I recently had a patient ask me about activated charcoal for tooth whitening. I’ve been doing a little research and what I’ve found is there isn’t much scientific research out there!
Charcoal is an absorbent and abrasive compound, which would lead me to think that it will remove stains about as well as baking soda, though not as well as hydrogen peroxide or carbamide peroxide. The peroxide whitening pastes and gels actually soak into the first few layers of tooth and get the stains out of there in ways that an abrasive cleaning the surface cannot.
The problem I sometimes see with baking soda is that due to it being very abrasive people often like to scrub their teeth with it, and can actually brush away their gums causing recession and brush away their enamel causing sensitivity and weakening the tooth. These same problems are likely to happen with the activated charcoal.
My advice on brushing with charcoal is that it’s not worth the risk! Whitening gels are more effective. If you choose to use charcoal, do so with care and caution so you don’t damage your teeth or gums.