Restorative- Amalgam Build up and Finishing and Polishing

Created by rachel_dunn 

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#19 Anatomy

3 facial cusps (Mesiobuccal, distobuccal, distal)
2 lingual cusps (Mesiolingual, Distolingal)
2 buccal grooves (MB and DB)
3 Fossae (M, D, C)
2 triangular ridges

Buccal cusps

even in size and height

Distal cusp

higher than marginal ridge of #18
narrower than other cusps

Ginigval floor

extends to facial

Build Up armamentarium

contra angle toffelmire and extended matrix band
anatomical burnisher

Condensing technique

large area
many cavosurfaces
overfill

Marginal ridges

relatively the same height in the same quadrant

Pins*

The dentist may place only the retention pin, nothing else*
help retain the amalgam into the prep when one or more cusps have been lost. are placed in holes that have been drilled entirely within dentin, not enamel
one pin/ cusp missing*

Pin depth

2 mm in dentin with 2 mm exposed

Pin condensing

must be condensed around as it is layered

Types of pins

screw type
cemented
friction lock

Screw

threaded so it can be screwed into the hole
hole is slightly smaller than screw

Cemented Pin

small than the hole in order for room for cement

Friction lock

slightly larger than hole and must be tapped into the hole

Preperation shape

missing DB cusp and groove and all of distal cusp

Rubber dam for #19

one behind, two in front
rubber wedge on mesial of #21

Benefit of contra-angled retainer

can be placed on lingual so the smooth part of the matrix can be adapted to the buccal
also can be angled up over the mand. ant. teeth

Wedges for #19

placed facially for better adaptation

pg 117 pic*

contoured #2 matrix band

Criteria for matrix and wedge

retainer is placed ligually, slots and smaller opending toward ginigva
occlusal .5-1.5 and gingival extension .5-1.0 mm
secure and stable
wedge adapts band snugly without entrapment
proximal contact is visual with adjacent tooth

Condensing pattern

most inaccesible area first
carry two increments to one area at one time using both ends of the carrier
condense toward the proximal contact, but not too much

Anatomy goals

form the central groove where you can rest on intact cusp contours and form the missing cusps last

Never..

permit the amalgam to entirely conver the unprepared tooth cusps

Missing cusps

formed like a mountain, MB can be used as a guide when ironing the other cusps

Marginal ridges

form the height first
form mesial first
marginal ridges should be concave at first

Immediately

evaluate margins with the hollenback

Proximal contacts

resist without fraying
occlusal to middle 1/3, never gingival
continous embrasures

Occlusion

not grossly out of occlusion, should be within curve of spee

Advantages of finishing and polishing

once hardened (24 hours) they ma be perfected (finished) and smoothed (polished)
two seperate steps

Finishing

perfecting

Polishing

smoothing

Benefits of finishing and polishing

improves corrosion resistance
reduces marginal breakdown
makes restoration easier to keep clean

Polishing*

relatively low speed with intermittant strokes under moist conditions to achieve luster

Finishing burs

used for finishing amalgam
different than cutting because of more, smaller, cutting ridges

Flutes

small, cutting ridges on finishing burs
reduces potential for cutting away enamel

Basic set-up

flame
round (large and small)
football or pear

Finishing bur characteristics*

made from steel, prone to rust
smaller flutes than prep bur
have fine mulitflutes
have more flutes per bur than a cavity prep bur

Super-Greenie cup and point

light green with yellow ring
finest grit used last

Green cup and point

are greeen
medium grit

Brownie cup and point*

brown
coarse grit used first

Green stone

gross excess

White stone

perfecting submarginal areas <.2mm
removes enamel
never remove cementum--->sensitivity

Ideal finished amalgam

perfectly reproduced anatomy and even occlusion margins are flush and a surface that is smooth and shiny without lumps and bumps

Finishing

use of instruments or burs to perfect the shape of the amalgam as needed
margins, anatomy, occlusion, contour

Finishing margins

either too much amalgam or too little amalgam

Overextension

bumps up from tooth to amalgam

Flash

extended beyond the margins

Flame

smooth convex surface
used as a hollenback
follow contour
do not remove tooth

Slow speed handpiece

finishing burs
forward

Finishing discs

used for removing flash on class V and buccal or lingual class II
one abrasive side one non abasive side

Abrasive side

adapted to the tooth
grazing strokes
coarse to fine

Coarse discs

darker
finishing

Fine discs

polising

Rinse

between each type of disc
to remove scratches

Gold Knife

overextensions can be removed
shaving similar to hollenback

Gold File

rubbing motion

Submarginal areas

bumps from restoration to tooth
removed with finishing stone (white)
less than .2 mm
do not expose dentinal tubules

Burnished facets

marks that are shiner than the rest of the amalgam and are flattened like the facet of a diamond
high occlusion
don not flatten but contour or deepen fossa

Temperature *

>140
can cause pulpitis, bring Hg to surface-->suceptibility to corrosion and dull cloudy surface

Pear shaped/Football shaped

concave surfaces and ridges
deepen fossae
similar to cleoid

Small round

accentuate grooves

After finishing

all margins flush anatomy is defined and reasonable smoothness

Polishing*

process of removing minute scratches and producing a shiny surface with no visible surface pits

Benefits of polishing

easier to keep clean

Rubber cups, points, discs

used to impregnate the abrasives for polishing
brownies, greenies, super greenies\
contour determines

Abrasives

coarse to fine
rinse between

Slow speed

polishing handpiece
prevents rubber disintegration

Polishing strokes

one off
do not stay in one spot

Points

fossae

Cups

smooth surfaces

Discs

embrasures

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