Liverpool University Dental Hospital
Please note that if you do not comply with the instructions in this leaflet then your treatment may be cancelled.
What is Penthrox Conscious Sedation?
Many patients are anxious about dental treatment. Sedation
usually reduces anxiety allowing you to accept dental treatment.
This form of sedation involves using an inhaler device, sometimes
referred to as a green whistle, as seen in the image on the right.
The sedative drug involves you taking normal breaths in and out through the inhaler mouthpiece until you are feeling relaxed.
Once you are feeling more relaxed, local anaesthetic will be used in the mouth to “numb” the area to be treated. You are still awake and able to talk to us. You may need to take more breaths through the inhaler mouthpiece throughout the treatment, to ensure that the sedative effect of Penthrox is maintained.
Conscious sedation is not a general anaesthetic.
After treatment you will stay in the department until the dentist and nurses feel you are ready to go home with your escort.
What problems might occur?
You may experience some dizziness, coughing, nausea or headaches after treatment. You may also feel tired or drowsy afterwards, you may not have good balance, and your judgement is likely to be impaired. Your memory of the treatment session may be affected by the sedative; some patients are affected more than others. Some patients do not remember any of the treatment however this cannot be guaranteed.
What should I do?
On the day of your appointment:
Clothing
- Wear loose fitting, comfortable clothes allowing access to your arms as we will need to take your blood pressure.
- Wear flat shoes as you may be unsteady on your feet after treatment.
- Do not wear nail varnish as this may interfere with our monitoring equipment.
Eating
Eating and drinking before sedation depends upon any medical conditions you have and the treatment you require. Please follow the advice bellow that has been chosen for you (clinician to tick as appropriate):
(If you have diabetes there may be alternative fasting instructions please ask)
Medication
- Take your routine medication at the normal time
Alcohol and drugs
-
Do not drink alcohol or use recreational drugs for 24 hours before or after your appointment as it may interfere with the sedative drug
Driving
Do not drive or ride any vehicle until the next day
You must attend for your appointment with an escort who must:
- Be an adult, who is prepared and able to assist you with activities of daily living.
- Not bring any children or vulnerable adults to the appointment.
- Not be responsible for the care of any other person.
- Must come with you, stay within the department and take you home.
- Be aware of their responsibilities for your care.
On arrival for your appointment let us know:
- If you have seen a doctor/nurse or had any changes to your medical history since your last dental visit.
- If you are unwell.
- If you are pregnant or you are trying for children.
- If you are breast feeding.
- If you are wearing contact lenses- we may ask you to remove them.
- If you have any concerns regarding your proposed treatment.
After your treatment and until the following morning:
You should:
- Travel home with your escort. We advise car or taxi. Public transport is not recommended.
- Have a responsible adult to stay with you and look after you.
- Have somebody else to care for any children, elderly or sick relatives you usually look after.
- Take your regular prescribed medication as usual.
- Follow any other post-operative instructions given to you by the dentist.
- Relax for the rest of the day; do not do any strenuous exercise.
You should not:
- Drive or ride a motorcycle/ bike.
- Operate machinery – including domestic appliances such as irons, kettles etc.
- Return to work.
- Travel alone.
- Make important decisions or sign business or legal documents.
- Climb ladders.
- Take any other non-prescribed drugs or alcohol.
Be wary of using the internet/ social media (your judgement may be impaired).
If you have any questions, please ask a member of staff who would be happy to help.
If there are any problems after treatment contact the Oral Surgery Department on Tel: 0151 706 5307 / 0151 706 5309
We try to keep to your appointment time but sometimes we may run behind. Unfortunately if you arrive late then we may need to reappoint you.
If you miss an appointment without first cancelling it, or keep cancelling appointments at short notice you will be discharged back to your own dentist. We always try to be helpful but we do need your cooperation.
If you need to cancel your appointment please give as much notice as possible as this may allow somebody else to be treated.
Tel: 0151 706 5307 / 0151 706 5309. Text phone number: 18001 0151 706 5307
Feedback
Your feedback is important to us and helps us influence care in the future.
Following your discharge from hospital or attendance at your outpatient appointment you will receive a text asking if you would recommend our service to others. Please take the time to text back, you will not be charged for the text and can opt out at any point. Your co-operation is greatly appreciated.
Further information
Oral Surgery Department,
Liverpool University Dental Hospital
Tel: 0151 706 5307 / 0151 706 5309
Text phone number: 18001 0151 706 5307
NHS: 111 / Tel: 111
Author: Oral Surgery, Liverpool University Dental Hospital
Review date: May 2026
PI 3247 V1