Table 3.

Measurement of released fluoride [µM] from the different UCNPs in water and DMEM culture medium at 37 °C after 24 h and 48 h incubation. n.d.: not determined.

UCNPs	F-Release 37 °C Water [µM] after 24 h	F-Release 37 °C Water [µM] after 48 h	F-Release 37 °C DMEM [µM] after 24 h	F-Release 37 °C DMEM [µM] after 48 h
UC-bare-20 (BF4)	239.47	297.37	5.79	5.79
UC-citrate-20 (P1)	263.68	330.53	14.21	16.84
UC-SiO2-thin	100.58	164.26	4.74	8.42
UC-SiO2-thick	3.16	4.42	8.42	11.58
UC-bare-20 (HCl)	124.39	156.32	n.d.	n.d.
UC-AA-20	94.39	123.46	n.d.	n.d.
UC-EDTMP-20	26.49	25.30	n.d.	n.d.