Believe it or not, February 9th is "Toothache Day"! What causes a toothache? Is there a way to keep from having toothaches? All good questions!
In most cases, your tooth will be hurting because something has happened to the tooth's nerve. Your tooth's nerve sits in a space at the center of your tooth that we call the dental pulp. Around the dental pulp is a material called dentin, which is made up of many tiny tubules that run between the nerve and the tooth's outer covering (called enamel).
As best we can tell, any time a tooth nerve is aggravated, it gives off a pain response. Yes, even when we perceive it as something like cold sensitivity, it is still a pain response--it's just our brains interpreting that response that makes it seem different to us. This is important because a small cavity or a small break to the tooth can result in what we think of as "sensitivity". Sweets, cold, or even just your tongue moving saliva across the tooth can cause that twinge or "ooh" reaction. Think of this as an early warning system--whatever is in your mouth is different than what's in the dentin tubules. Your body's response is to want those two areas to be equal, and as it strives to accomplish this, you feel the twinge. This is the best time for you, with the help of your dentist, to figure out what's going on and get it fixed--and hopefully avoid the worse toothache sensation by doing so.
In the case of a chipped or broken tooth that's into the dentin, over a period of time, sometimes minerals in our foods and beverages or in our toothpastes will plug up the open ends of the tubules. If that happens, often the sensitivity goes away, or at least gets less intense. Your dentist may determine that the area is shallow enough that this is all that's needed--but remember that dentin is easier for mouth bacteria to break down than enamel is--so your dentist may determine that the break is deep enough that you should repair it to protect the tooth from future damage.
Traumatic events can cause an immediate opening into your dental pulp with the resulting symptoms or the nerve damage can show symptom years later. Let's use falling off a bike as an example.
If you're riding your bike and fall, and break your tooth in half, it is likely the nerve of your tooth is exposed. In this case, usually you will experience pain (a toothache) everytime something moves across that broken area--whether it is air, saliva, food, liquid, or whatever.
However, if you're riding your bike and fall, and hit the tooth so that it jams up into the jaw, but doesn't break, you might have some immediate soreness and pain from the trauma, but the tooth may or may not be the culprit for that pain right at the beginning. But think about what's happened. Your hard tooth and your hard jaw bone were pushed together in a way they weren't intended to be. Because the nerve of your tooth enters at the bottom of the tooth root, the tooth nerve (and the blood vessels that accompany it) is often pinched between these two hard surfaces. For some people, the problem with the dental pulp happens fairly soon after, and for others, the problem can occur decades later--often long after the traumatic event has been forgotten! The result, however, is the same. As the dental pulp is affected, it creates gasses that build up. Because your tooth is hard, the gasses cannot escape, so the resulting pressure pushes on the tooth nerve--and the nerve reacts with, you guessed it!, pain!
Dental decay (a cavity) has a similar effect on a tooth. It creates a path for mouth bacteria to follow and if that path leads to the dental pulp, the bacteria infect it. The infection creates gasses, and the same effect occurs.
So . . . can you keep from having toothaches? The answer is often yes. If your dentist finds a cavity, have it fixed while it is smaller and able to be filled, rather than waiting until it bothers you or until it hurts. Cavities continue to grow until your dentist fixes them, and eventually they're going to get large enough to cause you problems. Sometimes, your dentist will see that your tooth needs a root canal (or removal) before you've had symptoms such as pain. To avoid a toothache, have the root canal (or removal) done soon after the recommendation is made.
If you've had trauma to your teeth--whether from a fall, a sports injury, or an accident or other injury--see your dentist as soon as possible afterward. Unfortunately, this is the one time where it's hard to predict when the nerve damage might show itself. It may be something that you and your dentist need to follow on an ongoing basis--watching for symptoms and signs as best we can. And if you change to a new dentist, it's important to let him or her know of the past trauma to that area.
To show how unpredicatable they are:
I have one patient who broke the root of a tooth after being hit during a basketball game. Since the break was surrounded by bone, the tooth root healed itself, much like a broken bone would, and the tooth is still alive to this day, over 5 years later. (That's not to say that it migh not develop problems in the future.)
Another patient broke the part of the tooth that's visible in the mouth after being hit during a basket ball game. The tooth needed a root canal within the first 3 years of the trauma.
I hope this has helped explain why toothaches happen and what's going on when you have one. Unfortunately, once you have a toothache, your treatment choices are much more limited (often to having a root canal or having the tooth removed). So, do what you can to avoid getting to that point. One of the easiest ways to avoid sports injuries is to wear a custom fitted mouthguard during sports.
We'll explore mouthguards and what you can do if you have a toothache in future blog articles.
*Note: Information in this article is not meant to replace the clinical judgement of your dentist and other healthcare providers.