Evaluation of resorption rate-controlled calcium carbonate ceramics as a substitute bone material.

Artificial bone, primarily composed of calcium carbonate, demonstrates a higher resorption rate than calcium phosphate-based counterparts, suggesting potential for early bone replacement. Animal experiments using porous calcium carbonate ceramics have demonstrated bone formation superior to commercially available artificial bone after short-term implantation. Long-term implantation has yielded suboptimal results owing to resorption of both newly formed bone and implantation material. We prepared calcium carbonate ceramics added with silica (Si-CaCO₃) to regulate the resorption rate. After 12 weeks of implantation, Si-CaCO₃ ceramics exhibited bone formation comparable to that of β-tricalcium phosphate (β-TCP) but less variability in the distribution of bone formation within the tissue. An in vitro dissolution test, serving as an indicator of in vivo resorption rate, revealed that Si-CaCO₃ ceramics exhibited an intermediate dissolution rate between high-purity calcium carbonate and β-TCP ceramics. Silica doping in CaCO₃ ceramics presents an effective approach for aligning material resorption with bone formation and growth.