Resin Modified Glass Ionomer Cements Flashcards Preview

BDS2 Dental Material Science > Resin Modified Glass Ionomer Cements > Flashcards

Flashcards in Resin Modified Glass Ionomer Cements Deck (11)
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1
Q

what is the chemical composition of the powder of RMGIC?

A
  • fluro-alumino-silicate glass
  • barium glass
  • vacuum dried polyacrylic acid
  • potassium persulphate
  • ascorbic acid
  • pigments
2
Q

what is the purpose of potassium persulphate in RMGIC?

A

redox catalyst to provide resin cure in the dark

3
Q

what is the chemical makeup of the liquid aspect of RMGIC?

A
  • HEMA
  • polyacrylic acid with pendant methacrylate groups
  • tartaric acid
  • water
  • photo-initiators
4
Q

what is HEMA?

A

water miscible resin

5
Q

what is the purpose of tartaric acid found in RMGIC?

A

speeds up the setting reaction

6
Q

what photoinitiator tends to be found in RMGIC?

A

camphorquinone

7
Q

what is different about the setting reaction of RMGI compared to GI?

A
  • on mixing the acid base reaction begins in the same way as GIC
  • the redox reaction begins
  • on light activation a free radical methacrylate reaction occurs resulting in a resin matrix being formed
  • the redox reaction continues for about 5 mins after mixing
  • acid base reaction continues within the resin matrix for several hours
8
Q

what are some good properties of RMGI/

A
  • good bond to enamel and dentine
  • better physical properties (compared to GI because of resin matrix)
  • lower solubility
  • fluoride release
  • better translucency and aesthetics
  • better handling
9
Q

some negative properties of RMGIC compared to GIC?

A
  • polymerisation contraction
  • exothermic setting reaction
  • swelling due to uptake of water (HEMA is v hydrophilic)
  • monomer leaching
  • reduced strength if not light cured
10
Q

overall, what makes RMGIC superior to GIC?

A
  • better aesthetics
  • easier to use
  • stronger
11
Q

what are advantages of using RMGIC over composite?

A
  • easier to use

- fluoride release