Groups Stress at 4% (103 Pa) Stress at 6% (103 Pa) Stress at 8% (103 Pa) Stress at 10% (103 Pa) Group 1 Untreated 55.7 ± 17.16 ( = 1.1 × 106 Pa) 101 ± 37.72 ( = 1.8 × 106 Pa) 171.3 ± 73.89 ( = 3 × 106 Pa) 270.3 ± 119.1 ( = 4.8 × 106 Pa) Treated 51.3 ± 11.8 ( = 1 × 106 Pa) 93.7 ± 29.5 ( = 1.7 × 106 Pa) 157.7 ± 59.7 ( = 2.7 × 106 Pa) 249.0 ± 100.5 ( = 4.3 × 106 Pa) Group 2 Untreated 57.3 ± 13.2 ( = 1.2 × 106 Pa) 104.7 ± 31.0 ( = 1.9 × 106 Pa) 181.0 ± 59.1 ( = 3.2 × 106 Pa) 287.7 ± 88.9 ( = 5.2 × 106 Pa) Treated 56.3 ± 6.6 ( = 1.1 × 106 Pa) 96.7 ± 12.7 ( = 1.7 × 106 Pa) 164.0 ± 27.4 ( = 2.8 × 106 Pa) 254.3 ± 37.8 ( = 4.5 × 106 Pa) Group 3 Untreated 52.7 ± 9.6 ( = 1.1 × 106 Pa) 94.7 ± 16.5 ( = 1.8 × 106 Pa) 160 ± 25.2 ( = 3 × 106 Pa) 260.7 ± 40.5 ( = 4.9 × 106 Pa) Treated 88.3 ± 26.3 ( = 2 × 106 Pa) 184.3 ± 75.8 ( = 3.6 × 106 Pa) 351.7 ± 171 ( = 6.3 × 106 Pa) 603.3 ± 316.7 ( = 11.0 × 106 Pa) Group 4 Untreated 63.7 ± 14.0 ( = 1.1 × 106 Pa) 112.7 ± 22.4 ( = 1.8 × 106 Pa) 187.3 ± 31.6 ( = 2.8 × 106 Pa) 292.7 ± 45.5 ( = 4.4 × 106 Pa) Treated 51.7 ± 15.3 ( = 0.9 × 106 Pa) 87.0 ± 26.9 ( = 1.5 × 106 Pa) 134.0 ± 43.3 ( = 2.3 × 106 Pa) 201.3 ± 60.2 ( = 3.6 × 106 Pa)