Black toothpastes with activated charcoal are a big hit with influencers, but they can also cause problems. These pastes remove surface stains on the teeth because of their abrasive ingredients, but they can also subtly damage the enamel. Activated charcoal is a strong absorbent and could “suck” from your teeth the microelements necessary for their health. In addition, a single scientific study compared the whitening effect of activated charcoal with the effect of using standard whitening toothpastes, and the result was not in favor of this innovation.
Vaz, V., Jubilato, D. P., Oliveira, M., Bortolatto, J. F., Floros, M. C., Dantas, A., & Oliveira Junior, O. B., „Whitening toothpaste containing activated charcoal, blue covarine, hydrogen peroxide or microbeads: which one is the most effective?“, Journal of applied oral science : revista FOB, 27 (2019)