Details, please!

Posted on | July 28, 2010 | 3 Comments

Moving to a new town brings lots of errands to run. Today I took care of going to the dentist. Everything went fairly well until the last part of the exam. The dentist and the hygienist fiddled with some kind of equipment that made noises of changing frequency, then they applied a handheld device, similar to an electric toothbrush, to my teeth. The dentist quoted a few numbers to the hygienist (“45, 32, 57″), patted my shoulder, and said, “well, there’s two on the right and two on the left. I’ll see you two times in the coming weeks to take care of these.”

“Take care of what?” I asked. He replied, “you’ve got four cavities.” I was shocked! I put it all together and realized that he was using this new-to-me equipment to make this measurement. Instantly I was skeptical and asked what exactly was the equipment measuring. (I was also skeptical because I’ve had good dental reports for the past few years.)

“Well, you see, if the number goes above 20 that indicates that there is some tooth decay below the surface. The higher the number, the deeper the decay,” he explained. So, I put on my scientist cap (which is pretty much sewed to my head, never mind about putting it on) and asked what measurement was being made. He couldn’t explain! All he could say that it was a laser. The hygienist gave me a brochure but it says nothing about the science either.

I asked some probing questions about how he is using this equipment to diagnose cavities and how that compares to what I’m used to dentists doing (probing the surface with a metal utensil and looking at cavities). He assured me that it’s just a better way of determining cavities without waiting for them to break the surface.

I still wasn’t content with his answer, so I did a little research (i.e., surfing the internet.) It turns out the DIAGNOdent works by measuring the fluorescence of a light 655nm in wavelength. Apparently, research has shown that the bacteria that cause cavities fluoresce at this wavelength, whereas normal teeth do not. The more bacteria that fluoresce in response to the light, the more tooth decay that is present.

Has anyone else heard of this device or way of measuring tooth decay? Do you think this is an example of overdiagnosis? What would you do if a health care provider was using a device to aid in diagnosis without fully understanding how it worked?

Let’s hope that the dentist will ready up a real answer to those who want to know the science behind the technology.

Image by Flickr user sappymoosetree, Creative Commons licensed

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