AMC Alumina-Toughened Zirconia DLP Freeze Foam History of engineering & technology Raman spectroscopy Technology: general issues Zirconia-Toughened Alumina alumina alumina matrix composite bioactive composites bioceramics biocompatibility biomaterials biomimicry bone cements bone grafts bone regeneration bone repair bone replacement calcium phosphate calcium phosphates calcium-based biomineralization carbon fibers case series ceramic additive manufacturing ceramic-on-ceramic critical grain size dental implants flexural strength