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Dental Sedation and General Anaesthetic: What to Expect

How local anaesthetic, sedation and general anaesthetic differ, the types of dental sedation, who they may suit, how to prepare, and why you need someone to take you home.

Updated September 2026·By the OHA editorial team·9 min read·How we write
Key takeaways
  • A local anaesthetic numbs the area while you stay awake. It is used for treatments such as fillings.
  • Sedation calms you but you stay conscious. It can be breathed in (happy gas), taken as a tablet or given into a vein (IV sedation), usually alongside a local anaesthetic.
  • A general anaesthetic puts you fully asleep. In the UK, dental general anaesthetics have been given only in hospital since 2002.
  • Rules on eating and drinking beforehand differ between services. Follow the instructions you are given exactly.
  • After IV sedation or a general anaesthetic you need an adult to take you home and stay with you, and no driving for at least 24 hours.

The American Dental Association (ADA) says local anaesthetic injections are used for treatments such as fillings, and more complex treatment may need deeper sedation. For people who are very anxious or cannot manage treatment while fully alert, the dental team may offer sedation or a general anaesthetic. See also dental anxiety and having a tooth out.

Local anaesthetic, sedation and general anaesthetic: what is the difference?

  • Local anaesthetic numbs part of the mouth by blocking the nerves that sense pain (ADA). University College London Hospitals (UCLH) says the numbness usually lasts 2 to 3 hours.
  • Sedation uses medicine to reduce anxiety. You stay awake and can talk, although you may remember little afterwards (UCLH, Wirral Community Health and Care NHS Foundation Trust). The Rotherham NHS Foundation Trust says teeth still need numbing with a local anaesthetic.
  • General anaesthetic uses medicines to make you unconscious, so you do not feel pain, move or know what is happening. It is given by an anaesthetist, a specialist doctor (healthdirect Australia).

Types of sedation

Inhalation sedation ("happy gas" or "gas and air")

You breathe a mixture of nitrous oxide and oxygen through a small nosepiece (Oral Health Foundation, Great Ormond Street Hospital) or a mask (Better Health Channel, Victoria). It works within a few minutes and wears off quickly, and you stay awake. Great Ormond Street Hospital says it does not work with a cold or blocked nose, and Wirral says it suits children old enough to understand and breathe through their nose. The Better Health Channel says a few people dislike the feeling.

Tablets or liquid

The Better Health Channel says a dentist or doctor may prescribe a small, short-acting dose of anti-anxiety medicine, usually taken an hour before the appointment. Kent Community Health NHS Foundation Trust applies the same escort and aftercare rules to tablet, nasal spray and IV sedation.

Intravenous (IV) sedation

A thin tube called a cannula is placed in a vein in the hand or arm, and the sedative is given through it (Wirral, Rotherham). The Better Health Channel says it is sometimes called twilight sedation: you may drift into a light sleep but can still respond. It is given by a dentist with advanced sedation training or an anaesthetist, at a practice with extra equipment or in hospital. Rotherham says there is usually an assessment appointment first.

Who might sedation suit?

The ADA says the choice depends on the procedure, your overall health, any allergies and how anxious you are. The Better Health Channel says not all dentists offer sedation, and some medical conditions or medicines limit which type you can have. Tell the team if you are or might be pregnant or are breastfeeding (Rotherham, UCLH). See also learning disabilities and dental care and autism and dental care.

Is it safe?

Wirral describes conscious sedation as very safe, with your breathing and oxygen levels monitored throughout. Rotherham lists common effects as drowsiness, memory loss, dizziness or confusion, feeling sick and bruising where the cannula was. UCLH says a medicine can reverse the sedation if you become too drowsy.

Rotherham says a very serious complication from a general anaesthetic is very rare, about 1 in 100,000 for a healthy adult, but much more likely than with IV sedation. healthdirect lists common side effects of a general anaesthetic as nausea, dizziness, tiredness and a sore throat.

Before the appointment: eating, drinking and medicines

Follow the instructions your own team gives you. Different services give different advice, as these NHS examples show.

For IV sedation in adults:

  • Kent: a light, non-fatty meal up to 2 hours before.
  • Wirral: nothing to eat or drink for 2 hours before, apart from small sips of water.
  • Rotherham: for a morning appointment, no food after midnight; for an afternoon one, a light breakfast before 7am; a glass of water up to 2 hours before.
  • UCLH: you may have a light meal before the appointment.

For inhalation sedation in children, Great Ormond Street Hospital and Wirral say fasting is not needed; Great Ormond Street suggests a light, non-greasy meal an hour or two before.

For a general anaesthetic, healthdirect says you must fast so that food cannot come up and be breathed into the lungs. Wirral's leaflet for adults says nothing to eat for 6 hours. Its leaflet for children says to stop food and milk 6 hours, breast milk 4 hours and sips of clear fluids 1 hour before arriving, and not to fast children for longer.

Kent, Wirral and UCLH also say to take your usual medicines unless told otherwise, and Kent and Wirral say no alcohol or recreational drugs for 24 hours before, flat shoes and no nail varnish. Tell the clinic if you have a cold or feel unwell (UCLH, Great Ormond Street Hospital).

Getting home and aftercare

For IV or tablet sedation, the NHS leaflets say:

  • A responsible adult must come with you, stay during treatment and take you home by car or taxi, not public transport (Kent, Wirral, UCLH, Rotherham). Kent says they must be over 18 and not caring for anyone else.
  • Someone should stay with you for up to 24 hours (Kent); UCLH says possibly overnight.
  • For 24 hours, do not drive, cycle, use machinery or household appliances, drink alcohol, look after children, sign legal documents or make important decisions (Kent, Wirral, UCLH, Rotherham).

After a general anaesthetic, healthdirect says you cannot drive home and it is best to have someone with you for 24 hours. Wirral says you may feel tired for a few days.

Driving after sedation: sources differ

The Oral Health Foundation says you can usually drive about 15 minutes after gas and air. The Better Health Channel says to avoid driving home after any sedation. The NHS says not to drive for 24 hours after a sedative injection or 48 hours after a general anaesthetic. Great Ormond Street Hospital says children should avoid active sports, cycling and crossing roads alone for the rest of the day after gas and air. Ask your dentist.

Where is it offered, and what does it cost?

United Kingdom

A 2002 British Dental Journal paper records that 31 December 2001 was the last day a general anaesthetic could be given in a UK dental practice; since then it must be given in a hospital with immediate access to critical care. In Scotland, government guidance set the rule from 1 April 2001. Sedation, by contrast, can be given in the dental surgery (Rotherham). The NHS says people who need specialised treatment may be referred to Special Care Dentistry, and that your dentist should tell you the cost before starting treatment. See dental costs and help.

Australia

The Better Health Channel says a general anaesthetic is given in hospital by the dentist and an anaesthetist, with an assessment beforehand. It adds that a general anaesthetic does not help you learn to cope with dental visits. It points to public dental services for eligible people; see dental costs and help.

United States

The ADA says sedation may involve gases, pills or injected medicine, and general anaesthesia is used on occasion. The Medicaid and CHIP Payment and Access Commission (MACPAC) says sedation can take place in a dental office, an ambulatory surgery centre or a hospital, and deep sedation or general anaesthesia is often given in hospital. Writing about adults with intellectual and developmental disabilities on Medicaid, it says access is limited by the number of qualified providers and operating rooms, with reported waits of up to two years in one state.

Children

The ADA says a dentist may recommend sedation or anaesthesia so that some procedures can be completed safely in a child. Wirral says a general anaesthetic may suit better if a child is too young or anxious for happy gas, or the treatment is complex. Great Ormond Street Hospital says the person with parental responsibility must sign a consent form. See also early childhood tooth decay.

When to see a dentist
  • Anxiety is stopping you getting treatment: ask about sedation or referral.
  • Your health or medicines have changed, or you might be pregnant: tell the team before the appointment (Kent, Wirral).
Get help urgently
  • After a general anaesthetic, healthdirect says to go to your nearest emergency department if you have trouble breathing, new bleeding, uncontrolled pain or vomiting, are very drowsy, or seem to be getting worse.
  • Wirral advises A&E for uncontrolled bleeding, severe facial swelling or feeling generally unwell after treatment. See also dental emergencies.

Frequently asked questions

Will I be asleep during sedation?

No. You stay conscious and can respond, although you may feel drowsy, drift into a light sleep or remember little (UCLH, Better Health Channel). Only a general anaesthetic makes you fully unconscious.

Do I still need an injection?

Usually. Rotherham says teeth being filled or taken out still need a local anaesthetic, but once you are sedated a numbing paste can be used first.

Can I go back to work the same day?

Not after IV sedation. Rotherham advises not returning to work for at least 24 hours, and UCLH says not to return to work immediately.

Sources

  1. Anesthesia and sedation, American Dental Association (MouthHealthy), accessed September 2026
  2. Relaxation and sedation, Oral Health Foundation, accessed September 2026
  3. Dental anxiety and phobia, Better Health Channel (Victoria), accessed September 2026
  4. General anaesthetic, healthdirect Australia, accessed September 2026
  5. Intravenous sedation, University College London Hospitals NHS Foundation Trust, accessed September 2026
  6. Having dental treatment under intravenous conscious sedation, Wirral Community Health and Care NHS Foundation Trust, accessed September 2026
  7. Information for parents and guardians on inhalation sedation, Wirral Community Health and Care NHS Foundation Trust, accessed September 2026
  8. Pre and post-operative information for adult patients having dental treatment under general anaesthesia, Wirral Community Health and Care NHS Foundation Trust, accessed September 2026
  9. Preparing my child for their dental general anaesthetic, Wirral Community Health and Care NHS Foundation Trust, accessed September 2026
  10. Oral, intranasal and intravenous sedation, Kent Community Health NHS Foundation Trust, accessed September 2026
  11. Information about dental care using intravenous (IV) sedation for adult patients, The Rotherham NHS Foundation Trust, accessed September 2026
  12. Inhalation sedation for dental procedures, Great Ormond Street Hospital, accessed September 2026
  13. Wisdom tooth removal, NHS, accessed September 2026
  14. How to find an NHS dentist, NHS, accessed September 2026
  15. How much NHS dental treatment costs, NHS, accessed September 2026
  16. The provision of general anaesthesia in dental practice, an end which had to come?, Landes DP, British Dental Journal 2002 (abstract on the UK Health Security Agency research portal), accessed September 2026
  17. Guidance on general anaesthesia and sedation for dental treatment, HDL(2001)29, Scottish Executive Health Department, accessed September 2026
  18. Access to dental services for adults with intellectual and developmental disabilities (PDF), Medicaid and CHIP Payment and Access Commission, accessed September 2026

This article is general information about oral health. It is not a diagnosis or a substitute for advice from a dentist or doctor who knows your situation. If you have pain, swelling, bleeding that does not settle, or a problem that is getting worse, see a dental professional. In an emergency, contact your local emergency service.

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