While sitting in the dentist chair the other day, I wondered about the fluoride being applied to my teeth.
It's hard to tell from the nice teeth of modern movie actors, but in the old days, tooth decay used to be a major health problem. Even today, tooth decay remains second only to the common cold as the most common disease in the world. Oral bacteria, like Streptococcus mutans, feed on sugars and produce acids that dissolve tooth enamel.
Fluoride hardens tooth enamel so it is less likely to get caries (cavities). It may also help make the tooth surface smoother so that cavity-causing bacteria cannot stick as easily. It may even disrupt the action of the bacteria directly. Fluoride can be applied through dental products or by fluoridating drinking water. Fluoride is the element fluorine combined with other elements. Sodium fluoride is the most common form. It tastes better and is cheaper than its predecessor stannous fluoride, known by the trade name Fluoristan. Stannous refers to tin (and has nothing to do with Stannis Baratheon in Game of Thrones). Fluoridation can involve other forms of fluoride, too.
The discovery of the effects of fluoride on teeth began about a hundred years ago when dentists noticed mottled staining on the teeth of some people in certain communities. Further studies showed their drinking water had naturally high levels of fluoride and that residents in these areas had fewer dental caries than average. The staining, called dental fluorosis, resulted from excess mineralization on the teeth. This can still be a concern wherever fluoride concentrations in the drinking water is high. Prolonged exposure to high amounts of fluoride can even lead to skeletal fluorosis, which damages bones.
Various studies in the 1940s, led to a Goldilocks solution of finding a fluoride concentration that was not too little so it would still lower the occurrence of cavities, and not too high, which would lead to fluorosis. Fluoridation was seen as an effective, economical solution to improve dental health, especially for children who didn't brush their teeth properly or couldn't visit the dentist regularly. Brantford, Ontario, the birthplace of Wayne Gretzky, was the first place in Canada to have fluoridated water in 1945. Too bad a hockey puck knocked out the benefits of fluoridation for Wayne.
Fluoridation has been considered one of the top ten greatest medical advances in the twentieth century. The Canadian and American Dental Associations still advocate fluoridation. Fluorosis is the most credible potential risk to inadequately controlled fluoridation. Other concerns seem to be exaggerated or irrelevant.
But as a slower, more subtle process than topical application, clean evidence for the benefits of fluoridation can be difficult to gather. Furthermore, the prevalence of fluoridated toothpastes and regular dental care, bottled water and the abundance of sugar and other carbohydrates in our diets, complicates the assessment of how effective fluoridation is nowadays. In British Columbia, fluoride occurs naturally in the water in some areas. However, Victoria and Vancouver do not subscribe to fluoridation. Calgary recently decided to stop fluoridating its water and a study is now looking at the impacts.
Fluoridation is a sticky subject and I am still chewing over what I think about all this. Some people dislike having choices made for them about their health and people can differ in how they weigh risks and benefits when making decisions. What about you? What do you think about fluoride?