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 p-calcium silicate (beta-CaSiO3, beta-CS) bioactive ceramics were investigated in a rabbit calvarial defect model, and the results were compared with porous P-tricalcium phosphate (beta-Ca-3(PO4)(2), beta-TCP) bioceramics. The porous beta-CS and beta-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 beta-CS was much higher than that of beta-TCP. The TRAP-positive multinucleated cells were observed on the surface of beta-CS, suggesting a cell-mediated process involved in the degradation of beta-CS in vivo. The amount of newly formed bone was also measured and more bone formation was observed with beta-CS as compared with beta-TCP (p < 0.05). Histological observation demonstrated that newly formed bone tissue grew into the porous beta-CS, and a bone-like apatite layer was identified between the bone tissue and beta-CS materials. The present studies showed that the porous beta-CS ceramics could stimulate bone regeneration and may be used as bioactive and biodegradable materials for hard tissue repair and tissue engineering applications. (c) 2008 Elsevier Ltd. All rights reserved.