Table 3 Mean changes in apical foramen length at baseline and 18-month follow-up

Mesial root (mm)

Baseline

Mean ± SD

5.13 ± 1.27

5.27 ± 1.33

0.880

Median

5.30

5.51

Interquartile range

3.87–6.51

4.04–6.25

18 months

Mean ± SD

3.39 ± 1.02

3.90 ± 1.20

0.290

Median

3.51

4.03

Interquartile range

2.38–4.27

2.51–4.74

Z

2.803

2.803

P

0.005*

0.005*

Apical foramen length mean difference

Mean ± SD

-1.75 ± 0.52

-1.37 ± 0.52

0.049*

Median

-1.86

-1.32

Interquartile range

-2.18-(-1.43)

-1.91-(-1.11)

Distal root

(mm)

Baseline

Mean ± SD

3.67 ± 1.26

3.64 ± 1.34

1.000

Median

4.25

4.25

Interquartile range

2.55–4.70

2.54–4.76

18 months

Mean ± SD

2.27 ± 0.85

2.34 ± 0.96

0.880

Median

2.33

2.39

Interquartile range

1.59–3.07

1.58–3.28

Z

2.803

2.803

P

0.005*

0.005*

Apical foramen length mean difference

Mean ± SD

-1.41 ± 0.84

-1.31 ± 0.57

1.000

Median

-1.37

-1.36

Interquartile range

-1.93-(-0.58)

-1.84-(-0.67)