Why does my tooth hurt after the filling?
The tooth wasn’t bothering you whatsoever before you had the filling done.
You know oral care is important and you religiously visit your dentist twice a year for a cleaning and check-up. You were surprised when he said you had a cavity but you followed his recommendation and scheduled an appointment right away to take care of it before it gets any larger.
And now you can’t even chew on that side.
After almost a week, you contact the office and are told to come in. The doctor asks, “Does your bite feel normal?” You honestly don’t know because it hurts when you put your teeth together. He numbs your mouth – again, the second time in two weeks – and puts the blue paper in and requests that you tap up and down. He repeats this.
“Well, your bite appears normal,” he concludes, satisfied. But you know that once the anesthetic wears off, your tooth will still hurt. He stands up as if the problem has been solved. “Just baby it and come back in a few weeks if the sensitivity doesn’t resolve.”
“Are you sure the filling’s OK?” you ask. He reassures you that the filling looks “perfect.” You are dumbfounded. Although you really like this dentist, he has somehow made you feel that it’s your fault that the tooth now hurts.
What the heck is going on?
With any medical procedure, it’s not unusual to experience post-operative discomfort. When you get a flu shot, your arm may be sore for a day or two. A more extensive procedure, such as knee replacement, will require weeks if not months of healing and physical therapy.
After a filling, you may experience some gum tenderness:
Around the tooth – A clamp or a wedge may have been used during the procedure. This discomfort should be minor and will disappear spontaneously within a few days.
At the injection site – Although rare, a condition known as trismus can develop right away or up to five days following an injection. If you received multiple injections at the same site, the chances of trismus increase. Trismus may be marked by pain and an inability to open your mouth to maximum capability. Usually this resolves with warm, moist compresses. If the condition persists, pain medication, muscle relaxants and jaw opening exercises may be indicated.
An allergic reaction
In isolated instances, you may have an allergic reaction to the filling material that results in itching or the development of lesions in the gum or skin. This includes both silver amalgam and white composite resin fillings. Although the mercury in amalgam is known to be toxic in high quantities, the incidence of a true allergic reaction to mercury is exceedingly rare.
As for the tooth, most of the time there will be no symptoms once the anesthetic wears off. But if it does happen, don’t immediately blame your dentist because he may not have done anything wrong. These are some of the main reasons for pain afterwards:
The bite is high
This is probably one of the most common reasons for postoperative discomfort. When I was a dental student doing one of my first fillings, I thought I had done such a good job reproducing the original shape of the tooth. My patient called me in tears that night complaining that her tooth hurt. The following day I sanded off part of the filling, thereby bringing her bite back to normal. Within less than 24 hours, all the symptoms abated.
Hers was a silver amalgam filling. Although less routinely employed as a material today, amalgam has a limited working time during which it turns from soft and malleable to hard and unworkable. Its brittleness in the early stages also makes it difficult to reliably check the bite. The dentist doesn’t want the patient to bite down too hard, lest the brand-new filling crack. In my inexperienced and slow attempt to create an ideally shaped filling, I ran out of time to adequately check the bite.
If you suspect that the bite is off, don’t wait a week before returning to your dentist. Try and get this taken care of right away. There should be no additional charge associated with this adjustment.
The filling material irritates the tooth
The majority of fillings done in the U.S. use a tooth-colored resin composite. The filling stays in place through a process called bonding where chemicals are applied to the tooth to allow the filling to adhere.
In the earlier generations of this material, it was commonplace for teeth to be sensitive to temperature and biting after a composite was placed. Primarily this was due to two reasons. Shrinkage of the composite material leads to tension between the two sides of the tooth – and corresponding discomfort. In addition, the phosphoric acid used to create microscopic channels to enhance bonding causes sensitivity.
Today’s modern composites have reduced the incidence of sensitivity substantially. If it does occur, the sensitivity usually resolves within six weeks. However, sometimes it can take six months to a year before the tooth is symptom free.
Composite resin fillings
The cavity is big
Whenever the cavity is large and close to the nerve – or pulp – of the tooth, there stands a chance that the nerve can become irreversibly inflamed. If the sensitivity escalates to outright pain, especially spontaneous pain that arises unprovoked, the tooth may require a root canal.
In these cases, your dentist should warn you for this eventuality prior to starting the filling.
There is an existing large filling
Oftentimes cavities develop next to vulnerable areas in existing large fillings. Referred to as recurrent decay, sometimes these fillings can be repaired and patched without removing the entire thing. Or the whole filling will need to be removed and redone. Whenever dental work is undertaken on a tooth that already contains a fair amount of previous work, there is a risk of sensitivity. Furthermore, a remote risk of nerve damage is a possibility.
Galvanic response
A galvanic response is an electric shock-like feeling when disparate metals touch. This can occur between a fresh silver amalgam filling and gold, especially if the amalgam contains zinc. Over time, the galvanic shock will lessen. In the meantime, your dentist can also apply silver nitrate to the amalgam to alleviate symptoms.
What should you do?
Avoid ice cold drinks
Or drink with a straw
Unless there’s an obvious cause, such as a high bite or galvanic response, the best approach is to do nothing. Resist the temptation to have your dentist remove the filling as this may further irritate the tooth. Perhaps you’ve lost confidence in your dentist and decide to seek another opinion. Consider carefully before you allow the new dentist to jump in and do something. It’s natural for the new provider to try and “fix” the problem in order to gain you as a patient.
Almost always, the sensitivity will go away with time, typically over the course of several weeks to a couple months.
In the meantime, “baby it,” as your dentist suggested. Eat soft foods. Keep cold and hot liquids and foods away from the area. Drinking with a straw may help. Take over-the-counter pain medication as needed.
However, if the sensitivity progresses into an actual toothache – or it wakes you up at night – it may be an indication that the nerve is irreversibly damaged. Contact your dentist. A root canal may be the next step.
If the sensitivity is not declining and persists beyond six weeks, again contact your dentist and have the tooth examined.
When is an x-ray helpful?
It takes a minimum of six weeks from the date of the filling for an x-ray to show any significant changes in the tooth. Prior to that, an x-ray may represent your dentist’s desire to try and do something to help.
