Titanium is considered to be one of the most biocompatible metals and is FDA approved to be used in medical and dental procedures as a component of many implantable devices. We as dentists use titanium and its alloys all the time as we place dental implants and abutments and substructures. I have faced scores of patients that claim they are allergic to these metals, some wanting the removal of titanium implants and others not wanting metal in their mouth in the first place. But how common is this problem in practice?
Well the prevalence of titanium allergy is estimated to be about 0.8%. A true allergy may present with a variety of symptoms that may include dermatitis, stomatitis, chronic inflammation in adjacent tissue, impaired wound healing, acne‐like facial inflammation, drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, chronic fatigue syndrome, muscle and joint pain, and neurological problems. What we also know is that some people don’t present with true allergy but a sensitivity to titanium which can lead to similar presentations.
To my knowledge there is no epidemiological data on the prevalence of titanium allergy in the general population, and, as no reliable diagnostic test is available, the clinical test data that is available is probably of low reliability. That is not to say that the allergy or sensitivity does not exist. Concurrent to this is the fact that many of the uses of titanium are in the form of an alloy which in itself contains metals that may trigger a reaction such as aluminum, nickel, vanadium etc.
In vitro blood tests such as the commercially available memory lymphocyte immunostimulation assay (MELISA®) may be useful in detecting allergy and sensitivity to titanium. The MELISA® test offers testing for a variety of metals. The sensitivity, specificity and reproducibility of MELISA® against up to 20 different metals, including Ti, were analysed in a recent study 150 of 250 patients with a suspected type IV allergy to a metal. The authors concluded that MELISA® was reliable for detecting metal allergy.
We know that metal sensitivities are quite common, reactions to costume jewelry, nickel cobalt and other common metals have a high prevalence in the general population, up to 17% of women and 3% of men are allergic to nickel and that 1-3% are allergic to cobalt and chromium. Since these metals are likely in many of the devices we use, albeit in small quantities, I would rather not put them in.
So my modus operandi in practice is that if one of my patients is reporting a sensitivity, whether confirmed or not, to any metal I will not be putting metal in their mouth. For implants we will be using ceramic and the same for the restorations. Dentistry has come a long way and we have options.
Ref: Fage, S.W., Muris, J., Jakobsen, S.S. and Thyssen, J.P. (2016), Titanium: a review on exposure, release, penetration, allergy, epidemiology, and clinical reactivity. Contact Dermatitis, 74: 323-345.