Calcium Phosphate Cement Reinforced by Nanocrystalline Cellulose

The aim of this study is to investigate the effect of nanocrystalline cellulose (NCC) with favorable mechanical properties on the compressive strength of calcium phosphate cement (CPC). Compressive test, Gilmore needle test, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyze the physicochemical properties of CPC influenced by different contents of NCC. Scanning electron microscope (SEM) and fluorescence microscope were used to observe the morphologies of CPC and the dispersity of labeled-NCC in CPC, respectively. NCC significantly increased the compressive strength of CPC up to about 27 MPa when the content of NCC was 2%. Setting times of CPC were prolonged with increased NCC, but still met the clinical requirements when the content of NCC was not more than 2%. XRD and XPS indicated that the combination of NCC with Ca 2+ could form unstable coordination compound and NCC promoted the dissolution and conversion of dicalcium phosphate dehydrate (DCPD) and CaCO 3 . SEM showed that CPC became denser with fewer pores and cracks by addition of NCC. Fluorescence microscope demonstrated the homogeneous dispersion of labeled-NCC in CPC.