Fluoride Release and Recharge Ability of A Novel Fluoride Release Composite Resin

Objective: To evaluate the fluoride release rates and fluoride recharge capability of a experimental resin composite, a compomer, a giomer and a resin-modified glass ionomer cement. Methods: Ten disc specimens of each material were prepare and polished with abrasive paper, followed by clearing with oil-free compressed air jet. The specimens were placed in a plastic vessel containing 5ml deionized water immediately after fabrication. Each specimen was removed and put to a new a vessel containing deionized water each day, and the sample solution was test for fluoride concentration each day using a compound fluoride ion selective electrode and a conductivity meter. All specimens were removed from container after 28 days and were "recharged" by immersing in a fluoride foam solution for four minutes. Then fluoride release from these recharged samples was measured daily for 7 days. Recharge was repeated three times. Result: Fuji II LC demonstrated the highest fluoride release (p <0.01), followed by experimental resin and Compoglass. Both Beautufil and Charisma presented the lowest fluoride release (p <0.01) during the first two weeks. All materials except Charisma demonstrated a sharp decline of fluoride release, followed by a comparatively stable stage of fluoride release for about twenty days. All materials presented fluoride release increase substantially one day after recharge but declines rapidly almost to the baseline level after 2 days except for Fuji II LC that showed a continual fluoride release for 5 days. Conclusion: The experimental composite resin has a capability of fluoride release and recharge that are comparable to compomers.