Relatively speaking, of course, there's nothing quite as bad as tooth sensitivity, especially the kind that follows a filling or root canal. Tooth sensitivity not only means sensitivity in general, owing to the work that's recently been preformed in your mouth; tooth sensitivity refers specifically to the way a tooth reacts to heat and cold. Your tooth, after all, has this great, snake-like nerve slithering down through it, and nerves, as everyone knows, can cause horrible agony when exposed to the elements. Some people are born with greater tooth sensitivity than others. These days there are special toothpastes you can use to alleviate this inborn sort of problem. But what about the sensitivity that assaults your teeth right after you leave the dentist's office? What can you do about that? You might as well not live with pain a single second longer than you have to. Keeping this profound truth in mind, let's consider five ways in which a person can avoid sensitivity after a filling or root canal.
1.    First, when it comes to tooth sensitivity, keep in mind that it's not completely avoidable. In other words, you're probably going to have to live with some sensitivity following a filling or root canal no matter what you do. The reason you want to keep this in mind is that you'll probably be more effective with what you can control if you do. You're not attempting, really, to completely and totally abolish tooth sensitivity following a filling or root canal, as that'd be impossible-your tooth has just been brutalized, after all, and it's going to feel brutalized for a little while at least afterward. What you're attempting to do with tooth sensitivity is take the edge off-make it more bearable-make it so that you can work, eat, and function at more or less full capacity.
2.    I mentioned a special sort of toothpaste a little earlier-you can find it at your local pharmacy or grocery store. There are a more than a few different kinds, most of them with a title that cleverly makes use of the word "sensitive." So, right before your filling or root canal, or right afterward, go out and get yourself some of this toothpaste. That's a very basic step to take, as any dentist will tell you, should you bother to ask him.
3.    Staying with the "stuff" theme, there's some other stuff you can get besides toothpaste, a little stronger, a little more potent, a little quicker working. It's basically a numbing agent that you rub on the afflicted tooth and the surrounding gum area as well. And what it does is-numbs the tooth and the surrounding gum area as well. Ask your local pharmacist about it, he'll point you in the right direction.
4.    To avoid tooth sensitivity following a filling or a root canal, avoid really cold and really hot foods. Don't eat ice cream, maybe, until the day after, or at least until you notice a big difference in the way your tooth feels. Don't eat hot soup maybe right afterwards. In other words, there's no better method of avoiding tooth sensitivity than avoiding the substances that cause tooth sensitivity in the first place, or, if it's there already, that make it worse.
5.    You'll want to confer with your dentist or doctor when it comes to any medication, but basic aspirin has been known to help with tooth sensitivity following a filling or root canal. Ask your dentist about possible combinations of over-the-counter pain medications in your quest to avoid tooth sensitivity.
Again, you're never going to be able to escape tooth sensitivity altogether, assuming you've had significant work done on said tooth; to insist otherwise would be like insisting that your arm shouldn't feel any soreness at all once its been set for a broken bone. But by following a few simple steps you should be able to at least noticeably reduce the sensitivity in your teeth.