Phase and Microstructural Evolution of Calcium Aluminum Phosphate Cement for Potential Biological Applications: Effect of Aluminum Hydroxide Sources

Calcium aluminum phosphate cement (CAPC) requires a practical composition for biological applications. This research aims to investigate the effect of aluminum hydroxide sources (aluminum hydroxide, boehmite, and hydratable alumina), where SECAR 71 cement and phosphoric acid are in the composition, regarding the mechanical, biological, and microstructural properties of CAPC. In vitro assessments were evaluated by immersing the samples in simulated body fluid (SBF) solution for 7 days, 14 days, and 28 days, and by MTT testing (cytotoxicity of MG-63 cells). The results revealed that the composition including hydratable alumina was superior concerning the lowest final setting time (50 min), in situ formation and growth of hydroxyapatite on its surface, as well as the compressive strength which reaches to 42 ± 10 MPa after 28 days in SBF solution. However, regarding the cytotoxicity, the cements consisting of boehmite have priority. A more detailed biological analysis is recommended to evaluate the clinical application of CAPC.