Fluoride Release, Recharge, and Mass Stability of Restorative Dental Materials: An In Vitro Study

Background/Objectives: Fluoride ion plays a crucial role in protecting teeth against caries by re-mineralizing the caries lesion. The objective of this study was to quantify and compare the fluoride release and recharge of restorative dental materials and their correlation with mass stability. Methods: For this study, 5 × 5 × 2 mm blocks were prepared from GIC, RMGI L, GIOMER, Resin Composite, and RMGI R using a customized silicone index. The amount of fluoride released from each material was quantified using a fluoride electrode at 0 h, 1 day, 3 days, 1-week, and 2-week periods. The fluoride recharge of each material was calculated by quantifying the amount of fluoride uptake from high concentration fluoride solution over a period of 1-week. The mass stability of the materials was measured be quantifying the weight loss/weight gain during fluoride release and recharge phase. The correlation of fluoride release/recharge with weight loss/gain were analyzed using Pearson correlation. Results: One-way ANOVA showed a statistically significant difference in the amount of fluoride released from each group (p < 0.05). The maximum amount of fluoride release was observed on the 3rd day in all the groups except the GIC group, which showed an ascending concentration of fluoride release till 2 weeks. One-way ANOVA showed statistically significant differences in weight loss/gain among the rested group (p < 0.05). GIC showed the highest amount of weight loss and weight gain among the tested materials. Conclusions: The GIC material has the highest fluoride release and RMGI L has the highest fluoride recharge capability. The conventional GIC showed the least mass stability during fluoride release/recharge.