Researchers in Maryland have confirmed that excessive use of zinc-based denture adhesive cream may cause neurological damage and other problems from zinc poisoning.
According to report from dentistry experts at the University of Maryland Dental School in Baltimore, existing evidence seems to provide support for long-standing concerns that using too much denture adhesive to compensate for ill-fitting dentures may leave users with permanent nerve damage if the product contains zinc.
The study, conducted by Drs. Amar Patel and Nasir Bashirelahi, is titled "What Every Dentist Should Know About Zinc" and was published in the April 1 issue of General Dentistry. Patel and Bashirelahi reviewed existing literature and case studies on zinc-based denture cream and found that some patients had been exposed to as much as 200 times the recommended daily allowance of zinc.
According to the FDA and the University of Maryland researchers, the existing science indicates that the side effects of denture cream with zinc can include zinc toxicity and neurological damage, including symptoms of myeloneuropathy of the extremities and blood dyscrasias. However, the American Dental Association (ADA) has indicated there is no proof confirming a causal link between zinc denture adhesive and nerve damage.
Myeloneuropathy is neurological damage often caused by copper deficiency. It can manifest as tremors and weakness in the extremities and difficulty walking. Blood dyscrasia is a catch-all term for unspecified blood disorders, usually due to abnormal material in the blood.
"Dentists are suddenly hungry for more information on zinc," said Bashirelahi in a press release. "It is used in dental products abundantly, especially denture adhesives or pastes." Other dental products that the researchers said sometimes contained zinc included mouthwashes, toothpastes and some restorative materials.
A growing number of Fixodent lawsuits and Super Poligrip lawsuits have already been filed against the manufacturers of those denture adhesive products, which were sold for years without any indication that they contain zinc or that using too much of the denture cream may cause zinc poisoning.
According to allegations raised in the complaints, the denture adhesives can lead to increased levels of zinc in the body and deplete copper levels, causing a condition known as hypocupremia, which is known to increase the risk of significant neurological problems that can leave users with permanent and debilitating physical injuries, such as neuropathy, numbness, tingling, pain, weakness, loss of sensation, loss of balance, paralysis and difficulty breathing.
In February, the FDA called for the removal of zinc from all denture adhesives. GlaxoSmithKline previously agreed to reformulate Super Poligrip to remove zinc last year. However, Proctor & Gamble has denied that zinc in their denture cream products is causing any problems, and continues to sell Fixodent denture adhesive with zinc.
