THE EFFECT OF IN-VITRO FLUORIDE-ION TREATMENT ON THE ULTRASONIC PROPERTIES OF CORTICAL BONE

The mechanical properties of composites are influenced, in part, by th e volume fraction, orientation, constituent mechanical properties, and interfacial bonding. Cortical bone tissue represents a short-fibered biological composite where the hydroxyapatite phase is embedded in an organic matrix composed of type I collagen and other noncollagenous pr oteins. Destructive mechanical testing has revealed that fluoride ion treatment significantly lowers the Z-axis tensile and compressive prop erties of cortical bone through a constituent interfacial debonding me chanism. The present ultrasonic data indicates that fluoride ion treat ment significantly alters the longitudinal velocity in the Z-axis as w ell as the circumferential and radial axes of cortical bone. This sugg ests that the distribution of constituents and interfacial bonding amo ngst them may contribute to the anisotropic nature of bone tissue.