An electric toothbrush is more efficient than a regular toothbrush. It's battery-powered so you don't have to mess with any cords, and the brush head moves in rotating movements.
From Joom
Oral B Kids Electric Toothbrush Soft Bristle Waterproof Gum Care Oral Hygiene Teeth Bush For Children Powered by 1 AA Battery
Vitapoint Health & Beauty
Oral-B Stages Disney Frozen Kids Electric Toothbrush with Battery and Timer App
This product is also available at 1 unverified merchant.