Summary cards

Question 1

What is the composition of dental amaglam?

Answer 1

50% mercury
50% metal alloy

Question 2

what is in dental amalgam alloy?

Answer 2

silver, tin, copper, zinc

Question 3

what is silver and coppers properties in dental amalgam?

Answer 3

strength

Question 4

what is tins properties in dental amalgam?

Answer 4

corrosion

Question 5

what is zincs properties in dental amalgam?

Answer 5

deoxidiser - prevents oxidisation of other metals in the alloy

Question 6

what happens to zinc in dental amalgam is contaminated with moisture?

Answer 6

it can expand

Question 7

what is it called when amalgam is mixed?

Answer 7

trituration

Question 8

what components are involved in the setting reaction of dental amalgam?

Answer 8

mercury and silver

Question 9

what does dental amalgam setting reaction involve in?

Answer 9

3 phases:
Y
Y1
Y2

Question 10

What is the Y phase of dental amalgam setting?

Answer 10

unreacted silver-tin alloy

Question 11

what is the Y1 phase of dental amalgam setting?

Answer 11

strong silver-mercury matrix

Question 12

what is the Y2 phase of dental amalgam setting?

Answer 12

weak tin-mercury

Question 13

why is the Y2 phase of dental amalgam setting weak?

Answer 13

susceptible to corrosion and creep

Question 14

what is creep?

Answer 14

deformation of amalgam under compressive stress

Question 15

on trituration what are the dimensional changes?

Answer 15

30mins shrinkage
30-60mins

Question 16

what is an advantage of corrosion products?

Answer 16

margin seal

Question 17

when does dental amalgam reach its peak strength?

Answer 17

24 hours

Question 18

what are the 2 alloy types for dental amalgam?

Answer 18

conventional
high copper

Question 19

what percentage of copper differentiates types of amalgam alloys?

Answer 19

12%

Question 20

why is high copper alloy better for dental amalgam?

Answer 20

doesnt result in Y2 phase = less corrosion and creep

Question 21

what are the 2 types of dental amalgam alloy particles?

Answer 21

spherical and admixed (spherical and lathe-cut)

Question 22

what are 3 advantages of a spherical alloy for dental amalgam?

Answer 22

easier to condense
stronger
sets faster

Question 23

what is an advantage of an admixed alloy particle for dental amalgam?

Answer 23

better proximal contact

Question 24

what minimum depth should amalgam be placed in?

Answer 24

2mm

Question 25

how should dental amalgam be placed and filled?

Answer 25

in 2mm increments overpack carve back mercury layer

Question 26

are enamel or dentin bonds weaker?

Answer 26

dentine

Question 27

why are enamel bonds stronger than dentine?

Answer 27

enamel has more mineral content enamel rods are parallel and more etchable

Question 28

why has dentine got weaker bonds than enamel?

Answer 28

more organic matter and water collagen fibres that are maze like dentinal fluid smear layer

Question 29

what is used for acid etching?

Answer 29

30-40% phosphoric acid

Question 30

how long do you leave acid etch on for?

Answer 30

15 seconds

Question 31

what does acid etching do?

Answer 31

cleans surface debris and removes smear layer widens dentinal tubules

Question 32

what does enamel look like after it has been etched?

Answer 32

frosty white

Question 33

what component of primer allows for a good bond?

Answer 33

HEMA

Question 34

How does HEMA allow for a good bond?

Answer 34

infiltrates enamel prisms and dentinal tubules and WETS dentine to prevent collagen collapsing

Question 35

what are the contraindications of HEMA in primers?

Answer 35

can cause allergic reaction on skin - contact dermatitis

Question 36

What is the component of bond/ adhesive?

Answer 36

Bis-GMA

Question 37

What does bond/ adhesive do?

Answer 37

chemically bonds to underlying primer and overlying composite resin

Question 38

what is the key to great bond strength?

Answer 38

hybrid layer

Question 39

what does the hybrid layer create?

Answer 39

mechanical interface between tooth and adhesive

Question 40

what are resin tags?

Answer 40

extensions of primer into dentinal tubules

Question 41

what is resin composite made of?

Answer 41

resin matrix (Bis-GMA) and glass filler particles (silica)

Question 42

what is in resin composite that promotes adhesion between resin matrix and filler?

Answer 42

coupling agent

Question 43

what does coupling agent do in resin composites?

Answer 43

coats filler particles to promote adhesion between resin matrix and filler

Question 44

what makes resin composite radioopaque?

Answer 44

filler

Question 45

what setting reaction does resin composite undergo?

Answer 45

polymerisation

Question 46

what are the 2 pastes involved in self curing composite?

Answer 46

benzoyl peroxide (initiator) tertiary amine (activator)

Question 47

what component allows composite to be light cured?

Answer 47

camphorquione (photo initiator)

Question 48

how strong does light need to be to initiate polymerisation?

Answer 48

468nm

Question 49

What makes up a glass ionomer?

Answer 49

acid (polyacrylic acid) base (aluminosilicate glass)

Question 50

what are the good properties of glass ionomer?

Answer 50

self-adhesion to tooth fluoride release less overall shrinkage

Question 51

what process makes glass ionomer self adhesive?

Answer 51

chelation

Question 52

what are the bad properties of glass ionomer?

Answer 52

weaker longer setting time lack of control when setting

Question 53

adding light curing resin to glass ionomer makes it a?

Answer 53

resin-modified glass ionomer

Question 54

what setting reactions do resin-modified glass ionomers undergo?

Answer 54

acid base free radical addition polymerisation

Question 55

what ways can resin-modified glass ionomers be set?

Answer 55

light and/or chemical

Question 56

what is vitrebond??

Answer 56

resin-modified glass ionomer liner

Question 57

what are good properties of resin modified glass ionomers?

Answer 57

more rapid polymerisation fluoride release

Question 58

if a cavity is deep to pulp what would you use before vitrebond and why?

Answer 58

dycal as vitrebond is an irritant to pulp