RMGI Flashcards
what is the purpose of adding resin to GIC?
light curing (command set)
improved physical properties
better aesthetics
what are the powder components?
fluro-alumino-silicate glass barium glass -rpovides radiopacity vacuum dried polyacrylic acid potassium persulphate -redox catalyst provides resin cure in the dark ascorbic acid pigments
what are the liquid components of RMGI?
HEMA -water miscible resin polyacrylic acid w/ pendant methacrylate groups tartaric acid -speeds up setting water -allows reaction between polyacid and glass photo-initiators
what is dual curing?
initially on mixing the acid base reaction begins in same way
light activation - free radical methacrylate reaction occurs resulting in formation of resin matrix
acid base reaction continues w/i resin matric for several hours
why does RMGI need to be placed in layers?
materials quite opaque so light does not penetrate deeply into the material
redox caused problem
describe tri curing
initial acid base reaction
redox begins
free radical formation result in resin matric
redox continues
acid base continues in resin matrix for several hours
final hardening of acid/base with aluminium polyacrylate formation can take days
what are the advantages of RMGI?
good bond to enamel and dentine lower solubility fluoride release better translucency and aesthetics better handling
what are the disadvantages of RMGI?
polymerisation contraction exothermic setting reaction -polymerisation & dark cure swelling due to uptake of water -HEMA extremely hydrophilic monomer leaching -HEMA toxic to pulp must be polymerised completeky reduced strength if not light cured
compare RMGI to GIC
better aesthetics
easier to use
stronger
compare RMGI to composite
easier to use
fluoride release
uses?
dressing fissure sealant endodontic access cavity temporary filling luting orthodontic cement restoration deciduous rest. base/lining similar to GIC but more common for rest/linings
when is RMGI/GIC more appropriate?
RMGI better for anterior’s GIC better for posteriors
