Brittle and ductile adjustable cement derived from calcium phosphate cement/polyacrylic acid composites

Objectives. Bone filler has been used over the years in dental and biomedical applications. The present work is to characterize a non-dispersive, fast setting, modulus adjustable, high bioresorbable composite bone cement derived from calcium phosphate-based cement combined with polymer and binding agents. This cement, we hope, will not swell in simulated body fluid and keep the osteogenetic properties of the dry bone and avoid its disadvantages of being brittle. Methods. We developed a calcium phosphate cement (CPC) of tetracalcium phosphate/dicalcium phosphate anhydrous (TTCP/DCPA)-polyacrylic acid with tartaric acid, calcium fluoride additives and phosphate hardening solution. Results. The results show that while composite, the hard-brittle properties of 25 wt% polyacrylic acid are proportional to CPC and mixing with additives is the same as those of the CPC without polyacrylic acid added. With an increase of polyacrylic acid/CPC ratio, the 67 wt% samples revealed ductile-tough properties and 100 wt% samples kept ductile or elastic properties after 24 h of immersion. The modulus range of this development was from 200 to 2600 MPa after getting immersed in simulated body fluid for 24 h. Significance. The TTCP/DCPA-polyacrylic acid based CPC demonstrates adjustable brittle/ductile strength during setting and after immersion, and the final reaction products consist of high bioresorbable monetite/brushite/calcium fluoride composite with polyacrylic acid. (C) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.