OPTIMIZING OF NEW APPROACH SINTERING METHOD ON CARBONATED HYDROXYAPATITE BIOCERAMIC

Abstract

Synthetic carbonated apatite ceramics are considered as alternative to autograft and allograft materials for bone substitute. This study was to investigate and compare the effect of carbonation introduced during cooling down of sintering of dense CHA with two kind of wet CO₂ atmosphere (direct wet CO₂ and dry CO₂ flow through water). Pelletized samples were sintered to 800°C and soaked for 120 minutes. Upon cooling down to 150, 200, 250 and 300°C, carbonation with wet CO₂ in desiccators were performed. The sintered CHA after carbonation at the various cooled temperatures was found to retain as B-type CHA. Carbonation of sintered CHA by dry CO₂ through water showed an overall better results as compared to carbonation by direct wet CO₂. Sample D200 with carbonation temperature of 200^oC has the highest carbonate content (3.35%) and relative density (94%) while D250 with carbonation temperature of 250^oC has the highest DTS value (18MPa). In vitro testing using SBF solution showed that apatite layer formed on the sintered CHA surface after one week of immersion, thus indicating the bone-forming ability. This indicated that the CHA synthesized in this study has sufficient biocompatibility to be applied as bone substitutes.