Numbness from a dental local anaesthetic usually wears off within one to five hours, though the exact timing depends on the anaesthetic used, where it was given, and your own body. The tooth stops feeling numb before the lip and tongue do, because the soft tissues hold the effect longer.
Key takeaways
- Soft-tissue numbness of the lip, cheek, or tongue commonly lasts about 3 to 5 hours, sometimes up to 6 with longer-acting anaesthetics.
- Lower jaw injections (nerve blocks) stay numb longer than the upper jaw, because a whole nerve is numbed rather than a small area.
- The numbing of the tooth itself fades faster, often within about an hour, which is why a filling can be finished well before your lip feels normal.
- Do not eat or drink anything hot while numb, to avoid biting or burning yourself. Numbness that lasts well beyond a day is worth a call to your dentist.
How long different anaesthetics last
Most dental locals include a small amount of vasoconstrictor, which keeps the anaesthetic working in the area for longer. The table below gives general ranges for soft-tissue numbness.
| Common anaesthetic | Numbness of the tooth | Numbness of lip, cheek, or tongue |
|---|---|---|
| Lignocaine with vasoconstrictor | About 60 minutes | About 3 to 5 hours |
| Articaine with vasoconstrictor | About 45 to 75 minutes | About 3 to 6 hours |
| Anaesthetic without vasoconstrictor | Shorter | Often 1 to 2 hours |
These are typical ranges, not guarantees. Your dentist chooses the anaesthetic to match the length and type of treatment.
Why the lower jaw stays numb longer
For work on lower back teeth, dentists often use a nerve block, which numbs the main nerve to that side of the lower jaw. This spreads numbness across the lip, tongue, and several teeth, and it takes longer to wear off than the small, targeted injections used in the upper jaw. That is why your tongue and lower lip can feel thick for hours after a lower filling.
What affects how long numbness lasts
- Type and amount of anaesthetic. Longer-acting agents and larger doses last longer.
- Whether a vasoconstrictor was used. It holds the anaesthetic in place, extending the effect.
- Injection type. A nerve block lasts longer than a small local injection.
- Your metabolism. People clear medications at different rates.
- Infection. An infected, inflamed tooth can change how the anaesthetic behaves.
How to help numbness wear off
The safest approach is simply to wait, but a few things can help you feel normal sooner.
- Gentle activity. Light movement such as a short walk increases blood flow, which helps clear the anaesthetic.
- Gentle massage. Lightly massaging the cheek or lip (once you can feel it returning) can encourage circulation.
- Warmth. A warm compress on the outside of the cheek may help, but never anything hot inside the mouth while numb.
- Rest and time. For most people, patience is all that is needed.
In some cases a dentist can give a reversal agent that speeds the return of feeling in the soft tissues by roughly half. Ask your dentist if getting sensation back quickly matters for your day.
Staying safe while you are numb
While your mouth is numb it is easy to injure yourself without noticing.
- Avoid chewing on the numb side, and do not test the numbness by biting your lip or cheek.
- Skip hot drinks and hot food until feeling returns, to avoid burns.
- Take extra care with children, who may bite or chew a numb lip out of curiosity.
Once feeling returns you can usually eat normally. Our guide on eating after a filling explains what is safe and when.
When to contact your dentist
Numbness that lingers well beyond the expected window, especially more than a day, or that comes with tingling, a burning feeling, or persistent altered sensation, is worth a call. Prolonged numbness is uncommon and usually settles, but your dentist will want to know. Lingering sensitivity in the tooth afterwards is different and often settles on its own, as our guide on sensitive teeth explains.
Frequently asked questions
Why is my tooth not numb but my lip still is?
The tooth numbing wears off faster than the soft tissue. It is normal for the filling to be finished while your lip stays numb for hours.
Can I speed up dental numbness wearing off?
Light activity, gentle massage once feeling returns, and time all help. A dentist can also give a reversal agent in some cases.
Is it safe to eat while numb?
It is better to wait. Eating while numb raises the risk of biting your cheek, lip, or tongue, or burning yourself on hot food.
How long is too long for numbness?
Beyond about a day, or if it comes with tingling or a burning sensation, contact your dentist. This is uncommon and usually resolves.
Does the injection site staying sore mean something is wrong?
Mild tenderness where the needle went in is common for a day or two and settles by itself. Increasing pain or swelling should be checked.
Booking with the team at Lumi Dental
If you have a filling or other treatment coming up and want to know what to expect, the team at Lumi Dental is happy to talk it through. See current new patient offers on our offers page or read about general dental care at Melrose Park. If a temporary filling is part of your plan, that guide covers the aftercare.
