Listerine Advanced Defence Gum Treatment Mouthwash Listerine Advanced Defence Gum Treatment Mouthwash is clinically proven to treat gum disease for healthier gums in as little as 2 weeks. You may think bleeding gums are normal, but they are often a sign of gum disease or gingivitis. Gingivitis is an inflammation of the gums caused by plaque & bacteria sticking to your teeth & gums. If left untreated this can lead to further problems such as receding gums & even tooth loss. Listerine Advanced Defence Gum Treatment Mouthwash creates an invisible protective shield that prevents plaque germs from attaching to tooth surfaces, allowing gums to repair & restore themselves to a natural, healthier state.