Bioactive bone cements of calcium phosphate-mono(methacryloyloxyethyl) acid phosphate composite

摘要

We have prepared bone cements of calcium phosphate/mono(methacryloyloxyethyl) acid phosphate (P-1M) composite and investigated their physicochemical and mechanical properties. Calcium phosphate used in this study is as follows ; alpha - and beta -tricalcium phosphate ( alpha - and beta -TCP), and hydroxyapatite (HAp). When the ratio (wt percent) of P-1M to each calcium phosphate was 1/2, mixture was paste-like due to the high viscosity of P-1M, and then it hardened after 30 min. The compressive strength was 26 approx 31 MPa for alpha -TCP/P-1M composite, 20 approx 22 MPa for beta -TCP/P-1M composite, and 19 approx 21 MPa for HAp-200/P-1M composite. It decreased to 3 approx 8 MPa by heating alpha 0TCP/P-1M and HAp-200P-1M composite at 300 approx 600 deg C because they became to be porous. But, it was almost constant for beta -TCP/P-1M composite. After alpha -TCP/P-1M composite was soaked in 0.9percent NaCl aqueous solution for 24 hours, the surface (thickness: approx 0.3 mm) of the block specimen changed to calcium hydrogen phosphate dihydrate (DCPD) from alpha -TCP, and the inside had different structure from the surface. The shape of the surface material was rectangular plate and the inside material formed network.