One day, I was in my chiropractor’s office. He has that great candy at the front desk, the kind that you are supposed to let dissolve in your mouth. I can’t do that. Maybe you can’t either. I have to chew it. Well, I did chew it and all of a sudden, I was chewing on more than the hard candy. I was chewing on part of my tooth.
That leads me to this column, because for 15 years prior to that incident, that tooth would bother me every once in a while when I bit down the wrong way. It had a small crack, but I lived with it.
So let’s go back to the beginning. How can a tooth crack? It can crack for any one of a number of reasons. The tooth itself can be inherently weak and can split right down the middle, well below the gum line, even if it’s never had a filling. There is nothing that can be done to save a tooth that is split deeply below the gum line. It should be removed, and is usually best replaced with a dental implant.
A tooth can crack because it is weakened by tooth decay. Tooth decay undermines the structural integrity of the tooth. Often, that crack will occur above the gum line. We drill out the decay, put in a filling, to restore the tooth. But essentially now the tooth is divided by the filling. Remember when you lived up north and when the snow melted in the spring, there would be potholes in the road? Road Maintenance would fill those potholes with asphalt. But what happened to those pothole repairs? They’d often have to be redone the next year, because the walls of the pothole expanded and cracked, leaving a bigger pothole. Same thing happens with a tooth with a filling. The walls of the filling, meaning the remaining tooth structure, expand and contract and cracks develop. Sometimes, it hurts to bite down on the tooth because there are “micro cracks” that are so small and so deep, that we as dentists can’t even see them.
I am often asked the question, “How can my tooth still hurt when I had a root canal done on the tooth?” After all, the “nerve” of the tooth has been removed. How can it hurt? The answer is that the periodontal ligament around the outside of the tooth also has nerve fibers. So while the inside of the tooth may be nerve-free because of the root canal, the outside of the tooth under the gum line still has its ligament holding the tooth to the bone. The fracture touches that ligament. So if you notice pain when you bite down, the fracture is likely touching the ligament and “stretches” it under biting pressure.
If you feel some slight intermittent discomfort only when you bite down and can live with it, it may be best to do just that. But if you feel severe pain when you bite down, and it is interfering with your eating lifestyle, something needs to be done. Dentists will often place a temporary crown to see if the pain in the tooth is relieved before asking you to invest in major dental work on the tooth. If the pain goes away, then the investment in the permanent crown may be worth it. But if pain on biting pressure remains after placing a temporary crown, it may be better to extract the tooth now than invest in more procedures to “save the tooth”. A year and a half later, I visited by chiropractor again. He had the same candy. I chewed it instead of dissolving it. And I fractured another tooth. You’d think I’d learn.
Lee N. Sheldon, DMD