Methods: The glass ionomer containing restoratives included in this study were Fuji IX Extra (FE), Fuji IX Fast (FF), Fuji II LC (FL) and Beautifil II (BF). Six specimens of each material (8.5mm x 1mm) were prepared and allowed to mature for 24 hours at 370C ± 100% humidity. The matured specimens were immersed in 15ml of deionized and the medium was changed weekly for 4 weeks. After 28 days, the specimens were recharged using Colgate Total (CT) and Tooth mousse (TM). The re-release values of fluoride were determined using Combination Ion selective electrode Model 9609 BNWP (Orion Research, Beverly, USA). Statistical analysis was performed using one way Anova, Post hoc Scheffe's.
Results: For CT, FE, FF and FL re-released significantly more fluoride than BF for days 1 and 2. The highest amount of fluoride re-release was observed by FE (0.5 ± 0.04 ppm) whereas BF re-released the least (0.03 ± 0.002 ppm). From day 3 to 7, FE re-released the highest amount of fluoride followed by FF, FL and BF. For the recharge medium TM, a generally similar trend was observed.
Conclusions: The amount of fluoride re-released after recharging varies with the material type and recharge medium used. FE and FF showed more re-release of fluoride than FL and BF.