An orthodontic flosser comprising an elongated handle and a head coupled to the handle is disclosed. A projection extend for suspending floss is sized for insertion of floss between a wire affixed to a tooth and the tooth. A source spool of fresh floss is configured to feed fresh floss incrementally into suspension from the projection while a take-up bobbin is configured for taking up used floss and applying tension to the suspended floss. A button may be used for releasing the source spool to rotate, and for holding the source spool against rotation. The source spool and take-up bobbin may be disposed in separated chambers to reduce cross contamination. A retie flange in the take-up bobbin and a retie slot in a take-up chamber are configured for retiying broken floss around a spindle of the take-up bobbin.