Microleakage comparison of dentin bonding systems with glass ionomer

Glass-ionomer cements have been suggested as substitutes for dentin-bonded composites. This investigation was designed to compare microleakage of glass-ionomer restorations with that of dentin-bonded composite restorations. Eighty extracted human molars were used in this study. Class V cavities were prepared on the mesial and distal surfaces of each tooth. The distal cavities were restored with Ketac-Fil Glass Ionomer (ESPE). The mesial cavities were divided into four groups and treated with four different dentin bonding systems: Gluma (Columbus Dental), Tenure (two-part powder system; second version, Den-Mat), Scotchbond 2 (3M), and an experimental ferric oxalate system. The commercial materials were placed according to the manufacturers' instructions. The teeth were then thermocycled 3800 cycles between 5 degrees C and 55 degrees C, subjected to silver nitrate staining, and sectioned for microleakage evaluation by three evaluators on a scale of 0 to 4. The ferric oxalate system exhibited significantly less microleakage (median score = 1; Wilcoxon paired testing, p = 0.01) than the glass ionomer (median score = 3). The other dentin bonding systems were similar in microleakage to the glass ionomer (median score = 3).