Abstract: Objective To prepare biomimetic mineralized nano-calcium phosphate and explore its sealing performance on dentinal tubules. Methods The amorphous calcium phosphate (DACP) was prepared based on DMEM biomimetic mineralization strategy, and its physical and chemical characterization was observed by the transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectra and other tests. Human oral keratinocytes cells (HOK) and dental pulp cells (DPC) were selected to co-culture with the materials for 24 h, respectively, and the biocompatibility of the materials was evaluated by CCK-8. Demineralized dentin disks were prepared by collecting intact and caries-free teeth, and applied evenly by DACP material suspension. Positive group with NovaMin and blank group were prepared. After treatment for 1 day and 7 days respectively, scanning electron microscope (SEM) was used to evaluate the surface and cross-sectional sealing effect of dentin disks on DACP group. Results TEM showed that DACP was uniform amorphous spherical nanoparticles, and the particle size increased with the extension of mineralization time. CCK-8 results showed that the cell viability of HOK and DPC were good under 25 μg/mL, 50 μg/mL, 100 μg/mL and 200 μg/mL DACP, suggesting that the material has good biocompatibility. After treated for 1 day, most of the dentinal tubules of DACP group were closed. After treated for 7 days, all dentinal tubules surface of DACP group was completely closed and cross-sectional images showed that DACP could penetrate into tubules. Conclusions The nano-calcium phosphate prepared based on DMEM biomimetic mineralization strategy has good biocompatibility and sealing effect on dentinal tubules, which is expected to be a new desensitization material.

Key words: nano-calcium phosphate, dentinal tubule, biomimetic mineralization, dentin hypersensitivity