- Nancy Volkers
- InteliHealth News Service
New information suggests that an ingredient still found in some dental products can increase the risk of potentially cancerous lesions. A study by researchers at Ohio State University found that people who used an older formulation of Viadent products (toothpaste and/or mouth rinse) were, on average, nearly 10 times more likely to develop the lesions – known as oral leukoplakia – than people who had never used the products.
Sanguinarine, an antibacterial agent that comes from Sanguinaria canadensis, or bloodroot, was once a key ingredient in Viadent products but has been removed. The products are produced by Colgate-Palmolive. “The sanguinarine was the only thing we could identify that made [the Viadent products] unique,” said Carl M. Allen, professor of oral pathology and dentistry at Ohio State University, who conducted the study with two colleagues.
The researchers examined 148 people diagnosed with leukoplakia lesions in 1997 and 1998, and compared them with 148 people who did not have leukoplakia. Each patient was asked about tobacco use, alcohol use and the use of Viadent products. Tobacco and alcohol use both are linked to the development of leukoplakia, which can lead to oral cancer. The study showed that people who had used Viadent products were 9.7 times more likely to have been diagnosed with leukoplakia than with people who had not used the products.
People who used the Viadent products several times each day were more likely than those who used it less frequently to be diagnosed with leukoplakia. The risk was highest in patients who had used both toothpaste and mouth rinse, followed by the users of the rinse only. Toothpaste users had the lowest risk. The study also showed the risk increased with age. “The lesions look just like any other leukoplakia lesions,” Allen said, although most of the lesions were located between the upper cheek and gum in an area called the maxillary vestibule. Normally, leukoplakia lesions are most common on the floor of the mouth or on the tongue. Allen said the majority of the lesions discovered in the study did not produce symptoms and were not precancerous. However, he said they could become precancerous or cancerous at any time. “We do see a small percentage of biopsies with definite precancerous changes.” At this point, he said, the group has identified only one Viadent user with a cancerous lesion.
The study came about after anecdotal reports on a possible link between Viadent and leukoplakia. “Initially I didn’t take [the idea] seriously,” Allen said, “but…we started keeping track. Every time we’d identify one of these lesions, we would add a note to the biopsy report about whether the patient had ever used Viadent products. We found that a huge percentage of them had.” These observations led to the study, which Allen said is the first controlled research into a possible link between the products and leukoplakia. “We feel it establishes the relationship much more firmly,” he said.
Colgate has replaced sanguinarine in its Viadent products with another antibacterial agent, but Allen warned people to watch out for the ingredient in other brands of dental products, particularly “natural” ones. “There are a lot of folks who think that if something is natural, it must be good for them. That’s not always the case.”