Comparison of shear bond strength of a composite resin to resin modified and conventional glass ionomer using different bonding systems

Glass ionomers are often used as a base under composite restorations in deep cavities by sandwich technique. The aim of this study was to compare the shear bond strength of composite to resin modified and conventional glass ionomer using total etch , self-etch and universal bonding systems.

Ninety glass-ionomer samples were prepared for this research: Fuji II (F II), IonoStar Plus (IS) and Fuji II LC (F II LC).Then the specimens were divided into 9 groups (n=10). The surface of the specimens were prepared with three types of bonding: Adper single bond2 (SB), Clearfil SE bond (SE) and Single bond Universal (SU).Then Z250 composite resin was applied on the glass ionomers. The specimens were incubated in distilled water for 24 hours at 37 ° C and then were tested for shear bond strength. The type of failure was determined by a ×40 stereomicroscope and the results of the study were analyzed by nonparametric statistical analysis and Kruskal Wallis test. P≤0.05 was considered significant.

The highest shear bond strength was observed in the Fuji II LC + Single bond2 group. There was a statistically significant difference in the shear bond strength of the composite to the two glass ionomers F II and F II LC using SB and SU bonding systems (P=0.033 and P=0.040, respectively).There was no significant difference between the groups regarding the type of failure.

Unlike the Fuji II LC and IonoStar Plus glass ionomers, the shear bond strength of the composite to the Fuji II conventional glass ionomer is affected by the type of bonding system. Total-etch and self-etch bonding systems can be used effectively in sandwich technique. Using a resin modified glass ionomer with total etch bonding can improve the shear bond strength of the composite to the glass ionomer.