Evaluation of the Fluoride Releasing and Recharging Abilities of Various Fissure Sealants

Purpose: To evaluate the fluoride release from different fissure sealants sold mainly in non-Western countries via a curve-fitting method, and to investigate the ability of these materials to be recharged with fluoride. Materials and Methods: Four different fissure sealants which the manufacturers claim to release F- were tested; glass-ionomer cement Argecem (AC), the composite resins Fisskhim (FK), Fissulight (FL), Helioseal F (HF). Helioseal (HS), a composite resin not declared to release F, was used as a negative control. Of each material, 10 disks 8.0 mm in diameter and 1.8 mm thick were produced. For fluoride measurements, a fluoride-ion specific electrode was used. On day 21, the specimens were recharged with fluoride by immersion in toothpaste slurry. Fluoride release was evaluated and statistically compared by fitting an exponential curve through the cumulative release values and statistically comparing curve parameters (t½, AUC and plateau value) among each other as well as before and after recharging. Results: Two materials (AC and HF) released a considerable amount of F- in the first 3 weeks after sample production. Furthermore, the increase of F- release after F- recharge was statistically significant (p 0.05) for the materials AC, FL and HF, but not for FK and HS. Conclusion: Fluoride release of Fisskhim and Fissulight was negligible, while Helioseal F and Argecem noticeably released fluoride and thus can enhance the caries preventive effect of fissure sealants. Comparing release curve parameters simplifies statistical procedures. Keywords: composite resin, fluoride, glass-ionomer cements, release curves, sealants