Last year large companies were sued because of negative side effects caused by the use of dental adhesives. It turns out that many of these products contain zinc, a trace mineral that can be potentially harmful in large doses.
Our bodies do not need a large amount of zinc (only 8-11mg). It is considered an essential trace mineral and we generally get it through the foods we eat. The properties of zinc decrease copper absorption, so high doses of zinc may cause a copper deficiency. For these reasons, if you are eating a regular diet and taking a daily multivitamin with zinc included some doctors recommend taking a copper supplement as well.
So what happens with zinc toxicity? Patients have been reporting signs and symptoms of neuropathy and neurological problems such as numbness and tingling, weakness in the arms or legs, lack of coordination when walking, or the sensation of wearing gloves or stockings on hands and feet even when they are bare. GlaxoSmithKline, the makers of Super PoliGrip dental adhesive products, tell consumers that have been using these products more than directed on the package, for several years, or have any concerns about their health to stop using these products, talk to their doctor, and use a zinc-free alternative.
The specific zinc-containing products from GlaxoSmithKline include: Super PoliGrip ‘Original’, ‘Ultra Fresh’, and ‘Extra Care’. Also, Proctor & Gamble’s Fixodent adhesive contains zinc, and should be cautioned for the same neurological side effects explained above.
Research has shown that the zinc toxicities were resulting from improper usage of the products. This occurs when using too much dental adhesive because of ill-fitting dentures, wearing dentures to bed (which increases the chances of ingesting the adhesive), and also the length of time/years the adhesives are used.
For those concerned, there are zinc-free dental adhesives available. Other options like adhesive pads, gels, and powders are recommended as alternatives. It might also be a good idea to visit the dentist and make sure your dentures fit properly, that way the smallest amount of product can be used.