Fluoride release of orthodontic cements before and after recharge with fluoride solution

Purpose: This study aimed to compare the fluoride release from glass ionomer cements (GIC) used for orthodontic cementation, before and after fluoride recharge. Methods: Three GIC were evaluated: Meron (VOCO), Vidrion C (SS WHITE), and Ketac-Cem (3M ESPE). Fluoride release was measured by means of an ion selective electrode connected to a ion analyzer after 1 h and 1, 3, 7, 14, 21 and 28 days. To analyze the fluoride recharge and capacity of fluoride retention, the specimens were immersed in a 0.221 % sodium fluoride solution (1,000 ppm fluoride) for 5 min at days 28, 30, 31 and 32 for fluoride measurement after 24 h. Data were analyzed by ANOVA and Kruskal-Wallis test at the significance level of 0.05. Results: The pattern of fluoride release was similar for the tested GIC: all materials showed higher fluoride release at the first day and a fast decrease up to day 7. The exposure to the fluoride solution provided higher fluoride release from all materials, but the fluoride levels were not as high as in the first day. Conclusion: Overall the cements Meron and Vidrion C had larger fluoride release rates than Ketac-Cem, before and after fluoride recharge. The use of fluoride solution may increase the quantity of fluoride released from GIC. Key words: Glass ionomer cement; fluoride