Fluoride to strengthen teeth and prevent decay
Sodium fluoride
A source of fluoride used to strengthen tooth enamel and help prevent tooth decay, available as tablets, drops, high-fluoride toothpaste and mouthwash.
What is Sodium fluoride?
Sodium fluoride provides fluoride, which strengthens tooth enamel and helps prevent tooth decay. It comes as tablets, drops, high-strength toothpaste and mouthwash, and is used for people at higher risk of decay or where the water has little fluoride. The main thing to be aware of is that too much fluoride is harmful: in young children whose adult teeth are still forming it can cause permanent mottling of the teeth (fluorosis), and swallowing a large amount is toxic. For these reasons it should be kept out of reach of children and used as directed.
Education and reference only. This is a plain-language guide to Sodium fluoride — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Sodium fluoride is a source of fluoride, a mineral that helps protect teeth against decay. It is available in several forms, including tablets and drops, high-fluoride toothpaste and fluoride mouthwash, and is used to top up fluoride for people who are at higher risk of tooth decay or who live in areas where the drinking water contains little fluoride. It is part of everyday dental care for many people, often recommended by a dentist, and is used to strengthen the teeth rather than to treat any general medical condition.
How it works
Fluoride strengthens the outer surface of the teeth (the enamel), making it more resistant to the acids produced by bacteria after eating sugary food. It also helps repair the very early stages of decay before a cavity forms and makes it harder for the bacteria themselves to cause damage. When fluoride is in contact with the teeth regularly, through toothpaste, mouthwash or other forms, it keeps building this protection. In children whose adult teeth are still developing, the right amount of fluoride helps form stronger teeth, but too much during this time can disturb the enamel and cause mottling.
Company & origin
Originated / developed by: Various manufacturers.
A widely used preparation in the UK that provides fluoride to strengthen teeth and prevent decay, as tablets, drops, high-fluoride toothpaste and mouthwash.
Practical use
How to take Sodium fluoride
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Use the form and strength recommended by your dentist, based on age and risk of decay.
- With toothpaste and mouthwash, spit out rather than swallow, and avoid rinsing straight after brushing so the fluoride stays on the teeth.
- Supervise children's brushing, use only the right amount of toothpaste for their age and discourage swallowing.
- Keep all fluoride products out of reach of children, as swallowing a large amount is toxic.
- Take tablets or drops exactly as advised, and avoid doubling up with other fluoride sources unless told to.
Weighing it up
Advantages & disadvantages of Sodium fluoride
Advantages
- Strengthens tooth enamel and is an effective way to help prevent tooth decay.
- Available in several convenient forms, including toothpaste, mouthwash, tablets and drops.
- Useful for people at higher risk of decay or with little fluoride in their water.
Disadvantages
- Too much in young children can cause permanent mottling of the teeth (fluorosis).
- Swallowing a large amount is toxic, so products must be kept away from children.
- Higher-strength products need a dentist's guidance to use safely.
Practical use
Good to know
The most important balance with fluoride is that the right amount protects teeth while too much is harmful. In young children whose adult teeth are still forming, swallowing too much fluoride over time can cause permanent mottling or staining of the teeth, called fluorosis, which is why fluoride toothpaste should be used in the right amount for a child's age, spat out rather than swallowed, and why fluoride products are kept out of reach. Swallowing a large amount at once is toxic and can cause stomach upset and more serious effects, so accidental swallowing should prompt urgent advice. The choice of form and strength, especially high-fluoride toothpaste, is guided by a dentist based on age and decay risk. Used as directed, fluoride is a safe and effective way to protect teeth.
Who should not take it / use with caution
- Young children should not use high-fluoride products or extra fluoride supplements unless a dentist advises it.
- Extra fluoride is not needed, and may be harmful, where the water supply is already well fluoridated, unless advised.
- People who have had a reaction to a fluoride product should avoid it.
Monitoring
- Reviewing decay risk and the right form and strength with your dentist.
- Checking children's teeth for any signs of mottling.
- Making sure the total fluoride from all sources is appropriate.
Side effects
- Used correctly, side effects are uncommon.
- In children, mottling or staining of the teeth (fluorosis) if too much is taken while teeth are forming.
- If a large amount is swallowed, stomach upset, nausea and, with very large amounts, more serious toxic effects.
Key interactions
- Taking fluoride at the same time as calcium-rich foods or some supplements can reduce how well it is absorbed, so space them out.
- Using several fluoride products together adds up, so avoid doubling up unless advised.
- Tell your dentist about all fluoride sources, including your water supply.
Available as: Tablets, drops, high-fluoride toothpaste and mouthwash.
Answers
Sodium fluoride: frequently asked questions
What is sodium fluoride used for?
It provides fluoride to strengthen tooth enamel and help prevent tooth decay, and comes as tablets, drops, high-fluoride toothpaste and mouthwash.
Can children have too much fluoride?
Yes. In young children whose adult teeth are still forming, too much fluoride can cause permanent mottling of the teeth (fluorosis), so the right amount and supervision matter.
Why must it be kept away from children?
Swallowing a large amount of fluoride is toxic, so tablets, mouthwash and toothpaste should be kept out of reach and children supervised when brushing.
Should I rinse after using fluoride toothpaste?
It is better to spit out and not rinse straight away, so the fluoride stays in contact with the teeth and keeps working.
Do I need extra fluoride?
It depends on your risk of decay and how much fluoride is in your water; your dentist will advise whether you need supplements or a higher-strength product.
Authoritative sources
- BNF
- NICE CKS
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