The effect of sintering process on the characteristics of hydroxyapatite from cuttlefish bone (sepia sp.)

This study aimed to determine the effect of the sintering process on the characteristics of hydroxyapatite which was produced from cuttlefish bone (sepia sp.). Hydroxyapatite was obtained by a hydrothermal reaction between 1M CaCO₃ of cuttlefish bone lamellae and 0.6M NH₄H₂PO₄ at 200°C in 12 hours. Followed by a sintering process with variations in the temperatures : 600°C, 800°C, and 900°C for 1 hour. Furthermore, the best results were taken from variation in time of 2 and 3 hours. XRD, SEM-EDX, and compressive strength test as well as MTT assay were performed to determine the characteristics of HA. The result of this study showed that an increase in crystallinity, crystal size, morphology, and compressive strength occurs by increasing the sintering temperature. In addition, an increase in temperature does not cause toxic effects on the HA as shown by cell viability which is more than 60%. Meanwhile, the increase in sintering time showed no significant changes to HA crystallinity, yet the mechanical properties of HA could still be improved. Based on the analysis, the optimal HA sintering temperature and time which are 900°C and 1 hour respectively, yielded the highest crystallinity with the high maximum diffraction peak of 1163.02 and compressive strength of (11.79900 ± 0.00057) MPa which is suitable for the application of cancellous bone.