Preparation and properties of binary oxide bioceramics

Candidate inert bioceramics based on Al2O3 and ZrO2 and on SiO2-TiO2 were prepared via slip casting and sol-gel/hot-pressing techniques, respectively. Their properties relevant to applicability in biomedicine-microstructure, microhardness and coefficient of thermal expansion-were determined. The affinity of the oxides with body-liquids was evaluated by wetting experiments at 37 degrees C. High-quality materials were achieved due to the advantages offered by the preparation techniques employed. The Al2O3 and ZrO2 based ceramics have high hardness, a constant coefficient of thermal expansion within a wide temperature range and low adhesion with biological liquids. The SiO2-TiO2 samples, the crystallinity of which depends on the preparation conditions, have lower hardness and lower coefficient of thermal expansion, which in the case of crystalline samples considerably changes at low temperatures, and display good affinity with biological liquids, strongly affected by the presence of glassy phase in the oxide.