Feb. 28, 2011 -- After receiving more than 360 complaints that long-term overuse of the popular denture cream Fixodent caused serious nerve damage, the Food and Drug Administration last week urged denture cream makers to remove zinc, modify package labels and conduct further research of risks.
As ABC News' Chris Cuomo reported on "World News with Diane Sawyer" and "Good Morning America" earlier this month, excessive long-term use of zinc-containing denture creams like Fixodent may cause serious and irreversible neurological damage.
Poligrip, the other leading denture cream, no longer contains zinc.
An exclusive ABC News investigation also uncovered that a paid consultant to Proctor & Gamble, maker of Fixodent, did not disclose a possible conflict of interest when he peer-reviewed a scientific study of four patients that suggested a link between an overuse of denture cream containing zinc and nerve disease.
In a Notice and Recommendation Action dated Feb. 23, 2011, the FDA wrote: "Although zinc is an essential nutrient, overexposure may result in zinc toxicity. We are notifying all manufacturers of denture adhesives and asking for their assistance in dealing with this public health issue."
Consumers most at risk are those "using excessive amounts of the products over extended periods of time; people with poor fitting dentures; and people who are unable to read or understand product labeling," the FDA wrote.
It "strongly recommends" manufacturers of denture creams that contain zinc, including Fixodent, to consider "replacing zinc with an ingredient that presents less health risks in situations of overuse."
Proctor & Gamble today told ABC News that it is in active discussions with the FDA on this topic, that it takes the recent notice very seriously, and that it is "carefully considering the FDA's recommended actions."
The company also mentioned that it has already changed its product label to caution customers about overuse of the product, and said it is "always looking for new and improved formulas as we strive to improve our products."
"Clearly this captured the attention of the FDA," said medical ethicist David Rothman from Columbia University. "This is not a recall or a mandate, but if you are a manufacturer of such products, you would move quickly to get your product in order."
Dozens of Fixodent users have sued Proctor & Gamble claiming that they were injured after long-term overuse of the product.
"We are encouraging consumers to consult with their doctors if they use significant amounts of zinc-containing denture adhesives such as Fixodent and have tingling or numbness in their extremities," said plaintiffs' attorney Eric Chaffin of Chaffin Luhana.
"A simple zinc blood or zinc urine test and a copper blood test can confirm whether the patient suffers from zinc poisoning and copper deficiency," attorney Andy Alonso of Parker Waichman Alonso said.
The FDA told ABC News today that it currently has no evidence that zinc in dental adhesives is harmful when they are used in moderation, and not excessively.
It will "continue working with manufacturers to ensure that the products are properly labeled to communicate instructions to consumers on proper use and any potential risks," the FDA wrote in a statement.