Allergic Reactions to Dental Materials
Be prepared to react quickly to a patient’s adverse reaction
While in the dental chair, a patient can suddenly experience an adverse reaction to a drug, product, or material. Those most susceptible to allergic reactions are patients with asthma, a history of hay fever, or allergies to trees, grasses, animals, dust, molds and certain medications. Tailoring dental products to a patient’s health history is a proactive yet precautionary practice to minimize the occurrence of an adverse reaction. In the event that an adverse reaction does occur, recognizing the symptoms and reacting quickly is critical.
MATERIALS: Latex is most commonly found in gloves. Other dental materials that contain latex include latex dams, gutta-percha, mixing bowls, orthodontic elastics, some suction tips, bite blocks, and amalgam carriers.
SYMPTOMS: Adverse reactions can be classified as allergic contact dermatitis (Type IV hypersensitivity) or true latex allergy (Type I hypersensitivity). Allergic contact dermatitis is a reaction to the chemical additives used in the manufacture of latex gloves (OSAP, 2013). Symptoms take several hours to develop, and include swelling, redness, itching, and blistering/cracking of the skin. Conversely, true latex allergy is a reaction to the latex proteins. These proteins can infiltrate the body through skin and mucosa. If latex lightly powdered gloves are used, aerosolized latex proteins can also enter the respiratory system during gloving and ungloving. Reactions can range from erythema and hives to the most severe reactions characterized by anaphylaxis.
PRECAUTIONS: Patients with true latex allergy (Type I hypersensitivity) require the use of non-latex gloves, such as nitrile, neoprene or vinyl. Patients with allergic contact dermatitis (Type IV hypersensitivity) require the use of vinyl gloves, as nitrile and neoprene gloves contain the same chemical additives found in natural rubber latex.
PROBLEM: LOCAL ANESTHETICS
MATERIALS: Allergic reactions are only caused by ester-type anesthetics, which are used for topical application rather than local injection. Ester-type anesthetics, such as procaine, propoxycaine and chloroprocaine, are more
commonly known by their brand names: Novocain, Ravocaine, Nesacaine and Hurricaine. Amide-type anesthetics, like lidocaine, mepivacaine and prilocaine, can cause reactions resembling allergic reactions, but the anesthesia itself is not a true allergen.
SYMPTOMS: Most patient-reported “allergic” reactions to local anesthetics — namely heightened anxiety and increased heart rate — are really sensitivities to epinephrine. Occasionally, patients might experience a toxicity reaction, which can be attributed to preservatives (methylparaben) or antioxidants (bisulfites) contained in the solution. A toxicity reaction is more common when the anesthetic is used plain (i.e., does not contain a vasoconstrictor), which prevents the anesthetic from leaving the anesthetized site too rapidly.
PRECAUTIONS: Anesthetic cartridges without a vasoconstrictor should be used for patients with epinephrine sensitivity, or when a patient has severe heart disease or recent myocardial infarction. Topical anesthetics should be used sparingly, as excessive amounts or contact with the oral section of the pharynx could intensify a reaction.
PROBLEM: COLOR DYE
MATERIALS: Color dyes are typically found in prophy pastes, mouthwashes, fluorides and colored gloves. Red and yellow dyes are the main types of dyes that cause allergic reactions. Red #40, Yellow #5 and Yellow #6 are types of artificial dyes, whereas annatto is a natural coloring substance that comes from seeds of the annatto tree (Yacono, 2011).
SYMPTOMS: Skin irritations, such as eczema or hives, are common symptoms that develop after the ingestion of a particular dye. In rare cases, certain dies can cause anaphylactic shock. The effects of color dyes on behavioral issues—especially in children—are currently being researched.
PRECAUTIONS: Dye-free prophy pastes, fluorides, rinses, etc. are available alternatives and should be used with patients reporting a dye allergy, or as an option for pediatric patients.