Metal Allergies

Nickel metal allergy from removable partial denture framework caused inflamed gingiva
This inflamed rash shows the "footprint" of the patient's metal-frame removable partial denture. The rash ends where the denture ends, and the denture had been in use less than a week. The patient was found to be allergic to nickel, present in the denture's nickel-chrome reinforcing framework as an alloying element.

Metal allergies are relatively common in dentistry, most often experienced by women who wear removable partial dentures that have reinforcing frameworks made of metals contained in costume jewelry. The most common allergenic element is nickel, but allergies to cobalt, chromium and palladium are well documented in the professional literature. The significance of metal allergy lies in the fact that they are commonly used in the construction of denture frameworks, crowns, bridges, and orthodontic wires and brackets (orthodontics).

Last updated: 12/29/2013

Metal allergies associated with dentures are straightforward to diagnose. The dentist performs an examination of the affected tissues, and arrives at a diagnosis on the basis of the appearance, location, and history. Patients with an allergy to the material will typically have a soft-tissue imprint resembling a brand. Very often, a patient who is sensitive to nickel-containing denture alloys has a history of allergy to the metal. This often manifests as a chronic itch in skin that contacts nickel-containing jewelry.

Ruling out infectious conditions is generally straightforward, because contact allergies usually appear shortly after the denture is made, unlike infectious conditions (e.g. Candidiasis); and leaving the denture out produces rapid resolution of the problem. For cases which are not as clear cut, skin testing can be performed by an allergist. Allergies to orthodontic hardware can be harder to diagnose because they generally result in gingivitis—which is also common in non-allergic orthodontic patients, and usually due to poor oral hygiene.

Last updated: 8/7/2013

Typically, the denture framework (or other restoration) will need to be replaced with one that does not contain nickel, or other allergenic metals. Framework alloys (if needed) should be considered which form few if any corrosion byproducts. These may include noble and high noble alloys (e.g. gold and platinum), or titanium and ceramic materials. The expense of such exotic framework materials should be weighed carefully against other available treatment options.

Where rigid reinforcement is not required for strength, non-reinforced denture plastics may be an option. Non-reinforced dentures may have other limitations, including the inability to rest them partly on the remaining teeth, which minimizes the forces they apply to the gum tissues and underlying bone. Other treatment alternatives like fiber-reinforced denture acrylic, fixed bridgework (bridges), or dental implants may be an option.

Treating inflamed soft tissue may be as simple as rinsing with warm salt water several times a day as directed by your dentist. Including 0.12% chlorhexidine or Listerine® in the rinsing routine morning and evening may accelerate recovery.

Last updated: 8/7/2013

Contact allergies to denture materials (especially nickel-containing partial denture alloys) may resemble atrophic candidiasis (sometimes called thrush). Also, patients should realize that there are several options to removable partial dentures for the replacement of missing teeth. Any mouth sores which do not heal should be further evaluated to rule out malignancy. Several alloys used in dental casting are known mutagens and a few, including beryllium and cadmium are known carcinogens when present in certain forms. Grinding on the alloys containing these elements, for example, can expose laboratory technicians to dangerous levels of beryllium or cadmium dust. Despite these facts, however, there are no studies or cases in the literature documenting carcinogenic effects of wearing frameworks constructed with those alloy elements.

Last updated: 12/29/2013
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Background information

The following articles are intended to provide you with background information on the topic. These articles may or may not influence your decisions about care.

Treatment of a Patient With Metal Allergy After Orthognathic Surgery
Kitaura, Hideki, et al.
The Online Angle Orthodontist
2006 77 (5): 923-930

Contact stomatitis due to palladium in dental alloys: A clinical report
Garau, Valentino, DDS, MS, PhD, et al.
The Journal of Prosthetic Dentistry
2005 93 (4): 318-320

Effect of Nickel and Chromium on Gingival Tissues During Orthodontic Treatment: A Longitudinal Study
Ramadan, Ahmed Abdel-Fattah, MSD, PhD
World Journal of Orthodontics
2004 5 (3): 230-235

Principles of biocompatibility for dental practitioners
Wataha, John C., DMD, PhD
The Journal of Prosthetic Dentistry
2001 86 (2): 203-209

Biocompatibility of dental casting alloys: A review
Wataha, John C., DMD, PhD
The Journal of Prosthetic Dentistry
2000 83 (2): 223-234

Body piercing involving oral sites
Price, Shelia S., DDS, EdD, and Lewis, Maurice W., DDS
The Journal of the American Dental Association
1997 128 (7): 1017-1020

Last updated: 7/10/2011
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