STIMULATION OF BONE MARROW CELLS AND BONE FORMATION BY NACRE. IN VIVO AND IN VITRO STUDIES
11 cavities were prepared in the upper lumbar vertebrae of 5 sheep. The cavities were 3 mm in diameter and were filled by percutaneous injection of nacre powder or PMMA. The lumbar vertebrae were removed after 3 months. Histological studies showed that there was still nacre powder in the cavities wich contains also a large active bone marrow cell population. The particles of nacre appeared to be in the process of dissolution. In contact with or adjacent to nacre there were layers of newly formed bone that was physiologically active.