Protect your teeth with Listerine Fluoride Defense Anticavity Mouthwash. This mouthwash is clinically proven to kill millions of germs on contact.. The triple-action formula shields teeth from cavity-causing acids, rebuilds minerals, and strengthens enamel. This fluoride-rich rinse offers 50 percent stronger protection than just brushing alone,* and the smooth Mint Shield flavor leaves your mouth feeling fresh.