Professional fluoride therapy involves the application of fluoride gel or varnishes onto the teeth surface to make it more resistant to dental decay (cavities) or treat teeth sensitivity.

What are the benefits?

Fluoride helps prevent dental decay by making the tooth surface more resistant to acid attacks from sugar fermenting bacteria found in dental plaque. Fluoride also has the ability to reverse early decay by disrupting acid production of plaque bacteria and promote the tooth remineralisation.

Studies show that topical fluoride is very useful in fighting tooth decay in children and adults. This is especially true in people with conditions that predisposes them to an increased risk of decay, such as:

  • Dry mouth conditions (xerostomia) due to disease, medications or radiotherapy
  • Gum disease, which cause the roots of teeth to become exposed
  • High caries activity (one or more new cavities per year)
  • Presence of dental crowns, bridges or braces.

How does it work?

The tooth surface is constantly undergoing the process of demineralisation and remineralisation from daily activity. Minerals are lost when acids (formed by sugar fermenting bacteria or acidic drinks) attack the enamel layer. Once the acidic environment has been neutralized by our saliva, minerals such as fluoride, calcium, and phosphate (from food, drinks or dental care products) are redeposited onto the enamel surface. Cavities form when the demineralisation activity is not repaired by adequate remineralisation. Fluoride reduces this risk by the formation of fluorapatite, which contain fluoride ions that reduce the rate of tooth enamel demineralization and increase the rate of remineralisation during the early stages dental decay.

Types of topical fluoride that dentist use...

Professionally applied topical fluoride comes in 2 common varieties:


Fluoride gels are delivered with the use of trays, which contain a groove to hold the product. The tray is held in the mouth by asking the patient to bite lightly on it for about four minutes. The tray and excess gel is subsequently removed and the patient is instructed not to rinse, eat, smoke, or drink for at least 30 minutes after application. This method is suitable for whole mouth fluoride therapy in most patients, except for very young children who are unable to spit or follow instructions.


Fluoride varnish is painted on as a thin layer with a small brush. It sets within seconds, easier to apply and more precise for small areas. It also has the advantage of a sustained release of fluoride ions as long as it remains in place.

Are there any risks?

Professionally applied topical fluoride has a very good safety record. There is at present no evidence that its professional use causes fluorosis of teeth.