The Behavior of Osteoblast-like Cells on Different Crystal Systems of Calcium Phosphate Ceramics in vitro

Calcium phosphate (Ca-P) ceramics are well known for their excellent osteo-conductivity. However, factors critical to the mineralization process of Ca-P ceramics are not fully understood, including the importance of the crystal system, the Ca/P ratio, the solubility and the surface morphology of the materials. Therefore, this study was performed to evaluate the initial mineralization behavior of osteoblast-like cells on Ca-P ceramics of different crystal systems and Ca/P ratios but with similar solubilities and surface morphologies. Cell attachment and cell proliferation were not significantly different among hydroxyapatite, β-tricalcium phosphate and titanium. However, the activity of alkaline phosphatase, the concentration of osteocalcin and the formation of mineralized nodules revealed that the initial mineralization of osteoblast-like cells was better on Ca-P ceramics than on titanium, although no significant differences were found between β-tricalcium phosphate and hydroxyapatite. In conclusion, this study demonstrates that differences in the crystal system are not a predominant factor in the initial mineralization process of osteoblast-like cells, suggesting that the solubility of Ca-P ceramics may play an important role in the clinical implant treatment.