Comparison of stiffness tests among three groups under four load steps (a,b) axial stiffness test, (c, d) torsional stiffness test, (e, f) shear stiffness test, (g) failure test.

<p>Fig(Group A> Group B> Group C; <i>P</i>≤0.0207) Fig 4 c Torsional stiffness data for all subgroups. The maximum load of Group C was statistically different from both Group A and Group B, (Group A> Group C, Group B> Group C; *,#, <i>P</i><0.0001). The comparisons of Groups A and B for maximum load were not significantly different (<i>P</i> = 0.6086). Fig 4 d Torsional stiffness data for all subgroups. The torsional stiffness of Group C was statistically different from both Group A and Group B (Group A> Group C, Group B> Group C; *,#, <i>P</i><0.0001). The comparisons of Groups A and B for torsional stiffness were not significantly different (<i>P</i> = 0.2738). Fig 4 e Shear stiffness data for all subgroups. The maximum load showed statistical differences between the groups (Group A> Group B> Group C; <i>P</i>≤0.0044). Fig4 f Shear stiffness data for all subgroups. The shear stiffness of Group A was statistically different from both Group B and Group C (Group A> Group B, Group A> Group C; *,#, <i>P</i><0.0001). The comparisons of Groups B and C for shear stiffness were not significantly different (<i>P</i> = 0.0561). Fig 4 g The load-to-failure of Group A was statistically different from both Group B and Group C (Group A> Group B, Group A> Group C; *,#, <i>P</i>≤0.0131); however, no statistical differences were noted between Group B and Group C (<i>P</i> = 0.3655).