Table 1.

Radiopacities of cements prepared using oxide radiopacifier after ball milling treatment.

	Milling Time	Pristine	30 min	1 h	2 h	3 h
Material
Portland cement		0.91 ± 0.14	1.00 ± 0.18	N.A.	N.A.	N.A.
Bi2O3		5.10 ± 0.36	5.69 ± 0.35	5.52 ± 0.48	5.59 ± 0.35	5.57 ± 0.24
ZrO2		2.31 ± 0.36	2.65 ± 0.23	2.61 ± 0.26	2.65 ± 0.26	2.69 ± 0.29
HfO2		3.13 ± 0.19	3.65 ± 0.48	3.58 ± 0.16	3.61 ± 0.36	3.59 ± 0.44
Ta2O5		3.28 ± 0.42	3.71 ± 0.30	3.65 ± 0.27	3.70 ± 0.34	3.75 ± 0.46