The TerraCycle is a great program.
Have you tried toothpowders or oil pulls?
Oil pulls (using olive or coconut oil), 'pull out' the toxins when you swish and pull the oil between your teeth.
Toothpowders can be:
baking soda
magnisum
clove oil
peppermint oil
(other essential oil)
Stirred up and used similar to toothpaste.
Some people brush once a day. If you aren't eating sugar, keep your mouth clean and your gut happy your mouth should be fine (underlying conditions may cause problems, but if you have them brushing twice a day isn't likely going to help much). (50% less brushing is 50% of toothbrushes you'll be buying)
Some people 'brush' with their fingers.