When you floss, you help prevent your gums from becoming inflamed. What is happening when your gums are inflamed is that you have a chronic bacterial infection in your mouth. Dr. Donald Reid, Tahoe Dental Artistry comments, “This harms your arteries through two mechanisms: the bacteria find their way in to your arteries and hang out (causing plaques), and your body mounts a response to the bacteria in your mouth, causing inflammation, which in turn can cause your arteries to narrow.” This can lead to a serious immune response such as a cardiac (heart) event or a cerebral (brain) event. According to the American Dental Association (ADA), a toothbrush works by physically removing plaque, a sticky, bacteria-laden film, from your teeth with its soft bristles. Toothpaste enhances the effect of the toothbrush, and kinds that contain fluoride help reduce the amount of bacteria in your mouth. But brushing has one big drawback: A toothbrush's bristles can't adequately clean between the teeth or under the gums [source: ADA].