Fluorides are frequently found within nature and common drinks such as tea, beer, and natural water supplies. There has been a strong correlation between fluoride in public water and the reduction in tooth decay. The first evidence for this link was documented early in the last century. Since the link was established, fluoride has become more widely available, particularly in toothpaste, and strongly recognised as improving the oral health of the United Kingdom.
Fluoride is most effective when applied topically to your teeth multiple times throughout the day. Higher concentrations of fluoride, provide better protection against tooth decay. When fluoride is used for the prevention of tooth decay, the only health risk is dental fluorosis, and this will only occur if young children receive excessive levels. A balance is therefore essential, to gain the maximum benefit from this naturally occurring mineral, whilst also avoiding the risk of fluorosis.
The risk of fluorosis from ingestion of too much fluoride is linked more to the amount of toothpaste, rather than the concentration of toothpaste. The risk of aesthetically challenged front teeth is only relevant to the ingestion of fluoride for children under the age of three.
Demineralisation and Remineralisation
Each day, the enamel layer of your teeth undergoes both demineralisation and remineralisation, this is the process whereby minerals are added to, or removed from the surface.
When the bacteria and plaque in your mouth produce acid, this causes demineralisation and damages your enamel. Remineralisation occurs when minerals such as fluoride are redeposited to the enamel layer. Excessive demineralisation without sufficient remineralisation, and repair to the enamel, will result in tooth decay.
How Does Fluoride Work to Prevent Tooth Decay?
- Inhibits demineralisation of enamel – fluoride helps to strengthen your teeth and prevent the formation of cavities
- Enhances remineralisation of enamel – fluoride repairs minor tooth decay that hasn’t yet turned into a cavity
- Kills bacteria – fluoride doesn’t just prevent cavities, it is also antimicrobial
Each part of the United Kingdom’s water supply contains varying amounts of fluoride depending on where you live. Fluoride is added to the water to bring the concentration up to 1mg of fluoride per litre of water. Approximately, 6 million people or 10% of England’s population receive fluoridated water, either naturally or artificially at the optimum level. This concentration of fluoride within the water supply has been clinically shown to cause a significant reduction in the levels of tooth decay.
Water fluoridation decisions are made by the local authorities. The following areas of the United Kingdom have water fluoridation already in place:
- West Midlands
- East Midlands
- North East
- North West
- Eastern England
- Yorkshire and Humber
In other parts of the country, the public water supply naturally contains fluoride concentration levels similar to that in the above schemes. Your local water supplier will be able to offer more information about the concentration of fluoride in your local area and whether it has been added. You can often search online using a postcode checker.
There are a few schemes in England where school children receive fluoridated milk. They are provided in areas where the water is not fluoridated and there are high levels of tooth decay. Children who have fluoridated tablets or rinses daily should not participate in milk fluoridation schemes.
Oral Health Toothbrushing Principles
Two of the most common dental diseases of caries (tooth decay) and periodontal disease can be reduced with regular toothbrushing with a fluoridated toothpaste. Fluoride is the key active ingredient that prevents, controls, and stops tooth decay.
The higher the concentration of fluoride the better the control of tooth decay.
- Brushing should start as soon as the first tooth in the mouth erupts.
- Brushing should occur at least twice daily, last thing at night before bed and at least one other time during the day.
- Children under the age of three should use a toothpaste containing no less than 1,000ppm fluoride.
- Children under the age of three should use no more than a smear-sized amount of toothpaste (a thin film that covers less than ¾ of the brush). They should be advised not to eat or lick toothpaste.
- Children aged between three and six should use no more than a pea-sized amount of toothpaste
- For children seven years and above, a family fluoridated toothpaste containing 1,350ppm-1,500ppm offers maximum caries control for all children except those who cannot be prevented from eating toothpaste.
- Child toothbrushing should be helped or supervised by an adult until at least the age of seven.
- Rinsing your mouth with water after brushing should be discouraged. This avoids washing off the protective fluoride, therefore spitting out excess toothpaste is preferable. For the same reason of avoiding washing away the concentrated fluoride, using mouthwash immediately after brushing should be avoided.
- Brushing is more effective with medium texture bristles.
- More important than the brush, manual or electric, is ensuring the brush is effectively used twice daily.
There is high-quality evidence showing the effectiveness of fluoride varnish in the prevention of tooth decay, irrespective of the levels of fluoride in the water supply. Application of fluoride varnish at least twice a year has been extensively shown to reduce tooth decay in baby teeth by 37% and adult teeth by 43%. There is also evidence fluoride varnish can help stop decay on baby teeth and roots.
These studies often use fluoride varnish in the concentration of 22,600 parts per million. This is well accepted by dental professionals and considered safe. Fluoride varnish can be applied by professionals with minimal additional training. Following the application of fluoride varnish, individuals should avoid eating, drinking, or rinsing their mouth for 30 minutes afterward, and only eat soft foods in the following four hours.
Some fluoride varnishes do contain alcohol; however, it has been agreed by West Midlands Shar’iah council, they are suitable for Muslims as they are being used as a medicament, not for intoxication. The small amounts used would not cause intoxication and are not used for vanity purposes.
Prescription High Concentration Fluoridated Toothpaste
Prescription fluoridated toothpaste is available in both 2,800 and 5,000 parts per million concentration. Sodium fluoride 2,800ppm toothpaste is indicated for patients aged 10 years and above; at high risk of tooth decay, active decay, orthodontic appliances, a high sugar diet, or high sugar medication. Sodium fluoride 5,000ppm toothpaste is indicated for patients 16 years and above; at high risk of tooth decay, active decay, dry mouth, orthodontic appliances, overdentures, a high sugar diet, or high sugar medication.
Additional sources of fluoride such as fluoride tablets and drops are available, however, they do require compliance by families, and therefore may under or overused.
As dental professionals, we would recommend other sources of fluoride as a first-line approach. Fluoride rinses can be prescribed to patients aged eight and above and should be used in conjunction with twice-daily brushing using a toothpaste containing at least 1,350ppm fluoride. Rinsing requires compliance and should be used at a different time to toothbrushing. There is a greater concentration of fluoride in toothpaste compared to the fluoride mouth rinses which often contain 225ppm. Brushing twice daily with a fluoridated toothpaste containing at least 1,000ppm fluoride, or higher for those at higher risk, is a higher priority step and critical for lifelong oral health benefits.
Fluoride is one of the most important substances to be used in modern-day dentistry and critical for the maintenance and protection of your oral health. When used appropriately in the correct concentration, fluoride is safe and effective. There have been extensive studies and research into the effectiveness of fluoride in preventing tooth decay, and they all have conclusively confirmed the positive benefits outweigh the negligible risks.