Fluoride Release of Nano-ionomer and Compomer Materials with Adhesive Coatings

Objective: To compare the long term fluoride release of a nanofilled resin-modified glass ionomer restorative material versus a compomer with or without their recommended primer or adhesive.  Methods: Restorative materials included: Ketac^TM Nano nano-ionomer without (KN, 3M ESPE) or with Ketac Nano Primer (KNP) and Dyract ^TM Extra Compomer without (DY, Dentsply) or with Prime and Bond NT Adhesive (DYA).  Cured discs (20 x 1 mm) of the materials were prepared in triplicate. One set of each cured material was further coated on both sides with the recommended adhesive treatment, and light cured per manufacturer's directions. Fluoride release of each sample set (37C deionized water) was measured periodically between 1 to 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 Days (micro g F / g sample)
Material	Chemistry	1	7	14	28	90	180
KN	RMGI	173 ± 43	361 ± 47	480 ± 47	602 ± 48	1031 ± 68	1572 ± 91
KNP	RMGI	238 ± 31	454 ± 34	584 ± 34	722 ± 35	1228 ± 73	1733 ± 85
DY	Compomer	103 ± 47	136 ± 48	169 ± 49	218 ± 50	400 ± 64	710 ± 67
DYA	Compomer	107 ± 96	131 ±  97	152 ± 97	185 ±  53	382 ± 100	629 ± 100

Conclusion: ANOVA analysis was performed at p < 0.05 per Tukey's pairwise comparison test. The fluoride release rates of Ketac Nano with (KNP) and without (KN) primer were statistically comparable, and released significantly higher fluoride than either Dyract (DY) or Dyract coated with adhesive (DYA). DY and DYA were statistically equivalent. All of the materials exhibited sustained fluoride release over 6 months.