Resin-modified Glass Ionomer

Question 1

In terms of components, what is the main difference between GI and RMGI?

Answer 1

RMGI has HEMA, which is a resin. This makes the material much stronger.

Question 2

What happens in a dual cure RMGI?

Answer 2

Acid-base reaction occurs (same as GI), where hardening can take up to a few weeks ti fully set.
At the same time, following light cure, there is a polymerisation reaction with the HEMA, which forms a resin matrix.

Question 3

What happens in a tri cure RMGI?

Answer 3

Acid-base reaction (several days)
Redix reaction (dark cure) 5 minutes
Light activation, free radical methacrylate reaction occurs to form a resin matrix- 20 seconds.

Question 4

Name advantages of RMGI

Answer 4

Good bond to enamel and dentine
Better physical proeprties- stronger
Lower solubility
Fluoride release
Better aesthetics

Question 5

Name disadvantages of RMGI

Answer 5

Polymerisation contraction stress
Exothermic setting reaction- polymerisation and dark cure
HEMA is toxic to the pulp- must be cured completely.