Dental Implants Metal Allergy
Offering results that most closely replicate natural teeth, dental implants have rapidly become one of the more popular solutions for replacing lost teeth. This is due to dental implants replacing both the visible portion of the tooth (the crown) and the tooth roots using metal screws or posts embedded in the jawbone.
Because implant posts or screws are often made of titanium, people considering the devices may be concerned that an existing metal allergy could preclude them from being candidates for the procedure. Patients with metal allergies can rest easy as the condition generally does not eliminate them from obtaining dental implants.
Overview of Metal Allergies
Metal allergies are an immune system overreaction when a foreign material is introduced to the body. These reactions can range from something as minor as a skin rash to something life threatening like organ failure.
In general, metal allergies are caused by certain specific types of metals. For example, allergic reactions to nickel happens in approximately 17% of females and 3% of males. Reactions to cobalt or chromium also occur in smaller percentages. Frequently, metal allergic reactions occur when external contact between the skin and metal items cause skin rashes. In more serious cases, allergic reactions to replacement parts used in the body could cause rejection of the devices.
Metals, especially those in the dental amalgam fillings are made of, play an important role in dental treatments and have been used for many decades. Dental amalgam combines precious metals like gold or silver with other metals like copper, tin, and mercury (in trace amounts). Although dental amalgam has been safely used for decades, in rare cases, inflammation or rashes have been linked to its use.
With its superior biocompatibility properties with bone, titanium is highly regarded for medical and dental treatments. New bone cells can easily grow on and adhere to titanium which aids in strengthening the bond between the jawbone and implants. As such, titanium has been employed in dental implants since the 1960s. Even if a person has an allergy to metal, it is rare that issues would arise from titanium in dental implants. In fact, data from one study indicated that fewer than 1% of the 1,500 dental implant recipients reported adverse reactions to the metal.
Signs and Symptoms of a Titanium Allergy
Some people may not know they are sensitive to titanium until they experience signs or symptoms of a reaction. Common signs and symptoms of a titanium allergy may include:
- Erythema – redness in the tissues around the implant
- Urticaria – bumps or hives that form on the surfaces of the skin or gums
- Eczema – itchy, inflamed gums or skin
- Swelling, discomfort, or the development of sores or lesions in the mouth
- Necrosis – tissue or cell death around the implants
- Bone loss
- Dry patches of gum tissue
Testing for Titanium Allergy
Fortunately, patients that are concerned with possible metal allergies can get tested ahead of time. Dental professionals can do diagnostic testing, such as patch tests, prior to implant surgery to determine if the patient is allergic to the titanium used in dental implants. Some practitioners could also recommend blood tests such as the lymphocyte transformation test, the lymphocyte migration inhibition test, and the MELISA test to help identify any titanium allergies. These blood tests work by isolating white blood cells, exposing them to titanium, and measuring how the person’s immune system responds. When compared to traditional skin patch allergy tests, MELISA tests are more accurate and the recommended method for testing for an allergy before implant surgery.
Non-Metal Alternatives for Dental Implants
So far, those with known titanium allergies may think they are unable to receive dental implants. Fortunately, advancements in dental technology and materials have led to the creation of metal-free alternatives to titanium for use in dental implants.
Developed in 1987, Zirconia is one such alternative material that dentist frequently use in dental implants. Classified as a ceramic, Zirconia is a non-metallic material that is suitable for people with metal allergies. Zirconia bonds with bone well, resists corrosion, is strong, and highly durable. People considering dental implants but are worried about metal allergies, may find Zirconia to be an ideal solution to titanium.
Some of the benefits associated with Zirconia implants include:
- Low risk of allergic reactions due to non-metallic nature
- Corrosive resistant
- Reduces plaque accumulation making them more hygienic
- Superior aesthetics – Zirconia is white in color so there is no risk of dark material showing through the gums
Drawbacks of Zirconia Implants vs Titanium
Despite its numerous benefits, Zirconia does have some disadvantages when compared to titanium. Some drawbacks of Zirconia implants are:
- Fewer choices of designs and parts: Compared to titanium, which has been successfully used in dental implants for several decades, Zirconia implants are still young in their development. Important design improvements, such as two-piece screw-retained abutments, only became options in the United States around 2019. As such, there are more titanium part and design options currently available for dental implants compared to Zirconia. This is particularly true if multiple, or an entire set, of teeth need to be replaced.
- Long-term effectiveness not fully known: With decades of clinical development and use, titanium has a proven track record of long-term effectiveness. Zirconia, on the other hand, has not been used as long making its long-term effectiveness and the potential for complications, less well understood.
- Fracture and strength resistance: Less brittle than Zirconia, titanium has higher flexural and fracture strength. Although strong under compression, Zirconia has a higher likelihood of fracture under bending or flexing forces than titanium. As such, the risk of fracture or complication is higher with Zirconia over the long term.
- Not suitable for complex cases or implant-supported dentures: Zirconia implants are typically not suitable for patients that need to replace all their teeth or who need to use implant dentures. These types of treatments require significant amounts of planning and a variety of component options. Since titanium implants have a wider range of components in various size, purpose, and angulation options, they are ideal for the most complex cases.