The present invention provides a functionally graded 
bioactive glass / 
ceramic composite structure or 
bioactive glass / 
ceramic / 
bioactive glass sandwich structure for use in such applications as damage resistant, 
ceramic dental implants, immediate tooth replacement, endodontic posts, orthopedic prostheses, orthopedic stems, bone substitutes, 
bone screws, plates, and anchors, 
nonunion fractures repair, 
alveolar ridge augmentation, missing small bone parts (e.g. fingers, toes, etc), maxilla 
facial reconstruction, 
spinal fusion, and scaffolds for 
bone regeneration, comprising a residual bioactive glass or glass-ceramic layer at all accessible surfaces, followed by an underlying graded glass-ceramic layer, and then an dense interior ceramic. The residual bioactive glass or glass-ceramic layer can be further transformed to a 
carbonate apatite (CHA) layer by immersing in calcifying solution or 
simulated body fluid (SBF) with 
electrolyte composition similar to that of serum. The interior ceramic preferably contains yttria-
tetragonal zirconia polycrystal (Y-TZP) or ceria stabilized 
tetragonal zirconia polycrystal (Ce-TZP) or magnesia stabilized zirconia (Mg-PSZ) or calcia stabilized zirconia (Ca-PSZ) or 
alumina or zirconia-
alumina composites. Further, the invention provides methods for making the same functionally graded bioactive glass / 
ceramic composite structure or graded bioactive glass / ceramic / bioactive glass sandwich structure.