New review casts doubt on the efficacy of charcoal toothpastes

14 May 2019
3 min read

The review casts serious doubts on the marketing and benefits of such products.

Dentists are also urged to educate their patients about unproven oral health benefit claims and the possible health risks associated with the use of charcoal pastes and powders, which could also potentially increase the risk of developing tooth decay from use of non-fluoridated toothpaste, or possibly because the charcoal can deactivate the fluoride products inside the toothpaste.

Charcoal-based toothpastes and powders are promoted worldwide to consumers as fashionable oral health products, intended for tooth brushing, extrinsic stain removal and, mainly, tooth whitening.

The 2019 review ‘Charcoal-containing dentifrices’ by Greenwall provides an up-to-date overview of current knowledge and understanding of charcoal toothpastes and powders, considering all available evidence from 15 previous reviews and studies to assess claims made by the manufacturers of these products. The new study’s conclusion is that charcoal-based products may be over-reliant on marketing gimmicks and ‘folklore’ to substantiate their claims and that consumers must be educated better on ingredients before using them, especially if there is potential for increased abrasivity.

As part of the overall review, reference is made to a 2017 literature analysis by Brooks et al based on 118 articles and a database of detailed data on 50 charcoal-based toothpastes. The product information considered indicated that as few as eight per cent of the pastes contained fluoride. More than 50 per cent were claimed to have therapeutic benefits and 96 per cent were claimed to have tooth whitening capabilities. Other claims included remineralisation, strengthening or fortification of the teeth (30 per cent), low abrasiveness (28 per cent), a capacity for detoxification (46 per cent), antibacterial or antiseptic properties (44 per cent) and antifungal benefits (12 per cent).

Consumer-appealing terms such as eco-friendly, ecological, herbal, natural, organic and pure, appeared in the product advertisements for 88 per cent of the products, with 54 per cent using at least two such terms. Only 10 per cent included some form of dental professional endorsement. None of these claims have yet to be proven.

Regarding whitening capabilities, dental experts regard the high absorbency of charcoal to contain insufficient availability of any free radical bleaching agent in a charcoal-based paste or powder capable of chemically reducing intrinsic staining present in enamel and bony tissue.

In addition, possible health risks associated with the use of charcoal-based toothpastes may also be related to the possible inclusion of human carcinogenic polyaromatic hydrocarbons in charcoal (a group of chemicals that occur naturally in coal, crude oil, and gasoline) and the use of bentonite clay in some charcoal-based pastes which hold the plaque, bacteria and stained material in the pores of the charcoal (or clay). When brushed away, supposedly it leaves the tooth surface free of any deposits. However, as with many of the claims made for charcoal-based toothpastes and powders, there is insufficient supporting scientific data.

“The most worrying aspect about the marketing of charcoal pastes and powders, appears to be a strong emphasis on the benefits which appeal to consumers, which have yet to be disproved. This ‘scientifically claimed until proved wrong’ approach is favoured over substantiated, evidence-based promotion.”

Joseph Greenwall-Cohen, co-author of the study and member of the British Dental Bleaching Society, explains, “Many people are seduced into thinking that these charcoal-based products are ‘healthy’ due to clever marketing tactics and claims. However, these are completely unfounded as there is no evidence whatsoever that proves this. Just because these toothpastes are fashionable, it does not mean they are healthy for you.”

The British Dental Bleaching Society advises, “If you are considering whitening your teeth, it is advisable to visit the dentist to see if you are a candidate for tooth whitening. The dentist will evaluate your teeth and check the health of your mouth prior to whitening your teeth. The UK legislation is strict concerning tooth whitening. Only a dentist and their trained team can undertake tooth whitening. Most tooth whitening techniques involve the use of a specially made tray for your teeth and the prescribed whitening gel is placed into the trays to whiten your teeth. The dentist will supervise you while you undertake this treatment. Whitening toothpastes do not whiten teeth, they help to clean surface plaque off teeth and help to maintain a white smile following professional tooth whitening. Charcoal toothpastes do not whiten teeth. They may help to remove yellow plaque from the surfaces of your teeth, but they do not whiten teeth.

“Patients seeking to whiten their teeth by means of toothbrushing may be better advised to consider using one of the well-known brands of regular fluoride-based toothpaste formulated to have a whitening effect and to brush their teeth effectively, removing plaque and extrinsic staining and giving the teeth a whiter appearance.”