An electric flossing device includes a body, an electromechanical driving mechanism, and a flossing adapter that houses a flossing string insert. The flossing adapter has a head with forward extending arms. String floss is retained at the distal end portions of the arms and moves up-and-down and side-to-side to work the floss down between the users teeth, while simultaneously scraping the teeth. The flossing adapter and flossing head remains stationary as the flossing string insert moves, to reduce fatigue and avoid injury to the user. This motion emulates manual flossing and permits the device to be moved forward and back slightly to follow the entire curvature of the tooth and ensure complete cleaning.