Recently there has been an increase in the number of people that have asked us about whitening with activated charcoal toothpaste. Unfortunately, there is currently not a lot of good data available about the safety, or effectiveness of brushing your teeth with activated charcoal. However, we can look at some basic dental principals and still come up with some statements that may be able to provide some guidance.
The first issue of course is safety, some people may believe that brushing with charcoal could cause their teeth to wear at an increased rate. This is a valid concern because many believe that even regular toothpaste can cause tooth wear in certain areas. Wear from abrasion has much to do with the hardness of the two items that are being rubbed together. Tooth enamel is much harder than activated charcoal, therefore tooth enamel wear is highly unlikely. The layer of the tooth under the enamel is of similar hardness to activated charcoal, therefore this layer, which can be exposed near the gumline as a result of gum recession, or on the biting surface from regular age related wear, could possibly be worn by brushing with activated charcoal. As mentioned earlier, regular toothpaste can also wear these areas, so activated charcoal is likely as safe as any regular toothpaste for the tooth.
The second question is of course related to the effectiveness, will activated charcoal whiten your teeth? The answer in my opinion is no. While external tooth stains may be able to be scrubbed off by activated charcoal, it will not give you Hollywood white teeth. This is because the majority of stain comes from the layer of your tooth underneath the enamel darkening with time. Therefore, the only way to really whiten your teeth would be to use something that has the ability to penetrate through the tooth enamel so that these stains can be broken down. This takes a chemical that can actively break down stains, and enough contact time to allow it to work. Activated charcoal fits neither of these criteria. Tooth whitening gels which contain hydrogen peroxide release oxygen ions. This oxygen can travel through the enamel, to break down stains under the surface. It requires repeated application, for periods of time from 30 minutes to 2 hours at a time depending on the strength of the gel. Activated charcoal has neither the ability to penetrate the enamel, or to chemically break down stains, and brushing with it does not provide enough contact time to be effective even if it could do those things.
Since it is likely to be ineffective, I would not suggest using activated charcoal toothpaste. If you are looking for a natural product to brush your teeth with I would use a toothbrush with just plain water on it. It will be cheaper, equally as effective, and less likely to cause staining of your gums that could possibly develop over time by brushing with a gritty black substance. If you would like to minimize tooth wear in areas where the enamel has worn through, but still would like to have the cavity fighting benefits of fluoride, then you could use one drop of an over the counter fluoride liquid on your toothbrush.