amalgam restoration Flashcards
amalgam for what class cavities
class I, II, V (posterior only), class III distal of canine
when would u use amalgam over composite
where moisture control is difficult
areas that are significantly deep
advantages of amalgam
less technique sensitive
low cost
adequate strength to maintain contour and occlusion
sets on its own
disadvantages
less conservative prep, needs retentive features
lack of bonding to tooth structure
dental amalgam is a mix of what
amalgam alloy + mercury
what is in the alloy
silver 40-74%
tin 25-30%
copper 2-30%
zinc 0-2%
what is the purpose of silver, tin, copper, and zinc in the alloy
silver - provides strength, increases expansion of setting of restoration
tin - increase flow, decrease strength and expansion
copper - hardness/strength
zinc - scavenger for oxide
beige cap vs blue cap for amalgam capsules
beige cap - extended carving time (for larger things)
mix amalgam for how long
8 sec
work from floor of prep then condense against lateral walls until cavosurface margins covered and then prep is overfilled by how much
1mm
how long should the condensing phase take
approx 2.5-3.5 min
purpose of pre carve burnishing
remove excess mercury (bring mercury to surface)
improves margin adaptation
pre carve burnishing done w what tool and immediately after what
done w large ball burnisher
done immediately after completion of condensation
post carve burnishing purpose and done w what tool
improves smoothness
done w small ball burnisher
burnishing pushes and adapts the material contiguous to the margins to eliminate
voids
