Evaluation of calcium phosphates and experimental calcium phosphate bone cements using osteogenic cultures

In this study, rat bone marrow cells (RBM) were used to evaluate two biodeg radable calcium phosphate bone cements and bioactive calcium phosphate cera mics. The substances investigated were: two novel calcium phosphate cements , Biocement F and Biocement H, tricalcium phosphate (TCP), surface-modified alpha-tricalcium phosphate [TCP (s)] and a rapid resorbable calcium phosph ate ceramic consisting of CaKPO4 (sample code R5). RBM cells were cultured on disc-shaped test substrates for 14 days. The culture medium was changed daily and also examined for calcium, phosphate, and potassium concentration s. Specimens were evaluated using light microscopy, and morphometry of the cell-covered substrate surface, scanning electron microscopy, and energy di spersive X-ray analysis and morphometry of the cell-covered substrate surfa ce. Areas of mineralization were identified by tetracyline labeling. Except for R 5, rat bone-marrow cells attached and grew on all substrate surfaces . Of the different calcium phosphate materials tested, TCP and TCP (s) faci litated osteoblast growth and extracellular matrix elaboration to the highe st degree, followed by Biocements H and F. The inhibition of cell growth en countered with R 5 seems to be related to its high phosphate and potassium ion release. (C) 2000 John Wiley & Sons, Inc.