The resin modified glass ionomer cements(RMGICs) have been used for years since 1989.
Recently it has been developed for luting of fixed restorations. To evaluate the bond strength and
marginal leakage of RMGICs for luting usage, the 80 extracted human molars which had uniform
area of exposed dentin were cemented with 3 types of RMGICs(Fuji Duet, Advance, Vitremer), a
conventional Glass Ionomer Cement(GIC-Fuji I), and a resin cement(Panavia 21) to base metal
alloy(Ni-Cr-Be). After thermocycling the specimens were immersed in basic fuschin dye for
measuring marginal leakage. The shear bond strength was measured with Instron and the
maximum dye penetration was measured to 0.1mm. The type of fractured patterns were
determined with stereoscope(×7.5). The results are as follows.
1. The difference between 3 RMGICs and a conventional GIC in shear bond strength was not
statistically significant. It seemed that RMGICs had lower shear bond strength than resin
cement.(p<0.01)
2. The mean scores of marginal leakage had no significant difference between the resin cement
and 3 RMGICs but it was much higher in conventional GIC than the RMGICs(p<0.05)
3. It was determined that the manufacturer and the methods of dentin pretreatment determined
the pattern of fracture surface and the frequency of adhesive failure between teeth and 3
RMGICs standed as in following order-Vitremer, Advance, Fuji Duet.(p<0.01)
When the fracture pattern was analyzed, it could be said that the materials and the method of
dentin pretreatment have much effect on bonding states. This means that the dentin bonding
agents should be improved. But the limited products in this experiment can not evaluate the
physical properties of the entire RMGICs. Therefore a further study which can evaluate various
RMGICs should be in progress to develop better cements.