RESUMO
<p><b>OBJECTIVE</b>To synthesize a novel nano-antibacterial inorganic filler and provide a new way to give dental composite resin antibacterial property.</p><p><b>METHODS</b>Quaternary ammonium iodide N,N,N-trimethyl-3-(trimethoxysilyl) propan-1-aminium iodide were organically synthesized firstly and then the N,N,N-trimethyl-3-(trimethoxysilyl) propan-1-aminium iodide was grafted to the nano-silica particle to synthesize the antihacterial inorganic fillers nano-silica particle grafted with quaternary ammonium salt. All the products were analyzed and identified by infrared spectrum analysis. Then Streptococcus mutans were chosen as experimental object to analysis the antibacterial property of nanoantibacterial inorganic filler.</p><p><b>RESULTS</b>Quaternary ammonium salt was grafted to the surface of nano-silica particles successfully by infrared spectrum analysis. Compared with the control group, the nano-silica particle grafted with quaternary ammonium salt had a strong bactericidal effect on Streptococcus mutons (P < 0.01).</p><p><b>CONCLUSION</b>The nano-silica particle grafted with quaternary ammonium salt has a strong antibacterial property and could be used to improve dental composite resin antibacterial property.</p>