Effect of Time, Temperature, and Storage on Fluoride Release and Recharge of Esthetic Restorative Materials

Introduction: The fluoride-containing restorative materials act as fluoride reservoir and release fluoride into the oral fluids gradually, thereby inhibiting secondary caries and restoration failure. The study can be utilized to develop improved regimes for topical fluoride delivery. The study evaluated and compared the influence of temperature, time, and storage conditions on the fluoride release and recharge of esthetic restorative materials. Materials and Methods: Silorane-based composite, methacrylate-based composite, compomer, and glass ionomer cement (GIC) were investigated for fluoride release and recharge with the fluoride selective ion electrode after immersion in distilled water and artificial saliva at 4°C, 37°C, and 55°C. Comparison between immersion media was performed with student t test, and comparison between materials and time interval (weeks and days) was performed with one-way ANOVA and Tukey post hoc test. The assessment of variation over time was assessed with repeated measures ANOVA. P-value was established to be significant at P < 0.05. Results: The highest rerelease was seen with GIC, followed by Dyract AP, Filtek P90, and Z100. Fluoride rerelease was greatest in GIC followed by Dyract AP in artificial saliva when compared to distilled water. Fluoride release was more significant at a higher temperature of 55°C. Also, fluoride recharge was highest at week 3 where the greatest rerelease was seen on day one. Conclusion: Fluoride release and recharge increase with temperature, time interval, and in artificial saliva.