Several million Americans wear dentures and require a denture cream to affix them to the gums. While the Food and Drug Administration has generally considered such denture creams to be safe, it has been discovered in recent years that these creams, which are not required to list their ingredients on their packaging, contain high concentrations of zinc. It has been hypothesized that this zinc may be absorbed into the bloodstream through the skin on a person's gums, as well as swallowed when the creams are used excessively, resulting in high zinc levels in the bloodstream. High enough levels of zinc can result in zinc poisoning, a type of heavy metal poisoning. The Departments of Neurology and Clinical Sciences from the University of Texas Southwestern Medical Center in Dallas, the Department of Pathology from the University of Colorado Health Sciences Center, and the Department of Laboratory Medicine and Pathology from the Mayo Clinic in Rochester, MN, recently published a study supporting the claims that denture adhesives containing zinc can cause zinc poisoning in otherwise healthy adults.

The beginning stages of zinc poisoning include symptoms such as nausea, vomiting, and diarrhea. If zinc exposure continues for a prolonged period of time, neurological symptoms may develop. At times, such symptoms are irreversible and permanent. These neurological symptoms may include numbness or tingling in the extremities, increased sensitivity, partial paralysis, or even loss of bowel control.

In response to these findings, product liability lawsuits have been filed against the companies that produce denture creams, such as Fixodent and Poligrip. In February 2010, one of the companies against whom these suits have been filed, GlaxoSmithKline, released a statement acknowledging the potential danger of overusing zinc-containing denture creams. Although the company maintains that these denture creams are completely safe when used according to the directions, they have voluntarily taken measures to stop producing denture adhesives that contain zinc due to the dangers of overuse. GlaxoSmithKline will now only manufacture and market zinc-free denture creams and all packaging will reportedly be clearly labeled as "zinc-free."

Any persons who regularly use denture adhesives should be watchful of any symptoms that could potentially indicate zinc poisoning as previously described. If zinc poisoning continues untreated, the resulting neurological indications could be irreversible. If any possible symptoms of heavy metal poisoning arise, please contact a doctor immediately for a health evaluation. Any persons regularly using a zinc-containing denture cream and who suffer from the effects of zinc poisoning, especially irreversible neurological effects such as neuropathy should contact a personal injury lawyer. Persons suffering damage from the use of zinc-containing denture adhesives may be entitled to a portion of any settlement reached in these suits.