Reconstruction of calvarial defect of rabbits using porous calcium silicate bioactive ceramics

In this study, the in vivo bone-regenerative capacity and resorption of the porous β-calcium silicate (β-CaSiO3, β-CS) bioactive ceramics were investigated in a rabbit calvarial defect model, and the results were compared with porous β-tricalcium phosphate (β-Ca3(PO4)2, β-TCP) bioceramics. The porous β-CS and β-TCP ceramics were implanted in rabbit calvarial defects and the specimens were harvested after 4, 8 and 16 weeks, and evaluated by Micro-CT and histomorphometric analysis. The Micro-CT and histomorphometric analysis showed that the resorption of β-CS was much higher than that of β-TCP. The TRAP-positive multinucleated cells were observed on the surface of β-CS, suggesting a cell-mediated process involved in the degradation of β-CS in vivo. The amount of newly formed bone was also measured and more bone formation was observed with β-CS as compared with β-TCP (p < 0.05). Histological observation demonstrated that newly formed bone tissue grew into the porous β-CS, and a bone-like apatite layer was identified between the bone tissue and β-CS materials. The present studies showed that the porous β-CS ceramics could stimulate bone regeneration and may be used as bioactive and biodegradable materials for hard tissue repair and tissue engineering applications.