Marginal leakage of combinations of glass-ionomer and composite resin restorations.

This study compared the microleakage of four different combinations of glass-ionomer and composite resin restorations. Forty class V cavities were prepared in permanent posterior teeth. The gingival margin of the cavities were placed in cementum and the occlusal wall in enamel. The cavities were restored as either 1) light-cured glass-ionomer cement (LC-GIC); 2) chemically cured glass-ionomer cement (CC-GIC); 3) composite resin (with dentin bonding agent); or 4) light-cured glass-ionomer and composite resin (sandwich). Marginal microleakage was assessed by methylene blue dye penetration after thermocycling between 5 degrees C and 60 degrees C for 300 cycles. Microleakage of LC-GIC restorations and the dentin-bonded composite resin restorations were significantly lower than the CC-GIC and the LC-GIC sandwich technique restorations. There was no significant difference in the microleakage between the LC-GIC and the dentin-bonded composite resin restorations. The degree of microleakage of the sandwich restorations was significantly lower than the CC-GIC restorations. Light-cured glass-ionomer and dentin bonded composite resin restorations exhibited a lower degree of leakage than the glass-ionomer/composite sandwich and chemically cured glass-ionomer restorations at the gingival margins of class V restorations.