How Long Does Dental Numbness Last? Eating, Smoking, Children

How Long Does Numbness Last After the Dentist?

Dental numbness is the local anaesthetic quietening the nerves of your lip, cheek and tongue as well as the tooth, and in adults it typically wears off within two to three hours. In two multicentre randomised trials of 484 people who had a vasoconstrictor-containing anaesthetic for fillings or scaling, sensation returned after a median of 155 minutes in the lower lip, 125 minutes in the tongue and 133 minutes in the upper lip (PubMed 18682623). As these are medians, some people stay numb for longer.

Children recover on a similar timescale. In 152 children treated with lidocaine and adrenaline, normal lip sensation returned after a median of 135 minutes in the control group (PubMed 18682624). In a telephone follow-up of 204 children aged 2 to 14 who had articaine, 40% were still numb 3 hours after the injection and 11% after 5 hours (PubMed 18942603). The authors described prolonged numbness as the most common side effect in children and advised that parents are told about it in advance.

The lower jaw often stays numb over a wider area because lower back teeth are usually numbed with a nerve block, which also numbs the lower lip, chin and half of the tongue on that side. Upper teeth are mostly numbed with an injection next to the tooth, so the numb area stays smaller.

Can You Make Dental Numbness Wear Off Faster?

There is no proven way to shorten dental numbness at home. The two methods that have been studied, a reversal drug and laser, are both given at the clinic. Choosing an anaesthetic without a vasoconstrictor did not help either: in 60 adults, two anaesthetics without adrenaline did not shorten lower lip numbness after a lower jaw injection compared with lidocaine plus adrenaline (PubMed 7499650).

The reversal drug that has been studied is phentolamine mesylate, injected where the anaesthetic was given once treatment is finished. In the 484-person trials it cut the median time from 155 to 70 minutes in the lower lip and from 125 to 60 minutes in the tongue (PubMed 18682623). A meta-analysis of 6 randomised trials found it more effective than placebo for the lower lip and tongue, but described the evidence as limited (PubMed 26409985). A safety review of 9 studies found no severe complications, although mild and moderate side effects were more common with phentolamine (PubMed 31134227).

Low-level laser is a newer option. In a randomised trial of 24 children aged 5 to 8, laser shortened the time for numbness to wear off by a mean of 31 minutes compared with a sham treatment (PubMed 42291654). It was a small trial. We could not find published studies showing that warm compresses, massage, facial exercises or drinking water shorten numbness. If faster recovery matters to you, raise it with your dentist before treatment.

Eating and Drinking After a Local Anaesthetic

Wait until the numbness has gone before chewing food or having hot drinks, because a lip, cheek or tongue you cannot feel can slip between your teeth or be scalded without you noticing. In the 484-person trials, measured functional deficits and the changes patients reported in function, sensation and appearance all improved as the anaesthetic wore off (PubMed 18682623).

Water and drinks that are not hot can be sipped on the side that is not numb. If you are hungry, something soft, lukewarm and easy to swallow on the other side of the mouth is the safer choice. Leave chewing gum, hard or sticky food and hot soup until feeling returns. If the treated tooth aches as the anaesthetic fades, ask your dentist which painkiller suits you.

How long you wait depends on the numbness. A light-cured composite filling is already hard when you leave the chair, so after a filling you are only waiting for the anaesthetic to wear off; more on that in our guide to eating, smoking and pain after a filling. On a treatment trip with several appointments in a day, plan meals for after feeling returns. An extraction has extra rules to protect the wound and the blood clot even after the numbness has gone.

Smoking After a Local Anaesthetic

Do not smoke until the local anaesthetic has completely worn off; if a tooth was taken out, the waiting time is set by the extraction wound rather than by the numbness. A numb lip cannot properly feel the filter or the heat of a cigarette, which can lead to burns or bites. We found no study measuring the risk of smoking while numb; this advice follows from the numbness itself.

Fillings, root canal treatment and scaling leave no open wound that needs to heal, so smoking once feeling has returned will not undo the treatment, although it still harms your gums and teeth.

Extractions are different because the clot in the socket has to be protected. A systematic review of 11 studies found dry socket, where the clot is lost early and painful bone is left exposed, in about 13.2% of smokers compared with 3.8% of non-smokers, with more than 3-fold higher odds in smokers (PubMed 35877395). So after an extraction the answer is a much longer wait than the numbness alone. How long to wait and how to protect the clot is covered in our guide to smoking after a tooth extraction.

Children Biting Their Lip After Dental Work

While numb, children can bite, suck or chew their lip, cheek or tongue without realising; it is one of the most commonly reported problems after a local anaesthetic in children. In a study of 320 children aged 2 to 18, 13% had a soft tissue injury afterwards: 18% of those under 4, 16% at ages 4-7, 13% at 8-11 and 7% over 12 (PubMed 11132502). Among 204 children given articaine, 14% had an injury by 3 hours, most often those younger than 7, and the lip was the site injured most often (PubMed 18942603).

In a prospective study of 241 children, self-inflicted soft tissue injury occurred in 9% of children without intellectual disability and 19% of those with intellectual disability, and age 6 or under and lower jaw injections raised the risk (PubMed 31898299). The choice of anaesthetic does not seem to matter here: a meta-analysis of 8 randomised trials found no significant difference between articaine and lidocaine in soft tissue injury after treatment (PubMed 37997231).

The parent's job is to watch the child until feeling comes back. Tell your child their lip will feel big for a while and that they must not bite it, hold off food until the numbness has gone, and keep fingers and dummies out of the mouth. A recent systematic review of 21 studies reported that phentolamine, mouth guards and laser have all been tried to reduce these injuries, but the studies were too different to compare directly (PubMed 40856087). If a bitten lip develops a sore or swelling over the next few days, show it to the dentist. How children's treatment is planned is explained on our paediatric dentistry page.

When Dental Numbness Does Not Wear Off

Numbness from a dental local anaesthetic wears off within hours; loss of feeling that is still there the next day, lasts for days or comes with tingling, burning or a change in taste should be reported to your dentist. Lasting numbness caused by the injection is rare. A review of Ontario professional liability records from 1973 to 1993 found 143 reports of numbness not linked to surgery; all followed lower jaw injections, the tongue was affected most often followed by the lip, and the rate was projected at 1 in 785,000 injections (PubMed 7736335). A systematic review of 15 studies on nerve-related side effects of lower jaw nerve blocks also described nerve damage as a rare event (PubMed 35162650).

Numbness that lingers after surgery, such as removing an impacted wisdom tooth, is usually related to the procedure rather than the injection and needs assessment by the surgeon. The risks of each type of removal are explained on our wisdom tooth extraction page.

A sore or swollen lip after the numbness has gone is often tissue that was bitten while numb. Other causes of a sore or swollen lip are covered in our article on lip pain after dental crowns. If you develop breathing difficulty or rapidly increasing swelling of the face or throat after an injection, do not wait and seek emergency medical care straight away.