Experimental development of a chitosan-bonded beta-tricalcium phosphate bone filling paste

Bone filling substances are needed to meet several requirements including nontoxicity, setting time, changes in pH values, and amount of dissolved elements as well as mechanical properties. In this study, the bone-generating composites were prepared by employing the in vivo absorbable beta-tricalcium phosphate as a parent matrix kneaded with CaO, MgO, and ZnO as bone mineral additives with different compositions. The setting time, pH values, compressive strength were investigated as a function of the amount of these bone mineral additives. It was found that the setting time was shortened by increasing CaO, MgO, and ZnO contents. Increasing ZnO contents resulted in the pH value lower, while the pH values increased by increasing CaO and MgO contents. Increasing ZnO contents caused the compressive strength stronger, on the other hand, the compressive strength was weakened by increasing MgO contents. Furthermore, calcium appears to be selectively released from the hardened composite sample.