It is the trendy toothpaste backed by celebrities including X Factor judge Nicole Scherzinger.
But charcoal toothpaste has no evidence it works and may actually increase the risk of tooth decay, it has been warned.
The popular whitening product available in high street chemists often contains no fluoride, which is needed to destroy plaque.
Experts from King’s College London and the University of Manchester say charcoal products are reliant on ‘marketing gimmicks and folklore’.
The charcoal may in fact absorb the fluoride needed to prevent tooth decay, while it does not make teeth whiter but merely removes stains – much like regular brushing.
Nicole Scherzinger has said she brushes her teeth with ‘coal’ to make them whiter, while charcoal toothpastes and powders are advertised by reality television stars.
High street stores Holland & Barrett and Boots are among those selling charcoal toothpastes and powders which do not contain fluoride, while Superdrug is one of those selling charcoal products for tooth ‘whitening’.
Dr Joseph Greenwall-Cohen from the University of Manchester Dental School and British Dental Bleaching Society, reviewed dozens of scientific studies on charcoal products as co-author of an article in the British Dental Journal.
He said: ‘The problem is that there are so many celebrity endorsements and social media posts about these products, but the claims made about them are unsupported by the evidence.
‘The high abortive nature of charcoal limits the amount of active fluoride in the toothpastes required for prevention of dental decay.
‘Additionally the “whitening effect” of the toothpaste is limited to removal of staining and may be no more than the whitening effect of any regular toothpaste.’
Health food store Holland & Barrett says charcoal toothpaste is a ‘natural teeth whitener’ which helps to ‘brighten teeth’ by removing plaque and the stains caused by drinking coffee and red wine.
But the new review states that charcoal’s abrasive properties, which rub away stains, can also wear away teeth.
Charcoal was apparently first used for tooth-cleaning by Hippocrates, an Ancient Greek physician who died c.370BC, but the review adds: ‘Consumers are advised to check the ingredients in the charcoal toothpaste.’
A previous review two years ago from the US found as few as eight per cent of charcoal products contain fluoride.
Professor Damien Walmsley, scientific adviser for the British Dental Association, said: ‘Charcoal-based toothpastes offer no silver bullets for anyone seeking a perfect smile, and come with real risks attached.
‘These abrasive formulations may be effective at removing surface stains, but prolonged use may also wear away tooth enamel. Research now shows it could even cause discoloration of the gums.
‘The vast majority of these toothpastes are fluoride-free so aren’t even offering the basics required to protect teeth from decay.
‘So don’t believe the hype. Anyone concerned about staining or discoloured teeth that can’t be shifted by a change in diet, or improvements to their oral hygiene, should see their dentist.’
Source: Daily Mail