GIC vs RMGIC

glass/silica powder tartaric acid / polyacrylic acid Dissolution: silica powder and acid react. acid begins to dissolve the silica powder. Cations from the powder begin to leave the powder and into the surrounding medium. Gelation: calcium bivalve to ions begin to cross link between carboxylic acid chains from the polyacrylic acid. Hardening: Ca double crosslink matrix is replaced by trivalent aluminium ions.

Same as GIC with acid base reaction resulting in silica dissolution. Light activation then initiates free radical addition polymerisation of the methylacrylate. This creates a solid resin component. Within solid resin component, the acid base reaction carries on for multiple hours to harden within the resin component.

class 5 or 3 restorations fissure sealants cavity base / liners temporary endodontic fillings orthodontic cement deciduous restorations

low micro-leakage high fluoride release no contraction on setting chemical bond to enamel and dentine good thermal properties once set; less prone to discolouration or staining compared to composite

poor handling and wear resistance moisture dependant, if water interacts then will set it early. Swelling due to water content and uptake - decrease strength brittle poor aesthetically and translucency

less water sensitive (still a little due to HEMA) good thermal properties light curing chemical bond to enamel and dentine little micro-leakage better aesthetics and translucency fluoride release

less fluoride than GIC brittle and poor handling monomer leaching can cause pulp toxicity from resin component contraction on setting due to resin component exothermic setting water uptake due to hydrophilic HEMA

Dissolution and acid attack as seen in conventional GIC Redox reaction begins Then photo initiation of the dimethylacrylate model through light curing. Resin component sets Redox carries on for around 5 minutes Acid base carries on for multiple hours.

Pre-existing calcium in enamel forms cross links between carboxylic acid chains on polyacrylic acid.

Through contamination. Aluminium ions may diffuse out of the GIC, excess drying may also result in water loss. Saliva contamination too All of these cause the GIC to weaken. It can be avoided by covering the GIC restoration / liner etc with either a varnish, a resin or petroleum jelly.