Background. This article reviews the rationale for incorporating effective antimicrobial, mouthrinses into a daily oral hygiene regimen along with mechanical plaque control methods. Types of Studies reviewed. The author previewed studies demonstrating the essential etiologic role of a pathogenic studies dental plaque biofilm in the development of gingivitis, as well as studies indicating that most people fail to maintain a level of mechanical plaque control sufficient to prevent disease. In-addition, he did a brief review of studies of oral microbial ecology that identified the oral mucosal tissues as surfaces, and he summarized a reservoir of bacteria that colonize tooth six-month clinical studies of marketed antimicrobial mouthrinse ingredients and products. 'Conclusions- There is a twofold.. rationale for daily use of antimi obial mouthrinses: first, given the inadequacy of mechanical plaque control by the majority of people, as a component added to oral hygiene regimens for the control and prevention of periodontal diseases; second, as a method of delivering anti microbial agents to mucosal sites throughout the mouth that harbor pathogenic bacteria capable of recolonizing supragingival and subgingival tooth surfaces. thereby providing a complementary mechanism of plaque control. The efficacy of several mouthrinse ingredients and products is supported by published six-month clinical trials. implications. The daily use of an effective antiplaque/antigingivitis antimicrobial, mouthrinse is well-supported by a scientific rationale and can be a valuable component of oral hygiene regimens.