Calcium phosphate cements are biomaterials made of a mixture of calcium phosphate powder with water or with aqueous solutions of inorganic or organic salts, forming a paste that reacts at room or body temperature and hardens as a result of precipitation reactions. Calcium phosphate cements are commonly used in both dentistry and orthopedic bone filling surgeries, which require extremely invasive procedures. The innovation consists in formulate an injectable paste by incorporation of additives. In this work, three different additives (carboxymethylcellulose, agar polymer and calcium alginate) were incorporated in alpha-tricalcium phosphate (alpha-TCP), in concentrations of 0.4%; 0.8%; 1.6%; 3.2% and 6.4% wt%. Results showed that it was possible to obtain injectable compositions of tricalcium phosphate cement. It was verified that the injectability, measured by a novel method, depends on the rheological behavior of the pastes and injection time. In this study, pastes with sufficient viscosity for good homogenization and injection were obtained. In this study, pastes with 1.6% carboxymethylcellulose, 1.6% agar and 0.8% sodium alginate present sufficient viscosity for good homogenization for cement injection.
Bone cement; tricalcium phosphate; additives; injectability
