Abstract: Abstract: Objective　To evaluate the physicochemical and sealing properties of silver and zinc incorporated mesoporous calcium-silicate nanoparticles (Ag-Zn-MCSNs) as a canal sealer. Methods The pH values, solubility and flow values of MCSNs, Ag-MCSNs, Zn-MCSNs, Ag-Zn-MCSNs(Ag:Zn=1:1, molar ratio) and AH-Plus were measured. MCSNs, Ag-MCSNs, Zn-MCSNs, Ag-Zn-MCSNs and AH-Plus were used as canal sealers and prepared permanent teeths of single-canal root were obturated using warm vertical compaction technique. Enterococcus faecails (ATCC 29212) leakage test was used to evaluate the sealing properties and Micro-CT was used to calculate the percentage of voids within canals. Results The solution of four groups was strongly alkaline. They had lower solubility and higher flow values (P <0.05). Ag-MCSNs group had least leaked samples(25%), followed by Ag-Zn-MCSNs and AH-Plus groups(35%), while MCSNs group had most leaked samples(50%)(P>0.05). All experimental groups showed low ratios of voids after obturation on average 2.09% (P＞0.05), which had the largest values in the apical sections, followed by the middle and coronal sections (P＜0.05). Conclusions　MCSNs paste possessed good fluidity and Ag-MCSNs, Ag-Zn-MCSNs could reduce E.faecalis leakage, which showed good sealing properties.

Key words: mesoporous calcium-silicate nanoparticles, root canal sealer, bacterial leakage, root canal sealing ability