Dental Materials Amalgams

Front 1

What is it about amalgams that has prompted approximately a 40% drop in its use over the past 15 years?

Back 1

Lack of esthetics and concerns about its safety.

Front 2

What is an alloy?

Back 2

A mixture of 2 or more metals.

Front 3

What is the alloy used in dental amalgam composed of primarily?
What other metals are in the dental amalgam?

Back 3

Primarily Silver.
Also contains Copper and Tin
(Small amounts of palladium, iridum & zinc may be present as well.)

Front 4

What is mixed that creates the reaction known as amalgamation?

Back 4

Silver-based alloy is mixed with Mercury

Front 5

What consistancy is the amalgamation in that allows it to be packed into the cavity prep?

Back 5

It’s a putty-like consistancy. (But it will set Hard)

Front 6

What is the phase that amalgam can be carved to the anatomic shape of the tooth?

Back 6

Firming Phase…once it reaches it initial set it can no longer be carved.

Front 7

How long does it take amalgam to reach a full set?

Back 7

24 hours

Front 8

How many phases are there when the allow and the mercury are mixed?

Back 8

3

Front 9

What is the 1st phase called?

Back 9

Gamma Phase…it is the silver alloy phase

Front 10

Which phase is the strongest phase and involves the least corrosion?

Back 10

The gamma phase

Front 11

What is the phase called that consists of mercury reacting with silver?

Back 11

Gamma -1 Phase..it is strong and corrosion resistant.

Front 12

What is the third phase called and what does its reaction consist of?

Back 12

Gamma -2 Phase.
It's reaction is of mercury and tin.

*It happens many years later. Gamma -2 is weak and corrodes easily.*

Front 13

The oxidation that attacks the surface of the amalgam and can extend slightly below the surface is called….

Back 13

Tarnish…it results from CONTACT with oxygen, chlorides and sulfides in the mouth.

Front 14

Is the dark, dull appearance of tarnish destructive to the amalgam?

Back 14

No

Front 15

What causes corrosion?

Back 15

a CHEMICAL REACTION between amalgam and substances in saliva/food resulting in oxidation.

Front 16

What can occur when 2 dissimilar metals interact in a solution which contains electrolytes?

Back 16

Corrosion

Front 17

What is the electrical current called that occurs between dissimilar metals resulting in corrosion?

Back 17

Galvanism (galvanic shock)

Front 18

What is Creep?

(Besides a mean kid on the play ground)

Back 18

A gradual change in shape of the restoration.

Front 19

What causes Creep?

Back 19

Compression by the opposing dentition.

Front 20

What phase is Creep associated with?

Back 20

Gamma -2…can result in deterioriation of the margins and pitting of the restoration.

Front 21

What is the result of dimensional changes in the restoration?

Back 21

micro-leakage if it contract excessively or fracture of the cusps if the material expands too much

Front 22

What is a direct vs an indirect restoration?

Back 22

Direct is made chair side. Indirect is sent to a lab.

Front 23

What is among the strongest of the Directly placed restorations?

Back 23

Amalgams

Front 24

Amalgams are stronger in compression than _____________ or ______ ___________.

Back 24

Composites or Glass Ionomers

Front 25

_______ copper alloys are used almost universally as they have superior properties to _______ copper alloys.

Back 25

High-Copper

low-copper

Front 26

What is the most hygenic way to work with the dispensing opf alloy and mercury?

Back 26

Pre measured capsules.
(Chances for contamination of material of spills are fewer.)

Front 27

What is the machine called that powder and mercury are mixed in?

Back 27

Triturator or amalgamator

Front 28

What is the consistancy of properly mixed amalgam?

Back 28

Putty-like

Front 29

If the material is under-triturated, how will it appear?

Back 29

Dry and crumbly, its sets too quickly.

Front 30

If the material is over-triturated, how will it appear?

Back 30

Wet, it sets quickly producing heat

Front 31

What is the appearance of properly titrurated amalgam?

Back 31

Satin-like

Front 32

What is the material placed into after mixing?

Back 32

An amalgam well

Front 33

Amalgam is picked up in small increments with the use of….

Back 33

an amalgam carrier

Front 34

____________ are used to work the material into all areas of the tooth preparation?

Back 34

Condensers.

Front 35

Why must the tooth prep be over filled with amalgam?

Back 35

To allow room for carving the anatomy of the tooth.

Front 36

What is done before carbing to produce a smoother denser surface?

Back 36

Burnishing…it also helps to seal the margins and enhance the longevity of the restoration.

Front 37

What is it called where any restoration meets the natural surface?

Back 37

Cavosurface Margins

Front 38

What is a restoration called that goes beyond the tooth? In otherwards the restoration isn't flush with the tooth.

Back 38

An overhang.

Front 39

What are the risk with having an overhang? (4)

Back 39

Plaque retention
Floss breakage
Caries risk
Perio risk

Front 40

What should you check before cleaning a Pt's teeth who has amalgam restorations?

Back 40

Check the RADS to see if there are any visable overhangs first.

Front 41

What is it called when a restoration doesn't meet the bottom of the prep?

Back 41

Open Margin

Front 42

What types of problems can occur with open margins?

Back 42

Instruments can get caught
Recurrent caries,
Floss breakage
Gingival inflammation
Hypersensitivity

Front 43

What is an over contoured margin?

Back 43

A restoration with excess material in the interproximal area that doesn't need to be there.

Front 44

What difficulties can an over contoured margin create? (3)

Back 44

Gingival Inflammation
Caries and
Root Caries

Front 45

Excess material on the occlusal surface can cause….

Back 45

Flash

Results in hypersensitivity of the actual tooth and the opposing tooth.

Front 46

What is an undercontoured margin?

Back 46

A restoration that doesn't have enough material…isn't flush againts the tooth surface

Front 47

What is it called with there isn't enough material on the occlusal surface of a restoration?

Back 47

Ditch or Groove…can result in a food trap causing recurrent caries or hypersensitivity.

Front 48

What is the difference between finishing and polishing?

Back 48

Finishing: removes marginal irregularities

Polishing: brings the surface to a high luster using a sequence of mild abrasives.

Front 49

As a DH what can I do to finish a restoration?

Back 49

Use an ultrasonic scaler or a very sharp sickle scaler

Front 50

Concerning "Brownies" & "Greenies" which is used first any why to polish a surface?

Back 50

Brownines are used first. They are more abrasive and will remove the rougher spots first. Then follow with the greenies which are less abrasive.

Think of how you file your nails.

Front 51

What do Brownies & Greenies fit on?

Back 51

the polisher…they are pre-treated

Front 52

What do you do to extend the life of an amalgam restoration?

Back 52

Polish it in the following conditions:
Tooth anatomy can be maintained
Overhang is small/moderate
Proximal contact is intact
No caries/fractures present
Overhang is accessible
Tarnish and/or corrosion is present

Front 53

When should an amalgam be replaced?

Back 53

The overhang requres excessive time to reshape Recurrent caries is present
Contact is no longer intact
Margins are fractured, chipped or cracked.

Front 54

What should be avoided when finishing & polishing procedures?

Back 54

Avoid generating excessive heat…don’t want to damage the pulp or release mercury.

Front 55

Is amalgam bonded to the tooth surface or retained mechanically?

Back 55

Retained mechanically.
Think of the undercut in the prep as holding it in.

Front 56

When working with mercury what do you need to be sure and do?

Back 56

Wear proper PPE and be sure the space is well ventalated

Front 57

If an old amalgam restoration is being removed what do you need to do to minimize vapor?

Back 57

Use a water spray

Front 58

FYI --->

Back 58

Mercury is toxic at high levels. The amount of mercury that is released from a SET amalgam is minimal.

No substantiated research as proved otherwise!

Front 59

If you work with mercury in any form what must you have on hand?

Back 59

A Mercury Spill Kit!

*Remember disposing of amalgam must be done properly..there are commercial containers available for scrap amalgam disposal and recycling.*

Front 60

What do you NEVER EVER DO with amalgam scrap?

Back 60

Never throw into a trash can.
Must be disposed of properly.

Front 61

Another FYI -->

Back 61

Mercury Free Amalgam is no longer used in the US…not a good alternative
Be sure and educated PT's about pro's and con's of a material being used so they can make informed decisions.