Table 2.

Radiopacity (shades of gray) and the aluminum equivalent in millimeters (mm Al) of the different materials evaluated.

	Mean gray	Radiopacity value (mm Al equivalent)
Tetric Ceram	84.20 (±9.68)A	3.10 (±0.32)x,y
TPH	72.20 (±7.05)B	2.65 (±0.31)x,y
SDR	52.60 (±3.51)CD	1.94 (±0.14)x,y
Z350	48.20 (±2.77)DE	1.78 (±0.12)x,y
Z350 flow	38.40 (±3.97)E	1.44 (±0.16)x,y
P90∗	25.60 (±1.00)F	0.99 (±0.12)y
Enamel	22.60 (±5.86)	0.91 (±0.22)
Dentin	14.20 (±2.28)	0.63 (±0.12)

Different letters: significant difference between resins, p < 0.05 (ANOVA-Tukey test).

Significant difference for the enamel (x) and dentin (y), p < 0.05 (ANOVA-Dunnett's test).

^∗No significant difference for the 1 mm Al, p > 0.05 (one-sample t-test).