Green Hands USA: America Volunteers

We all like white, healthy teeth, but are electric toothbrushes the greenest way to get them?

According to a study put out last year by the United Nations, you can cut your carbon footprint by 48 grams of CO2 a day by using a good old-fashioned manual toothbrush instead of an electric model.

Of course, the entire picture is much more complex than that. You need to look not only at how you use something, but the manufacturing and product lifecycle. Traditional toothbrushes are thrown away when they're used up, and can't be recycled. Electric toothbrushes have replaceable heads, so you are actually creating less waste every time you need to change your brush.

But electric toothbrushes don't last forever. After a few years, they stop holding their charges, and tend to end up in the trash. That's e-waste, which is bad for the environment.

Still, you can maximize the potential of your electric toothbrush (and reduce its carbon footprint) with one simple step: stop leaving it plugged in all the time. Even if your toothbrush is fully charged, that charger is probably still sucking electricity from the wall outlet. That's waste, pure and simple, and a lot of needless carbon emissions. Instead, wait for your brush to start to lose its charge, and only then plug it all in. (Then unplug it a few hours later.)

There's no simple conclusion here -- I don't think any one choice in oral care is going to change the planet -- but since you have to change your toothbrush every few months no matter what, this gives you a few options to come up with the green option that works best for you.