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Sensitive Teeth

Why Teeth Hurt
©Vladimir Gjorgiev/

There are several easy answers to the question, “Why do teeth hurt?”  For example, teeth hurt because you don’t take care of them.  But, that’s not what I want to talk about in this article.  I want to talk about why it is that teeth hurt so much.  They’re so small, yet if you’ve ever had a toothache that kept you up at night, you know that teeth can hurt almost as much as any other feeling of pain you’ve ever felt.

Teeth Hurt Because They Are So Hard

Why Teeth HurtTeeth hurt because they are so hard.  When the tissue inside of the tooth (the pulp) gets hurt, it has no room to expand.  Here’s an example.  Let’s say someone punches you in the shoulder.  Your shoulder might get warm and swollen.  Your shoulder has room to get bigger.

Now let’s say that someone punches your tooth and chips the bottom of it.  The force of the blow will likely irritate the pulp of your tooth and cause it to get warm and swollen.  Here’s the problem, when the pulp gets swollen, it wants to get bigger, but there’s nowhere to go!  The pulp is encased in a hard shell known as the dentin and enamel of your tooth.  Pressure builds up inside of your tooth.  Suddenly, the tooth that was hurting due to the initial trauma is now also hurting because of the pressure.

Not sure what the difference between pulp, dentin, and enamel is?  Read my article about the anatomy of a tooth.

Here is what happens in technical terms when the pulp becomes inflamed.  It’s a quote taken from the book, Cohen’s Pathways of the Pulp by Hargreaves:

Inflammation in the pulp takes place in a low-compliance environment composed of rigid dentinal walls. Compliance is defined as the relationship between volume (V) and interstitial pressure (P) changes: C = Δ V/ Δ P. Consequently, in the low-compliant pulp, an increase in blood or interstitial volume will lead to a relatively large increase in the hydrostatic pressure in the pulp. The acute vascular reactions to an inflammatory stimulus are vasodilatation and increased vascular permeability, both of which will increase pulp interstitial fluid pressure and may tend to compress blood vessels and counteract a beneficial blood flow increase.

Other Parts of Our Body Experience Similar Pain Levels

Why Teeth HurtThe dental pulp isn’t the only tissue that experiences high levels of pain when it is inflamed.  Most places in the body that are enclosed in a rigid structure experience lots of pain.

This is why headaches can be so painful, the skull is rigid and there’s no room for the swelling to go.

Another example is when you smash your fingernail and you get lots of inflammation underneath the fingernail.  Some people have even gone so far as to burn or poke holes through their fingernails to relieve the pressure that builds up.


Teeth hurt because when the pulp gets even slightly injured, it wants to expand and there’s no room for it to expand.

Do you have any questions related to tooth pain?  Leave them below in the comments section.  Thanks for reading!

Cold Sensitive Teeth
©Jan Mika/

Does the thought of eating ice cream or any cold foods make you cringe because you know how bad your teeth will hurt? You could be one of the millions of Americans that suffer from sensitive teeth. While the causes of sensitive teeth can vary, there are some toothpastes that can help alleviate the symptoms.

Ice Cream Sensitive TeethIf your teeth are sensitive and you don’t think that it is caused by reversible or irreversible pulpitis, then you may want to try a toothpaste that is made especially for sensitive teeth.

Toothpastes made for sensitive teeth usually contain two extra ingredients that help decrease painful tooth sensitivity.  These two extra ingredients are:

Potassium Nitrate and Strontium Chloride.

Both of these ingredients work by acting on the dentin tubules.  In order to understand how these ingredients work, I will first give a brief explanation of dentin tubules.

What Are Dentin Tubules?

The dentin tubules are tiny tubes that go from the outside of your teeth (when dentin is exposed to the outside surface, which usually happens with gum recession) to the dental pulp.  If the dentin tubules are openly exposed to the inside of your mouth, then it is easy for sensations to be transferred to the nerves in the dental pulp.

It is this transmission of various stimuli, such as heat, cold, and sweets, that cause the nerves to send the message of pain to your brain.  After all, the only sensation that the dental pulp can send to the brain is the sensation of pain.