You had the tooth sorted out on Tuesday, and here you are on Thursday night with it aching, wondering whether something has gone wrong in there. It happens to an enormous number of people, and most of the time the tooth is simply settling down.
Is it normal for a tooth to hurt after a filling?
Yes, and once you know what is inside a tooth it makes complete sense.
Under the hard white enamel, and under the softer layer beneath it, every tooth has a small chamber holding the living nerve and its blood supply. That chamber has solid walls on every side, so when the nerve gets irritated and swells even very slightly, it has nowhere at all to expand into. It is like trapping your finger and then finding you cannot get your ring off: the pressure has to go somewhere and there is nowhere for it to go.
Now think about what that nerve has just been through. The decay was already working its way towards the chamber, which is irritating in itself. Then it was drilled out, and drilling makes heat and vibration, and then a new filling was packed in and set hard against the freshly cut surface. None of that is damage. That is a nerve that has had a very busy morning, and it grumbles for a while afterwards.
The grumbling usually shows up as one of two things. Cold goes straight through the tooth, a sharp little zing off a glass of water or a gust of air, gone a second later. Or the tooth feels bruised when you bite on it, a dull ache rather than a sharp one. Both are the ordinary picture after a filling, and both generally fade over a few days to a couple of weeks. The deeper the filling, the longer that takes, because the drill finished closer to the nerve and the nerve has further to come back. If your dentist mentioned the decay was deep, expect the tooth to take its time.
Why does it hurt most when I bite down?
This one is worth knowing about, because it is the most common reason a filling carries on hurting, and it is also the easiest to put right.
When the filling goes in, the dentist rebuilds the chewing surface to the shape of your tooth, then asks you to bite so it can be tapped down to match. The catch is that your mouth is numb while this is happening. You cannot bite properly, and a bite you cannot feel is a bite you cannot judge. So a filling can end up sitting a fraction of a millimetre proud of where it ought to be, and you would never see it.
Your teeth, though, measure in fractions of a millimetre for a living. If one tooth touches first, it takes the whole force of your jaw every time you close, before any of the others get a say. Think of a stone in your shoe. The stone is tiny and the shoe is perfectly fine, and yet a hundred steps later you are limping. Your tooth gets a few hundred of those steps at every meal, and the little cushion of fibres that slings it into its socket gets bruised, which is why it aches and why it can feel oddly taller than its neighbours.
Here is the good part. A high bite is sorted out in a matter of minutes. You bite on a strip of coloured marking paper, the colour shows precisely which spot is landing first, and the dentist polishes a whisker off that spot. Often the relief arrives the same afternoon. So if biting is what hurts, and a few days have gone by without it improving, ring. There is no prize for putting up with a stone in your shoe.
What does it mean if cold still goes right through it?
Cold is what people worry about most, and it is also the most useful signal your tooth gives you.
A sharp zing that arrives with the cold drink and has gone by the time you swallow is a sensitive nerve, and that is the pattern that settles. The nerve is inflamed, so it overreacts to the temperature, and as the inflammation goes down over the following days the zing goes with it.
Pain that lingers is a different message. If cold sets the tooth off and it throbs for minutes after the cold is long gone, or it starts aching on its own with nothing setting it off, or it wakes you in the night, that tells a dentist the nerve may not settle by itself. Those are the same signs that bring people in for root canal treatment, and they deserve a phone call rather than another fortnight of hoping. It is still an ordinary day’s dentistry. It is simply a different fix.
Why does my tooth still hurt after a root canal, when the nerve is gone?
This is the question that catches people out, and it is a fair one. The whole point of a root canal is to take the nerve out, so afterwards the tooth has nothing left to feel hot and cold with. And yet it can be sore to bite on for days. What is going on?
The soreness is coming from outside the tooth. Every tooth hangs in its socket on a thin sling of fibres, a sort of hammock, and that hammock has nerves of its own. It is what lets you feel a poppy seed between your teeth. When a tooth has been infected, the hammock and the bone at the tip of the root have been inflamed for a while already, and the treatment itself works all the way down to the end of that root, which stirs the area up further. So the tooth goes quiet on temperature and stays tender under pressure, which feels strange until you know why.
Our own root canal page puts the usual picture plainly: tender to bite on for a few days, occasionally a week, with ordinary painkillers from the packet covering it. You eat on the other side for a bit and go to work the next day. And if your tooth has a temporary dressing in it while you wait for the second visit, that dressing can sit high exactly as a filling can, so everything above about a high bite applies to it too.
One more thing tends to reassure people. The bone at the tip of the root carries on healing quietly for months after the tooth has stopped hurting, and a dentist sees that healing on an x-ray at a later check-up. A tooth that feels normal three weeks later is behaving precisely as it should.
When should I ring instead of waiting it out?
Let us keep this simple, because the moment your face hurts is no time for a decision tree.
Ring if the pain is keeping you awake or stopping you eating. Ring if the filling or the crown has come out, or a piece of the tooth has broken away. Ring if there is a swelling in the gum or the face. And ring if the pain is climbing rather than easing, because a settling tooth gets gradually better week on week, so a tooth that is worse on day six than on day two is worth a look.
You do not have to work out what is wrong first. That is the dentist’s job, and the emergency appointment exists for exactly this: seen the same day in practice hours, £27.90 for the visit and £150 outside them, covering the examination and getting you comfortable. Nobody will ask you to justify ringing. If it hurts, that is reason enough.
One situation does not wait for a dentist: a swelling of the face that is closing an eye, or making it hard to breathe or swallow, which is A&E rather than us.
What will the dentist actually do about it?
Very little, most of the time, and that is the reassuring part.
The bite gets checked first, because it is the commonest culprit and the quickest thing to fix: coloured paper, a tap of the teeth together, a polish on whichever spot is landing early. Then the filling itself gets a proper look, at the edge where it meets the tooth, at whether anything has chipped away, and at whether the seal is intact. And then, if the story warrants it, an x-ray of that tooth, which shows the nerve chamber, the roots and the bone around them, so the conversation stops being guesswork.
Often that is the entire visit, and you go home with an adjusted tooth and an explanation. Where the nerve has clearly not settled, the honest answer is to deal with the nerve, and the first stage of that, dressing or removing it, is £76.60 and takes the pain away on the day. The full root canal is planned and priced after that, and what a root canal costs has a post of its own.
What helps between now and the appointment?
If it is late and you are reading this on your phone, here is what genuinely helps tonight.
Chew on the other side. That gives the bruised hammock of fibres a rest, because it cannot calm down while it is being hammered at every meal. Go gently on very cold and very hot things for the same reason, and if cold air on the walk to the car sets it off, breathe through your nose for a minute.
Painkillers from the packet, taken as the packet says, do a genuinely good job on this particular kind of ache. Leave the aspirin in the box though, because an aspirin held against the gum burns the skin and adds a second problem to the first. And let the tooth alone: prodding it with your tongue all evening only keeps reminding the nerve that it exists. If you would rather somebody looked at it tonight than in the morning, we have written about what is open out of hours.
Hold on to the main thing while you wait. The great majority of teeth that ache after a filling are doing nothing more sinister than settling down, and the way it ends is quietly: the soreness fades, the cold stops mattering, and one morning a fortnight later you realise you have not given that tooth a thought in days.
