Table 1.

Effect of UV/O₃ irradiation on surface roughness of untreated and H₃PO₄-modified HA samples.

Sample	Irradiation time (min)	Surface roughness Ra (μm)
Untreated surface	0	0.23 ± 0.02	a
	120	0.21 ± 0.03	a
Modified surface	0	0.91 ± 0.04	a
	120	0.86 ± 0.03	a

^aP > 0.05 indicates no significant difference between non-irradiated samples and samples irradiated for 120 min.