Electric toothbrushes generally work by using tufts of nylon bristles to stimulate gums and clean teeth in an oscillating or rotary motion. Some tufts are arranged in a circular pattern, while others have the traditional shape of several bristles lined up on a row. When first using an electric toothbrush, expect some bleeding from your gums. The bleeding will stop when you learn to control the brush and your gums become healthier. Children under 10 should be supervised when using an electric toothbrush. Avoid mashing the tufts against your teeth in an effort to clean them. Use light force and slow movements, and allow the electric bristle action to do its job.