Fluoride is a naturally occurring mineral that is found in rock, soil, plants, and fresh and salt water. It is odourless, colourless, and tasteless and is best known for its oral health benefits.
- Protects teeth against decay in both adults and children.
- Reduces sensitivity by encouraging remineralisation.
- Aids in the formation of healthy, strong permanent teeth.
- It is a safe and inexpensive way to improve the oral health of whole communities.
- Reduces the need for invasive dental procedures such as fillings.
The science behind how fluoride protects our teeth is quite complicated, but we’re going to try our best to demystify it. On the outside of our teeth we have a hard, protective layer called enamel. This layer is almost entirely made up of hydroxyapatite – a mixture of phosphate, calcium and hydroxyl groups. We also have phosphate and calcium in our saliva. Every moment of every day, our bodies are constantly balancing the levels of phosphate and calcium between our enamel and our saliva. This occurs through the processes of demineralisation and remineralisation.
Demineralisation predominantly occurs when the environment in our mouth becomes acidic. When our mouths are acidic, we lose phosphate from our saliva. To replenish these stores, phosphate, calcium and the hydroxyl groups are leeched from our teeth, resulting in a breakdown of that hard enamel layer. Constant demineralisation leaves the teeth weak, eroded and vulnerable to cavitation and decay.
During remineralisation, the minerals are moving in the opposite direction – back into the teeth. Deposition of phosphate, calcium and hydroxyl back into the enamel repairs demineralisation on a microscopic level and helps to prevent further damage.
When fluoride is present in the mouth it safeguards the teeth from demineralisation and promotes remineralisation. Fluoride replaces the hydroxyl groups and combines with phosphate and calcium to form fluorapatite, which is then deposited onto the teeth instead of hydroxyapatite. Fluoride makes the teeth more resistant to demineralisation during times of acid stress, as it is less readily dissolved than hydroxyapatite. Remineralisation in the presence of fluoride results in stronger, more resilient enamel.
Fluoride is most effective when it is in direct contact with the teeth. Most toothpastes will contain fluoride. The simplest way of achieving constant contact, especially for younger children, is through water fluoridation. Adding a small amount of fluoride to drinking water means that every time someone takes a sip of water their teeth are bathed in some beneficial mineral. Although the benefits are more seen in younger children that are “building” their adult teeth, consistent exposure to fluoride protects against tooth decay in adults as well. Research conducted by the Australian Research Centre for Population Oral Health has shown that children who have lived more than half of their lives in areas with fluoridated water have up to 50% less tooth decay than those who have not.
Yes! There have been countless studies conducted around the world that have concluded that water fluoridation has no harmful health effects. In 2007, the National Health and Medical Research Council (NHMRC) conducted a systematic review of all scientific evidence on water fluoridation and deemed it to be the most effective community strategy for reducing tooth decay. Since then, the NHMRC has remained a strong supporter of this effective public health measure. Water fluoridation is endorsed by the World Health Organisation, the Australian Dental Association, and the Public Health Association of Australia.
Fluorosis occurs when maturing permanent teeth are exposed to high concentrations of fluoride – usually before the age of eight. Too much fluoride can cause them to appear stained with white or brown spots, streaks, or lines. Most of the time, fluorosis is due to taking fluoride supplements, using adult toothpaste with a high fluoride concentration as a child, or swallowing large amounts of toothpaste (you have to be eating a lot!). If you’re unsure which toothpaste is appropriate for your child’s age, check out Dr Will’s review article . It is important to note that consumption of fluoridated tap water at normal rates will not cause dental fluorosis by itself.
If you are unsure about what toothpaste to use, what your children should be doing with fluoride, or any questions in general about mineral and teeth, feel free to ask your dentist at your next appointment. In the meantime, keep hydrated and stay motivated in brushing. We’ll see you at your next check-up!