Table 2.

Results of Mann Whitney U test of ion release after different times of AgCuLi NRs and AgCu NRs

Metal measured	Release time (hrs.)	Type of metallic NRs	Na	Sum of ranks	Mean rank	Mann–Whitney U	Asymp. Sig. (2-tailed)
Cu	2	Tri	32	796	24.8	268.00	0.00
		Bi	36	1550	43.0
	24	Tri	32	765.5	23.9	237.50	0.00
		Bi	36	1580.5	43.9
Ag	2	Tri	32	992.0	31.0	464.00	0.169
		Bi	36	1354.0	37.6
	24	Tri	32	1050.0	32.8	522.00	0.50
		Bi	36	1296.0	36.0

^aSize of the sample