Histological analysis of calcium phosphate bone grafts for surgically created periodontal bone defects in dogs

A calcium phosphate cement (CPC-1), prepared by mixing an equimolar mixture of tetracalcium phosphate and dicalcium phosphate anhydrous with water, has been shown to be highly biocompatible and osteoconductive. A new type of calcium phosphate cement (CPC-2), prepared by mixing a mixture of α-tricalcium phosphate and calcium carbonate with pH 7.4 sodium phosphate solution, was also reported to be highly biocompatible. The objective of the present study was to compare the osteoconductivities of CPC-1 and CPC-2 when implanted in surgically created defects in the jaw bones of dogs. At 1 month after surgery, implanted CPC-1 was partially replaced by new bone and converted to bone within 6 months. In comparison, at 1 month after surgery, the defect filled with CPC-2 was mostly replaced by new bone. Therefore, bone formation in CPC-2-filled pocket was more rapid than in CPC-1-filled pocket. These findings supported the hypothesis that CPC-2 converted to bone more rapidly than CPC-1.