ABSTRACT
<p><b>OBJECTIVE</b>To prepare three quaternary ammonium salt (QAS) monomers, and to compare their antibacterial activities against four oral bacterial strains.</p><p><b>METHODS</b>Three antibacterial monomers [methacryloxyethyl benzyl dimethyl ammonium chloride (DMAE-BC), methacryloxyethyl m-chloro benzyl dimethyl ammonium chloride (DMAE-m-CBC), methacryloxyethyl cetyl dimethyl ammonium chloride (DMAE-CB)] were synthesized according to the general structure of target monomers. Their antibacterial effects were investigated using the broth dilution test on Gram-positive and Gram-negative bacterial strains (Streptococcus mutans, Streptococcus sanguis, Porphyromonas gingivalis, Prevotella melaninogenica ).</p><p><b>RESULTS</b>Three different monomers were successfully obtained. All the tested bacterial strains were susceptible to the three monomers, among which DMAE-CB exhibited the lowest minimal inhibitory concentrations (MIC) ranging from 1.2 to 4.8 mg/L.</p><p><b>CONCLUSIONS</b>All these three QAS monomers have different antibacterial activities against four oral bacteria strains. The data indicate that DMAE-CB may be a candidate antibacterial agent for oral infectious diseases.</p>