Evaluation of Fluoride Release, pH and Microhardness of Glass Ionomer Cements

Objective: To evaluate fluoride release, pH and microhardness of glass ionomer cements (GIC). Material and Methods: Four different cements: Vidrion (R) R (G1), Vitro Fil (R) (G2), Maxxion (R) (G3) and Magic Glass (R) (G4) and a composite resin (G5 control group) comprised the sample. Thirty specimens were manufactured (10 mm x 3 mm) and stored in deionized water. Analyses were performed after 24 hours, 7 days and 28 days. The following devices were used for measurements: fluorometer, pH meter and microhardness tester. Data were analyzed by Kruskal-Wallis, Mann-Whitney, Friedman and Wilcoxon tests (a = 0.05) using the SPSS (R) software (Statistical Package for Social Sciences) version 17. Results: GICs were able to release fluoride; however, the amount released decreased with increasing immersion time (p < 0.002). The pH of all products increased over time, the lowest value was identified for Magic Glass (5.93) and the highest for Maxxion (6.94) at time of 24 h. Materials showed significant decrease in surface microhardness, especially G4 for presenting the lowest recorded values (p < 0.05). Conclusion: GICs are fluoride-releasing restorative materials with pH favorable to oral homeostasis and good mechanical behavior.