Listerine: past, present and future--a test of thyme.

Listerine, a mouthrinse composed of a mixture of essential oils, was created in 1879 and was originally formulated as a surgical antiseptic. In spite of its known antimicrobial properties it was thought of as a product in search of a use and promoted as a deterrent for halitosis and as a floor cleaner. In the last several years Listerine has emerged as a bona fide therapeutic agent for reduction of plaque induced oral diseases. In contrast to the inconsistent history of Listerine, systemic antibiotics discovered in the 1940's were heralded as miracle drugs. However, the value of prophylactic usage of antibiotics has come under scrutiny as a result of increasing resistance and adverse reactions. Moreover, reports by both American and British professional societies have led to a re-evaluation of the relative risks associated with plaque induced bacteremia when twice-yearly visits to dental professionals are compared to daily activities. These new recommendations and revelations open the door for local antimicrobial approaches to reduce the challenge of plaque-induced bacteremias. These issues will be discussed in the context of Listerine, its intricate and complicated past, and its connection to current uses in oral health and beyond.