If you brush with brand-name toothpastes, you could be getting a mouthful of plastic with that minty fresh taste.
The tiny blue dots found in many dental products are made of polyethylene – the same material used in plastic bags. Dental hygienists have been finding these plastic "microbeads" embedded in patients' gums, Fox News reports. Fox quoted a dentist as saying that microbeads may trap bacteria in the gums, leading to gingivitis and periodontal disease.
But the Canadian Dental Association said the dangers of microbeads in oral hygiene may be overblown.
"We're not concerned about the issue," said Dr. Euan Swan, CDA's manager of dental programs. Although it's plausible that microbeads could cause gingivitis, he said, "I think it's all very theoretical." He added that the CDA has not received calls from the public or dentists about microbeads being found in the gums.
Nevertheless, Crest manufacturer Procter and Gamble has said it will remove microbeads from its toothpastes by March, 2016.
"While the ingredient in question is completely safe," the company said in a statement, "we understand there is a growing preference for us to remove the ingredient. So we will."
Concerns about microbeads came to light earlier this year when Trish Walraven, a dental hygienist in Dallas, blogged about them at DentalBuzz.com.
The intrepid hygienist published photos of microbeads caught in patients' gums.
Walraven also tracked down an explanation of polyethylene on Crest's website, which has since been removed. In the copy she saved, P&G describes microbeads as "a safe, inactive ingredient used to provide colour." In other words, they're just for decoration.
But Crest is hardly the only brand using microbeads to add a sparkly, futuristic look.
In the past five years alone, "more than 200 new polyethylene-containing toothpastes have been introduced in 43 countries by more than 15 manufacturers worldwide," said Procter & Gamble spokesperson Dr. Leslie Winston in a statement posted in August by the CDA. The toothpaste industry may think adding plastic is a brilliant idea, but scientists have shown that microbeads are a major threat to marine life – and they're not doing our teeth any favours.