Tutorial amalgam

Which one of the following phases in dental amalgam restoration is most prone to electrochemical corrosion?

1- Ag-Sn 2- Cu-Sn 3- Sn-Hg 4- Ag-Hg

Which one of the following phases in dental amalgam restoration has the best mechanical properties?

1- Ag-Sn 2- Cu-Sn 3- Sn-Hg 4- Ag-Hg

Which one of the following is not true about high-copper dental amalgam 1- Better corrosion resitance than low copper.

2- Contain both Sn and Ag in the composition as well.

3- Produce excessive creep .

4- Restorations are more brittle than low-copper amalgam.

Which of the following is not a criteria for a failed high copper amalgam.

1- Marginal ditching along occlusal margins 2- Creep of the restoration out of the cavity preparation in proximal areas.

3- Wear along the occlusal contact areas 4- None of the above

Dental personal can do which of the following to limit their exposure to mercury?

1- Sterilize amalgam scrap.

2- Vacuum up a spill immediately.

3- Avoid touching freshly mixed amalgam.

4- Avoid polishing amalgam.

The primary difference between high and low copper amalgam is: 1- The amount of copper 2- The amount of copper and zinc 3- The amount of copper and tin 4- The amount of copper and silver

The primary difference in the reaction products of low and high copper amalgam in which of the following?

1- low copper amalgam has Gamma 2 phase and high copper amalgam has no Gamma 2 phase.

2- Low copper amalgam has higher gamma 1 3- High Cu amalgam has Cu-Sn phase, Low Cu amalgam does not 4- Both a and c

Ideally, the set amalgam should do which of the following?

1- Expand greatly to provide marginal seal against the tooth.

2- Shrink to provide space for corrosion products to seal the margins.

3- Have little dimensional change 4- None of the above

The physical properties most desirable in set amalgam are which of the following?

1- High strength, low creep, low corrosion.

2- Low strength, low creep, low corrosion.

3- High strength, high creep, low corrosion.

4- High strength, high creep, high corrosion.

Higher mercury left in amalgam leads to which of the following?

1- Higher creep 2- Higher strength 3- Lower corrosion 4- All of the above

Which of the following occurs when dental amalgam is overmixed?

1- Compressive strength decreased 2- Corrosion decrease 3- Tensile strength decrease 4- Both a and b 5- Both a and c

Which type of amalgam (spherical or lath-cut) would you choose for a restoration that had to survive higher occlusal forces shortly after placement and why?

B/c a high condensing force Why do most new amalgam brands not include zinc? B/c delay expansion You examine set amalgam under an electron microscope and observe that all original Gamma particles have reacted. What will you predict about physical properties of this amalgam? why? High copper amalgam, no Gamma 2 phase, Increase strength, decrease creep, decrease corrosion, good marginal integrity and low polish surface.

You see an old amalgam in a patient's mouth. Its dark and needs polishing. How can you determine if the amalgam has corroded or is just tarnished? If the amalgam has occurred what is the remedy for this restoration?

Tarnish if polished it ’s removed but corrosion it ’s change in mechanical properties, bad test .ttt. Replacment restoration

One goal of amalgam condensation is to remove excess mercury from the amalgam. Why is this desirable?

What special percautions should be taken to limit the exposure of the dental team and patient to mercury during removal of an amalgam.