Characteristics of synthetic hydroxyapatites and attempts to improve their thermal stability

Synthetic hydroxyapatites (HA) with widely different crystallinity degrees were prepared starting from calcium hydroxide and phosphoric acid. The powders were carefully characterised by various physico-chemical techniques. Additions of Ca(OH)2 were performed in order to improve HA thermal stability to firing treatments up to temperatures significantly higher than those commonly employed for safe HA sintering. A positive effect in this sense was...