amalgam Flashcards
what is the composition of amalgam?
silver, copper, zinc, tin, mercury
how is amalgam classified?
composition- conventional or high copper
properties- lathe or spherical cut
setting reaction- self curing or capsule activated
why does amalgam need to be 2mm or more in depth?
weak in thin sections- will fracture
why do we pack amalgam?
as amalgam is packed- mercury pushed to surface and amalgam overfilled-carved back to leave mercury depleted layer
is there a replacement for amalgam?
no- but there are other viable options i.e composite
what are the advantages of using amalgam?
- durable and strong
- long lasting
- relatively cheap
- minimal shrinkage
what are the disadvantages of using amalgam?
- not conservative of tooth tissue - requires retention
- moisture control
- risk of mercury exposure
- environmental pollution
- allergies to components
- poor aesthetics
- not bonded to tooth- risk 2ndry caries
when does amalgam reach
functional strength
final strength
15-20 mins
24 hrs- avoid eating on side of mouth
why is amalgam being replaced by composite?
- better aesthetics
- more conservative of tooth tissue
- more viable alternatives
- more versatile
- minimata treaty- not when P/BF or <15yo
Concerns on safety: - mercury is toxic to CNS
- highest mercury exposure during placement/contouring/ removal of amalgam
- can cross placenta
- concerns
Concerns of env pollution - requires mercury removing water filters in dental units
- released during cremations- requires filters
