Low porosity CaHPO4.2H2O cement

Compaction can be used to reduce the porosity of cements thereby improving their mechanical properties. In this study a brushite calcium phosphate cement that set following the mixture of monocalcium phosphate monohydrate (MCPM), beta-tricalcium phosphate (beta-TCP) and water was uniaxially compacted at pressures of up to 100 MPa prior to setting. The resultant cements exhibited wet compressive strengths in serum of up to 43% higher than uncompacted cement. Compaction reduced the extent of the setting reaction from 95% with no compaction to 78% after 100 MPa of compaction. Although, compaction inhibited the setting reaction it was an effective means of improving the compressive strength of brushite cement and may provide a method to control the degradation rate in vivo.