Sure, everybody knows dental floss when they see it (we hope), and if you're in a periodontal program, you may be using miles of it. But do you recognize this gizmo? It's for "interdental" hygiene, especially useful for people with substantial spaces between their teeth at the gum line. Some studies show that interdental brushing, in combination with regular brushing and flossing, does a real number on plaque. Go gently, though. Any extreme pressure between the teeth, particularly in the presence of gum problems, can disturb the tissue.