Normally, having a dental filling done eases the discomfort and hypersensitivity of an untreated cavity. In some cases, though, patients are surprised when the local anesthetic wears off and they still have a toothache. If you find yourself in this painful predicament, here are some of the potential causes, along with tips on what you can do about it.

Normal Sensitivity

While many people don't have any trouble with dental fillings, others find that they tend to have some sensitivity for a week or two after having one placed. This often occurs because the filling material used transmits heat and cold better than your dental enamel. When a hot or cold substance hits the filling, the sensation can go right toward the nerve of the tooth, causing pain. This type of discomfort is generally mild and easily treated with over-the-counter medications, like ibuprofen or acetaminophen.

You should let your dentist know about any sensitivity you have after a filling; the next time you need a cavity treated, he or she might choose a different filling material or place a barrier between the tooth and the filling to reduce your chances of having the same problem.

Filling That Is Too High

It's difficult to tell whether your filling feels right when you are still numb after having dental work done. Your dentist will have you bite on a piece of transfer paper to show him or her if there are any spots that are uneven or hitting too hard on the opposing tooth, but this method is not foolproof. If you get home and it feels like you're hitting that tooth first when you close your mouth, the filling might be too high. If the filling (or a newly placed crown) is high by even a millimeter or less, the pain can feel like a bruise.

If you ignore this issue, you'll likely have more and more pain over the coming days as the tooth becomes more irritated. Luckily, there is a quick fix: See your dentist for a bite adjustment. This takes only a few minutes and you will not need any anesthetic. You will begin to feel better almost immediately, if this is the issue.

Filling That Is Too Close to the Nerve

If you've had a large filling placed, it's possible that it's very close to the nerve of your tooth. Your dentist might have told you this was a possibility already, and he or she might have placed a sedative material in the cavity before filling it in an effort to avoid pain later. Many people will have discomfort after a large filling, and if you do, you might be told to wait and see what happens. In some cases, the pain will resolve on its own after a few days or a week, but in other cases, it will continue to get worse as time goes on.

Tooth pain caused by a large filling that is close to the nerve can be treated with root canal therapy. It is important to see your dentist if the pain does not lessen over a week or so, because if bacteria gets into the nerve space, you could be at risk of developing an infection. Either your general dentist or an endodontist can perform a root canal, which treats the pain and reduces the risk of infection. During a root canal, the nerve of the tooth is removed, which eliminates the pain caused by a filling sitting too close.

If you have problems after having a filling placed, give your dentist a call to discover more about the issue.. In many cases, it will be something easily treatable. Even if  your discomfort is mild or solved by taking an over-the-counter medication, it's helpful for the dentist to know so steps can be taken during the next filling to minimize the chances that you'll have the same problem again.