Fluoride varnish does for your teeth what a porcelain varnish does for delicate antiques. Dental fluoride varnish preserves and protects your teeth so that they stay strong and healthy for your entire life. By working with a highly-qualified dentist, like one of the Scottsdale dentists at AZ Dentist, this treatment approach can help you maintain your best smile.

What is a fluoride varnish?

Fluoride is a naturally occurring mineral that is found in the ocean, some bodies of fresh water, and certain foods. For dental uses, fluoride varnish has been shown to protect teeth from cavities and even repair teeth in the early stages of tooth decay.

Fluoride varnish is a concentrated form of fluoride that your dentist applies to your enamel, dentin, and cementum of the tooth. Also referred to as a fluoride treatment, fluoride varnish helps replace the fluoride your teeth lose daily from demineralization. This demineralization is a natural part of tooth wear. It can accelerate if you consume a diet high in sugar, fat, and acidic foods regularly.

Dental fluoride varnish is sticky and adheres to the teeth for several hours after application. The fluoride varnish soaks into the teeth and helps prevent cavities. It can also repair teeth damaged by tooth decay.

What’s involved with a fluoride varnish application?

Fluoride varnish application might look different, depending on who is getting the treatment. For both adults and children, the first step in a fluoride varnish treatment is a thorough teeth cleaning and flossing. After that, the teeth are dried in preparation for the fluoride varnish.

Your dentist will apply a highly concentrated fluoride varnish (usually a 5% solution) directly to your teeth with a cotton swab or small brush. Fluoride dries on the teeth and naturally wears off over the course of the day.

Fluoride varnish dries rapidly and is used in small quantities. For children, this is a plus because there is less possibility of swallowing fluoride. The treatment is available in different flavors, too, which can also be a plus for kids with sensitive taste buds.

For children receiving fluoride treatments, fluoride can also be applied using trays. The fluoride treatment is placed in trays (like a deeper mouth guard). A dentist will insert the trays into the mouth for a brief period and then remove them.

Many young patients, however, find the trays uncomfortable and opt for application with a cotton swab or brush.

When are fluoride treatments necessary?

Fluoride treatments offer many advantages to patients for a variety of conditions. Research from the American Dental Association has shown that fluoride prevents cavities in both children and adults while repairing any existing damage due to tooth decay.

Fluoride varnish treatment can also help with the following conditions:

  • Hypersensitivity
  • Dry mouth
  • Dental work and orthodontia
  • Gum disease

Let’s look at those in more detail.


For patients with sensitive teeth, fluoride varnish can help create a strong layer of calcium between the painful stimulus (e.g., hot coffee and cold ice cream) and the affected nerves.

Fluoride varnish for adults is often used after scaling and root planing in patients who experience sensitivity. Patients with sensitivity due to receding gums (approximately 33% of people in the U.S.) may also experience relief with fluoride application.

Dry mouth

Saliva helps to breakdown food for digestion but also clears away food particles and bacteria that can cause tooth decay and periodontal disease.

For patients with dry mouth, fluoride offers extra protect against rapid demineralization that can lead to cavity.

Dental work and orthodontia

Patients with dental work from bridges to braces and crowns to veneers can benefit from an extra layer of fluoride protection.

These types of dental procedures may make teeth more susceptible to tooth decay along the margins of the work. Fluoride treatment can prevent further damage.

Gum disease

Periodontal disease has its roots in tooth decay. Often, a cavity left untreated will progress to more serious forms of infection that lead to periodontal disease and potential tooth loss.

Fluoride varnish as part of a regular program of brushing, flossing, and professional dental cleanings can help treat existing periodontal disease (and protect against future infection).

Are there any fluoride varnish side effects?

With all of the advantages of fluoride varnish, there are some disadvantages to consider.

  • Discoloration of teeth: In some patients, there is a chance of lingering tooth discoloration after fluoride treatment.
  • Dental fluorosis: There is a chance of dental fluorosis, especially in children. This condition occurs when you ingest excess fluoride. It results in small white spots that appear on permanent teeth.
  • Other side effects: In very rare cases, some patients may experience nausea, vomiting, and abdominal pain. Exceedingly rare side effects include gastrointestinal bleeding and issues with the bones. Typically, patients will only experience this when they’re exposed to massive amounts of fluoride over an extended period of time.

Fluoride varnish also costs more than less concentrated fluoride gels and foams. Additionally, fluoride varnish requires a prescription and you dentist applies it at their office. Dental insurance may cover part of this additional cost.

Fluoride varnish is generally considered unnecessary for children under three and those who live in areas with fluoridated water. Patients with open cavities or those who are concerned about discoloration for aesthetic reasons can elect not to receive fluoride treatments.

How long to leave fluoride varnish on teeth?

Once your dentist applies the fluoride, they’ll typically advise you not to eat or drink for at least 30 minutes following treatment. This gives the fluoride a chance to soak into your teeth.

You may notice a slight tooth discoloration that gradually subsides over the day. This is typical and normal as the fluoride varnish wears off. Some dentists may advise you not to brush your teeth until the following day and to avoid extra hot beverages and food until the following day as well.

You can repeat fluoride treatments up to four times a year, depending on your individualized treatment plan. Always work closely with your dentist to come up with the best approach.

The healthiest smiles start with a complete dental exam. Give us a call today at AZ Dentist to schedule your appointment.