A replacement head for an electric toothbrush has a simplified drive construction and desired bristle carrier retention. The replacement head includes a neck with a head at one end and a brush shaft disposed within the neck. An eccentric extension extends from the brush shaft parallel with the longitudinal axis and an axial extension extends parallel to the eccentric extension. The eccentric extension engages an angled slot in the bristle carrier to drive the bristle carrier. The brush shaft, including the eccentric extension and the axial extension, may be formed together as a single unitary piece.
