Allergic Reactions to Metals in the Mouth, 3rd Edition

Course overview

A wide variety of materials used for the construction of dental restorations, prostheses, and dental implants have the potential to cause allergic reactions among dental patients. More than 50 million Americans suffer from an allergy, and allergies are the sixth leading cause of chronic illness in the United States (Griffin, 2021). Rates of metal sensitivity are thought to increase with exposure, and an estimated 15% to 20% of people within the Western population are considered to be hypersensitive to at least one metal (Chung et al., 2023; Sadrolvaezin et al., 2023). Hypersensitivity to metals in biomaterials used in dentistry and medicine requires all dental professionals to be aware of metals to which patients may be allergic and to exercise caution when selecting restorative materials (Di Spirito et al., 2024; Itoh et al., 2020; Vrbova et al., 2021). Crowns, bridges, removable partial dentures, and implants are fabricated from metals such as noble and seminoble alloys, base metal alloys, and titanium-based alloys. Adverse reactions in hypersensitive patients are possible with all metals. Some effects that have been reported include intraoral redness, swelling and pain of the oral mucosa and lips, oral/gingival lichenoid reactions, stomatitis, cheilitis, extraoral urticarial or eczematous lesions, and combinations of two or more of these conditions. Increasing numbers of patients complain of intraoral and extraoral lesions, metallic taste, and skin reactions, which may be related to the dental materials used for restorations. This basic-level course reviews the importance of metals for human health, identifies common harmful metals and their role in disease, and discusses hypersensitivity reactions, with particular regard to metal allergies in medical and dental patients. Corrosion is also discussed relative to its role in the hypersensitivity reactions experienced by dental patients. Chronic exposure to metal corrosion in the oral environment has been associated with oral manifestations such as bone resorption, oral lesions, oral edema, oral cancer, and extraoral issues such as fatigue, hair loss, and eczematous rashes in individuals who are hypersensitive to metals (Sukumaran et al., 2020; Vrbova et al., 2021). For these reasons, it is imperative that dental professionals understand the different types of metals used in biomaterials, factors that increase dental restorations' corrosion susceptibility, and corrosion's potential to increase patient hypersensitivity to metals. Doing so will help dental professionals make better-informed decisions about which biomaterials are the safest and most effective.