Tensile Mechanical Properties Of Porcine Cortical Mandibular Bone

Objectives: To determine the mechanical properties of cortical bone as related to: level (basal vs. alveolar), location (posterior vs. anterior), region (buccal vs. lingual) and axis (mesio-distal vs. occluso-gingival). Methods: Seven porcine mandibles were selected. Cylindrical specimens (n=112) were obtained using a trephine drill (2.6x1.5 mm) from different areas along the mandible. Specimens were loaded as Diametral Tensile Strength test configuration via loading machine up to failure. Automatic Data of load vs. displacement were acquired. Two parameters were determined: Stiffness (slope of the force-displacement curve) and maximal load. The data was analyzed by 4 way ANOVA with repeated measures and post-hoc paired t-test. Results: Stiffness: Values varied between 398.65-1679.85 N/mm. Basal bone level values were 40% higher compared to alveolar (P<0.017); posterior location values were 46% higher compared to anterior (P<0.001); lingual region values were 18.8% higher compared to buccal (P=0.072); mesio-distal axis had 31% higher values compared to occluso-gingival (P<0.01). Maximal load: Values varied between 105.05-246 N. Basal bone level were 29% higher compared to alveolar (P<0.049); posterior location values were 13% higher compared to anterior (P<0.02); lingual region values were 14.8% insignificantly higher compared to buccal (P=0.113); occluso-gingival axis had 23.5% higher values compared to mesio-distal (P<0.027). Conclusion: Although cortical bone doesn't behave like a brittle material, definite stiffness values can be obtained using DTS configuration with small bone specimens. The stiffness is the more appropriate parameter to disclose differences in the mechanical properties of cortical bone using DTS test.