According to the U.S. Centers for Disease Control and Prevention, about half of all Americans will have periodontal disease at some point in their lives. Characterized by inflamed gums and bone loss around teeth, the condition can cause bad breath, toothache, tender gums and, in severe cases, tooth loss. Now, in ACS Nano, researchers report development of a membrane that helps periodontal tissue regenerate when implanted into the gums of rats.