Fluoride, hydrogen ion and HEMA release from light-cured GIC restoratives

To quantitatively measure the amount of fluoride, hydroxy ion and hydroxyethyl methacrylate (HEMA) released from various light-cured restorative materials.

Three resin-modified glass-ionomer cements (RMGI): Photac-Fil Aplicap, Vitremer, and Fuji II LC and two polyacid-modified resin-based composites (compomer): Dyract and Variglass VLC were used in this study. Disc-shaped specimens were made as per manufacturer's recommendations and the surfaces were polished with a 600 grit abrasive paper. Immediately after setting, each disc was immersed into 10 ml of distilled water at 37 degrees C and the eluates were collected after 8- or 24-hour immersion. The concentration of HEMA in the eluate was determined by high performance liquid chromatography. In addition, the concentration of fluoride ion and pH were measured by the respective ion selective electrode.

The RMGIs released the greater amount of fluoride and smaller amounts of HEMA compared to the compomers at both the 8- and 24-hour eluates. Although there were no significant differences in pH of the 8-hour eluates among the restoratives, the pHs of the RMGI were significantly higher than those of the compomers for the 24-hour eluates.