Thirty- four million Americans rely on dentures to replace their missing teeth. But a small number of denture wearers have had difficulty with balance and walking -- a medical mystery that some experts have linked to their denture creams. 15 separate lawsuits claim denture cream is cause of health problems.
Denture cream is used to hold false teeth -- dentures -- in place. About a third of denture-wearers use it, and most consider it like any other everyday beauty or hygiene product, such as toothpaste or shampoo. But some doctors say "excessive" use of denture cream may force people who were once independent to use wheelchairs or walkers just to get around.
For Ellen Isaacs, it began with a tingling in her toes. Four years later, her balance was gone and simple tasks have become impossible. After multiple rounds of tests, Ellen's neurologist, Dr. Rachel Nardin of Beth Israel Deaconess Medical Center in Boston, eventually concluded that denture cream was the source of the problem. "Stopping the denture cream use was a key part of her treatment," said Nardin.
Isaacs said that for at least 10 years she applied Super Poligrip to her dentures once a day and kept them in overnight. But what she didn't realize was that the cream contained zinc, which can cause serious illness in high doses. "I would have never equated use of denture cream to what was going on with my body, said Isaacs.
Doctors say too much zinc drives down copper levels in the body. This sets up a chain reaction that affects the spinal cord and makes it hard to walk and maintain balance. Nardin said, "Small amounts of denture cream are certainly safe for people. It's people whose dentures are ill-fitting, who are using excessive amounts ... who are at risk of running into trouble with zinc toxicity."
The authors of a 2008 study published in the Journal of Neurology theorize that long-term denture cream overuse was the culprit in the cases of four patients who had unexplained limb weakness and poor balance. Dr. Sharon Nations, who led the study, is an associate professor in the department of neurology at the University of Texas Southwestern Medical Center. "The patients were using at least two tubes of denture cream a week. ... So, it was long exposure to very high amounts of denture cream that led to their problem."
The FDA does not require that manufacturers list the amount of zinc, so the researchers tested the products themselves. The zinc varied from 17 to 34 milligrams per gram of denture cream. Significant amounts, according to the researchers. Dr. Jaya Trivedi, also an associate professor in University of Texas Southwestern Medical Center's neurology department, said, "If you have poorly fitting dentures, then seek professional help. Go and see your dentist, because we don't want them to be using large amounts of denture cream to keep the dentures in place." The researchers said more study is needed.
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Case study prompts questions on denture creams
Posted June 1, 2009
The ADA has received calls from members concerned about what to tell patients regarding the safety of denture creams.
The calls came on the heels of a recent "Good Morning America" story and television commercials seeking plaintiffs for a potential lawsuit against manufacturers of the products Fixodent and Poli-Grip denture creams. If a lawsuit is filed, the plaintiffs will likely claim that the zinc these particular creams contain as an ingredient caused them to experience hypocupremia-(copper insuffiency) induced neuropathy.
The issue has apparently arisen because of a case study titled Denture Cream: An Unusual Source of Excess Zinc, Leading to Hypocupremia and Neurologic Disease, which was published in the June 4, 2008, issue of Neurology, the official journal of the American Academy of Neurology. The study reviewed the case histories of four denture-wearers who exhibited neurological problems. These individuals reported that for years they had used two or more tubes of denture cream adhesive per week, although the manufacturers' directions indicate that a single tube should last up to 10 weeks.
The authors posit that the four denture-wearers consumed significant amounts of zinc from the excess denture cream they presumably swallowed over a prolonged period. The authors then hypothesize that the four individuals' symptoms are attributable to their consumption of zinc from that source and conclude that the creams, when used in excess, "may result in hypocupremia and serious neurological disease."
The ADA has issued a statement that the Association is "not aware of any reports of neurological problems resulting from use of a denture cream following the manufacturer's instructions, nor indeed of any other reports of neurological or other health problems related to the use of denture cream products under any conditions."
To date, the FDA has not issued any advisory to the public or the profession on this issue.
The ADA Division of Science will be looking out for any additional information that might come out on this topic and recommends that dental professionals remind patients to follow the directions on the label when using these products. For more information on denture adherents and other consumer products with the ADA Seal of Acceptance visit "www.ada.org/ada/seal/category.asp".
In separate but unrelated denture news, the Food and Drug Administration posted a Public Health Notification in March 2008 for health professionals on its Web site regarding possible allergic reactions from denture cleansers.
The PHN says the reactions—which include irritation, tissue pain, gum tenderness and respiratory conditions—can occur soon after the patient begins using the product or after years of use. All FDA safety alerts relevant to dentistry are posted on ADA.org. To access the one on denture cleansers, visit www.ada.org/public/topics/safety.asp.
