Electric toothbrushes are good because they do much more strokes every minute than is possible with a manual brush. Electric toothbrushes offer up to 7500 strokes each minute. So, this is why electronic toothbrushes are basically better at cleaning.
Floss your teeth every day. This helps prevent buildup between your teeth that causes plaque and tooth decay. It is important to properly floss for it to be effective. You can also use dental picks to clean between your teeth. They are easier to use and just as effective.