Evaluation of the fluoride release and ability to recharge in different glass ionomer cements

Objective To evaluated the ability to fluoride release and recharge in the different glass ionomer cements during simulation of cariogenic challenge. Material and method Twelve samples were made for each experimental group: conventional glass ionomer cements, Maxxion R (FGM), Ketac Molar EasyMix (3M ESPE); resin modified glass ionomer cement, Vitrebond (3M ESPE); and composite resin Filtek™ Z350XT (3M ESPE), negative control. The samples were immersed alternately in pH cycling method, remaining 6 hours in demineralization solution and 18 hours in remineralization solution and maintained at 37 °C. Fluoride release was measured 1, 2, 7, and 14 days before and after recharging with specific electrode coupled to the analyzer apparatus pH/fluoride, each measurement with calibrated solutions of sodium fluoride to 1 and 10 ppm, prepared with TISAB II. For reading was added 0.5 mL of sample to an equal volume of TISAB II. Recharging was made with neutral sodium fluoride to 2% for 4 minutes in the samples, washed and again immersed pH cycling solutions. Data were subjected to two-way ANOVA and Tukey’s post-hoc test (α = 0.05). Result The initial fluoride release (μgF/cm2) was 45.36 ; 37.49 and 26.35 for Maxxion R, Vitrebond and Ketac Molar EasyMix, respectively. Significant differences between the materials before and after recharging were observed (p=0.001). After topical application of fluoride, both showed ability to recharge. Conclusion The glass ionomer cements evaluated were capable of releasing fluoride in pH cycling solutions and may recharge through of a topical application.