Abstract :Chemical complements such as toothpastes and mouth rinses that contain antimicrobial agents have proven to be effective for the control of oral biofilm. When used with adequate mechanical measures, additional anti-plaque and anti-gingivitis clinical benefits are achieved. However, recent investigations have reported some adverse effects of the antimicrobial strategy for the control of oral biofilm. One adverse effect is that most of the antimicrobial agents failed to remove the biofilm structure. The residual structure may serve as a scaffold for the redevelopment of biofilm. The remaining structure causes adverse effects with regard to host response to pathogens, even if the microorganisms in the biofilm are completely killed. Another effect is that low-dose antibiotics may promote bacterial biofilm formation. The short exposure time of chemical agents will cause gradient of concentration inside the biofilm. It has been demonstrated that a variety of antibiotics or antimicrobial agents at sub-MIC levels can induce biofilm formation in vitro, interfering with bacterial biofilm virulence expression. Future strategies that promote the biofilm matrix detachment are therefore expected, without affecting bacterial growth targeting to polymeric substances.