Table 2 Peak equivalent von Mises stress in normal root canal group, oversized root canal group and dumbbell-shaped root canal group within restored tooth components: root, post-core, crown, cement layer p, and cement layer c (MPa)

Root

206.36

207.55

202.44

72.774

72.727

72.618

124.42

126.64

114.97

Post-core

34.288

23.802

185.99

14.776

12.605

45.022

25.276

14.271

124.77

Crown

386.7

389.85

357.4

60.783

69.773

54.53

163.72

161.47

169.61

Cement layer p

11.649

16.976

3.8416

2.9937

4.3468

0.94451

8.7653

33.329

2.5097

Cement layer c

4.3344

4.446

3.9895

2.1336

2.7365

0.80772

3.897

4.4172

2.4642