Sir, in certain South-East Asian countries, charcoal has been added to the bristles of toothbrushes, the bristles of which are black in colour (Fig. 1). Manufacturers of these toothbrushes claim that the blending of charcoal into nylon bristles can reduce halitosis (as charcoal absorbs any bad odour), reduce plaque and also kill bacteria that may develop in the bristles during storage, thus reducing the bacterial contamination of toothbrushes. However, according to our knowledge, these claims are not substantiated by any scientific studies/evidence. These brushes are used and are easily available in Hong Kong, Malaysia, Singapore and worldwide via the Internet.

Figure 1
figure 1

Toothbrush with charcoal bristles

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Al-Ahmad et al. conducted a study wherein toothbrush heads were coated with silver to test for its antimicrobial effects but the coating did not have any antimicrobial effect against residual bacteria present on the toothbrush head.1 Turner et al. studied the bacterial contamination of toothbrushes which were coated with chlorhexidine.2 The results of this study showed that there was no difference in the bacterial contamination of toothbrushes with or without chlorhexidine.2 Yaacob and Park performed a study on local Malaysians who were applying charcoal and salt with their forefinger to clean the teeth and found that all the patients had distinct forms of abrasion on the labial surfaces of the teeth.3 There have been references in ancient literature of Romans and English adding powdered charcoal to toothpastes for the purpose of decreasing bad breath.4 As evidenced by the studies performed,1,2 in today's era of evidence-based dentistry, products and technologies are driven by scientific evidence and not by ancient anecdotal literature. Dentists and the general public should be cautious while advising and choosing their toothbrushes and refrain from using those which still have not been proven scientifically.