For most people, getting a filling involves little to no pain during the actual procedure. The injection of numbing medication is usually the most uncomfortable moment, and even that lasts only a few seconds. What you’re more likely to notice afterward is temporary sensitivity that fades over a few days to a few weeks, depending on how deep the filling is.
What the Injection Feels Like
Before any drilling begins, your dentist numbs the area with a local anesthetic, most commonly lidocaine. The injection itself produces a brief pinch or sting that lasts a few seconds. Some dentists apply a topical numbing gel to the gum first, which reduces even that initial sensation. Lidocaine kicks in within one to three minutes for a direct injection into tissue, and the numbness typically lasts one to two hours, or up to four hours when paired with a vasoconstrictor (a compound that keeps the anesthetic concentrated in the area longer).
Once the anesthetic takes effect, the nerve signals between your tooth and brain are blocked. You won’t feel sharp or aching pain. What you will feel are sensations the anesthetic doesn’t eliminate: pressure from the instruments, vibration from the drill, and occasionally a cold sensation from the water spray. These feelings can be odd or slightly uncomfortable, but they aren’t painful in the way most people fear.
Why Some Fillings Hurt More Than Others
The depth of the cavity is the biggest factor. A shallow cavity that only affects the outer layer of enamel requires less drilling and sits far from the nerve. These fillings are sometimes done with minimal or even no anesthesia and cause very little discomfort. A deep cavity that extends close to the pulp (the inner tissue containing nerves and blood vessels) requires more work, and the proximity to the nerve means there’s a greater chance of sensitivity both during and after the procedure.
Location matters too. Back teeth (molars) can be trickier to numb thoroughly because of how their nerves branch. Lower molars, in particular, sometimes need a second injection or a different injection technique to achieve full numbness. If you feel a sharp zing at any point during drilling, tell your dentist. They can add more anesthetic before continuing.
How Dental Anxiety Changes the Experience
Anxiety and pain perception feed each other in a well-documented cycle. Research published in Acta Odontologica Scandinavica found that people with higher dental anxiety consistently report more intense pain, even when the physical stimulus is the same. Anxiety heightens sensitivity to oral sensations, so a feeling of pressure that a relaxed patient barely notices can register as genuinely painful for someone who is tense and fearful.
If anxiety is a factor for you, let your dentist know beforehand. Many practices offer nitrous oxide (laughing gas), which takes the edge off without putting you to sleep, or oral sedation for more significant anxiety. Simply knowing that the anesthetic will block pain, and that you can raise your hand to pause the procedure at any time, helps some people relax enough to change the experience entirely.
What to Expect After the Numbness Wears Off
Some degree of sensitivity after a filling is normal. The tooth has just been drilled into and sealed with a foreign material, and the surrounding tissue needs time to settle. Here’s the typical timeline:
- First 24 to 48 hours: This is when sensitivity peaks. You may notice discomfort with cold drinks, sweet foods, or pressure from chewing. Even within this window, the discomfort should feel like it’s gradually improving hour by hour.
- Days 3 to 7: Most people notice a significant drop in sensitivity. Occasional twinges from very hot or very cold foods may still occur, but they become shorter and less frequent.
- Weeks 2 to 4: Shallow to moderate fillings typically feel completely normal within two weeks. Deep fillings placed close to the nerve can take three to four weeks to fully resolve.
Over-the-counter pain relievers are usually enough to manage any post-filling soreness. The discomfort is more accurately described as “sensitivity” than “pain” for the majority of people.
When Post-Filling Pain Isn’t Normal
One of the most common culprits of lingering pain is a high bite. If the filling sits even slightly higher than your natural tooth surface, that tooth absorbs all the force when you chew. It feels like the tooth “hits first,” and you may notice pressure or a bruised sensation that only happens when biting down, not at rest. This is an easy fix. Your dentist can shave down the high spot in a quick, painless adjustment that often provides immediate relief.
A more serious concern is pulpitis, which is inflammation of the nerve inside the tooth. In its early, reversible stage, you might feel a sharp sensitivity to cold or sweets that goes away quickly. This can resolve on its own as the tooth heals. But if you develop sensitivity to heat that lingers for more than a few seconds, spontaneous throbbing pain, or aching that keeps you up at night, the inflammation may have progressed to an irreversible stage. At that point, the filling alone isn’t enough and additional treatment is needed.
As a general rule, any pain that is getting worse rather than better after the first 48 hours, or sensitivity that lingers long after the trigger is removed, warrants a call to your dentist. Normal post-filling sensitivity follows a clear downward trend. Pain that plateaus or escalates is telling you something different.
Composite vs. Amalgam: Does the Material Matter?
Tooth-colored composite fillings tend to feel smoother or slightly harder than the surrounding enamel. They bond directly to the tooth, which can mean less drilling overall. However, composite fillings are placed in layers that are each hardened with a curing light, and this process can sometimes cause slightly more post-procedure sensitivity compared to amalgam (silver) fillings. The difference is usually minor and resolves within the same general timeline.
Amalgam fillings are less commonly placed today but are still used in certain situations. They don’t bond to the tooth and instead rely on the shape of the cavity to stay in place, which can require slightly more tooth removal. Both materials, once placed and healed, should feel comfortable and natural when you chew.