After a cavity filling, your mouth will be numb for about one to three hours, and you may notice some sensitivity in the treated tooth for a few days to a couple of weeks. Most people can return to normal activities right away, but there are a few things worth knowing about eating, pain management, and what signals mean something needs attention.
How Long the Numbness Lasts
The local anesthetic used during your filling typically wears off within two hours. During that window, your lip, cheek, and tongue on the treated side will feel tingly and unresponsive. This makes it surprisingly easy to bite your cheek or tongue without realizing it, and drinking can be messy since you can’t fully feel your lips. The safest move is to avoid eating or drinking anything until sensation returns completely.
You may also notice some soreness around the spot where the anesthetic was injected. That tenderness is separate from any tooth sensitivity and usually fades within a day.
When You Can Eat Again
This depends on the type of filling you received. Composite (tooth-colored) fillings are hardened instantly with a UV curing light during the procedure, so they’re at full strength by the time you leave the chair. You can technically eat right away, though most dentists suggest waiting until the numbness wears off so you don’t accidentally bite yourself.
Amalgam (silver) fillings are different. They take roughly 24 hours to fully harden, so you should avoid chewing on that side of your mouth for a full day. Regardless of filling type, skip very hard or sticky foods for the first 24 hours. Things like caramel, taffy, or ice can stress the new restoration before it’s fully settled.
Sensitivity After the Filling
Some degree of sensitivity to hot, cold, or pressure is completely normal after a filling. It happens because the procedure irritates the nerve inside the tooth, causing mild inflammation in the pulp (the soft tissue at the tooth’s core). For most people, this resolves on its own within a few days to two weeks.
The deeper the cavity was, the more likely you are to experience sensitivity, and the longer it may linger. Teeth that had very deep decay reaching close to the nerve, or teeth that have undergone multiple procedures, are more prone to prolonged sensitivity. A brief zing when sipping something cold is normal during recovery. Lingering pain that continues well after the hot or cold stimulus is removed is not, and could indicate the nerve has been damaged enough to need further treatment.
Managing Pain at Home
Most fillings cause minimal discomfort, but if you’re sore, over-the-counter pain relievers work well. The American Dental Association recommends combining ibuprofen (400 mg, or two standard pills) with acetaminophen (500 mg, one pill) for effective relief. Taking your first dose about an hour after the procedure, before the anesthetic fully wears off, helps you stay ahead of any pain rather than chasing it.
Take these with a full glass of water and some soft food. Avoid alcohol while using this combination. For a straightforward filling, most people only need pain relief for the first day, if at all.
Signs Your Filling Needs Adjustment
One of the most common post-filling issues is a bite that feels “off.” When your mouth was numbed during the procedure, it was difficult to bite down naturally, so the filling may have been shaped slightly too high. A filling that’s even a fraction of a millimeter too tall can cause noticeable problems.
Signs of a high filling include:
- Pain or a sharp jolt when biting down, especially on the filled tooth
- A feeling that your teeth don’t meet evenly when you close your mouth
- Increased sensitivity to temperature, because the uneven pressure exposes deeper layers of tooth structure
- Jaw stiffness or headaches from the constant uneven pressure on your jaw muscles
If your bite feels uneven after the numbness wears off, give it a day or two. Sometimes the sensation resolves as you adjust. If it persists, a quick visit to your dentist for a bite adjustment is all it takes. They’ll smooth down the high spot in minutes, and the discomfort usually disappears immediately.
When Something Is Actually Wrong
Normal post-filling sensitivity improves gradually. Problems that warrant a call to your dentist look different. Contact your dentist if sensitivity hasn’t improved within two to four weeks, or if you develop a constant throbbing toothache. That kind of persistent, unprovoked pain can mean the decay was deep enough to compromise the nerve, and root canal treatment may be necessary.
Over time, fillings can also develop issues from everyday wear. Constant pressure from chewing, grinding, or clenching can cause a filling to chip or crack. When the seal between the filling and tooth enamel breaks down, bacteria and food particles can slip underneath, leading to new decay beneath the restoration. Signs of this include new sensitivity in a tooth that previously felt fine, visible cracks in the filling, or a piece of the filling breaking off.
Brushing and Flossing Afterward
You can resume your normal oral hygiene routine the same day for composite fillings, once the numbness wears off. For amalgam fillings, some dentists recommend waiting until the next day before flossing aggressively around the treated tooth. In either case, be gentle for the first few days. Slide floss carefully between teeth rather than snapping it down against the gums, and pull it out from the side rather than yanking upward.
Brush twice daily with fluoride toothpaste and floss once a day. Good hygiene around your fillings is one of the most effective ways to extend their lifespan and prevent new decay from forming at the edges of the restoration.
How Long Fillings Last
No filling lasts forever. Amalgam fillings are the most durable, lasting about 15 years on average, though some hold up for decades. Composite fillings average around 7 years, but research shows they can last 10 years or more if the filling is small and your oral hygiene is solid. Ceramic fillings match amalgam at roughly 15 years, while glass ionomer fillings (often used in low-stress areas) average about 5 years.
Grinding your teeth, chewing ice, or eating a lot of hard and sticky foods will shorten a filling’s life. If you grind at night, a mouthguard can protect both your fillings and your natural teeth. Eventually, every filling will need to be replaced, and your dentist will monitor their condition at regular checkups, catching wear or breakdown before it turns into a bigger problem.