Page 183 - Clinical relevance of current materials for cranial implants

Effects of sterilization on the mechanical properties of PMMA
Impact strength
NextDent C&B MFH showed a significantly higher Charpy impact strength (acU) after γ-irradiation and HPGP sterilization compared to the other materials. NextDent C&B MFH also had a significantly higher Charpy impact strength compared to Palacos R+G for the control. There was no significant difference found in the Charpy impact strength between the sterilization methods for Vertex Self-Curing and Palacos R+G. For NextDent C&B MFH there was a significant increase of the Charpy impact strength after γ-irradiation.
Table 3: Flexural strength (σ) in MPa, flexural modulus (E) in MPa, maximum stress intensity factor (Kmax) in MPa m1/2, total fracture work (Wf) in J/m2 and Charpy impact strength (acU) in kJ/m2 of the different materials after sterilization with ethylene oxide (EtO), hydrogen peroxide gas plasma (HPGP) and γ-irradiation.
Vertex Self-Curing Palacos R+G NextDent C&B MFH Vertex Self-Curing Palacos R+G NextDent C&B MFH Vertex Self-Curing Palacos R+G NextDent C&B MFH Vertex Self-Curing Palacos R+G NextDent C&B MFH Vertex Self-Curing
Control
66.8 (4.3) A,a 61.6 (2.8) A,a 91.8 (6.3) B,a 2166 (160) A,a 2256 (85) AB,a 2374 (118) B,b 1.70 (0.34) A,a 2.18 (0.31) B,a 1.42 (0.09) A,a 476.7 (163.2) A,a 940.0 (151.3) B,a 331.4 (34.1) A,a 7.6 (1.8) AB,a
EtO
66.4 (2.7) A,a 63.8 (1.8) A,a 89.2 (3.5) B,a † 2165 (68) A,a 2307 (76) B,a 2221 (78) AB,a 1.87 (0.35) B,a 2.40 (0.20) C,a 1.63 (0.12) A,ab 562.9 (193.2) A,a 981.1 (123.7) B,a 421.8 (51.0) A,a 7.8 (2.5) A,a
HPGP
68.3 (3.3) B,a
60.2 (2.5) A,a 94.0 (3.4) C,a † 2212 (104) A,a 2226 (90) A,a 2521 (96) B,c 1.98 (0.21) AB,a 2.24 (0.35) B,a 1.80 (0.14) A,b 579.9 (93.2) A,a 948.6 (135.7) B,a 443.5 (77.5) A,a 7.3 (1.1) A,a
γ-irradiation
80.0 (3.4) B,b 70.6 (3.2) A,b 109.3 (2.6) C,b 2265 (87) A,a 2244 (49) A,a 2238 (55) A,ab 1.83 (0.21) A,a 2.31 (0.22) B,a 1.77 (0.20) A,ab 494.5 (97.6) A,a 832.0 (74.8) B,a 405.3 (66.4) A,a 6.5 (2.5) A,a
Palacos R+G 4.7 (1.0) A,a 4.5 (1.4) A,a 4.5 (0.9) A,a 4.0 (1.1) A,a 9
NextDent C&B MFH
Values given as mean and standard deviation (SD). Identical letters indicate no significant difference between the groups. Capital letters indicate differences between the materials (split by sterilization method), the lowercase letters indicate differences between the sterilization methods (split by material).
†: n<10 because maximum strength could not be calculated, since some specimens did not fail during testing.
‡: Test was repeated because of an inordinate high standard deviation, both tests are combined in this result. ¶: n=9 because one specimen was broken during the sterilization process.
10.5 (4.0) B,ab ‡
7.3 (1.9) A,a
11.1 (2.3) B,bc ¶
14.2 (3.8) B,c
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acU Wf Kmax E σ