Short- and long-term fluoride release from glass ionomers and other fluoride-containing filling materials in vitro.

Test specimens of seven different glass ionomer filling materials and one fissure sealant were exposed to running water for 2 yr. One amalgam and one composite, both containing fluoride, were included for comparison. The fluoride release from the specimens was measured periodically after storing the specimens for 24 h or 1 wk in a small amount of water. The fluoride release from the glass ionomers decreased with time and a constant level was reached for most products during the 2-yr period. The release was increased by lowering the pH of the storage solution. The release from the glass ionomers was clearly greater than from the amalgam and the composite.