BIODEGRADATION OF SYNTHETIC BIPHASIC CALCIUM-PHOSPHATE AND BIOLOGICALCALCIFIED SUBSTRATUM BY CELLS OF HEMATOPOIETIC ORIGIN

Different types of osteoclastic cells (authentic osteoclasts from huma n giant cell tumor and bone marrow of newborn rats; newly-formed osteo clasts from adult rat bone marrow), giant multinucleated cells and mac rophages were studied for their effect on synthetic and natural minera lized substrata. Biphasic calcium phosphate ceramic consisted of hydro xyapatite and beta tricalcium phosphate was chosen for in vitro experi ments, and dentine served as a positive control for cell-resorbing act ivity. Our results show the limited capacity of authentic and newly-fo rmed osteoclasts to resorb synthetic ceramic as compared to that of na tural substrata. In vitro cell-mediated biodegradation included also m odifications of the synthetic substratum surface caused presumably by phagocytosis of the material.