16 February 2023

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Fluoride varnishes in the prevention of caries: are they safe?

Lara Figini

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Fluoride, in its many forms, is used in dentistry as a preventive measure of caries and in lower concentrations it can be applied by the patient or by a parent. Alternatively, in higher concentrations, it is applied in the office. Fluoride varnishes are now used regularly in the pediatric field and have been over the last 20 years due to effectiveness, acceptability and ease of use. These concentrations are widely recommended in children as early as two years old.

However, there is a scarcity of studies or data available in the literature on the specific safety of fluoride varnishes, and adverse events related to their application.

Materials and methods

In a study published in the Journal of the American Dental Association in May 2021, the authors evaluated whether fluoride varnishes could be considered safe or if instead they could generate side effects that should not be overlooked.

The U.S. Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database was identified by the authors as suitable for this type of study. In the U.S., the FDA is the federal agency whose mission is to protect and advance public health through the production of more effective and effective drugs, foods, cosmetics, biological products, medical devices and radiation-emitting devices safer (including dental devices).

The identified adverse events were then screened and categorized using appropriate keywords for the various signs and symptoms, outcomes, and treatment.

Results

During the 10-year period analyzed, only 65 adverse events were reported for fluoride varnishes, according to the study. Swelling, burning, itching or soreness and rash were the most reported signs and symptoms.

The area most affected by the adverse events was the lips. In 18.5% of the adverse cases, the patient was hospitalized and in 15.4% of the cases, emergency care was needed. No deaths have been reported.

Patients were treated primarily using diphenhydramine (Benadryl, Johnson & Johnson Consumer) or self-injecting epinephrine, other forms of epinephrine and prednisolone. A history of allergies was present in 16.9% of adverse cases. The adverse event rate is estimated to be between 0.099 and 0.105 per million for fluoride varnishes.

Conclusions

From the data of this study, researchers concluded that fluoride varnishes can be considered a safe dental product since the adverse events related to them and reported to the U.S. Food and Drug Administration were rare. In addition, the study authors noted the widespread use in the U.S. 

Clinical implications

The dentist can use fluoride varnishes in the prevention of dental caries with confidence, as adverse events related to them are rare in the U.S.

For more information, see "Is fluoride varnish safe?" authored by Ana Karina Mascarenhas.