Benefits and safety of charcoal dentifrices investigated
American Dental Association
BALTIMORE, USA: With promises of whiter and cleaner teeth, charcoal-based oral hygiene products have enjoyed a boost in popularity in recent times, with new products steadily entering oral hygiene racks and online shopping sites alike. However, the results of a literature review conducted by researchers at the University of Maryland School of Dentistry have now challenged the marketed benefits of these products.
“Recently, use of charcoal-based toothpastes has gained popularity in the marketplace. However, there is insufficient scientific evidence that these products effectively promote tooth whitening, oral detoxification, or provide any therapeutic properties—antibacterial, antifungal, or antiviral,” said lead author Prof. John K. Brooks from the Department of Oncology and Diagnostic Sciences at the university. For the review, the research team combed the MEDLINE and Scopus databases for clinical studies on the use of charcoal and charcoal-based dentifrices, as well as laboratory investigations on the bioactivity or toxicity of these products. Overall, 118 eligible articles published through February 2017 were considered in the study. In addition, the researchers selected the first 50 consecutive charcoal dentifrice offerings from searches on Google and Amazon in order to determine product assortment and advertising promotions. The results showed that the marketing claims of some of the charcoal products failed to reflect the actual benefits. For example, 38 percent of the products were promoted as strengthening or remineralizing teeth, according to the authors, yet only one of the examined products contained fluoride, a compound well established to enhance enamel mineralization. According to Brooks, the review further showed unproven claims of safety, particularly in regard to the principal ingredient, charcoal, and in some products, to bentonite clay. The latter belongs to a heterogeneous group of clays with various industrial applications and is an ingredient in skin care products, medication and toothpaste. Among other concerns, charcoal has been recognized as a mineral abrasive to the teeth and gingivae. Inclusion in products may cause damage to these tissues and could increase caries susceptibility owing to the potential loss of enamel. In this regard, 28 percent of the products reviewed in the study claimed to be low abrasion, although laboratory test results for dentin abrasiveness were provided for only one product, the authors noted. To establish conclusive evidence about the efficiency and safety of charcoal-based dentifrices, larger-scale studies are needed, the researchers concluded. Until then, dental practitioners should educate their patients about the unproven claims of oral benefits and safety associated with such products. Using charcoal for oral hygiene purposes is no new trend. In fact, powdered charcoal was used as an ingredient for toothpastes as far back as ancient Greece. For use in present-day oral hygiene products, charcoal is mostly activated by steam or chemical methods at an extremely high temperature. Once activated, charcoal has the ability to bind with toxins, stains, calculus and bacteria on the surface of teeth and the mouth in general—a process known as adsorption. Charcoal is further claimed to balance the pH of the mouth to a value that prevents bacteria from thriving and reproducing in the mouth, thus helping to protect teeth from infections caused by bacteria and other microorganisms. The study, titled “Charcoal and charcoal-based dentifrices: A literature review,” was published in the September issue of the Journal of the American Dental Association.