Effect of saturation and post processing on 3D printed calcium phosphate scaffolds

Three dimensional printing was investigated for fabricating hydroxyapatite (HA) and tricalcium phosphate ( -TCP) composite scaffolds using calcium phosphate based ceramics and calcium phosphate cement chemistry. Scaffolds were formed by printing an aqueous sodium phosphate solution on the powder bed consisting of a mixture of dicalcium phosphate anhydrous (DCPA) and calcium hydroxide powders. The sodium phosphate solution was functioning as a binder material and also as the initiator of the wet chemical reaction. Compressive mechanical properties of printed samples were examined as a function of saturation level that was inversely proportional to the powder to liquid ratio. To increase mechanical properties and obtain hydroxyapatite and -TCP composites, the printed samples were sintered. The effect of sintering parameters including dwell time and sintering temperature were also examined. X-ray diffraction (XRD) was used to examine material composition at different stages of the manufacturing process and to confirm the presence of HA and -TCP in the final stage. The effect of sintering procedure on the surface topology of the samples was examined using scanning electron microscopy (SEM).