Recently, activated charcoal has found its way into many health and beauty products. People are using activated charcoal to lose weight, care for their skin, and more recently, to whiten their teeth.
Activated charcoal is a highly porous and abrasive powder that is primarily used in filters to trap impurities. Sometimes it is used in cases of poisoning by health care professionals, since it does partially trap poison inside the gastrointestinal tract and prevents the body from absorbing it.
Now, brushing with activated charcoal powder possibly might remove plaque and superficial stains, especially if teeth are covered with a heavy plaque buildup. But, it would not do anything to remove the intrinsic stain on teeth, which is the result of long term exposure to staining from food and beverages.
There has been no scientific study comparing the teeth whitening power of activated charcoal against a blank powder. Brushing regularly with activated charcoal could be dangerous. Since it is an abrasive powder, it will damage the enamel of teeth, and eventually, eliminate it permanently. While brushing with activated charcoal sparingly may be the newest fad, using teeth whitening tooth paste, over the counter teeth whitening strips, or, the best option, getting professional teeth whitening performed by a dentist, are still the safest alternatives.