Fluoride release from dental materials

Objective: to evaluate, in vitro, the fluoride (F) release of four dental materials (3M-Espe), testing the hypothesis that the conventional glass ionomer cement (GIC) release more F than other materials. Methods: The materials used were as follows: KME- GIC (Molar Ketak Easymix); RX2- resin modified GIC (RMGIC) (Rely-X luting 2); VIT- RMGIC (Vitremer); Z250(control)- resin composite (Filtek Z250). The F release was evaluated in four periods: 1, 7, 14 and 28 days. The specimens (surface area= 86,4mm²) were made using a plastic matrix. Three specimens were made for each period. The specimens were placed into 10 ml of 37°C high-purity water by reverse osmosis until the analyses, which were done using a liquid membrane for selective F ion electrode (Orion 710). One reading/day was done for the periods of 7, 14 and 28 days and 4 readings were done in day 1. Data was statistically analyzed using Anova and Tukey. Results: Mean F release and standard deviation values (in ppm) are as follows.

	RX2	VIT	KME	Z250
6 h	A 2.46±0.48 b	B 0.98±0.35 b	C 0.34±0.04 b	D 0.02±0.001 a
1 day	A 14.93±2.85 a	B 2.92±0.87 a	C 1.46±0.35 a	D 0.01±0.001 a
7 days	A 1.59±0.31 bc	AB 0.71±0.15 b	BC 0.33±0.03 b	D 0.02±0.001 a
14 days	A 0.74±0.10 c	A 0.39±0.04 b	A 0.17± 0.006 b	B 0.02±0.001 a
28 days	A 0.79±0.21 c	A 0.39±0.08 b	A 0.16±0.01 b	B 0.02±0.001 a

Different capital letters in front of the values denote statistical differences in the line and different small letters after the values show differences in the column. Conclusion: RX2 released more F than the other materials in all periods (p<0,05). The greatest F release for all materials examined (except the control) occurred in the first day (p<0,05).