Fluoride Works…How, Exactly?

There’s an interesting double standard in medicine – dental and otherwise. Conventional practitioners can and do promote all sorts of treatments that haven’t been empirically proven or that work in ways we don’t yet understand. At the same time, many insist that “alternative medicine” isn’t valid because many of its treatments aren’t yet proven or understood. Yet when proof is provided, the tendency is to ignore it, discount it or move the goal-posts, holding traditional and natural healing practices to a higher standard than they hold their own. If we say there’s only one kind of medicine – that which works – then shouldn’t all of its premises and practices be held to the same standard?

Science is not a body of knowledge but a process – a way of understanding the world through what can be observed, measured and tested. The tools of science are also always evolving, letting us see more – or more precisely – than before. What can’t be proven in one era may be proved in another as knowledge and technology evolve. What seems like magic to one generation may come to seem common sense to later ones.

For decades now, conventional dentistry has put a large store of faith in fluoride. Fluoride toothpaste, fluoride supplements and fluoridated water have all been touted as important factors in preventing tooth decay. But research has helped our understanding evolve. We know now that ingested fluoride does little to prevent tooth decay yet contributes to a host of physical illnesses. We also see evidence that fluoride supplements may not be effective for children.

But what about fluoride in toothpaste? A new study published in Langmuir, the journal of the American Chemical Society, raises some questions.

In a study that the authors describe as lending credence to the idiom, “by the skin of your teeth,” scientists are reporting that the protective shield fluoride forms on teeth is up to 100 times thinner than previously believed. It raises questions about how this renowned cavity-fighter really works and could lead to better ways of protecting teeth from decay, the scientists suggest….

Scientists long have known that fluoride makes enamel — the hard white substance covering the surface of teeth — more resistant to decay. Some thought that fluoride simply changed the main mineral in enamel, hydroxyapatite, into a more-decay resistant material called fluorapatite.

The new research found that the fluorapatite layer formed in this way is only 6 nanometers thick. It would take almost 10,000 such layers to span the width of a human hair. That’s at least 10 times thinner than previous studies indicated. The scientists question whether a layer so thin, which is quickly worn away by ordinary chewing, really can shield teeth from decay, or whether fluoride has some other unrecognized effect on tooth enamel.

We might also ask, is it really the fluoride at all? For toothpaste really isn’t the biggest factor when it comes to good oral hygiene – which isn’t to say that it has no role. Its main role is to act as a mild abrasive to help break up the biofilm (plaque) that forms on your teeth between cleanings. (Toothpastes that contain elements such as antimicrobials play a dual role in supporting oral health, but their main function is still as an abrasive.) More important are things like brushing regularly and well, flossing and/or using a proxy brush – both of which have a much bigger impact on oral health than brushing alone.

As a dentist, I do not use fluoride, nor do I recommend it to my patients. For hygiene products I do recommend, click here.

Image by alles-schlumpf, via Flickr

Comments Off on Fluoride Works…How, Exactly?

Filed under Dental Hygiene, Fluoride

Comments are closed.