Elucidating the role of 45S5 bioglass content in the density and flexural strength of robocast β-TCP/45S5 composites

Composite bioinks made of 4555 Bioglass (R) and beta-TCP (beta-tricalcium phosphate) were elaborated from raw powders using carboxymethyl cellulose (CMC) as a single multifunctional processing additive. The developed inks were used to fabricate straight rods, which were then sintered at 1000 degrees C and 1100 degrees C. The densities and bending strengths of the sintered rods were measured, and both parameters were found to increase with the 45S5 bioglass content, most dramatically beyond 60 vol% of 4555 bioglass. X-Ray Diffraction analysis revealed the occurrence of significant changes in the phase composition of the material, including formation of new phases like parawollastonite, rhenanite or hydroxyapatite. Comparison of the results obtained for pure TCP with those of previous studies, where other processing additives different from CMC were used, suggests that CMC might be hampering the sintering of beta-TCP.