restoring cavities with amalgam

Question 0

What was the first amalgam made of?

Answer 0

Silver coins mixed with mercury

Question 1

Who first introduced amalgam and when?

Answer 1

Crawcour brothers. 1833

Question 2

Who developed the formula for amalgam and when?

Answer 2

G v black. 1895

Question 3

What did g v blacks formula for amalgam consist off?

Answer 3

Silver, tin copper and zinc

Question 4

In what way was the developed formula of amalgam superior?

Answer 4

It over came expansion on setting

Question 5

When would amalgam be indicated?

Answer 5

When there is poor moisture control
Poor patient cooperation
High occlusal loading
Cusp replacement
Patients financial restraints
No enamel margins
If cavity extends subbing ally

Question 6

What is the significance of high copper alloys?

Answer 6

Improves strength and reduces creep

Eliminates the gamma 2 phase

Question 7

What happens at the gamma 2 phase?

Answer 7

Tin/Mercury phase
Weakest phase
Causes expansion

Question 8

What is lathe cut amalgam?

Answer 8

Where the particles are all different shapes and sizes

Question 9

What’s occurs in Mercury free amalgam?

Answer 9

Increased corrosion

Excessive post setting expansion

Question 10

What is meant by outline form re. Class ll amalgam restorations?

Answer 10

Gaining access to caries
Gain access occlusally
Leave slither of enamel
Remove remaining enamel with excavator or gingival margin trimmer

Question 11

Describe the process of removing caries re. Amalgam

Answer 11

Remove caries
Clear contact point
Remove unsupported enamel
Ensure retention and resistance form included

Question 12

Describe the process of restoration re. Amalgam?

Answer 12

Line as necessary
Place band
Pack
Carve

Question 13

What are therapist controlled variables re. Amalgam?

Answer 13

Trituration
Condensation
Burnishing
Polishing

Question 14

What is trituration?

Answer 14

Mixing time.

Question 15

What happen if overtrituration occurs?

Answer 15

Hot mix
Sticky
Decreases working time
Increase in setting contraction

Question 16

What happens if under trituration occurs?

Answer 16

Grainy crumbly mix

Question 17

Describe condensation technique re. Lathe cut alloys

Answer 17

Small condenser
High force
More pressure to condense

Question 18

Describe condensation technique re. Spherical alloys

Answer 18

Larger condenser
Easier to displace
Less sensitive to the amount of force

Question 19

Describe condensing technique re. Admixture

Answer 19

Intermediate handling between lathe cut and spherical

Question 20

Rules re. Placing amalgam

Answer 20

Condenser must fit
Place amalgam in increments
Condenser with pressure.hear squeak
Over pack

Question 21

Why over pack?

Answer 21

This removes the Mercury rich layer by carving

Question 22

Describe rule re. Carving

Answer 22

Carve back to cavity outline 
Removes HG rich layer
Stimulate lost anatomical form
Aim for smooth enamel/ amalgam junctions
Don't reproduce deep fissures
Remove gross gingival excess
Check occlusion!

Question 23

Why burnish?

Answer 23

Less leakage

Improves smoothness

Question 24

Why polish and when?

Answer 24

Increases smoothness
Decreases plaque retention
Decreases corrosion
Avoids overhangs

Only after 24 hours

Question 25

When would you use a bonded amalgam?

Answer 25

When not enough tooth structure for retention
To achieve good marginal seal
- prevents ingress of bacteria
- protects the pulp

Question 26

What are the advantages of a bonded amalgam?

Answer 26

Reduced need for prep re. Retentive features
No need for pins
Reduced marginal leakage
Reinforcement of tooth structure

Question 27

What are the disadvantages of a bonded amalgam?

Answer 27

Time consuming
More expensive
Lack of data re. Long term effectiveness

Question 28

Describe the technique of a bonded amalgam

Answer 28

Vitrebond liner
Acid etch margins
Prime and bond
Rely x- chemical cured resin based cement
Leave un cured
Pack amalgam
Condense
Etc.

Question 29

Describe safety techniques re. Handling amalgam

Answer 29

Avoid spilt Mercury
Store waste appropriately
Well ventilated surgery
Aspiration 
Venting externally with HG. Removal filter

Question 30

Signs and symptoms of mercury poisoning

Answer 30

Headaches
Fatigue
GI upset
Fatigue
Irritability
Oedema of face and ankles
Character changes