What toothbrush(es) do you use? Why those?
ours: http://www.amazon.com/Fuchs-Ekotec-Toothbrush-Soft/dp/B0014B2Q74 and http://www.amazon.com/Toothbrush-Adult-Medium-Refill-0-Kit/dp/B000N3LIF0 (or similar; i couldn't tell from the pictures). I like the first one b/c it is small, but the second seems to clean a skosh better.
Re: S/o plastic waste... toothbrushes
Preserve. You can put them back in the plastic cases they came in and send them to the Preserve company, who will recycle them, and Preserve sends you a new one every three months.
http://www.preserveproducts.com/products/personalcare/toothbrush.html
http://www.preserveproducts.com/toothbrush-subscription.html
This week I picked up a couple of Radius brushes because they were on clearance at the drug store and they are nice! The heads are replaceable and they are larger and more fluffy (more, finer bristles than other brushes) which feels really nice and seems to clean well.
This is the link on the Radius site:
http://www.radiustoothbrush.com/index.asp?Category=16&PageAction=VIEWCATS