Effects of sintering temperature, powder loading and ionic substitution on the dissolution property of apatite microspheres

Abstract

Silver, silicon co-substituted hydroxyapatite (Ag,Si-HA) was fabricated as microspheres for better control of the degradation rate. It is the aim of this work to study the effects of sintering temperature, powder loading, and ionic substitution on the dissolution property of Ag,Si-HA microspheres. Sintering at 1150°C resulted in the formation of calcium oxide, causing disintegration of the microspheres. Microspheres sintered at 800°C were the most stable, maintaining its structural integrity during the 14 days of immersion in Dulbecco’s phosphate-buffered saline, along with the dissolution of calcium ions. Microspheres became smaller when powder loading was reduced from 40 to 20 wt-%, which promoted the release of Ca²⁺ ions. With Ag and Si co-substitution, the dissolution of microspheres was increased too. Results demonstrated that surface area of the microspheres played a role in affecting the rate of dissolution, and could be influenced by the sintering temperature and powder loading.

Keywords:

• Dissolution
• hydroxyapatite
• microspheres
• silicon
• silver

Disclosure statement

No potential conflict of interest was reported by the authors.