- Zinc and Potential Risk
- Reports of Problems
- Advice for Denture Wearers
- Reporting Problems to the FDA
Denture adhesives are pastes, powders or adhesive pads that may be placed in/on dentures to help them stay in place. Sometimes denture adhesives contain zinc to enhance adhesion.
In most cases, properly fitted and maintained dentures should not require the use of denture adhesives. Over time, shrinkage in the bone structure in the mouth causes dentures to gradually become loose. When this occurs, the dentures should be relined or new dentures made that fit the mouth properly. Denture adhesives fill gaps caused by shrinking bone and give temporary relief from loosening dentures.
Zinc is a mineral that is an essential ingredient for good health. It is found in protein-rich foods such as shellfish, beef, chicken and nuts, as well as in some dietary supplements.
However, an excess of zinc in the body can lead to health problems such as nerve damage, especially in the hands and feet. This damage appears slowly, over an extended period of time.
Overuse of zinc-containing denture adhesives, especially when combined with dietary supplements that contain zinc and other sources of zinc, can contribute to an excess of zinc in your body.
The FDA is aware of case reports in the medical literature linking negative reactions such as nerve damage, numbness or tingling sensations from denture adhesives that contain zinc to chronic overuse of the products. The subjects of these case reports used at least two tubes of zinc-containing denture adhesive each week. Some product instructions indicate that one tube should last seven to eight weeks.
The FDA has also received reports of adverse events linked to use of denture adhesives. However, the FDA’s adverse event reporting system is not designed to establish injury rates and individual reports vary in the amount and reliability of data included.
Neither published data nor FDA adverse event surveillance data are adequate to associate injuries with specific device types or brands.
The FDA has not found conclusive evidence that these problems result from using zinc-containing denture adhesive as instructed in the product labeling.
To help address the potential risk that overuse of zinc-containing denture adhesives may pose, the FDA asked makers of zinc-containing denture adhesives to consider:
- Including directions that will prevent overuse if zinc is an ingredient. (Some companies include graphics of the amount of adhesive to use or the amount of time that a tube should last under correct usage.)
- Modifying the labeling to specify that the product contains zinc as an ingredient, if appropriate and consider replacing zinc with an ingredient that presents less health risks in situations of overuse.
Manufacturers, importers and distributors of denture adhesives are required by the FDA to register their facilities, list their products and report adverse events. In addition, they are required to adhere to other general regulatory controls such as good manufacturing practice and adequate directions for use or a clear definition of an unsafe dosage or methods or duration of application.
Denture wearers may have difficulty determining the proper amount of denture adhesive to use if the instructions are not clear. If a denture wearer is uncertain about how much to use, he or she should contact a dental health professional to help determine the correct amount.
Denture wearers should know that a large amount of denture adhesive will not necessarily address problems with ill-fitting dentures, and prolonged use of ill-fitting dentures may lead to an increase in bone loss.
The FDA recommends that consumers of denture adhesive products:
- Follow the instructions provided with the denture adhesive. If the product does not come with instructions or the instructions are unclear, consult with a dental professional.
- Do not use more adhesive than recommended.
- Understand that some denture adhesives contain zinc, and that although they are safe to use in moderation as directed, if overused, they could contribute to harmful effects if over-used.
- Know that manufacturers may not always list their product ingredients.
- Know that there are zinc-free denture adhesives products.
- Stop using the denture adhesive and consult your physician if you experience symptoms such as numbness or tingling sensations in the extremities.
- Start with a small amount of adhesive - if the adhesive oozes off the denture into your mouth, you are likely using too much adhesive.
- Know that a 2.4-ounce tube of denture adhesive used by a consumer with upper and lower dentures should last seven to eight weeks.
- Track how much denture adhesive you use by marking on a calendar when you started a new tube, and when the tube is empty.
- Consider speaking to your dentist to see that your dentures fit properly. Dentures can become ill-fitting as a person's gums change over time.
Prompt reporting of adverse events can help the FDA identify and better understand the risks associated with medical products. If you suspect problems associated with the use of denture adhesives, we encourage you to file a voluntary report through MedWatch, the FDA Safety Information and Adverse Event Reporting program.