The toothbrush includes a handle portion which has a disc spring assembly driven by a solenoid coil. The upper end of a central shaft which extends from the solenoid is connected to a drive flexible membrane assembly which in operation moves back and forth under the positive action of the solenoid central shaft and the return action of the spring on the central shaft. The drive membrane acts on hydraulic fluid which extends through a stem portion of the toothbrush to the brushhead, which includes a movable brushhead membrane. The moving fluid acts on the brushhead membrane to move it.