Table 6 Mean and SD values of color difference of zirconia materials in three sections

UG

Cervical

1.79 ± 0.28^a

0.83 ± 0.30^b

1.53 ± 0.71^a

1.77 ± 0.40^a

9.811

< 0.001

Body

1.54 ± 0.25^a

0.63 ± 0.29^b

1.41 ± 0.62^a

1.78 ± 0.23^a

17.348

< 0.001

Incisal

1.56 ± 0.31^a

0.57 ± 0.15^b

0.97 ± 0.47^b

1.45 ± 0.37^a

17.618

< 0.001

UM

Cervical

1.07 ± 0.48

0.82 ± 0.82

1.06 ± 0.39

1.19 ± 0.28

0.823

0.490

Body

0.96 ± 0.32

0.63 ± 0.50

1.11 ± 0.42

1.07 ± 0.39

2.759

0.056

Incisal

1.01 ± 0.59

0.70 ± 0.31

1.03 ± 0.63

1.46 ± 0.97

2.197

0.105

CX

Cervical

0.87 ± 0.35

1.00 ± 0.46^A

0.97 ± 0.55

1.13 ± 0.44

0.561

0.644

Body

0.85 ± 0.35

0.71 ± 0.31^A,B

1.03 ± 0.47

1.21 ± 0.63

2.342

0.089

Incisal

1.10 ± 0.52

0.59 ± 0.27^B

1.23 ± 0.71

1.08 ± 0.68

2.386

0.085

LE

Cervical

1.90 ± 0.44^a

0.72 ± 0.27^b

0.62 ± 0.24^b

0.97 ± 0.32^b

31.806

< 0.001

Body

2.18 ± 0.49^a

1.13 ± 0.40^b

0.77 ± 0.49^b

0.99 ± 0.50^b

17.633

< 0.001

Incisal

1.95 ± 0.78^a

1.04 ± 0.53^b

0.82 ± 0.52^b

1.07 ± 0.44^b

7.293

0.001