Zinc-coated carbonate apatite derived from avian eggshell for potential use as bone substitute. Part I: preparation and properties.

Purpose: To develop antibacterial bone substitutes derived from avian eggshell using microwave processing to convert natural calcium carbonate (CaCO3) into zinc-coated carbonate apatite (CHA).

Methods: Zinc-coated carbonate apatite was prepared using domestic microwave and then characterized with scanning electron microscopy (SEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and energy dispersive x-ray analysis (EDXA). The trial animal study was conducted by filling different bone substitutes into 5-mm-diameter standard defects on the parietal bone of New Zealand rabbits to observe new bone formation for 8 weeks.

Results: SEM, XRD, FT-IR, and EDXA confirmed characteristics of zinc-coated CHA derived from avian eggshell using microwave method. Histological analysis demonstrated that the defects filled with carbonate apatite had more calcified bone and less uncalcified bone formation than other groups.

Conclusions: The present research demonstrated the efficient use of microwave in the conversion of natural CaCO3 into CHA with zinc coating. The examined properties showed the potential use of the new material as an antibacterial bone substitute in oral surgery. The trial animal study implied favorable osteoconductive ability of carbonate apatite in new bone formation.