Fluoride release and neutralizing effect by resin-based materials.

This study evaluated the fluoride-releasing and neutralizing abilities of resin-based materials containing fluoride in water and aqueous lactic acid. Two composites, containing a low-solubility fluoride component (Heliomolar) and a fluoroalumino-silicate glass (UniFil S), and two giomers, containing surface reaction type prereacted glass-ionomer filler (Beautifil) and full reaction type glass-ionomer filler (Reactmer paste), were used. Resin-modified glass-ionomer cement (Fuji II LC) was used as a control. The fluoride release and pH value in storage medium, after immersion in each material, was measured for 10 weeks. For UniFil S and Beautifil, the amount of fluoride released in acid solution markedly increased compared to storage in water (p<0.05). Although all materials, except Heliomolar, neutralized the storage media, the neutralizing ability of these resin-based materials in acid solution sharply decreased with aging of the specimens, except for Fuji II LC. These results suggest that the nature of fluoride incorporated into resin-based materials affect the fluoride-releasing and neutralizing ability of materials in water and aqueous lactic acid.