Gelcasting Processing of Natural Hydroxyapatite ? Zirconia Bone Scaffolds

A. OZOLS, L. GARRIDO, D. VEMPERE, LIGA CIMDINA-BERZINA

Dublin

Congreso; 24th European Conference on Biomaterials; 2011

European Society for Biomaterials

The search of bioceramics based on zirconia (ZrO2) Z, is dated from late 90´s. Since that time, composites of Z with Hydroxyapatite, (Ca10(PO4)6(OH)2)HA were tested. HA is similar in composition to mineral component of bone. The aim has been the combination of the excellent mechanical properties (toughness, wear resistance) of Z with the biocompatibility and osteo-conductive potential of HA1-4.  This combination has been probed in porous coatings on metal implants1, and bone scaffolds for easy Osseo-integration2. The forming of Z based composites must take in mind the Z tetragonal to monoclinic phase transition above 1000 °C, which represents a dimensional change, responsible of cracking of sintered monolithic pieces. This problem can be solved by incorporating Y2O3 (yttria), MgO or CaO to Z, in order to make stable the high temperature tetragonal phase4. This stabilized zirconia has mostly formed by pressing and sintering at temperatures ranged from 1300 up to 1500 °C3,4. The above antecedents move this preliminary work in order to evaluate: o        The feasibility of gelcasting processing of porous bone scaffolds based on HA-ZrO2 composites, which can be sintered at 1350 °C, lower than Z. sintering temperature. The phase distribution and solid state transformations