Fluoride Release from Glass Ionomer Cements and Compomers in vitro

Objective: To measure the fluoride released from a group of glass ionomer cements and compomers, in vitro using the fluoride ion specific electrode over a period of four months. Materials and Methods: The daily fluoride release of three conventional glass-ionomer cements (Ketac-Fil, Fuji IX GP and Fuji VII), two light cured glass-ionomer cements (Fuji II LC and Vitremer) and two compomers (Dyract AP and F-2000) was measured over a period of four months. Ten cylindrical specimens (surface area= 1.996 cm²) were made of each of the materials, 10 mm in diameter and 1.5mm in thickness using the same mould. Measurements of the fluoride release in 5 ml of deionized water (25°C) were performed at intervals of one day, weekly for the rest of the first month, and monthly for the remaining three months. Results: A burst effect of fluoride release was observed initially with at least a ten-fold decrease occuring for all the materials by the end of the first week. Compomers were found to release significantly less fluoride than the glass-ionomer cements during the first four months. The (mean ± SD) daily fluoride release for the materials at four months was: Fuji VII (0.31± 0.06 ppmF), Ketac-Fil (0.31± 0.08 ppmF), Vitremer (0.27± 0.05 ppmF), Fuji II (0.12± 0.03 ppmF), FujiIX (0.09± 0.05 ppmF), F2000 (0.07± 0.05 ppmF) and Dyract (0.06± 0.01 ppmF). Conclusions: The most fluoride was released by Fuji VII and Ketac-Fil. Dyract released the least fluoride of all the materials.