A Crash Course on Tooth Decay: Dental MMIs

History

Tooth decay or dental caries was once thought to be caused by a worm. And if you think about it, this is sensible. Back then, most rotten or decayed fruit and veg was caused by worms. The worms would burrow through the food, creating little holes and this is more or less what tooth decay is- small holes in the teeth.

What causes tooth decay?

Since then, tooth decay has become the world's most common disease with 90% of people experiencing tooth decay at least once and with 1/4 adults in the US with untreated decay. Now, there are 2 main accepted ideas of what causes tooth decay. With bacteria being discovered, people decided tooth decay was indeed caused by bacteria. It was/is believed that bacteria foods on sugars in your mouth and converts them into acids. As soon as the pH drops, tooth enamel dissolves. In fact, we are experiencing a mild form of tooth decay throughout the day but our teeth have enough time to remineralize.

The second hypothesis is that tooth decay is caused by dysbiosis- an imbalance of the oral microbiome. If you've seen my post on It's All in Your Mouth, you will know how important the oral microbiome is to your entire health. Basically, disruptions in the microbiome can be caused things like lots of sugar, cigarettes and alcohol and this is now thought to cause tooth decay. This is called the ecological plaque hypothesis.

I'm not entirely sure which hypothesis is most accepted amongst dentists so this could be a good question to ask in the interview to show your interest and curiosity.

How to tell if you have tooth decay

So there are pretty obvious symptoms for tooth decay, like pain, bad breath and stuff, and you can easily search these up. More interestingly, tooth decay doesn't start with the dark spot commonly associated with it. Instead, it starts with a white spot or a chalk stain which occurs due to demineralisation. This is called caries incipiens and can be stopped and reversed. The problem is that at this point, some dentists start pulling out drills when there is really no need. More recently, there has been a shift towards minimally invasive dentistry and preventative dentistry- areas very much worth a look at- again, you should read It's All In Your Mouth if you're interested.

Interesting study: Weston Price

A very interesting study that's pretty impressive if you bring up in your interview is the research done by Weston Price. In summary, Price went to remote civilisations to study their oral hygiene. What we found was that despite not having products like tooth paste and tooth brushes, people were immune to tooth decay. He concluded this was due to their diet- a diet similar to the way our ancestors ate- and that our modern, highly processed diet is very much a risk factor in tooth decay.