Sensitive teeth are common, really common. Sensing that this is a profitable industry, big pharmaceutical companies like Colgate, Sensodyne (GSK) and Oral-B bombard you with information about sensitivity and how their products can help with it. Now, take a step back and put your thinking caps on. These pharmaceutical companies sometimes manipulate information just to market their products a lot better. Trust me, you may not have sensitive teeth, but after seeing a Sensodyne product packaging and how well it’s made to fix sensitivity, you may think you have sensitive teeth too. That’s how good their marketing is!
I am here to write the unadulterated truth regarding sensitive teeth. I’m gonna delve into the detailed biology of it, what causes it and how you can read product packaging better. This is not coming from a pharmaceutical salesperson, this is coming from a young dental student eager to help everyone out there!
Due to the extent of the content I intend to write in this article, this post will be the first in a two-part series on dental sensitivity.
Now, you may recall that I blogged about anatomy of a tooth, I am going to build on that. The most important bit of information that you need to know is the presence of dentinal tubules in your dentine. The picture below illustrates that perfectly.
Enamel is the hardest substance in the human body and is a non-living, mineralised hard tissue. So it’s basically a rock.
Dentine, on the other hand, is vital tissue. It is a living, breathing segment of the tooth and dentinal tubules are part of that vitality. These microscopic tubes connect the outermost surface of the dentine to the pulp where the nerve lives. You see where this is going?
In sensitive teeth, dentine becomes exposed, i.e. no enamel protection or gum coverage. There is a direct link between the tubules and the outside world, connecting straight to the pulp. It’s almost as if your nerve is exposed itself, yikes!
Brännström’s Hydrodynamic Theory
This theory answers why cold & hot drinks trigger intense pain in sensitive teeth.
Dentinal tubules are filled with fluids, and lined by cells called odontoblasts on the inner surface of the dentine, surrounding the pulp. When you drink cold & hot drinks, it triggers changes in fluid pressure and movement in the dentinal tubules. These in turn trigger the odontoblasts, activating pain receptors within the pulp and sending these signals to the pain.
So this is how dental sensitivity works. The key concept here really is the exposed dentine, dentinal tubules and the hydrodynamic fluid changes within these tubules. Now, take a moment be in awe of the intricate details of this biological design. This is why I love biology so much.
I do realise that people have relatively short attention spans these days, so this is the end of part 1 on dental sensitivity. Stay tuned for part 2, where I will talk about the causes of dental sensitivity, and the practical part of choosing the right toothpaste!