Biodegradation of Synthetic Biphasic Calcium Phosphate and Biological Calcified Substratum by Cells of Hemopoietic Origin

Di fferent types of osteoclastic cell s (authentic osteoclasis from human giant cell tumor and bone marrow of newborn rats; newly-formed osteoclasis from adult ra t bone marrow), gian t multinucleated cell s and macrophages were studied for their effec t on syn thetic and natu ral mineralized substrata. Biphasic calcium phosphate ceramic consisted of hydroxyapatite and beta tricalcium phosphate was chosen for in vitro experiments, and dentine served as a posi ti ve control for cell resorbing activity . Our results show the limited capacity of authentic and newly-formed osteoclasis to resorb synthetic ceramic as compared to that of natural substrata. In vitro cell-mediated biodegradation included also modi ficati ons of the syntheti c substratum surface caused presumably by phagocy tosis of the material.