Allergies are a lot more common than they used to be. But while food allergies seem to command the most attention, other kinds have been on the rise, too. Data from the World Health Organization, for instance, shows that
the number of allergy sufferers rose from 3% to 30% between 1960 and 1995. In the 2013 study on Adult Health in Germany (DEGS1), nearly 20% of respondents reported an allergic disease during the last twelve months. The most common allergic diseases were hayfever (14.8%), bronchial asthma (8.6%) and contact dermatitis (8.1%) (Langen et al. 2013). Allergic contact dermatitis has thus reached an alarming frequency similar to that of diabetes mellitus (Brasch et al. 2014). The introduction of new materials into dentistry also increased the likelihood of an allergic intolerance reaction as a result of dental treatment (Stoll 2007).
The 2018 study citing those statistics aimed to investigate those dental allergies.
Heavy Metals Top the List of Dental Allergens
Eighty-six patients – mostly female – took part in the study, all of whom had oral symptoms of a contact allergy. Information was collected about their general medical history, history of allergies, and objective symptoms. Each patient underwent an oral exam, with close attention to changes in all tissues that came in contact with materials used for crowns, implants, dentures, and the like.
Which materials were found most apt to cause a reaction? Metals sat on top of the list, including nickel, cobalt, and, of course, mercury.
Bear in mind that this study focused mainly on contact allergies, not systemic effects, although the other identified metals have those, too. Nickel, for instance, is extremely toxic. It’s known to contribute to oxidative damage, impaired kidney and liver function, reproductive problems, and more.
And nickel is very common in dentistry. It’s used in stainless steel crowns, orthodontic brackets, and retainers. Trace amounts of nickel have been found in titanium implants, as well.
Other common dental materials that were found to cause reactions included components in some resins used to make dentures, local anesthetics, toothpastes, fluoride gels, nylon, and even some ceramics.
Choosing Materials Wisely with Biocompatibility Testing
“We recommend that in daily clinical practice dental professionals pay more attention to symptoms of contact allergy and allergy in the patient’s history,” suggested the study authors.
It is the dentist’s responsibility to choose which materials and combinations of materials to use. Detailed medical and dental history and material knowledge are crucial in preventing sensitization of individual material components and side effects. The appropriate material cannot be chosen by dentists and/or allergists alone, because both groups do not know all the component ingredients in dental materials and, more importantly, which ingredients may actually be released in the oral cavity (Reichl et al. 2012; Sevkusic et al. 2014; Hogg et al. 2016). The manufacturer’s safety data sheet does not usually show all ingredients in their product (dental materials).
However, it’s just not true that dentists can’t choose appropriate materials. We can when we’re guided by biocompatibility testing. The gold standard Clifford test uses a small sample of your blood to identify the brand-name materials that you’re most and least likely to be reactive to. The test focuses on antibodies formed against 94 chemical groups and screens for 16,000 individual dental products. It considers not just the materials themselves but byproducts they may release.
It’s hard to overemphasize the importance of this testing and choosing dental materials carefully. In the case of restorations (fillings, inlays, onlays, and crowns) and prosthetics (implants and dentures), the materials are in your mouth 24/7. There’s never any break from exposure.
True, there are some materials that are considered broadly biocompatible – zirconia, for instance, and some BPA-free composite resins. Still, no two people are exactly alike. Each of us is genetically different, with different environmental influences and health histories.
Each of us deserves to be seen and treated as a unique individual – which is exactly how we treat each patient who entrusts us with their dental care, knowing that we do so with their whole body health and well-being in mind.
