OBJECTIVETo prepare three quaternary ammonium salt (QAS) monomers, and to compare their antibacterial activities against four oral bacterial strains.

METHODSThree 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 ).

RESULTSThree 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.

CONCLUSIONSAll 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.