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25 terms

Amalgam Restoration

STUDY
PLAY
Alloy
2 or more metals
1)silver
2)tin
3)copper
4)zinc
5)ratio of alloys depends on what the operator prefers
Mercury
liquid metal (hazardous material)
Alloy and mercury combined to form amalgam
Advantages of Amalgam
a)easy to insert into the cavity prep
1)adapts readily to cavity walls
b)limited dimensional change
c)remains plastic long enough to allow for placement, condensation, and carving
d)good compressive strength
e)limited marginal leakage
f)withstands corrosion
Disadvantages of Amalgam
a)does not match tooth color
b)will tarnish in time
c)inadequate edge strength
d)high rate of thermal conductivity
e)needs mechanical retention to be held in place
Uses
a)restore teeth for class 1, 2, and 5
b)core build-up for crowns
c)retention pins
Mixing of amalgam
a)armamentarium
1)amalgamator
2)pestle
3)mortar
4)cotton pliers
5)dappen dish, amalgam well, squeeze cloth
Ratio
1 pellet of alloy to 1 drop of mercury
Length of Time
according to manufacturer's directions
Armamentarium and procedure for a class 2 amalgam
a)Armamentarium
1)local anesthetic
2)rubber dam set-up
3)basic set-up
4)hand cutting instrument
5)cotton pellets
6)cotton rolls
7)cavity varnish and cavity liner
8)zinc phosphate cement
9)matrix and tofflemire
10)wedges
11)HVE tip
12)saliva ejector
13)amalgam carrier
14)condenser
15)burnisher
16)carver
17)interproximal knife
18)high and slow speed
19)contra angle attachment
20)burs
21)articulating paper
Procedure
1)the doctor checks the tooth with a mouth mirror and an explorer
2)placement of local anesthetic
a)set-up of anesthetic depends on the tooth being worked on
3)placement of the rubber dam
a)used to isloate the area to keep dry and free of debris
Operator prepares class 2 cavity prep with the high speed handpiece
a)assistant suctions with the HVE to keep area clean and dry
b)the operator may use hand instruments to finish the prep and retention grooves
c)the operator may use the slow speed with the contra angle attachment to buff and refine the prep
Category Depths
1) the assistant will mix the cavity liner
a)operator or RDA places the liner in the deepest part of the prep
The assistant mixes the base cement
1)operator or RDA places the base on the floor of the prep
Assistant prepares the varnish
1)operator or RDA places varnish on the floor and walls of the prep
Tofflemire and Matrix are placed around the tooth
a)operator or RDA
b)wedges placed on missing walls of cavity prep
NOTE
NOT ALL AMALGAM RESTORATIONS NEED A TOFFLEMIRE AND MATRIX
Assistant prepares amalgam and places it into the dappen dish amalgam well or squeeze cloth
a)assistant uses the amalgam carrier to pass the amalgam to the operator
b)the condenser and amalgam carrier are passed back and forth until the cavity prep is filled
Assistant passes the carver and the operator carves down the excess amalgam
assistant suctions the excess amalgam with the HVE
Tofflemire and Matrix are removed
a)assistant passes the cotton pliers to help remove the matrix
b)rinse out the mouth after removal of matrix
Procedure Continue
a)Assistant passes the carver to the operator to finish carving the restoration
b)assistant passes the interproximal knife to check the mesial and distal area of the restoration
c)assistant passes the burnisher to smooth the restoration
The rubber dam is removed
a)rinse out the mouth
Assistant passes the articulating paper to check the bite
a)if the bite is right; the patient is given post-op instructions and dismissed
b)if the bite is too high, pass the carver to reduce restoration and recheck the bite
Post-Op instructions
a)do not chew on the side of the restoration for a least 4-6 hours
(24 hours to completely set-up)
Handling of Amalgam
1)at any time during mixing or placement of amalgam; it should not be touched with your hands
2)the cavity prep must be dry and moisture free
Storage of excess amalgam
1)amalgam scraps should be stored in a sealed container with water or fixing solution