title: Effect of bioactive ceramic composition and structure on in vitro behavior. III. Porous versus dense ceramics.
abstract: In vitro reaction kinetics of surface transformations of porous and dense bioactive ceramics were studied after immersion in simulated physiologic solution (SPS). Porous ceramics with identical macroporosity were commercially obtained: calcium carbonate marine coral (I-CC), coralline HA (I-HA), and a product, labeled as beta-tricalcium phosphate, which was partially transformed into beta-calcium pyrophosphate (I-beta-CP). Previously studied dense ceramics were used for comparison: Ca-deficient HA (CDHA), stoichiometric HA, both well and not well crystallized (wc and nwc s-HA), beta- and alpha-tricalcium phosphate (beta- and alpha-TCP). The induction time to precipitation increased as follows: CDHA, nwc HA < wc HA, I-HA < beta-TCP, I-CC << I-beta-CP. The reaction kinetics of ceramics with identical macroporosity varied substantially depending on composition, crystal structure, and ultrastructure. One of the porous ceramics, I-beta-CP, showed an inhibiting effect on precipitation reactions.
authors: Department of Bioengineering, University of Pennsylvania, Philadelphia 19104.
authors: S R
authors: SR
authors: Radin
authors: P
authors: P
authors: Ducheyne
mesh_terms: D001711:Biotransformation; D002118:Calcium / Q000378:metabolism; D002516:Ceramics / Q000737:chemistry* / Q000145:classification; D008422:Materials Testing; D010758:Phosphorus / Q000378:metabolism; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010758:Phosphorus; D002118:Calcium