How Fluoride Fights Cavities

1 July 2023

Fluoride is a naturally occurring mineral commonly found in water, to varying degrees across the UK. Amounts of concentration can be higher in areas with harder water such as the south of the UK, with lesser amounts in soft water spots or areas with wellsprings such as Yorkshire. So, what are the benefits of fluoride, and how do they contribute to the fight against cavities?

To understand how instrumental fluoride is, we have to understand what it fights against. Tooth decay, also known as dental caries or cavities, occurs when the hard outer layer of the tooth, known as enamel, becomes damaged by acid produced by bacteria in the mouth. Sugary foods and beverages provide nourishment for these bacteria, leading to the production of harmful acids that erode the enamel, creating cavities over time. Fluoride tackles this with two primary mechanisms:


Fluoride enhances the remineralisation process, which is the natural repair mechanism of the tooth enamel. When the tooth enamel is exposed to acids, minerals such as calcium and phosphate are lost. Fluoride helps replenish these minerals, aiding in the remineralisation of the enamel. This process strengthens and repairs weakened areas, making the enamel more resistant to acid attacks, and preventing the progression of early cavities.

Inhibition of acid production

Fluoride also inhibits the growth and activity of bacteria that produce acid. By reducing the number of acid-producing bacteria in the mouth, fluoride helps create an environment less conducive to cavity formation. This action helps to control the bacterial population and limit the acid attacks on the teeth, further protecting them from decay.

So how can I make the most out of fluoride?

The good news is, you probably already are if you use a toothpaste containing fluoride. When you brush your teeth with a fluoride toothpaste, the fluoride is directly applied to the surface of your teeth. You may also use fluoridated mouthwash, which if used after brushing your teeth can rinse away bacteria and provide an additional protective layer of fluoride. Drinking tap water will also aid in strengthening the enamel of your teeth as a naturally occurring mineral.

However, fluoride is also used for more professional dental treatments. Some dentists may recommend that individuals at a higher risk of developing cavities, such as children, adolescents, or those with certain medical conditions undertake professional fluoride treatment. These treatments involve the application of a highly concentrated fluoride solution by a dental professional. The fluoride is usually in the form of a gel, foam, or varnish, and it is applied to the teeth for a specific duration to provide an intense dose of fluoride and enhance its benefits.

Is there a recommended amount of fluoride I should intake?

In short, yes. Most fluoride toothpastes will have the measurement of fluoride contained measured in parts per million or PPM. We would recommend you look for a toothpaste containing 1,350 to 1,500ppm. Children under 6 years old or younger should brush at least twice daily with a small amount of toothpaste containing at least 1,000 ppm as they are one of the most vulnerable demographics likely to develop cavities.

In addition, it is at the discretion of local authorities to determine how much fluoride is injected into local water supplies. Currently, the parts of the UK that have instructed for fluoride to be inserted into the water supply include:

  • the West Midlands
  • the North East
  • the East Midlands
  • Eastern England
  • the North West
  • Yorkshire and Humber

Is fluoride safe?

Yes. In small quantities such as in dental products like toothpaste and mouthwash, fluoride is perfectly safe. In regards to the water supply, several studies have been conducted over the safety of the amount of fluoride used as well as the effectiveness in reducing cavities amongst the local population, many of which are available online. The data of which is used by local authorities to determine how much needs to be inserted into the water supply to successfully reduce cavities at a safe level.

Is there anything else that I need to know?

In short, no. Using a fluoride toothpaste and mouthwash, as well as drinking and rinsing with tap water is only a part of maintaining a good oral hygiene routine. In addition, you should avoid acidic foods and drinks where possible, or if you do drink through a straw. Eating hard crunchy vegetables can strengthen the structural integrity of your teeth as well as regularly visiting your dentist at least twice a year.

If you have concerns about cavities or have any enquiries concerning fluoride treatments, we are here to help. Serving our patients in Pateley Bridge and across Nidderdale, you can contact us on 01423 712799 or by using our contact form here.