Fluoride is a common ingredient used to prevent tooth decay, and it can be found in many products, such as toothpaste, water, mouthwashes, and varnish. Toothpaste comes in both fluoride and fluoride-free versions, so any fluoridated toothpaste is usually labeled and contains about 0.5 mg of fluoride per gram of toothpaste.
Dental professionals recommend brushing your teeth for 2 minutes twice a day using toothpaste that contains fluoride, with a typical strength of 1000 to 1500 parts per million (ppm), which is the equivalent of 1 – 1.5 mg per gram.
Consider that a pea-sized portion of toothpaste, weighing about 0.75 g, contains around 0.4 mg of fluoride, whereas a full-cover portion of toothpaste, weighing about 2.25 g, contains around 1.0 mg of fluoride.
So, someone diligently brushing their teeth twice a day with a fluoridated toothpaste could deliver 0.8 to 2.0 mg of fluoride per day, depending on the specific regimen used.
Although the maximum allowable fluoride concentration varies by age and country, toothpaste with higher fluoride levels can increase the risk of swallowing it, which could lead to excessive fluoride intake and increased risk of fluorosis.
How fluoride toothpaste works
Fluoride toothpaste works on your body in one of two ways: topically or systemically.
When we brush our teeth with a fluoridated toothpaste, the fluoride acts topically to protect our teeth and prevent tooth decay. Plaque, which is a sticky film of bacteria on our teeth, feeds on sugar and food residues to produce acid. This acid can dissolve the surface of our teeth, a process called demineralization.
The topical effect of fluoride has the greatest effect on preventing cavities. Fluoride:
- Prevents plaque by killing or inhibiting bacteria and making them less able to produce acid.
- Prevents demineralization by fusing into crystals on the surface of the tooth, which improves the ability of enamel to resist acid
- Enhances enamel remineralization, which is the process of replacing minerals lost during demineralization. So fluoride speeds up this process while integrating fluoride in the minerals, which makes tooth enamel less soluble to acid.
Therefore, topical fluoride helps to keep our teeth healthy and strong by protecting them from decay caused by acid produced by bacteria in plaque.
Systemic fluoride, on the other hand, has no effect on cavities since it is ingested. However, research suggests that it interferes with the remineralization process, which makes it responsible for the development of fluorosis.
This is why you should avoid swallowing toothpaste, and only use a small amount that is sufficient to clean the teeth.
How much toothpaste should you use?
Most of the toothpastes available in the US (about 90% of them) contain fluoride in the form of monofluorophosphate or sodium fluoride, at about 1,000 ppm. The amount that you ingest when brushing depends on various factors, including:
- The amount used
- Your swallowing control
- How many times you brush with toothpaste
There is no research on the actual amount of Fluoride (F) that you’d have to consume for fluorosis to occur. That said, dental professionals agree on a threshold of 0.05 – 0.07 mg of Fluoride per KG or body weight for the individual user.
Some toothpaste tubes recommend covering the bristles with toothpaste.
A child‐sized toothbrush covered with a full strip of toothpaste holds approximately 0.75 g to 1.0 g of toothpaste, and each gram of fluoride toothpaste, contains approximately 1.0 mg of fluoride.
Children aged less than 6 years may swallow an estimated 0.3 g of toothpaste per brushing, which translates to 0.3 mg of fluoride, and can unconsciously swallow as much as 0.8 g.
The amount ingested on a daily basis may vary as follows:
- 1 to 0.3 mg for infants and children aged 0 to 6 years
- 2 to 0.3 mg for children ages 6 to 12 years
- 1 mg for adults
As a result, it is generally recommended that children aged 6 years and below be supervised when brushing their teeth with fluoride toothpaste, and only a ‘pea‐sized’ amount of the toothpaste should be used for children aged 3 – 6 years, and a smear for children under 3 years, to avoid symptoms associated with high fluoride in toothpaste.
If you’re concerned about using a fluoride toothpaste due to the risks, you can consider various alternatives as discussed “here”.
That said, it’s not necessarily better to use a fluoride-free or low-fluoride toothpaste. Rather, using a small amount of normal fluoridated toothpaste as required is better than using a fluoride-free or low-fluoride toothpaste.
Keep in mind that fluoride is important for dental health as it helps to strengthen tooth enamel, making it more resistant to decay. Research has shown that using fluoride toothpaste is effective in preventing cavities and improving overall dental health.
Fluoride-free toothpaste or toothpaste with low fluoride content may not be as effective in preventing tooth decay as they lack the concentration of fluoride required to strengthen the enamel. Also, some toothpastes with low fluoride content may not contain enough fluoride to provide significant protection against tooth decay.
Additionally, some people may not brush their teeth as frequently or as effectively with fluoride-free or low-fluoride toothpaste, which can further contribute to tooth decay.
In conclusion, using normal fluoridated toothpaste as required is the best option for maintaining dental health and preventing tooth decay.