Group B1 Control group

Group B2

(1.5% ZrO₂(

Group B3

(3% ZrO₂(

Group B4

(5% ZrO₂(

Group B5

(7% ZrO₂(

P-value

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

2.30^b

0.158

2.47^b

0.37

3.54^a

0.08

3.73^a

0.14

3.82^a

0.16

0.000^*