There's some debate about whether electric toothbrushes are less harmful to the environment than manual toothbrushes. Those who say yes note that you would go through a lot of "regular" toothbrushes (the heads of which aren't recyclable) before you dispose of an electric brush, most of which use replaceable heads. In fact, according to the environmental experts at Green Your, it takes between 14 and 42 toothbrush replacement heads to equal the amount of plastic in one manual toothbrush [source: Green Your].
Of course, you do eventually throw out your electric toothbrush body, because at some point it stops taking and holding a charge [source: Green Hands USA]. Still, many people feel electric toothbrushes are more environmentally friendly.