Amalgam Flashcards
3 main goals of condensation
adapt amalgam to preparation walls
create restoration free of voids
eliminate as much mercury as possible
overpack prep by about
1 mm
complete condensation within how many minutes of mixing
2-3 minutes
pre-carve burnish
a form of condensation
achieved with large burnisher
use heavy strokes in all directions
produces denser amalgam at the margins of the preparation
why carving
to remove functional anatomy that was removed during prep
grooves, fossa, cusp inclines
use remaining tooth structure as guide
choose carving instrument suitable for preparation and location
carving process
first remove excess amalgam
place blade perpendicular to cavosurface margin
half the blade should be on tooth structure
establish major anatomical features
avoid what when carving
carving deep occlusal grooves as this may thin amalgam at margins
avoid under carving as you may leave thin portions of amalgam on the unprepared tooth surface which will fracture
under carving causes
flash
post-carve burnish
smooths surface producing a satin finish
may help improve marginal integrity
burnish lightly
post-carve burnish should not place more grooves in the margins/surface
checking occlusion
visually inspect for high spots
use articulating paper
carve away spots that appear to be causing heavy occlusion of interferences
contacts should occur on… and not occur on…
marginal ridges, cusp tips, central pit
not on inclines
class I considerations
class I that extends to proximal, buccal or lingual ridges may need a matrix band
class II considerations
will require matrix band
place amalgam in proximal box first
condensing action should consist of gingival followed by lateral condensation
add to proximal areas until filled to level of pulpal floor
continue placement as in class I
class II carving
with matrix still on, run explorer around marginal ridge
carve down height to that of adjacent tooth
remove gross amounts of amalgam before removing matrix band
remove matrix band
carve proximal margins
floss
occlusion
class V considerations
may want to have another instrument holding amalgam in one side of the prep while condensing other
best with explorer
imperative for gingival health
smooth with moistened cotton pellet
when should amalgam be polished
24 hours after placement
class I
occlusal surface of post teeth
occlusal 2/3 of buccal or lingual surface of post teeth
lingual aspect of ant teeth
one surface
class II
involve proximal surfaces of post teeth
can be two or three surfaces
class III
involve proximal surfaces of ant teeth
do not involve incisal edge
usually be prepped from lingual or facial
class IV
involve proximal surfaces of ant teeth
also involve incisal edge
class V
restorations on gingival 1/3 of tooth
both ant and post
restore root caries or abfractions
Class VI
cusps of post teeth
very incisal edge of ant teeth
before amalgam placement
line cavity prep with copalite varnish
acts as an insulator to prevent transfer of heat and cold to the pulp
can also seep into dentinal tubules
can sooth the nerve
capsules
mercury at one end separated from alloy particles by a diaphragm
push ends together
trituration
shake the capsules to mix
mixes in a figure 8 motion for maximum wetting of alloy particles
