Effects of calcination temperature on Ca/P ratio of calcium phosphate from freshwater snails (Sulcospira testudinaria) shells

Abstract

Calcium phosphate (CaP) bioceramics, including hydroxyapatite (HAp), tricalcium phosphate (TCP), and tetra-calcium phosphate (TTCP), demonstrate applicability in the restoration of damaged hard tissues such as bones and teeth. CaP can be fabricated from natural calcium oxide (CaO) materials, such as freshwater snails (Sulcospira testudinaria). In this study, we investigate the influence of the calcination temperature of freshwater snail shells on the calcium per phosphorus (Ca/P) ratio in the produced CaP to obtain HAp. Characterization was performed using a scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDX) to analyze the sample’s morphology and calculate Ca/P ratio. The calcination process, conducted for 1 h with temperature variations at 800°C, 900°C, 1000°C, and 1100°C, was complemented by the synthesis of CaO using a hydrothermal method. SEM analysis indicates that particle morphology becomes smoother and more uniform at higher temperatures, specifically at 1000°C and 1100°C. EDX analysis reveals that the variation in calcination temperature does not significantly affect the Ca/P ratio. While the Ca/P ratio in this study does not align with the commercial standard for HAp, it suggests the presence of TTCP. Nevertheless, This study shows the potential to achieve convergence between the synthesized HAp and the commercial standard by increasing the calcination time during the synthesis process.