My Filling Fell Out and My Tooth Hurts | What the Pain Is Telling You

Think of the filling as the lid on a jar. Underneath the hard white enamel, a tooth is made of dentine, which is a bundle of very tiny drinking straws, all pointing at the nerve. While the lid was on, nothing got down the straws. Now the lid's off, every sip of cold tea and every breath of October air goes straight down them, and the nerve gets the message loud and clear.

That's the mechanism behind the classic lost-filling pain: sharp, sudden and short-lived, in response to cold, hot, sweet or touch.

There's a second, less obvious reason. Fillings don't usually fall out for no reason. In my experience the cement gives up, or there's decay or a crack underneath that has quietly undermined it. So the tooth that's hurting may have had something brewing before the filling went, and losing the filling has simply taken the lid off that too.

The first thing I ask anyone who rings with this is "describe the pain". The pattern tells me a lot before I've even looked.

• Sharp and short, only with a trigger. Cold, sweet, air, your tongue. It stops within seconds of the trigger stopping. This is exposed dentine doing its thing. Uncomfortable, and the tooth needs sealing rather than rescuing.
• Lingering after the trigger. The cold has gone, but the ache hangs around for a minute or more. That's the nerve starting to get inflamed, and I'd want to see you this week rather than next month.
• Throbbing on its own, worse lying down, keeping you awake. That's an inflamed nerve that has moved past the "just irritated" stage. Call me today.
• Hurts when you bite. Either the edges of the cavity are catching, or the tooth has cracked, or the ligament around the root is sore. Cracks in particular love a tooth with a big old filling in it, so please don't test it on anything crunchy.
• Your cheek or tongue hurts, not the tooth. A sharp edge is rubbing. That's a different problem with a different fix.

Pain that comes with swelling of the gum or face, a bad taste, or a temperature isn't a lost filling story any more. That's infection, and it goes to the front of the queue.

I'll be straight with you: not necessarily, and I can't tell from a description. I split an angry nerve into two camps. Reversible means the nerve is irritated but will calm down once the tooth is sealed and protected; the pain is short, sharp and tied to a trigger. Irreversible means the inflammation has gone too far to settle; the pain lasts for hours, can be dull and throbbing, is hard to pin to one tooth, and typically keeps you awake at night. Heat can make it worse and, oddly, cold sometimes eases it.

My rule: if your pain is in the first camp, a proper filling usually sorts it. If it's drifting into the second, the tooth may need root canal treatment or, if it's beyond saving, taking out. The longer an open tooth sits there with the nerve being pelted, the more likely it slides from camp one to camp two. That's the whole reason I'd rather see you sooner.

Nothing below fixes the tooth. It just gets you to the appointment in one piece.

• Sensitive toothpaste, straight on the tooth. Put a smear on the exposed bit with a clean finger and leave it there. Don't rinse it off. This is the NHS advice and it works better than people expect.
• Avoid the triggers. Very hot, very cold and sweet food and drink, and keep sugar to mealtimes. Chew on the other side.
• Painkillers if you need them. Paracetamol or ibuprofen as the packet says, if they're safe for you. If they're not touching the pain, that's my cue to see you urgently, not yours to take more.
• A pharmacy temporary filling kit, as a stopgap only. It can cover the hole and take the edge off the sensitivity until your appointment. It's a plaster, not a repair.
• Keep it clean. Brush twice a day with fluoride toothpaste, gently around the hole.

Less than you're dreading. I'll have a look, gently check whether the tooth is tender to tap or bite on, test how the nerve responds to cold, and usually take a small X-ray to see what's underneath. Then, depending on what I find, the tooth gets a new filling, or a temporary dressing that calms the nerve down while I plan something more solid, or a conversation about a crown if there isn't enough tooth left to hold a filling. If the nerve has already had it, I'll tell you, and we'll talk through root canal treatment or removal without any pressure.

You can't work out which of those you need from your sofa. I can, usually in one visit.

The NHS says see a dentist for any toothache lasting more than two days. For a lost filling that hurts, I'd move faster than that. Call us today if:

• the pain lingers after hot or cold, throbs by itself, or kept you awake
• painkillers taken as directed aren't controlling it
• the gum or your face is swelling, there's a bad taste, or you feel unwell with it
• a sharp edge is cutting your tongue or cheek and you can't cover it
• a piece of tooth came away with the filling and it's wobbly

Call 999 or go to A&E, not a dentist, if:

• you're finding it hard to breathe, swallow or speak
• swelling is spreading towards your eye or down into your neck
• you can't open your mouth properly because of the swelling
• you think you've breathed the filling in rather than swallowed it (coughing, wheezing or chest discomfort since it went); that needs emergency care, not a dentist

Until you're seen: soft food, sensitive toothpaste on the tooth, and nothing very hot, cold or sweet on that side.

If you're near Harlow or Enfield and the tooth is getting worse rather than better, I'd much rather take a look than have you spend another night with your tongue in the hole. Ring your nearest Minti practice and tell us it's painful. We'll do our best to see you the same day. Anywhere else, or out of hours, call NHS 111.

This article is general information, not a diagnosis. Tooth pain needs examining in person to find the cause.