indications for use and hazards of dental amalgam

Question 1

composition of amalgam

Answer 1

mercury

alloy

Question 2

what is the percentage class of high copper

Answer 2

over 30%

Question 3

class of low copper grade

Answer 3

4%

Question 4

advantages of high copper amalgam

Answer 4

doesn’t corrode

stronger

Question 5

useful properties of amalgam

Answer 5

good compressive strength
good balance of working and setting times
fair resistance to marginal leakage
minimal dimensional change on setting
relatively resistance to contamination
low cost

Question 6

limitations of amalgam

Answer 6

not adhesive to tooth substance
brittle in thin sections
alloy/mercury proportions critical
detectable levels of creep
corrosion can weaken
affected by water during setting reaction
toxic components
anaesthetic
not conductive to minimal intervention

Question 7

when should we use amalgam

Answer 7

posterior teeth
when too late for OH intervention
when adhesive restoration not indicated

Question 8

what is needed for retention of amalgam

Answer 8

mechanical lock in restoration

undercuts

Question 9

how can you increase resistance of amalga

Answer 9

at least 3mm thick
no feather edges
cavosuface angel 90 degress
floor cut perpendicular to occlusal forces
smooth internal angles (use round ended burs)

Question 10

hazards of amalgam

Answer 10

mercury
alloy components (tin/silver) hazardous to enviroment

Question 11

issues with mercury

Answer 11

neurotoxic
adversely affects renal function
cumulative in the body and enviroment

Question 12

why is amalgam being phased down

Answer 12

envrioenmtn

Question 13

risk management of amalgam

Answer 13

PPE
rubber dam
avoid in pregnancy 
use capsules for correct proportions
aspirator and isolation
proper disposable

Question 14

waste amalgam

Answer 14

density of amalgam is higher

- needs to be separated with a cartridge for filtration

Question 15

placement of amalgam steps

Answer 15

isoalte
triturate amalgam
place and condense(condenser and plugger)
burnishing 
carving

Question 16

what do you remove from amalgam when condensing

Answer 16

Hg rich layer on the surface

Question 17

when can you finish

Answer 17

after 24 hours after placing the restoration
reduced corrosion
adjust occlusion and morphology

Question 18

mercury released most likely at

Answer 18

when setting and upon polishing

Question 19

when placing restorations consider

Answer 19

biological effects
potential retention and resistance form
chose most appropriate material 
adapt cavity to suit material
use PPE and isoalte pateint

Question 20

disadvantages of composite

Answer 20

cost
shorter life in patient
environmental impact
toxicity unknown