Glass Ionomer Cement Flashcards
1
Q
Name the components of the Polyacid
A
Polyacrylic acid - copolymers of acrylic and itaconate
Tartarate- alters the setting characteristics
2
Q
Name the components of the powder base
A
Silica Alumina Calcium Fluoride Sodium Fluoride Aluminium Fluoride
3
Q
What increases radiopacity of GIC
A
The inclusion of strontium and lithium salts in the powder base
4
Q
Recite the setting reaction for GIC
A
MO. + SiO2 + H2A –> MA + SiO2 + H2O
Glass + acid > Salt + Silica gel and water
5
Q
Discuss Dissolution
A
- acid into solution
- H+ ions attack glass surface
- Ca, Al, Na, F
- leaves silica gel around unreacted glass
6
Q
Discuss Gelation
A
- Initial set is due to Ca2+ ion cross linking w/ polyacid matrix
- bivalent so can bind to two carboxyl groups
- chelation can happen
- formation of calcium polyacrylate
7
Q
Discuss Hardening
A
- Aluminium ions cause cross linking
- trivalent molecule
- forms aluminium polyacrylate
- improves mechanical properties
8
Q
List properties of GIC
A
- Can bond to tooth w/o use of prime and bond
- poor bond strength
- poor tensile strength
- high solubility compared to other materials
- usually seals well
- Fluoride release
- carboxyl group bond to calcium in enamel