Fluoride Release of a New Nano-Ionomer Restorative Material

Objective: To compare the long term fluoride release of a novel resin-modified glass ionomer (RMGI) restorative material versus other RMGI and conventional glass-ionomers (GI).  Methods: Materials used were Ketac^TM Nano nano-ionomer (KN, 3M ESPE), Vitremer^TM (VM, 3M ESPE), Fuji IX (F IX, GC) and Fuji II LC (F II LC, GC). Fluoride release from three cured discs (20 x 1 mm) of each product in 37C deionized water was measured after 1, 7, 14, 28, 120, 180 days using fluoride selective electrode and TISAB buffer solution.  Results: The mean values for cumulative fluoride release, including the standard deviations, are summarized in the following table:

		Cumulative Fluoride Release after following Days (micro g F / g sample)
Material	Chemistry	1	7	14	28	120	180
KN	RMGI	292 ± 28	781 ± 59	1071 ± 63	1358 ± 65	1933 ± 105	2285 ± 106
VM	RMGI	365 ± 26	734 ± 84	940 ± 85	1249 ± 87	1876 ± 88	2309 ± 89
F II LC	RMGI	254 ± 5	701± 30	991 ± 32	1183 ± 34	1846 ± 41	2266 ± 55
F IX	GI	160 ± 30	399 ±  50	557 ± 51	698 ±  53	937 ± 55	1053 ± 58

Conclusion: ANOVA analysis was performed at p < 0.05 per Tukey's pairwise comparison test. While the six-month cumulative fluoride release of KN nano-ionomer, VM and F II LC, all resin modified glass-ionomer, were statistically comparable, they significantly released greater fluoride than F IX, a conventional glass-ionomer.  All conventional and resin modified glass-ionomer restorative materials exhibited sustained fluoride release over six months.