Microleakage of resin-modified glass ionomer cement restorations: an in vitro study

Microleakage of two resin-modified glass ionomer cement (GIC) restorative materials was compared with that of two conventional GIC restorative materials. Forty-five noncarious extracted human molars were prepared with standardized Class V cavity outlines on the buccal and lingual surfaces. The occlusal margin was in enamel and the gingival margin was in dentin/cementum. All were restored according to the manufacturers' instructions. After thermocycling, 30 teeth were placed in 2% basic fuchsin dye for 24 h, sectioned and viewed with a stereomicroscope to assess microleakage. The other 15 teeth were sectioned, replicated and prepared for marginal gap evaluation using a SEM. Differences in microleakage scores between materials were compared using Kruskal-Wallis and Mann-Whitney U tests. One resin-modified GIC restorative material showed significantly less microleakage against enamel and dentin/cementum compared to the conventional GIC restorative (p < 0.01). Marginal gap formation for both resin-modified GIC restorations was limited to the axial wall of the restorations.