Glass Ionomer Cement

Question 1

Name the components of the Polyacid

Answer 1

Polyacrylic acid - copolymers of acrylic and itaconate

Tartarate- alters the setting characteristics

Question 2

Name the components of the powder base

Answer 2

Silica 
Alumina
Calcium Fluoride
Sodium Fluoride
Aluminium Fluoride

Question 3

What increases radiopacity of GIC

Answer 3

The inclusion of strontium and lithium salts in the powder base

Question 4

Recite the setting reaction for GIC

Answer 4

MO. + SiO2 + H2A –> MA + SiO2 + H2O

Glass + acid > Salt + Silica gel and water

Question 5

Discuss Dissolution

Answer 5

• acid into solution
• H+ ions attack glass surface
• Ca, Al, Na, F
• leaves silica gel around unreacted glass

Question 6

Discuss Gelation

Answer 6

• 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

Question 7

Discuss Hardening

Answer 7

• Aluminium ions cause cross linking
• trivalent molecule
• forms aluminium polyacrylate
• improves mechanical properties

Question 8

List properties of GIC

Answer 8

• 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