MORPHOLOGY AND ULTRASTRUCTURE OF THE INTERFACE BETWEEN HYDROXYAPATITE-POLYHYDROXYBUTYRATE COMPOSITE IMPLANT AND BONE

A composite of polyhydroxybutyrate (PHB) polymer, reinforced with synt hetic hydroxyapatite (HA) particles, with potential as a bone-analogue material, was examined microscopically using scanning electron micros copy and transmission electron microscopy. These imaging techniques pr ovide the means of understanding and monitoring the morphological and structural behaviour of retrieved implants. Scanning electron microsco py was used to assess the overall mechanism of new bone formation at t he implant interface after up to 6 months implantation. This procedure was followed by a detailed ultrastructural examination at lattice pla ne resolution level, using high resolution electron microscopy and sel ected area diffraction of the regions showing bone apposition. Fine hy droxyapatite crystallites were found to form at the interface after in vivo implantation into cortical bone.