A Miami man in his 60s suddenly has trouble walking. A Colorado woman in her 40s starts losing the use of her legs. A Texas woman in her 20s feels tingling, then numbness that starts in her feet and crawls up to her thighs.
All three blame an unlikely suspect: denture adhesives.
A growing number of lawsuits are being filed against the manufacturers of popular products like Super Poligrip and Fixodent, alleging that the zinc in the adhesives is leading to serious neurological problems — and in one case, death. In Miami alone, more than 70 such cases have been filed, and although none is in Tampa Bay area courts, local prosthodontists say their denture-wearing patients are asking how they can protect themselves.
The suits claim that denture adhesive manufacturers GlaxoSmithKline (Super Poligrip) and Procter & Gamble (Fixodent) failed to adequately warn consumers that ingesting the high levels of zinc found in many of their products could be dangerous.
Bolstering the cases are recent studies, including one headed by the University of Texas Southwestern Medical Center, which link heavy denture adhesive usage to serious neurologic disease.
Denture adhesive manufacturers "didn't tell anybody the right amounts to use. They didn't warn people that if they didn't use the right amounts that they could be crippled," said attorney Ed Blizzard, who filed a suit in Miami in December against GlaxoSmithKline on behalf of the family of Rodney Urbanek.
Urbanek, a longtime Super Poligrip user, started having trouble walking in late 2006, according to his wife, Gisela. Eventually he became paralyzed below the waist and died in May 2008 at age 64 in a hospital in South Carolina, where the couple moved after living in Miami for many years. Blizzard said an autopsy showed Urbanek's paralysis and death were linked to his use of denture adhesive.
GlaxoSmithKline officials maintain that their denture adhesive products "are safe when used as directed," spokeswoman Malesia Dunn said in an interview last week.
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Zinc is an essential mineral found in foods such as shellfish, meat, beans and cereals, and it's also sold in supplement form. Zinc helps wounds heal, keeps the immune system functioning properly and is required for proper sense of taste and smell. In denture products, zinc helps dentures adhere better to the gums.
But too much zinc can cause nausea, abdominal cramps and diarrhea, according to the National Institutes of Health's Office of Dietary Supplements. Chronic high usage can result in copper deficiency, which can cause neurologic disease. Copper helps keep blood vessels, nerves and bones healthy.
The U.S. Recommended Daily Allowance for zinc is 11 milligrams for men and 8 mg for women. Products like Super Poligrip and Fixodent contain 17 to 38 mg of zinc per gram of adhesive (there are 68 grams in a 2.4-ounce tube).
Certainly, the adhesives are not meant to be swallowed, but because they are used in the mouth, it's inevitable that users will ingest at least some of the product.
Both Super Poligrip's and Fixodent's manufacturers say on their Web sites that swallowing small amounts of adhesive is not harmful. The Fixodent Web site says the amount of zinc an average user would ingest from daily use is less than what's in most daily multivitamins, or in six oysters.
The problem, Blizzard says, is that the product instructions don't state clearly how much to use. And until last year, Super Poligrip products did not warn users of the potential dangers of ingesting large amounts of zinc.
Super Poligrip instructions tell users to "start with a small amount." But Blizzard notes the packaging also says "use more if needed."
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Rodney Urbanek often needed more adhesive. He had worn dentures since the mid 1990s. His wife said he used Super Poligrip every day, sometimes several times a day. She estimated he went through one to two 2.4-ounce tubes a week.
Super Poligrip's new product inserts say that a tube that size should last eight to 10 weeks.
In late 2006, Gisela Urbanek said her husband began to feel numbness in his legs, making it difficult to walk. He went from needing a cane to a walker in a few months. By June 2007, he could no longer feel anything in his legs.
In early 2008, Urbanek's doctors told him he had copper deficiency due to excess zinc. He stopped using denture adhesive and began taking copper supplements. His zinc and copper levels returned to normal, but he never regained feeling in his legs, Blizzard said.
Urbanek died on May 30, 2008, of respiratory distress syndrome, which Blizzard said was linked to his neuropathy.
Gisela Urbanek said her husband had no idea the denture adhesive could be dangerous. "How would he have known?" she said. "If there was some kind of warning, he would not have risked his health."
Blizzard said Mrs. Urbanek and Deanne Urbanek, Mr. Urbanek's daughter from a previous marriage, want GlaxoSmithKline to pay for what they say Super Poligrip did to Mr. Urbanek. How much? "We haven't put a number on it," Blizzard said.
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Blizzard believes Urbanek's is the only denture adhesive case that resulted in death. The others involve a range of neurological problems, some of which have improved with treatment.
The University of Texas study examined patients with various neurologic abnormalities. Each patient wore dentures and used a lot of denture adhesive. One was a 41-year-old woman with numbness and weakness in her arms and legs. She used two tubes a week. Another woman, 42, who used three tubes a week, experienced weakness in her hands, especially in her fingers.
In both cases, the patients showed elevated levels of zinc and decreased levels of copper. But after discontinuing use of denture adhesives and receiving copper supplements, both reported improved sensation and strength.
The 2008 findings led researchers to conclude that chronic excessive use of zinc-containing denture adhesives may result in copper deficiency and serious neurologic disease.
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Though there are no known cases involving Tampa Bay residents, the issue has caught the attention of many denture wearers, said Dr. Terry Kelly, a prosthodontist at Tampa's H. Lee Moffitt Cancer Center.
"They're asking about it," Kelly said. "Many older patients are concerned."
What does he tell them? For one, the patients who have suffered disabilities from denture adhesives, such as the ones in the 2008 study, used an excessive amount.
He also tells them that denture adhesive is not the solution for ill-fitting dentures.
The American College of Prosthodontists says that ideally, dentures should fit so well, no adhesive is needed. If your dentures don't fit, you should see your doctor.
That's what Fred Trubey was doing on Friday. Kelly was fitting the 77-year-old from Lakeland for new bottom dentures. Trubey has worn dentures for more than 50 years, but only last year started using denture adhesive to help them stay in place.
Trubey said Kelly has told him of the dangers of ingesting too much denture adhesive, so he hopes a new set will do the trick.
"I want to try to use as little as possible," Trubey said.
Richard Martin can be reached at firstname.lastname@example.org or (727) 893-8330.