Extractable Protein Levels in Latex Products and their Associated Risks, Emphasizing American Dentistry

Background: Over 8% of the US population have detectable Type I hevea latex IgE antibodies and, upon exposure to natural latex and rubber products, are at risk for potentially dangerous reactions, especially in dental settings where these products meet mucosal membranes. Methods: Extractable antigenic protein levels were quantified in dental dams, examination gloves, and various other dental and rubber products. ASTM standards D6499 (antigenic protein) and D5712 (total protein) were used to quantify protein content. Results: In dental dams, extractable protein content ranged from low/non-sensitizing levels (<3 μg/dm2) to high/ sensitizing levels (130 200 μg/dm2). Also, while examination gloves from Malaysian glove manufacturers consistently exhibited a lower extractable protein content (<9 μg/dm2), than gloves from Thai manufacturers (16-23 μg/dm2) these levels should both still be non-sensitizing. There was no correlation between extractable protein content and the price or thickness of dental dams or examination gloves. Most of the other assorted dental products tested displayed low extractable protein content (<2.5 μg/dm2). Nearly all dental products made from natural rubber contained detectable antigenic Hevea proteins, subjecting previously sensitized patients and providers to risk of severe allergic reaction. A case study describes a female patient, with no previous history of Type I latex allergy, who reacted severely to a dental dam mouth exposure, necessitating her admission to the intensive care unit (ICU) of a local hospital for management of respiratory failure, with discharge after 4 days. Conclusions: Some dental products may pose a significant risk of Type I latex protein allergy sensitization, due to repeated contact, and that a single exposure can induce a severe reaction in a previously sensitized person, even when no prior latex allergy history is known.