Fluoride is a mineral that has been known for decades as an effective protection against cavities. In Germany, most people use fluoride toothpaste because it helps strengthen tooth enamel and prevent the development of cavities. However, the question repeatedly arises as to whether the consumption of fluoride in toothpaste can cause dental fluorosis (also known as “fluoridosis” or “dental fluorosis”), a condition caused by an overdose of fluoride. This article sheds light on the background and clarifies whether this concern is justified.
What is fluoridosis / dental fluorosis?
Fluoridosis is a disorder that occurs when the body absorbs too much fluoride over a prolonged period of time. It primarily occurs during the tooth development phase in childhood. The most common form is dental fluorosis, in which white or brown spots form on the teeth. In extreme cases, it can even lead to structural weakening of the tooth enamel. However, severe fluoridosis only occurs with very high fluoride intake, far exceeding the recommendations of the World Health Organization (WHO).
Fluoride in toothpaste: How much is actually absorbed?
Toothpastes for adults typically contain 1,450 ppm (parts per million) of fluoride, a level considered safe and effective. The key question is how much fluoride is actually absorbed by the body when brushing. Most people spit out the toothpaste after brushing, resulting in very small amounts being swallowed. Even if small amounts of toothpaste are accidentally swallowed, they are generally harmless.
Children and fluoride
The situation is somewhat different for children, as they often accidentally swallow toothpaste. Therefore, children’s toothpastes in Germany usually contain a reduced fluoride content of 500 ppm. Parents are also advised to use only a pea-sized amount of toothpaste and to supervise their children’s brushing. This minimizes the risk of overdose, so even swallowing is safe. One children’s toothpaste that has received excellent reviews from Stiftung Warentest, dentists, and consumers (the latter via Amazon reviews) is elmex children’s toothpaste, which is available in three different varieties::
- elmex-Zahnpasta Baby für Kinder von 0-2 Jahre
- elmex-Kinderzahnpasta für Kinder von 2-6 Jahre
- elmex-Zahnpasta Junior für Kinder von 6-12 Jahre
We – the operators of fluoridefree-toothpaste.com – also use the elmex children’s toothpastes linked above, with their optimal fluoride content, for our children and highly recommend them. However, following our dentist’s recommendation, we also use the “Children’s Toothpaste for Children 2-6 Years” for our baby’s first teeth (although with a very small amount), as the baby toothpaste contains too little fluoride. Our children actually enjoy brushing their teeth (thankfully) and have completely healthy, caries-free teeth.
Should I use fluoride tablets?
Fluoride tablets should only be used after consulting a pediatrician or dentist. Studies have shown that fluoride tablets are responsible for two-thirds of all fluorosis cases. Nevertheless, fluoride tablets also protect against cavities. They are usually recommended when fluoride toothpaste is not used—for example, in the case of babies before they get their first teeth (and therefore before they brush their teeth).
When using fluoride tablets, it may also be advisable to avoid using fluoride toothpaste and instead switch to fluoride-free toothpaste. It is best to consult a pediatrician or dentist beforehand.
Natural fluoride sources – tap water?
Fluoride is also found in food and drinking water. In Germany, fluoride levels in drinking water are comparatively low at 0.1 milligrams (mg) per liter. In the US, for comparison, the fluoride level averages 0.7 milligrams (mg) per liter. Canada, Ireland, Chile and Australia also have high fluoride levels in their tap water, whereas the rest of Europe have low fluoride levels. Other sources, such as fluoridated table salt, contribute to fluoride intake but also pose no risk under normal use.
Scientific studies on fluorosis
In countries like Germany, the prevalence of fluorosis has been declining for decades. A 1999 study found a prevalence (i.e., “frequency”) of fluorosis among adolescents of 15% (Schiffner & Reich, 1999). A 2008 study found a frequency of only 5.6% (Pieper et al., 2008). In this study, one of the groups of children examined used fluoride-containing children’s toothpastes from the first deciduous tooth onward, without detecting an increased incidence or more severe forms of fluorosis.
Overall, however, only very mild or at most moderate forms of fluorosis were observed across all studies. Severe forms do not occur with the use of fluoride for caries prevention, but have only been observed in areas with significantly elevated fluoride levels in drinking water due to volcanic activity (DenBesten & Li, 2011). Prof. Dr. Ulrich Schiffner, a leading dental health scientist who spent 25 years as a professor at the University Hospital Hamburg (UKE) researching dental fluorosis and the effectiveness of fluoride, points out that:
[Dental fluorosis] has no relevance for the general health of children. In contrast, however, severe carious defects are associated with severe impairments of the physical health as well as the psychological well-being of the affected children.
A widely cited scientific study from 2003 demonstrated that fluoride absorption from fluoride tablets is many times higher than from fluoride-containing toothpaste (Hetzer et al., 2003). Another study found that approximately two-thirds of fluorosis cases were caused by fluoride tablets (Pendrys, 2000).
In 2018, the German Federal Institute for Risk Assessment also concluded in an official statement that brushing with fluoridated toothpaste offers the best caries prevention, even in young children, but that additional intake of fluoride tablets should then be avoided (BfR, 2018).
Does fluoride make you stupid?
Fluoride opponents like to claim that fluoride makes people stupid, citing (supposedly) scientific studies. However, these studies – deliberately (?) – have significant flaws. For example, some simply compared areas in poor countries with varying levels of fluoride in their drinking water, without taking overall water quality and quality of life into account. It’s not surprising that children in a poor rural region with very high pollutant concentrations in the water develop less well or are, on average, less intelligent than children in a wealthier area with good water quality and quality of life. This is almost certainly not due to the higher fluoride concentration in the water in the poorer areas studied. It’s more plausible that drinking water managers in the poor region attempted to compensate for the poor water quality by adding more fluoride. While this increases the amount of fluoride, it has no effect on the children’s intelligence (although the poor living conditions do). DocCheck also investigated this theory and came to a similar conclusion.
Due to the topic’s media coverage, the German Research Foundation’s “Senate Commission on the Health Evaluation of Food” also investigated whether fluoride has a negative impact on intelligence. The result of the 2020 study was clear: “Based on the available scientific studies (published up to August 2019), current fluoride exposure in Europe is not cause for concern.”
Conclusion: Is the concern about dental fluorosis justified?
Developing dental fluorosis from using fluoride toothpaste is very unlikely under normal conditions – and even if it did, the most you’d get would be a few medically harmless stains on your teeth. If you forgo fluoride, however, it’s very likely you’ll cause long-term damage to your teeth, resulting in not only stained teeth, but also brittle and decayed teeth.
The fluoride content in toothpaste is strictly regulated, and if used properly, there’s no cause for concern. Especially with children, it’s important to monitor usage and use appropriate products that contain fluoride – absolutely necessary for effective caries protection – but in a reduced dose. Adults can safely use “regular” fluoride toothpaste to effectively protect their teeth from cavities. However, fluoride tablets should only be taken on the recommendation of a dentist (or, in the case of children, a pediatrician).
Fear of fluorosis should therefore not deter people from using fluoride toothpaste. Instead, the focus should be on maintaining good oral hygiene and healthy eating habits to keep teeth healthy throughout their lives.
Sources:
- Image: “Dentalfluorose” by Matthew Ferguson 57 – own creation, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=44946756
- Bundesinstitut für Risikobewertung (2008). Für gesunde Zähne, Fluorid-Vorbeugung bei Säuglingen und Kleinkindern. Stellungnahme Nr. 015/2018 des BfR vom 31. Mai 2018
- DenBesten, P., & Li, W. (2011). Chronic fluoride toxicity: dental fluorosis. Monographs in oral science, 22, 81–96.
- Deutsche Forschungsgemeinschaft (2020): Fluorid in der Diskussion: Das wissen wir über die Wirkung von Fluorid auf unseren Körper. Wissenschaft und Öffentlichkeit, 20. October 2020
- Dietrich, G., Sperling, S., & Hetzer, G. (2003). Molar incisor hypomineralisation in a group of children and adolescents living in Dresden (Germany). European journal of paediatric dentistry, 4, 133-137.
- Pendrys, D. G. (2000). Risk of enamel fluorosis in nonfluoridated and optimally fluoridated populations: considerations for the dental professional. The Journal of the American Dental Association, 131(6), 746-755.
- Pieper, K., et al. “WISSENSCHAFT-Originalarbeiten-Fluorosepravalenz bei 15-Jahrigen in drei Regionen mit unterschiedlichen Prophylaxeprogrammen.” Deutsche Zahnarztliche Zeitschrift 63.1 (2008): 16.
- Schiffner U, Reich E (1999) Prävalenzen zu ausgewählten klinischen Variablen bei den Jugendlichen (12 Jahre)