A resonance frequency technique to determine elastic modulus of hydroxyapatite.

A resonance frequency technique was applied to determine the elastic modulus of hydroxyapatite. A Free-Free Vibration Transducer was designed to determine elastic modulus in a longitudinal direction. A Fixed-Free Vibration Transducer was also designed to study elastic modulus of materials were specimens longer than 3 cm in length were not available. Six lots of hydroxyapatite were prepared utilizing the same process. The elastic modulus of hydroxyapatite varied between 3.94 x 10(10) (dyn/cm2) and 6.30 x 10(10) (dyn/cm2) in a longitudinal direction. For the same six lots, it varied between 1.95 x 10(10) (dyn/cm2) and 3.20 x 10(10) (dyn/cm2) in a cross direction. The elastic modulus values of cortical bone from dog tibias, fibulas, and femurs were also determined.