Rego GF, et al. – This study was designed to examine antimicrobial properties and surface texture of model composites with different concentration and alkyl chain length of quaternary ammonium monomers (QAS). Researchers reported that chain length and concentration of QAS influenced biofilm development and production of lactic acid. It was noted that longer chains and higher concentrations of QAS promoted better antimicrobial properties. whereas changes in surface texture caused by abrasion decreased antibiofilm properties.