amalgam manipulation dental material

1. Amalgam
Manipulation
1. Alloy selection
2. Powder and liquid Proportioning
3. Trituration and mix characteristics
4. Condensation and finishing

2. 1. Alloy Selection1. Alloy Selection
• Copper content
 High-Cu u.c, High-Cu admix or Low-Cu
• Zinc content
 Zn-containing or Zn-Free
• Particle shape
 lathe-cut, spherical or spheroid
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√
√
√ √
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3. 2. Proportioning2. Proportioning
powder & Liquidpowder & Liquid
• Weighing balance
• Powder scope and Hg dropper
• Alloy tablets & Hg dispenser
• Hand dispenser
• Automatic dispenser
• Pre-weighed capsules
The correct ratio is
1 : 1 by wt.
√

4. 3. Trituration (1. Mixing)3. Trituration (1. Mixing)
 Using pestle & mortar
 Using palm & Thumb or
pen grasp tech.
 Takes more time (45 s)
 Needs some experience
Hand
Trituration
Mechanical
Trituration
 Using amalgamator and
Pre-weighed capsules
 Using amalgamizer with
mechanical dispenser
 Accurate proportions
 Saves time (5-20 s)

5. 3. Trituration (2. Proper Mix)3. Trituration (2. Proper Mix)
Under Triturated
Properly triturated
 Shiny mass as a result of Hg diffusion into the alloy particles
 Cohesive & not adhere either to capsule or mortar walls (i.e. if tapped it is collected in
the center of the mortar)
 If the mass falls down from 2-3 inches high, it will remain coherent
 Plastic, easily molded and condensed
 Able to produce the finger print on light touch
Over Triturated
 The mass is shiny
 Adhere to mortar and capsule
walls
 Hard and difficult to be
condensed
 The mass is dull
 friable

6. 3. Trituration (3.Squeezing & Mulling)3. Trituration (3.Squeezing & Mulling)
Mulling is to redistribute mercury evenly
within the mixed, squeezed mass
….Usually done by rubbing the amalgam mass in rubber
fingers
Squeezing is to minimize the mercury
content of the mix
….Usually done by twisting the mixed amalgam mass in a
piece of gauze

7. 44..CondensationCondensation…..…..

8. 4. Condensation4. Condensation (Filling tooth cavities)(Filling tooth cavities)
Condensation is usually done by the use of hand, automatic
or ultrasonic condensers.
• Amalgam must be condensed with 3-5 kg force
• Amalgam increments are condensed by overlapping steps and lateral
pushing.
• Small condensers provide greater condensation force
• Ultrasonic condensers are not preferred to avoid mercury evaporation
• The cavity should be overfilled before carving to ensure proper closure of
margins and removal of mercury-enriched layer.
Objectives of condensation
1.Make coherent mass of filling
2.Minimize voids within the amalgam mass
3.Adapt the amalgam to all cavity walls, margins and line angles
4.Reduce the mercury content as much as possible

9. 4. Carving , Finishing & Polishing4. Carving , Finishing & Polishing
The newly inserted amalgam restorations is can be used safely after 24h
Carving
• should start 2-3 min after mixing
• should be stopped when
amalgam is felt hard (i.e. 5-10min
after mixing)
• done by the use of sharp hand
carvers.
Finishing and polishing
• should be carried out 24h after
amalgam insertion.
• provide better esthetic, and allow
prolonged service with minimal
corrosion.
• Use … rubber abrasive
points, fine abrasive pate

10. 4. Carving , Finishing & Polishing4. Carving , Finishing & Polishing
The newly inserted amalgam restorations is can be used safely after 24h
Carving
• should start 2-3 min after mixing
• should be stopped when
amalgam is felt hard (i.e. 5-10min
after mixing)
• done by the use of sharp hand
carvers.
Finishing and polishing
• should be carried out 24h after
amalgam insertion.
• provide better esthetic, and allow
prolonged service with minimal
corrosion.
• Use … rubber abrasive
points, fine abrasive pate