Millions of adults suffer from tooth decay in the UK, but brushing twice daily with a fluoride toothpaste is often enough to protect your teeth from wear and tear. In this blog, we look at how cavities are formed, and we ask, how does fluoride toothpaste cut down on cavities, and when should you be using a high-fluoride toothpaste? 

What are cavities and how are they caused? 

Cavities are small holes in your teeth, also known as dental caries. They are formed when the hard enamel that protects your teeth is worn away over time – tooth decay. 

Common symptoms of a cavity include: 

  • Pain when you eat or drink something cold, hot, or sweet 
  • Bad breath 
  • Tooth ache (but not in all cases) 
  • A bad taste in the mouth 
  • Grey, brown or black spots on the teeth 

Tooth decay is caused by a build-up of plaque – a soft, sticky film that contains bacteria. When it reacts with the sugar in our food and drink, it creates acid, which over time erodes the tooth’s outer coating. This exposes the soft pulpy centre of the tooth (known as dentin) and causes the pain you associate with tooth sensitivity.  

Almost one in three adults (31%) in the UK has tooth decay, but it is preventable¹. 

To prevent cavities, dentists recommend brushing twice daily with a fluoride toothpaste, and yet a quarter of adults don’t brush their teeth the recommended number of times, and 33% have never flossed or cleaned interdentally (between the teeth)².

What is fluoride, and why is it in toothpaste? 

Fluoride is a naturally occurring mineral that is found in water. In the 1930s, researchers discovered that it could help prevent cavities by strengthening tooth enamel. They found that there were fewer instances of tooth decay in young children who grew up drinking naturally fluoridated water than those who grew up without it. 

Since then, it has been used in toothpastes and added to the water supply. In the UK, around 5.8 million people benefit from a fluoridated water scheme, which increases the level of fluoride in the water to reach volumes known to reduce tooth decay³

All toothpastes contain fluoride in small amounts – it’s measured in parts per million (PPM) and you can find the amount on the side of the box. If you are at risk of a cavity, you may be prescribed a high fluoride, prescription-strength toothpaste.  

According to the Oral Health Foundation, you are at risk of a cavity if you: 

  • Wear braces 
  • Have a history of tooth decay or dental caries
  • Have poor oral health and don’t visit a dentist regularly 
  • Suffer with a dry mouth or you are taking medication that can cause a dry mouth 
  • Eat sugar in large quantities or you have diabetes 

High fluoride toothpaste contains four times more fluoride (5000ppm) than standard, shop-bought toothpaste. A 2cm strip provides up to 3 to 5mg of fluoride.   

How does fluoride help to prevent cavities?  

Fluoride is involved in the remineralization process that is required to strengthen teeth and protect them from decay. Put simply, it can help rebuild the enamel you’ve lost.  

When you brush your teeth, the fluoride in the toothpaste mixes with your saliva to strengthen teeth from the outside. It does this by bonding to the calcium and phosphate found naturally in your teeth to create a hard material called fluorapatite. 

This not only protects your teeth from the bacteria in plaque, but it slows down the erosion that can eventually lead to cavities and relieves the pain of sensitive teeth.  

Other fluoride products include mouth rinses and varnishes. Fluoride varnish is painted on by a dentist and it’s usually applied twice a year to children from age three upwards, and more frequently for children with tooth decay or those at high risk of developing it.   

brush teeth

Is fluoride safe to use in children and adults?  

Fluoride is considered both safe and effective, and according to the NHS it poses no significant health risk. Public Health England and the Centre for Disease Control and Prevention (CDC) in America, have both approved the use of fluoride. 

Too much fluoride can cause a condition known as dental fluorosis. In extreme cases, it can cause a pitting or discolouration of the teeth, but this is rarely seen in the UK. 

If you are using a prescription-strength toothpaste, such as Colgate Duraphat 5000, you should avoid using any other fluoride treatments at the same time. Your dentist may ask you whether your water supply is fluoridated before they prescribe it. 

Fluoride and the prevention of cavities 

The message from oral health experts and dentists is clear – brushing your teeth twice daily with a fluoride toothpaste is the best way of preventing tooth decay

Fluoride toothpaste helps to remineralize the tooth’s outer-most layer, and by re-building the enamel you can strengthen your teeth and protect them from attack.  

If you’re at risk of tooth decay or you have a history of dental caries, you may benefit from using a high-strength fluoride toothpaste, which you can get from a private pharmacy, like Post My Meds. All you need to do is answer a few questions so we can make sure it’s safe for you to use, then pay for your order and we’ll do the rest. 

Although all of our content is written and reviewed by healthcare professionals, it should not be substituted for or used as medical advice. If you have any questions about your health, please speak to your doctor.

Authored Nov 30, 2021 by Joseph Issac, MPharm
Reviewed Dec 06, 2021 by Prabjeet Saundh, MPharm