amalgam manipulation dental material
-
Upload
dr-faisal-al-qahtani -
Category
Education
-
view
1.067 -
download
4
description
Transcript of amalgam manipulation dental material
Amalgam Manipulation
1. Alloy selection 2. Powder and liquid Proportioning 3. Trituration and mix characteristics4. Condensation and finishing
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
√
√
√
√ √
√ √
2. Proportioning 2. 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 is1 : 1 by wt.
√
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)
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
3. Trituration (3.Squeezing & 3. Trituration (3.Squeezing & Mulling)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
44 . .CondensationCondensation..… ..…
4. Condensation 4. 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 filling2.Minimize voids within the amalgam mass3.Adapt the amalgam to all cavity walls, margins and line angles4.Reduce the mercury content as much as possible
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