Table 1.

Radiopacity properties of sol-gel Bi_2–xZr_xO_3+x/2 powders.

Temperature (°C)	Means and Standard Deviations of Radiopacity * (mmAl)
	PC	PC/Bi2O3	0	0.2	0.4	0.6	0.8	1.0
	0.96 ± 0.07	4.69 ± 0.23
500			4.68 ± 0.13	4.90 ± 0.23	4.48 ± 0.23	3.89 ± 0.21	3.95 ± 0.21	3.75 ± 0.17
600				4.17 ± 0.10
650				4.61 ± 0.17
700				4.73 ± 0.15
750			4.99 ± 0.16	5.83 ± 0.22	4.45 ± 0.20	4.39 ± 0.22	4.01 ± 0.20	3.72 ± 0.16

PC: Portland cement, Bi₂O₃: commercial bismuth oxide (AVROS). * bold numbers indicate the x values of Bi_2–xZr_xO_3+x/2 powder prepared by sol-gel process.