Characterization of composite materials for cranial reconstruction

Materials used as bone substitute in cranial defects are composed by polymethyl-methacrylate (PMMA), however they are not reabsorbed by the host cells. Objectives: The aim of this study was to characterize the composition of materials used as bone cement, and determine its mechanical behavior with addition of inorganic compounds. Methods: Two commercial products used as bone cement (Subiton®, Argentina, Concert® Cranioplast, USA) were analyzed by scanning electron microscopy (SEM), infrared spectroscopy (IR) and Differential Scanning Calorimeter (DSC). Inorganic compounds consisted by natural calcium carbonate [CaCO₃], from echinoderm skeleton(mellita eduardobarrosoi), and synthetic hydroxylapatite [Ca₁₀(PO₄)₆ (OH)₂]were added to polymers and its mechanical properties (flexural and compression strength were determined in an Universal Testing Machine, Instron® model 4421. Control group consisted by commercial polymethyl methacrylate (Nictone®, Mexico) and poly/lactic acid (PLA). Results: IR spectra showed typical intensity bands of polymethyl methacrylate and tensile strength raged between 59.68 to 64.24 MPa for osseous cements, and 58.89 to 86.45 MPa for thermo cured polymethyl methacrylate. Formulations of composite materials had lower values than polymer only. Samples of inorganic compounds and PLA had less tensile strength values, between 11.39 to 14.17 MPa. Conclusion: Inorganic compounds added to PMMA have not difference on mechanical behavior, however composite of PLA/inorganic compounds had lower values, these were closer to bone.

This work was granted by DGAPA UNAM, PAPIIT project IN-113108.