Table 2 Histological findings in experimental and control groups

Intracanal tissue formation

No

-

4 (100%)

1 (12.5%)

1 (12.5%)

4 (50%)

2 (25%)

Yes

-

0 (0%)

7 (87.5%)

7 (87.5%)

4 (50%)

6 (75%)

P value

0.015*

Post hoc test

Negative vs. BC = 0.042*, Negative vs. i-PRF = 0.042*

Level of new tissue in-growth

Score 0: No tissue

-

4 (100%)

1 (12.5%)

1 (12.5%)

4 (50%)

2 (25%)

Score 1: Till apical third

-

0 (0%)

0 (0%)

0 (0%)

4 (50%)

0 (0%)

Score 2: Till middle third

-

0 (0%)

1 (12.5%)

0 (0%)

0 (0%)

1 (12.5%)

Score 3: Till cervical third

-

0 (0%)

6 (75%)

7 (87.5%)

0 (0%)

5 (62.5%)

P value

0.001*

Post hoc test

Negative vs. i-PRF = 0.028*, i-PRF vs. HA = 0.043*

Mineralized tissue formation

No

4 (100%)

4 (100%)

1 (12.5%)

1 (12.5%)

4 (50%)

2 (25%)

Yes

0 (0%)

0 (0%)

7 (87.5%)

7 (87.5%)

4 (50%)

6 (75%)

P value

0.003*

Post hoc test

NS

Periapical inflammation

None

4 (100%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

Score 0: mild

0 (0%)

0 (0%)

2 (25%)

0 (0%)

8 (100%)

8 (100%)

Score 1: moderate

0 (0%)

0 (0%)

6 (75%)

6 (75%)

0 (0%)

0 (0%)

Score 2: Severe

0 (0%)

4 (100%)

0 (0%)

2 (25%)

0 (0%)

0 (0%)

P value

< 0.0001*

Post hoc test

Positive vs. Negative < 0.0001*, Positive vs. BC = 0.014*, Positive vs. i-PRF < 0.0001*, Negative vs. HA = 0.005*, Negative vs. P-ECM = 0.005*, i-PRF vs. HA = 0.025*, i-PRF vs. P-ECM = 0.025*

Root resorption

None

4 (100%)

0 (0%)

4 (50%)

0 (0%)

3 (37.5%)

4 (50%)

Score 0: mild

0 (0%)

0 (0%)

3 (37.5%)

0 (0%)

3 (37.5%)

2 (25%)

Score 1: moderate

0 (0%)

0 (0%)

1 (12.5%)

7 (87.5%)

2 (25%)

2 (25%)

Score 2: Severe

0 (0%)

4 (100%)

0 (0%)

1 (12.5%)

0 (0%)

0 (0%)

P value

< 0.0001*

Post hoc test

Positive vs. Negative = 0.002, Positive vs. i-PRF = 0.014*, Negative vs. BC = 0.011*, Negative vs. HA = 0.044*, Negative vs. P-ECM = 0.022*