Quickly becoming the primary choice in dentistry for replacing one or more lost teeth, dental implants provide patients with results that more closely resemble their natural teeth than other restoration options. This is due to dental implants replacing both the visible portion of the tooth (crown) and tooth roots via metal posts embedded directly in the jawbone.
Because the devices are often crafted out of titanium, people with allergies to metal are often curious if they can still undergo an implant procedure. Fortunately, metal allergies are generally not prohibitive for someone considering implants.
Metal Allergies Explained
An allergic reaction to metal occurs when the immune system overreacts in response to a foreign material. The severity of these reactions can range from something mild, like a skin rash, to life-threatening, such as organ failure.
Specific types of metal contribute to most types of allergies. For example, nickel causes reactions in roughly 17% of women and 3% of men. Chromium and cobalt can also lead to reactions but in lower percentages. Allergic reactions to metal often result from external contact with jewelry or metal and the skin leading to a rash. The reactions can be more serious when replacement body parts are involved as the metal contained in the device can cause the body to reject it.
Metals Used in Dentistry
Metals, notably the dental amalgam that fillings are made from, have long served an important role in dental treatments. Dental amalgam combines metals like tin, copper, and mercury with precious metals like silver or gold. Although bolstered by decades of safe use, in rare instances, dental amalgam has been linked with rashes or inflammation.
Titanium is the most common metal that dental implants are manufactured from. Because of its superior biocompatibility with bone, commercial titanium is highly thought of for use in medical and dental treatments. Bone cells can easily adhere to and grow on titanium which allows the bond between the implants and jawbone to be strengthened. Even for those with metal allergies, it is rare for the titanium in implants to cause issues. So rare, that fewer than 1% of implant patients who took part in a clinical study reported experiencing adverse reactions from the metal.
Symptoms of Titanium Allergies
For most people, they will be unaware that they have a titanium allergy until exposure and symptoms develop. Common symptoms associate with titanium allergy include:
* Erythema – redness of tissue surrounding the implant
* Urticaria – hives or bumps that form on the gums or skin
* Eczema – itchy and inflamed gums or skin
* Pain, swelling, or development of oral sores
* Necrosis – tissue surrounding the implant dies
* Bone loss
* Patches of dry gum tissue
How to Test for Titanium Allergies
Fortunately, any patients suspecting they could have an allergic reaction to the titanium in dental implants can have their dental professional conduct diagnostic tests, like patch tests, prior to undergoing treatment. Some doctors may also recommend blood tests such as a lymphocyte migration inhibition, lymphocyte transformation, and MELISA test to diagnose a titanium allergy. These blood tests work by isolating white blood cells, exposing them to titanium, and measuring how the immune system responds from the exposure. The MELISA test, as opposed to allergy tests that simply rely on skin patches, is the recommend test to undergo before implant surgery because it offers a greater degree of accuracy.
Non-Metal Alternatives for Dental Implants
Reading to this point, people with known titanium allergies may be thinking they are not candidates for undergoing an implant procedure. Luckily, advancements in modern dental materials and technology have led to the development of alternative materials that can be used in lieu of titanium in implants.
Zirconia, developed in 1987, is one such material that is now often used in dental implants. This non-metallic alternative, classified as a ceramic, is generally suitable for people with metal allergies. Like titanium, zirconia bonds with bone well, is strong, corrosion resistant, and very durable. Because of these characteristics, zirconia is a great alternative for those concerned with a metal allergy that are seeking dental implants.
Some of the benefits offered by zirconia implants include:
* Virtually metal-free thereby lowering the risk of allergic reaction
* Exceptional strength
* Resists corrosion
* Hygienic – plaque cannot as easily accumulate
* Cosmetically appealing – zirconia is white so dark material will not show through the gums
Drawbacks of Zirconia Compared to Titanium
Although there are numerous benefits associated with zirconia, there are some drawbacks when compared to titanium. Some potential disadvantages associated with zirconia implants include:
* Fewer Available Design and Component Options: Unlike titanium, which has been used for several decades, zirconia is still relatively new and as such, its development is still early. Critical changes to designs, such as the two-piece screw-retained abutment, only became options in the United States around 2019. Currently, there are more design and component options for titanium implants compared to zirconia. If replacing a single tooth, this is not a huge concern but if multiple teeth or an entire set need replacement, it could be an issue.
* Long-Term Effectiveness Not Known: With decades of research, development, and effective use, titanium has a proven track record for dental implants that has led to a success rate of up to 98%. Zirconia, in comparison, has not been used as long making the long-term effectiveness less well understood.
* Strength and Resistance to Fracture: Titanium has higher flexural and fracture strength than zirconia and is less brittle. While zirconia is strong under compression, it is more likely than titanium to break under bending or flexing forces. As such, zirconia may be more prone to fracture and complications over the long term.
* Not Recommended for Complex Cases or Implant-Supported Dentures: Significant planning and a wide variety of component options are needed for patients that need to replace all of their teeth or who are replacing them with implant dentures. Because titanium has a wider selection of component sizes, purposes, and angulation options, they are ideal for even the most complex cases. In comparison, the options are limited and less versatile with zirconia bases implant systems.