Abstract
The effect of implants of fresh autogenous bone marrow (BM) and hydroxylapatite particles (HAP) in subcutaneous tissues and bone defects was studied experimentally in a monkey. HAP, BM and a mixture of HAP and BM (MIX) were implanted into the subcutaneous tissues and jaw bone defects. After the implantation, histological findings were studied at various intervals, particular attention was paid to new bone formation.
No bone formation was found in any cases using HAP alone in subcutaneous tissue, but, new bone was formed in cases using BM and MIX in subcutaneous tissues. The frequency of such bone formation in cases using MIX was higher than that of cases using BM. This result may be caused by the microenvironment around HAP with or without BM. The bone formation did not occur in direct contact with HAP, so HAP can not act as nidus for newly formed bone. Multinucleated giant cells in close contact with HAP appeared both in cases of HAP- and MIX-groups, and their numbers were greater in the MIX-group when compared to the HAP-group, while they disappeared as bone formation progressed. The bone formation in jaw bone defects was more prominent in the MIX-group than that in the HAP-group, and the HAP was completely surrounded by lamellar bone at 90 days in the MIX-group.
