Materials;11th ed
35. • The condensation is started at the center
& the condenser point is stepped little by
little towards the cavity walls
The procedure of adding an increment and condensing
it, adding another increment is continued until the
cavity is overfilled (about 1mm) and the filling is over
packed with larger condenser
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Explorer tine to
scrap the BLOTTING MIX
marginal
ridge
37
Phillip’s Science of Dental Materials;11th ed
36. GENERAL GUIDELINES
Modern amalgams are fast setting & so working
time is short
A fresh mix of amalgam should be ready if
condensation takes more than 3-4 minutes
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
After condensation of each increment –remove any
excess Hg
15 lbs of pres. of
condensation recommended
Avg force used is 3-4 lbs
(13.3 – 17.8 N)
38
Phillip’s Science of Dental Materials;11th ed
37. LATHE CUT AMALGAM
SPHERICAL AMALGAM
Small
High force
condensers
ADMIXED AMALGAM
Low Hg/alloy
ratio
Less condensation
force req.
Larger
condensers
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
intermediate handling between
More lateral and spherical
lathe-cut
condensation
39
Phillip’s Science of Dental Materials;11th ed
39. Precarving burnishing
• Form of condensation to ensure dense
amalgam at the margins & aids in
shaping of the restoration
Heavy stroke with large burnisher moving from the
center of the restoration outwards beyond the
margins
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
As crystallization of amalgam occurs, it's consistency
becomes much stiffer, it is suitable for carving
41
Phillip’s Science of Dental Materials;11th ed
41. CARVING OF AMALGAM
Initial carving consist of removal of the bulk excess
using a large spoon excavator
OBJECTIVES:
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
no undercuts
proper physiological contours
minimal flash
functional, non-interfering occlusal anatomy
Adequate, compatible marginal ridges
Proper size, location, extent & interrelationship of contact areas
Preserving Biological width
43
Phillip’s Science of Dental Materials;11th ed
42. The carving should not be started untill amalgam is
hard enough to be carved
scrapping or ringing sound
CARVING INSTRUMENTS:
1.Cleoid-Discoid
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
2.Spoon Excavator
3.Hollenback
4.Wards
5.Diamond shaped
44
Phillip’s Science of Dental Materials;11th ed
43. CARVING TECHNIQUE
Select an acorn burnisher that will be wide enough to
ride the isthmus without entering the preparation
After condensation induce heavy pressure through out
the length of the central and developmental grooves
Strokes – from tooth to amalgam surface, or laterally
along tooth – amalgam interface
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
All accessible embrasures established in restoration- sharp explorer
or lateral edges of hollenback carver
45
JPD 1981;VOL46;NO.5
44. Create triangular fossae – discoid, cleiod
carvers, diamond shaped carver
Define marginal ridges – sharp explorer
Carver moves parallel to the margin
Carver should rest on enamel as well as amalgam
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Surface is rendered smooth and free
of gross excess material by using a
tightly twisted cotton
46
JPD 1981;VOL46;NO.5
45. Guidelines for carving
Pulling strokes – mostly
Pushing stroke - developing occlusal anatomy
Occlusal anatomy should be kept reasonably
(shallow) to preserve a bulk of amalgam at the
margin
75 – 90 angle at
the margin of
occlusal amalgam
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Mesial and distal pit areas should be
carved slightly deeper than the
proximal marginal ridge
Undercarving leads to amalgams grown out appearance
47
48. Burnishing of amalgam
• it is a light rubbing of the carved
surface with the burnisher to improve
smoothness & produce a shiny
appearance & produce a denser
amalgam with more compaction ,
adaptation and sealing of amalgam at
the margins
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
50
Phillip’s Science of Dental Materials;11th ed
49. Burnishing is done with a ball burnisher using light
stroke proceeding from the amalgam surface to the
tooth surface
Heavy forces should not be used
Brings excess Hg to surface – discarded
If the temperature rises above 60 ͦC, mercury is
released which may cause corrosion & fracture at
the margins
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Pre carving and post carving burnishing > only Pre or post carving burnishing
Dental Materials, Volume 3, Issue 3, June 1987, Pages 117-120
51
Phillip’s Science of Dental Materials;11th ed
50. light closer is made and the surface checked for the
heavier burnished areas, lateral slide is used to
develop the desired eccentric occlusion
Articulating paper may be used to
check the occlusion
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Finally the grooves are enhanced with "conical amalgam
burnisher" and the amalgam is smoothened by a small
damp ball of cotton
52
Phillip’s Science of Dental Materials;11th ed
52. Finishing & Polishing
• is necessary to complete the carving, to refine
the anatomy, contours, and marginal integrity
and enhance the surface finishing of the
restoration
• they reduce the surface roughness of the
restoration with less prone to tarnish and
corrosion
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
54
Phillip’s Science of Dental Materials;11th ed
53. AFTER INITIAL SETTING
Prophy cup with pumice
provides initial smoothness to
restorations
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
55
Phillip’s Science of Dental Materials;11th ed
54. FINAL POLISHING
Done only after amalgam
sets, delayed at least 24 hrs
following condensation
High Cu single
composition spherical
alloy:
8 min after trituration
Always - low speed, low pressurevelvet finish
AVOID
UNDUE
PRESSURE
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
USE
ADEQUATE
COOLING
56
CRAIG’s Restorative Dental Materials;12th ed
55. FINISHING& POLISHING
instruments for amalgam
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Fig. From the left: five plain-cut plain steel finishing burs, two mounted stones,
three mounted abrasive rubber points from coarse to fine, and a mounted
abrasive rubber cup
57
Phillip’s Science of Dental Materials;11th ed
56. Finishing Discs
Technique
Use short, overlapping strokes and move
diagonally across the cavosurface margins.
Sequence
Discs are used in a sequence of more
abrasive to less abrasive grits.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Embrasures
When using discs in embrasure areas, care
must be taken not to damage the contact
area or papilla.
Phillip’s Science of Dental Materials;11th ed
57. Finishing strips
a) Types : fine or medium
b) Placed on both the tooth and the amalgam, and
move in a back-and-forth motion.
c) Avoid the contact area when using finishing strips,
and use caution in areas of the inter dental papilla
and surrounding tissue
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Wider strips may be cut in half lengthwise to make
narrow strips
59
Phillip’s Science of Dental Materials;11th ed
58. Finishing burs/stones
1. Green stone to remove excess material and
irregularities
2. Sequence
largest bur →→ smaller and less abrasive burs
3. Technique
Adapt the side of the bur or stone along the margin,
contacting both tooth and amalgam.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
4. Direction of stroke
Rotate the bur or stone from the amalgam to the tooth to
avoid fracturing the amalgam margins.
5. Direction of work
Always begin at the centre of the restoration and work
toward the cavosurface margin
60
Phillip’s Science of Dental Materials;11th ed
59. POLISHING POINTS & RUBBER CUPS
Abrasive-impregnated rubber cups & points are
brownies
in 3 colors
super greenies
Brown
Green
Yellow-banded green
greenie
USE
Cups
Points
•
•
•
- proximal surfaces
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
USED
Each color denotes different degree of
INTERCHANGEABLY
- abrasiveness
occlusal surface.
relatively low speed
light, intermittent strokes
wet conditions.
61
Phillip’s Science of Dental Materials;11th ed
60. PUMICE is mixed with TIN OXIDE slurries
rubber cup
brush
wheel brush
Continue to polish the amalgam until the tin oxide
begins to dry and a high luster is achieved.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Rinse and dry the tooth
Examine with mouth mirror and explorer
The amalgam surface MUST NOT be heated above 140'F by the
polishing procedure.
62
Phillip’s Science of Dental Materials;11th ed
61. REMOVAL OF AMALGAM
patient is draped with a plastic apron
rubber dam is
customized to fit the
existing tooth/teeth
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
underneath the dam, activated charcoal
or chlorella is placed, along with a cotton
roll and gauze.
A Safe Protocol for AmalgamRemoval
Journal of Environmental and Public Health
63
Volume 2012, Article ID 517391
62. goggles for the eyes and hair cap are placed
oxygen is supplied to the patient with a nasal
mask and the mercury vapor ionizer is turned on
The operators also protect themselves with a
filtered mask, eye and hair protection, and face
shields
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
A Safe Protocol for AmalgamRemoval
Journal of Environmental and Public Health
64
Volume 2012, Article ID 517391
63. new dental bur is used in the handpiece to
ensure easy removal
high volume suction and a continual addition of
water spray are supplied to the site where the
amalgam is being extracted
if possible, the amalgam
restoration is sectioned and
then scooped out to
eliminate as much mercury
vapor release as possible
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
A Safe Protocol for AmalgamRemoval
Journal of Environmental and Public Health
65
Volume 2012, Article ID 517391
64. oxygen and protective coverings are taken away
immediate inspection under the dental dam
gauze, cotton roll and activated charcoal are
wiped away
Gauze is then used to inspect the floor of the mouth
and tongue to make sure no particulates seeped
under the dam
once all mucosal tissues are fully inspected and cleaned,
the mouth is flushed with copious amounts of water,
again to ensure no ingestion or absorption of amalgam
particulates
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
A Safe Protocol for
AmalgamRemoval;Jou
rnal of Environmental
and Public Health
Volume 2012, Article
66
ID 517391
65. Recent advances in amalgam
Gallium based
alloys
consolidated silver
alloy system
Indium containing
alloy powder &
binary Hg-Indium
liquid alloy
Fluoride containing
amalgam
Low mercury
amalgam
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Bonded amalgam
Essentials of operative dentistry;
67
I Anand Sherwood
66. Gallium based alloys
HISTORY
Metallic element Gallium was 1st predicted by
Mendeleef in 1871, was 1st isolated by ‘de
Boisbandran’ in 1875.
1920s, Gallium (Ga) was one of the substitutes
suggested for Hg (Putt Kammer, 1928)
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
1950s work by Smith and Associates (Smith and Caul 1956)
showed the potential use of Ga system.
67. This direct filling
material contains no
mercury
Gallium is liquid at
room temperature
Its use is based on remarkable ability of liquid
gallium to wet surfaces of many solid
Melting temperature of Ga can be suppressed
below room temperature with addition of 44
appropriate amounts of In and Sn.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Commercial brands are available; Galloy, Bayswater, Gallium Gf
and Gallium GF II.
J Conserv Dent. 2010 Oct;13(4):204-8.
Dental amalgam: An update
68. Composition
Alloy:
Ag- 50%
Sn- 25%
Cu- 13%
Pd- 20%
Liquid: Ga – 62%
Ir – 25%
Sn – 25%
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
BDJ;VOL.183;NO.1;JULY,1997
69. gAmalgamation
CuGa2 and PdGa5 surrounding the unreacted alloy
particles which are held together by matrix of Ag9In4
Properties –
1 hr. Comp. Strength
1 day Comp strength
Tensile strength
Creep
Dimensional change
- 343 MPa
- 533 MPa.
- 57 MPa
- 0.17%
16 µm/cm
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
70. ADVANTAGES
Rapid solidification.
Good marginal seal by expanding on solidification.
Heat resistant.
Compressive & tensile strength increases with
time comparable with silver amalgam
Creep value are as low as 0.09%
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Sets early so polishing can be carried out the same
day
72
BDJ;VOL.183;NO.1;JULY,1997
71. DISADVANTAGES
low resistance to corrosion
moisture contamination leads to dramatic
expansion Dent Mat June' 98 14(3); 173-8.
Mix is mushy & sticks to everything except
tooth
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
high cost
73
BDJ;VOL.183;NO.1;JULY,1997
72. Mean hardness, the compressive strength, 24h
tensile Strength and 24h flexural strength of Pd free
Ga-alloy, were significantly lower than Tytin.
Dent Mat Mar 2001 17 (2), 142-8.
Galloy & Gallium GF II showed excessive expansion
when contaminated and/or placed in fluids containing
salts
Quint Int, Mar'99, 30(3) 185-91.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Ga-alloy were consistently rougher than Hg based
amalgam after polishing..
Dent, Mar-Apr’ 99 24(2) 103-8.
74
73. Galloy is more corrosionprone than high Cu Amalgam
(Permite).
Primary corrosion product of Galloy were -Ga2O3
and SnO2
Oper. Dent Sept – Oct’97;Vol 22, No. 209 - 16
The significant reduction in the 1 hr mean
compressive fracture strength and hardness identified
for Galloy® compared with Tytin® indicate a slower
setting reaction in the gallium-based alloy.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Dental Materials
Volume 17, Issue 2, March 2001, Pages 142-148
75
74. Consolidated silver alloy
system
• developed at the National Institute of
Standards and Technology
• Silver particles are suspended in a dilute
fluoroboric acid solution to keep the alloy
surfaces clean
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
• The alloy, in a spherical form, is condensed
into a prepared cavity in a manner similar to
that for placing compacted gold
J Conserv Dent. 2010 Oct;13(4):204-8.
76
Dental amalgam: An update
75. • 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
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
77
Dental amalgam: An update
76. Indium containing alloy powder &
Binary mercury-Indium liquid alloy
• Powell et al 1989, added pure indium powder into
disperse phase high Cu alloy & triturated with
mercury
• They found significant decrease in mercury
evaporation from amalgam
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
• This was marketed as ‘Indisperse’ & ‘Indiloy’
Essentials of operative dentistry;
78
I Anand Sherwood
77. Youdelis also found that less mercury is required for
mixing amalgam when it contains indium in
concentrations up to 10%.
Youdelis WV. J Canad Dent Assoc 1979
Indium-containing admixed high-copper
amalgam exhibited a reduction in creep and an
increase in strength.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Johnson GH, J Dent Res 1985
79
78. A five-year clinical study found that there was no
significant difference in surface luster or texture
between indium-containing alloys (5% and 10%)
and Dispersalloy.
Johnson GH, Bales DJ, Powell LV. Am J Dent 1992
Amalgam prepared with indium rapidly
forms indium oxide and tin oxide films which
reduce mercury release.
Nakajima H, Awaiwa Y, Hashimoto H, Ferracane JL, Okabe T. J Dent Res 1997
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Biological tests of indium-containing amalgam show
that it is no more cytotoxic or hemolytic than
standard ADA Certified amalgam.
Townsend JD, Hamilton AI, Sbordone L. J Dent Res 1983
80
79. Fluoride containing amalgam
Addition of fluorides to conventional amalgam was
proposed by Innes and Youdelis 1966, Serman 1970,
Stone1971
Mechanism of Fluoride release
dilution of salt crystals
that are in contact with
cavity wall
by corrosion that liberates
fluoride contained in mass
of amalgam, e.g.
Fluoralloy
“slow release device”
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
81
Dental amalgam: An update
80. A conventional (Minimax), two single-particle high-Cu
(Summalloy and Aristaloy CR), and two dispersed-phase
(Cluster and Phasealloy) amalgam alloys were each
admixed with 0.5 wt% of CuF2, InF3, SnF2, and CaF2, and
evaluated for F−, Cu, and Sn release
A ranking for F− release was
Cluster (highest)
Summalloy
Minimax
Phasealloy
Aristaloy CR
The effectiveness of the F− compounds in releasing F−
CuF2 (highest)
SnF2
InF3 (1.0%)
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
CaF2
82
DM, Volume 6, Issue 4, October 1990, Pages 256-265
81. Low mercury amalgam
• If alloy particles are closely packed
together, mercury content in
restoration can be reduced by 15-25%
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Essentials of operative dentistry;
83
I Anand Sherwood
82. Bonded amalgam
• ‘Baldwin technique’ here amalgam was
condensed onto upset ZnPO4 cement
• Other cements like Glass Ionomer
Cements (GIC), Zn polycarboxylate have
been used
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
• Recently, 4META has bee used for
bonding amalgam to cavity walls
J Conserv Dent. 2010 Oct;13(4):204-8.
84
Dental amalgam: An update
83. 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
Bond strengths achieved
with admixed alloys tend
to be slightly lower than
those with spherical alloy
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Teeth with bonded amalgams were less sensitive
than teeth with pin-retained amalgams
J Conserv Dent. 2010 Oct;13(4):204-8.
85
Dental amalgam: An update
84. Bonding amalgams, compared to placing them
conventionally, afforded no significant benefit
upon restoration longevity
Br Dent J. 2009 Jan 24;206(2):E3
Bonded amalgam
restorations prevent
over-preparation
and reduce the tooth
flexure
GIC under amalgam
provides chemical bonding
in between amalgam and
tooth structure and thus
reduces the microleakage
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent
advances
Sideeffects of
mercury
Durability
Future
Conclusion
Indian J Dent Res. 2011 Mar-Apr;22(2):252-5
86
85. Amalgam bonding technique
Self-etching primer is rubbed vigorously into the
tooth surface, with plenty of the liquid present.
Left in place for 30 seconds
excess primer is either removed with a cottonwool pledget or blown away. The cavity is
thoroughly dried
thin film of the adhesive resin-cement is smeared over the cavity
surface
Amalgam is packed rapidly into the unset resin and then carved
to the correct contour.
87
Picard’s manual of operative dentistry; 8th ed
86. The resin-cement shown is an ‘anaerobic adhesive’. This means
that it polymerizes when air is excluded. A gel containing a
reducing agent is therefore syringed around the margins to cause
complete polymerization of the resin-cement. This gel is washed
off within a few minutes
final restoration
88
Picard’s manual of operative dentistry; 8th ed
88. ALLERGY
• Allergic responses represent an
antigen-antibody reaction marked by
itching, rashes, sneezing, difficulty in
breathing, swelling , or other
symptoms
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
• Contact dermatitis or Coombs’ type IV
hypersensitivity reactions represent
the most likely physiologic side effect
to dental amalgam
90
CRAIG’s Restorative Dental Materials;12th ed
89. • Usually small %age of people are
allergic to mercury, when such a
reaction has been documented by
dermatologist or allergist, an alternative
material (e.g. Composite or ceramic)
must be used unless the reaction is self
limiting (usually within 2 wks)
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
91
CRAIG’s Restorative Dental Materials;12th ed
90. Immediate hypersensitivity reaction associated
with the mercury component of amalgam
restorations- a case report*
• The release of mercury induced an acute reaction
which resulted in erythematous lesions, severe
burning and itchy sensation and difficulty in
breathing
• Skin patch test results indicated a very strong
positive reaction to mercury
• Amalgam restorations were replaced with
composite filling material
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
* Br Dent J. 2008 Nov 22;205(10):547-550
92
91. Three Types of Mercury:
1. Elemental Hg
- Is Used in Dental Amalgam
• Heavy, odorless, silver-colored liquid
• Inhalation is the main source of toxicity
(Mercury poisoning can also occur from dermal exposure)
• Hg well absorbed by lungs.
• Need long-term exposure or one large exposure
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
93
CRAIG’s Restorative Dental Materials;12th ed
92. 2. Inorganic Hg
• Known as mercuric salts…i.e. mercuric
chloride, mercuric iodide, cinnabar
• Found in many folk medicine
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
• Corrosive and can damage the kidneys
• Long-term exposure can cause skin irritation,
staining, and nerve damage
94
CRAIG’s Restorative Dental Materials;12th ed
93. 3. Organic Mercury = Methylmercury
• More potent and more bioaccumulative
than other forms of mercury
• Form to which humans are primarily
exposed
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
• The EPA is most concerned about
methylmercury in the environment
95
CRAIG’s Restorative Dental Materials;12th ed
94. Estimated daily intake of mercury
( as given in Craig’s restorative dental materials, 12th ed)
Source
µg Hg
vapor
µg
inorganic
Hg
µg Methyl
Hg
Atmosphere 0.12
0.038
0.034
Drinking
water
Food, fish
Food, non
fish
-
0.05
-
0.94
-
20.00
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
3.76
96
CRAIG’s Restorative Dental Materials;12th ed
95. Sources of mercury
• Exposure to mercury can occur from many
different sources, including diet, water, air &
occupational exposure
• WHO has estimated that eating seafood once a
week raises urine Hg levels to 5-20 µg/L, 2-8
times the level of exposure from amalgam
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
1 µg/L=1mg/m³=1 part per billion(ppb)
97
CRAIG’s Restorative Dental Materials;12th ed
96. • Mercury blood levels that were measured in one
study indicated that the average level in patients
with amalgam was 0.7ng/ml compared with a value
of 0.3ng/ml for subjects with no amalgam. This
difference was found to be statistically significant
(P=0.01)
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
• However, a study in Sweden demonstrated that one
saltwater seafood meal per week raised avg blood levels
of mercury from 2.3 to 5.1 ng/ml , a seven fold increase
compared with that associated with amalgam
restorations(0.4 ng/ml)
98
PHILLIPS’ Science of Dental Materials;11th ed
97. The normal daily intake of mercury is:15µg from food,
1µg from air,
0.4µg from water
• On the basis of epidemiological studies,
blood & serum mercury levels correlate
with occupational exposures & diet,
whereas urine mercury levels relates to
amalgam burden
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
The actual body burden at any time is a function of
the dosage & time of exposure
99
PHILLIPS’ Science of Dental Materials;11th ed
98. THRESHOLD LIMIT VALUE(TLV): Allowable
exposure level to mercury vapor, 8hrs/day,
40hrs/wk
OSHA
RECOMMENDED
TLV=0.05 mg/m³
Normal Mercury Level in Urine=0-0.02mg/lt
Allowable max. limit in urine=0.15mg/lt
Allowable max. limit in blood=3µg/lt
Saliva & Urine normal levels are equal
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Most dental office mercury vapor levels lie below 0.05 mg/m³
The mercury enigma in dentistry;
JADA,VOL.92,June 1976
100
PHILLIPS’ Science of Dental Materials;11th ed
99. TOLERABLE MERCURY CONCENTRATION
IN URINE &BLOOD
Br Dent J 1997;182;413-417
Mercury vapor at a conc. of 25 µg/m³ in air results
in avg. conc. of 75 µg/lt (urine) & 10 ng/ml (blood)
The lowest air threshold for the general public
of 1 µg/m³ results in conc. of:
15 µg/lt in
urine
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
4ng/ml in
blood
101
100. • In one study, patients with amalgam
restorations were monitored with mercury
vapor detectors over a 24 hr period & the
amount of vapor inhaled was calculated to
be 1.7 µg/day
• 3 other studies have confirmed that the
magnitude of vapor exposure for a patient
with 8-10 amalgam restorations is in the
range of 1.1-4.4µg/day
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
102
PHILLIPS’ Science of Dental Materials;11th ed
101. TOXIC REACTIONS
3 -7µg/kg body
weight
500µg/kg body
weight
LOWEST DOSE TO ELLICIT
TOXIC REACTIONS
Paresthesia
1000µg/kg body
weight
Ataxia
2000µg/kg body
weight
Joint pain
4000µg/kg body
weight
Hearing loss
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
DEATH
103
CRAIG’s Restorative Dental Materials;12th ed
104. Minamata disease
• Came into existance after the Minimata Bay incident
in Japan in 1952
• A local chemical plant (Chisso Corporation) disposed
of its methylmercury waste into the nearby bay,
contaminating the shellfish & causing toxic levels of
mercury in the fish eaten by the local population
• Symptoms were:1.Ataxic gait
2.Convulsions
3.Numbness in mouth & limbs
4.Constriction in the visual field
5.Difficulty in speaking
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
106
Sturdevant’s Art & Science of Operative Dentistry; 5th ed
105. Industrial
waste into the
bay
Methymercury
consumed by the
fishes in the bay
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Child suffering from minamata
disease after eating the
contaminated fishes
107
106. In dental office, the source of mercury
exposures related to amalgam include:
Amalgam raw materials being stored for use ( usually as
precapsulated packages)
Mixed but unhardened amalgam during trituration,
insertion, & intraoral hardening
Amalgam scrap that has insufficient alloy to consume the
mercury present completely
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Amalgam undergoing finishing & polishing operations
Amalgam restorations being removed
108
Sturdevant’s Art & Science of Operative Dentistry; 5th ed
107. Amount of mercury released
during manipulation of amalgam
Br Dent J 1997;182;293-297
• Trituration=1-2µg
• Condensation=6-8µg
• Dry polishing=44µg
• Wet polishing=2-4µg
• Removal of amalgam restoration underwater
spray & high volume suction=15-20µg
• Additional evacuation for 1 min to remove
residual amalgam dust=1.5-2µg
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
109
108. Risks to dentists & office personnel
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
110
109. Store mercury in
unbreakable, tightly sealed
containers
Clean up any spilled
mercury immediately
Droplets may be picked up
with narrow bore tubing
connected ( via a wash
bottle trap) to the low
volume aspirator of the
dental unit
Storage locations should be
near an exhaust vent that
carries air out of the
building
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
111
Sturdevant’s Art & Science of Operative Dentistry; 5th ed
110. Use tightly closed capsules
during amalgamation
Reusable capsule with a
mechanical amalgamator
should have a tightly fitting
cap to avoid mercury leakage
Salvage all amalgam scrap &
store it under water that
contains sodium thiosulfate
(photographic fixer is
convinient) ,water, glycerine
Use conventional dental
amalgam condensing
procedures, manual &
mechanical, but do not use
ultrasonic amalgam
condensers
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
112
CRAIG’s Restorative Dental Materials;12th ed
111. Work in well
ventilated spaces
Avoid carpeting
dental operatories;
decontamination of
carpeting is very
difficult
If mercury comes in contact with
skin, the skin should be washed
with soap & water immediately
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
113
CRAIG’s Restorative Dental Materials;12th ed
112. Amalgam scrap & materials
contaminated with mercury
or amalgam should not be
incinerated or subjected to
heat sterilization
Adequate water spray &
suction should be used
during amalgam polishing
& removal
During the intra oral
placement & condensation
procedures, rubber dam &
high volume evacuation
should be used
Eye protection , a
disposable mask & gloves
are now standard
requirements for dental
offices
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
114
CRAIG’s Restorative Dental Materials;12th ed
113. Spent capsules & mercury contaminated cotton rolls
or paper napkins should not be thrown out with
regular trash, rather they should be stored in a tightly
capped plastic container or closed plastic bag for
separate disposal
Perform yearly mercury
determinations on all
personnel regularly
employed in dental
offices
Determine mercury
vapors levels in
operatories periodically
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Alert all personnel who handle mercury,
especially during training of the potential
hazard of mercury vapors & the necessity for
observing good mercury & amalgam practices
115
Sturdevant’s Art & Science of Operative Dentistry; 5th ed
118. The older generation of low-copper
amalgams (before 1963) had a limited
life span because they contained the
gamma-2 phase that caused
progressive weakening of the amalgam
through corrosion
Several clinical studies have
demonstrated that high-copper
amalgams can provide satisfactory
performance for more than 12 years
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
120
Dental amalgam: An update
119. This appears to be true even for large
restorations that replace cusps
In addition, high-copper amalgams do not
appear to require polishing after placement, as
was recommended for low-copper amalgams,
to increase their longevity
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
121
Dental amalgam: An update
120. Plasmins et al. evaluated the long-term survival of
multisurface restorations and found that extensive
amalgam restoration had no influence on the
survival rate
J Dent Res. 1998;77:453–60
this is in accordance with the results of a
retrospective study by Robins and Summitt, who
found 50% survival rate for 11.5 years
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Oper Dent. 1988;13:54–7
122
121. The satisfactory functioning of the extensive
amalgam restorations over a long period of
time results from the prevention of the most
important traditional mechanical failure of
amalgam restorations. These include marginal
fracture, bulk fracture and tooth fracture.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
123
Dental amalgam: An update
122. The zinc and copper content of the
alloy has been found to have a strong
impact on the survival rates of
amalgam restorations since it
influences the corrosion resistance of
the amalgam. High-copper amalgams
has higher survival rates than
conventional amalgams
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
124
Dental amalgam: An update
123. `
• Letzel investigated survival and
modes of failure of amalgam
restorations retrospectively. The
leading mode of failure was bulk
fracture (4.6%), followed by tooth
fracture (1.9%) and marginal ridge
fracture (1.3%). For other reasons,
0.8% Amalgam restorations: Survival, failures and causes of failure
of Mater. restorations failed
Dent the 1989;5:115–21
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
125
126. COMPOSITES…..
• Aesthetically superior
• Mercury-free
• Strengthens the tooth by chemical
bonding thereby reducing the chance
of tooth fracture
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
128
127. Safety of Composite resin
Br Dent J 1997; 183: 11-14
• Produce more cytotoxicity than amalgam in comparative
in vitro tests
• Classifiable as toxic restorative material
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
• Produce an inflammatory response in pulp when placed
in test cavities in animals
• Strongly allergenic
• Inhibit RNA synthesis of cells
129
128. Prospective clinical studies have shown
comparable annual failure rates of both
materials (Manhart et a!., 2004).
• However, three recently published
studies reported better longevity of
amalgam restorations compared with
composite restorations (Van
Nieuwenhuysen et at, 2003; Berrtardo
et at, 2007; Soncini at at, 2007).
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
130
129. amalgam has a greater longevity than composite
resin in posterior restorations
Longevity of Composite Resin and Amalgam Restorations in Posterior Teeth:
An Evidence-Based Review of the Literature
DEN300Y – Community Dentistry, winter 2009
Numerous studies have shown amalgam
restoration to last longer than resin composite
restorations
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Amalgam-Resurrection & Redemption
Quintessence Int 2001;32;525-535
131
130. 12-year Survival of Composite vs. Amalgam
Restorations
NJ.M. Qpdam*, E.M. Bronkhorst, B.A.C. Loomans,
and M.-C.D.NJ.M. Huysmans
JDentRes 89(10):1063-l067, 2010
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
132
132. Frequency of Posterior Materials
by Practice Type
Amalgam
Users
3%
7%
39%
51%
Amalgam
Amalgam
Free
Direct Composite
12%
Indirect Composite
Other
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
3%
8%
77%
134
Gen Dent 2005 Sep-Oct;53(5):369-75
134. Review of Clinical Studies
(Failure Rates in Posterior Permanent
Teeth)
% Annual Failure
8
6
4
2
0
Amalgam
Direct
Comp
Comp
Inlays
Longitudinal
Ceramic CAD/CAM
Inlays
Inlays
Gold
Inlays &
Onlays
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
GI
Cross-Sectional
136
J Adhes Dentistry 2001 Spring;3(1):45-64.
135. Review of Clinical Studies
(Failure Rates in Posterior Permanent Teeth)
% Annual Failure
15
10
Standard Deviation
Longitudinal and Cross-Sectional Data
5
AR
T
Tu
nn
el
GI
Am
al
ga
Di
m
re
ct
Co
Co mp
m
po
m
Co
er
m
p
Ce
In
la
ra
ys
m
ic
In
la
CA ys
D/
CA
M
Ca
st
G
ol
d
0
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
137
Oper Dent2004 Sep-Oct;29(5):481-508
137. 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 led to the elimination
of this inexpensive and durable material.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
139
Dental amalgam: An update
138. Mercury released from
dental amalgam
restorations does not
contribute to systemic
disease or systemic
toxicological effects
Allergic reactions to
mercury from dental
amalgam restorations
have been
demonstrated, but these
are extremely rare
Available scientific data do not justify the
discontinuation of dental amalgam use from
clinical practice or the replacement with other
single-tooth restorative dental materials. There
are cases where dental amalgam is the only
choice with no other alternative
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Biocompatibility of Dental Amalgams-a review
International Journal of Dentistry;Volume 2011, Article ID 981595,140
7 pages
doi:10.1155/2011/981595
139. possibility & perhaps
probability that
dental amalgam will
lose its importance in
some more distant
future
the importance of dental
amalgam at present and
at least in the near
future,
the fact that dental
amalgam is a material
unique to the dental
application
CRITICAL
ISSUES FOR
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
AMALGAM’S
FUTURE
DENTAL AMALGAM: REACTOR RESPONSE
141
Adv Dent Res 2(l):87-90, August, 1988
140. the longevity of dental restorations is
dependent on many factors, including
those related to materials, the dentist,
and the patient
Amalgam restorations are being
replaced because of alleged adverse
health effects and inferior aesthetic
appearance
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Is it the end of the road for dental amalgam? A critical review
Shenoy A; Conserv Dent. 2008 Jul;11(3):99-107
142
141. TEN CLINICAL & LEGAL MYTHS OF ANTIAMALGAM
Amalgam-Resurrection & Redemption –I
Quintessence Int,2001;32:525-535
FACT 1. Teeth with amalgam restorations have acusps
MYTH 1. Amalgams commonly cause fractured low
incidence of fractured cusps
MYTH 2. the majority of clinically sound amalgam
FACT 2. the vast majority of teeth with amalgam
restorations have recurrent caries; the majority of
restorations do not have recurrent caries
resin restorations do not
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
FACT 3. numerous studies restorations last as long as
MYTH 3. Resin composite have shown that amalgam
restorations longer than resin composite restorations
amalgam restorations
143
142. FACT 4. amalgam can be bonded to teeth; often
MYTH 4. amalgam cannot be bonded to teeth
yielding bond strength higher than obtained by resin
composite
FACT 5.5. because of recent advances in materials &
MYTH improvements in amalgam restorative material
& technique,in recent years have been as dramatic as
techniques most studies of resin composites are
those in resin compositeof amalgam are not
outdated ;most studies materials
FACT 6.6. resin composite restorations are superiorcan
MYTH like resin composite restorations amalgam to
often be repaired composites can be repaired
amalgam because
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
MYTH Amalgam’s is 100 yrs old; resin composite is
FACT 7.7. amalgamlongevity is testament to its safety &
much newer & thus better
efficacy
Amalgam-Resurrection & Redemption –I
Quintessence Int,2001;32:525-535
143. MYTH 8. The ADA refuseson the safety & efficacy of
FACT 8. ADA’s statements to admit that mercury
containing amalgam apparently unrelated to fear of
dental amalgam are is unsafe for fear of lawsuits
lawsuits
MYTH neither the holds the patent for amalgam &
FACT 9.9. The ADA ADA nor the ADA’S health
receives a have ever each amalgam restoration
foundationroyalty for received remuneration for any
placed
amalgam restoration ever placed
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
FACT 10. Dental amalgam has not been banned in any
MYTH 10. Amalgam has been banned in Germany &
country in the European union
Sweden
Amalgam-Resurrection & Redemption –I
145
Quintessence Int,2001;32:525-535
144. DISCUSSION
“OPERATIVE DENTISTRY In on the threshold of
postamalgam age , which is based on tooth colored
restorative material”
Krejci & Lutz;1995
Operative dentistry;1995,20,218-22
We should seek alternatives, if such alternatives can
meet the health needs of our patients equally well or
better
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Rory Hume;
Quintessence Int,1996;27:2
146
145. If composite resins ,which can be costly ,pose the
next biological risk in dentistry , what materials do
we move to next??
Steven Duke; Compendium; Feb2003;vol24, no22
The future of dental amalgam is dependent on
emotional & socioeconomic aspects that are
different in each nation
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Roulet, Zimmer, Losche & Noack;
Quintessence Int,1996;27:2
147
146. As other materials and techniques
improve, the use of amalgam will likely
continue to diminish, and it will
eventually disappear from the scene
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Yet, amalgam continues to be the
best bargain in the restorative
armamentarium because of its
durability and technique insensitivity
J Conserv Dent. 2010 Oct;13(4):204-8.
148
Dental amalgam: An update
147. “Amalgam will probably disappear eventually,
but its disappearance will be brought about by
a better and more esthetic 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”
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
Dental amalgam: An update
149
149. CONCLUSION
• Amalgam restorations have served the
profession well and will continue to do so in
the years to come.
In terms of longevity, they are probably
superior to composite resins, especially when
used for large restorations and cusp capping
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
J Conserv Dent. 2010 Oct;13(4):204-8.
151
Dental amalgam: An update
150. The new high copper single composition alloys
offer superior properties but may not offer as
good seal as older amalgams
The use of amalgam can be continued as a
material of choice if esthetics is not a concern.
Introduction
History
Amalgam wars
Classification
Components
setting reaction
Manufacture
Properties
Manipulation
Recent advances
Sideeffects of
mercury
Durability
Future
Conclusion
Prepare a tooth as conservative as possible, making
access large enough only for removal of carious
dentin and using resin sealants for non carious
fissures
J Conserv Dent. 2010 Oct;13(4):204-8.
152
Dental amalgam: An update
151. Dental Amalgam will not go away
even if it were to be immediately discontinued
as a restorative material.
It will keep going , going & going
153
152. REFERENCES
• PHILLIPS’ Science of Dental Materials;11th ed
Kenneth J. Anusavice
• CRAIG’s Restorative Dental Materials;12th ed
John M. Powers, Ronald L. Sakaguchi
• Materials science for dentistry;9th ed
B.W.Darvell
• Sturdevant’s Art & Science of Operative Dentistry;
5th
ed; Roberson, Heymann, Swift
• fundamentals of operative dentistry, a contemporary
approach; 3rd ed
Summitt, Robbins, Hilton, Schwartz
• Essentials of operative dentistry;
I Anand Sherwood
154
153. • Dental amalgam: An update
J Conserv Dent. 2010 Oct-Dec; 13(4): 204–208
• Effect of admixed indium on the clinical success of amalgam restorations
.
•
•
operative dentistry journal1992 Sep-Oct;17(5):196-202
JPD 1981;VOL46;.5
Dental Materials, Volume 3, Issue 3, June 1987, Pages 117-120
• A Safe Protocol for AmalgamRemoval
•
•
•
•
•
Journal of Environmental and Public Health;Volume 2012
BDJ;VOL.183;NO.1;JULY,1997
Dent Mat Mar 2001 17 (2), 142-8
Quint Int, Mar'99, 30(3) 185-91
DM, Volume 6, Issue 4, October 1990, Pages 256-265
Br Dent J. 2009 Jan 24;206(2):E3
• Immediate hypersensitivity reaction associated with the mercury
component of amalgam restorations
•
•
Br Dent J. 2008 Nov 22;205(10):547-50
The mercury enigma in dentistry;
JADA,VOL.92,June 1976
Mercury toxicity in the dental office: a neglected problem
JADA,Vol.92,June 1976
155
154. • Br Dent J 1997;182;293-297
• J Dent Res. 1998;77:453–60
• Oper Dent. 1988;13:54–7
• Amalgam restorations: Survival, failures and causes of failure
Dent Mater. 1989;5:115–21
• Br Dent J 1997; 183: 11-14
• Longevity of Composite Resin and Amalgam Restorations in
Posterior Teeth: An Evidence-Based Review of the Literature
DEN300Y – Community Dentistry, winter 2009
•
Amalgam-Resurrection & Redemption
Quintessence Int 2001;32;525-535
• 12-year Survival of Composite vs. Amalgam Restorations
JDentRes 89(10):1063-l067, 2010
• Review of the clinical survival of direct and indirect restorations in
posterior teeth of the permanent dentition
Oper. Dent. 2004 Sep-Oct;29(5):481-508
• Survey of general dentists regarding posterior restorations, selection
criteria, and associated clinical problems.
Gen Dent 2005 Sep-Oct;53(5):369-75; quiz 376, 367-8.
156
155. •
•
Longevity of restorations in posterior teeth and reasons for failure
J Adhes Dentistry 2001 Spring;3(1):45-64.
Review of the clinical survival of direct and indirect restorations in posterior
teeth of the permanent dentition
Oper Dent2004 Sep-Oct;29(5):481-508 Biocompatibility of Dental
Amalgams-a review
International Journal of Dentistry
Volume 2011, Article ID 981595, 7 pages
•
DENTAL AMALGAM: REACTOR
RESPONSE
Adv Dent Res 2(l):87-90, August, 1988
•
Is it the end of the road for dental amalgam? A critical review
Shenoy A; Conserv Dent. 2008 Jul;11(3):99-107
•
Amalgam-Resurrection & Redemption –I
Quintessence Int,2001;32:525-535
•
•
•
Operative dentistry;1995,20,218-22
Quintessence Int,1996;27:2
Steven Duke; Compendium; Feb2003;vol24, no22
157
With recommendations of no touch procedures for mercury mercury n alloy dispensers are replaced.
2) :.. 2 is also available. Gallium GF causes as a powder and contains; (by wt) - - Ag 50%, Sn-25.7%, Cu - 15%, Pd -9% and traces - 0.9%. It is also available as liquid containing Ga-65%, In - 18.85%, tin - 16% and traces -0.5%.