Your dentist may have recommended that you have intravenous sedation. This means that a sedative drug or drugs (medicine) is given to you by injection into a vein. The sedation makes you drowsy and helps reduce anxiety.

Intravenous sedation is usually given by using a single drug called midazolam. A dose of the drug is chosen for you individually. It is given by injection. This is usually into a vein in the back of your hand or in your arm through a cannula. A cannula is a thin flexible tube.

For more complex dental treatments and for more severe anxieties, an additional drugs may be used to deepen the effects of the sedative.

A needle is used to put the cannula in but is then removed immediately. It is normal to feel a sharp scratch when the cannula is inserted. A local anaesthetic paste or liquid can be used first to reduce the pain of the injection. Once the cannula is in the vein, the sedation drug can be given without using any more needles. The cannula remains in until the dentist has checked that you have recovered from the sedation but it will be removed before you go home.

It is usual to have at least two appointments. The first appointment will be an assessment when your dental treatment under sedation will be planned and discussed with you. The dental treatment under sedation will take place at the second and subsequent appointments. If the treatment is needed as an emergency, it may be possible to have some treatment under sedation at the first appointment.

Your dentist and members of the dental team are trained to give sedation. They watch you closely and treat any problems that may develop. They are also required to use appropriate monitoring equipment during sedation. There will be a recovery area or you will remain in the dental chair where you will be observed until you have made a full recovery from the sedation.

As with the administration of any medicines, there are risks associated with intravenous sedation. These might include:

• A reduction of oxygen in the blood stream due to poor breathing during sedation.

You may be asked by your dentist/sedationist to take deep breaths to correct this. Your breathing and oxygen levels will be monitored throughout the procedure.

• Bruising at the site of the cannula. This may take several days to fade completely.

Very rare risks include allergic reactions to the sedative drugs that you have been given or vomiting during the procedure. Your dentist/ sedationist will discuss any concerns that you may have prior to the procedure taking place.

It is important that you let the dentist know your medical history, including any medicines that you are taking. The dentist will need to know if you have ever had any problems with having either sedation or a general anaesthetic.

If you think you may be pregnant, you need to let the dentist know. You may need to come back to have your treatment at another time. You should let the dentist know if you are breastfeeding.

Your dentist will discuss with you and explain what you are able to eat and drink prior to your appointment. You will also be given this information in writing. It is important that these instructions are followed carefully.

The information provided here is a general guide for patients having dental treatment with sedation. As part of the face-to-face discussions with your dentist, you may be given advice that is specific to your treatment plan. This may differ in some areas to the general principles outlined here.

Before any treatment is started, the dentist will ask you to confirm consent. This means that you understand the planned treatment and how you will receive the sedation.

What to expect

You will remain conscious during this kind of sedation.

You may experience a temporary loss of memory during the time that you are sedated. Many patients have no memory of the procedure at all. You may feel unsteady on your feet for some hours after the procedure. Your ability to think clearly and make judgements may be affected for the next 24 hours. You may experience some forgetfulness.

Once you are sedated, the dentist can use local analgesia (pain relief that numbs the site of the dental treatment). Local anaesthetic as a paste is sometimes used to numb the site of the treatment. Any injections that you may need can be given through this numbed area to reduce the chance of any discomfort.

You will spend some time in the recovery area following your treatment. You will be checked by the dentist or the person giving you the sedation before you can go home. You must be accompanied by an able-bodied adult who can take responsibility for you following your treatment. This person may need to stay with you overnight. If arrangements have not been made for someone to accompany you after treatment, you will not be able to have the sedation.

If you have any questions or are unclear about having your sedation, then do not hesitate to ask your dentist.

After the treatment

Your judgement will be affected by the drugs. This is similar to the effects of consuming alcohol. You should not drive a car, ride a bicycle or operate machinery until the following day. In some cases, this may be for as long as 24 hours. You should also not take responsibility for the care of others, use sharp implements or cook. It would be unwise to make any irreversible decisions for up to 24 hours following your treatment. 

Owing to the after effects of the drugs used, care should be taken when using the internet for personal communication.

Before you are discharged, the dentist or dental nurse will give you and the adult accompanying you (escort) important information about your care. You will be given information relating to any local analgesia and the treatment you have received. The dentist will also provide details of pain relief as well as how and when to take other prescription medicines.

You will be given a telephone number of who to contact if you have any problems as a result of your treatment.

Reprinted and adapted from :

Standards for Conscious Sedation in the Provision of Dental Care

Report of the Intercollegiate Advisory Committee for Sedation in Dentistry 2015

The Dental Faculties of the Royal Colleges of surgeons and the Royal College of Anaesthetists