Abstract: This invention relates to the method of manufacturing a toothbrush adapted to be mounted on an automatic toothbrush power handle, and having as a power source vibratory energy in the ultrasonic range. The manufacturing process includes that of providing a plastic brush having a head portion including a plurality of apertures and positioning a bristle cluster respectively in each aperture; and effecting a flow of the plastic in the head portion into substantially surrounding relationship of the bristles in each aperture therein, such that the plastic solidifies in adhesive relationship to the bristles to transmit the ultrasonic vibratory energy from the brush head portion to the bristles.