Table 2. Average ± standard deviation values of surface roughness and Vickers hardness.

	Control	OUFBW6	OUFBW9	OUFBW11	OFEAS
Ra (μm)	0.1567 ± 0.006	0.1577 ± 0.006	0.1571 ± 0.009	0.1584 ± 0.009	0.1568 ± 0.007
VH (Hv)	19.49 ± 0.876	19.74 ± 0.664	19.25 ± 0.857	19.35 ± 0.937	19.58 ± 1.042

There were no significant differences among the groups in each analysis (Ra: n = 5, VH: n = 5, p > 0.05). OFEAS refers to ozone-free electrolyte aqueous solution of OUFBW11. OUFBW, ozone ultrafine bubble water; Ra, surface roughness; VH, Vickers hardness.