Injectable Apatitic Calcium Phosphate Cements and Microporous Biphasic Calcium Phosphate Granules Complex for Bone Repair

Different resorbable apatitic calcium phosphate bone cements are currently used. They present good mechanical properties and reasonable setting times. However they remain dense and do not provide rapid bone substitution because of the lack of macroporosity. The present study compared 3 kinds of CaP cements presenting different crystallinity characteristics and can be resorbed at different rates allowing the replacement by newly formed bone. Rabbits experiments at 3, 6 and 12 w, using a model of critical size defects, revealed similar biocompatibility but different kinetics of resorption. The presence of ACID into the cement enhances the resorption (MCPC (R) and alpha-BSM (R)) while high HA content after setting (SRS (R)) reduces resorption: The addition of Bioceramics granules into the cement (MCPC (R)) demonstrated when the cement matrix is dissolving, the formation of macroporosity involving in the core of the filled defect, bone ingrowth and osteoconduction on the BCP granules.