Table 1 Mean and standard deviation of dentin thickness (mm) and volume of root canal (mm³) in each group at 3 mm and 5 mm below the cement-enamel junction before and after root canal preparation and fracture resistance (N)

Control

1.39 ^a (±0.15)

1.09 ^b (±0.17)

1.32 ^a (±0.18)

1.12 ^b (±0.14)

1.32 ^a (±0.14)

1.06 ^b (±0.16)

1.32 ^a (±0.16)

1.07 ^b (±0.13)

1.37 ^a (±1.11)

3.11 ^b (±1.08)

581.12 ^A (±117.13)

Gates

1.39 ^a (±0.22)

1.17 ^b (±0.18)

1.36 ^a (±0.17)

1.16 ^b (±0.22)

1.24 ^a (±0.19)

1.06 ^b (±0.21)

1.21 ^a (±0.14)

1.02 ^b (±0.14)

1.34 ^a (±0.41)

2.61 ^b (±0.56)

404.59 ^B (±54.46)

WXN

1.45 ^a (±0.21)

1.24 ^b (±0.29)

1.51 ^a (±0.25)

1.25 ^b (±0.31)

1.31 ^a (±0.15)

1.11 ^b (±0.18)

1.37 ^a (±0.22)

1.15 ^b (±0.27)

1.90 ^a (±0.70)

3.16 ^b (±0.94)

551.47 ^A (±112.83)

Easy

1.57 ^a (±0.15)

1.23 ^b (±0.17)

1.46 ^a (±0.13)

1.09 ^b (±0.12)

1.39 ^a (±0.18)

1.07 ^b (±0.13)

1.39 ^a (±0.22)

1.03 ^b (±0.15)

1.65 ^a (±0.51)

3.01 ^b (±0.58)

521.44 ^A (±86.37)