Dental Anaesthesia

Dental Anaesthesia

There are different types of anaesthesia used in dentistry

Local anaesthesia, this is the most common, it is given to numb the area or tooth that is to be worked on. On the upper teeth the anaesthetic numbs the nerve as it branches out to the individual tooth or area. This injection is called an infiltration. In the lower jaw however the nerve supply is slightly different, to numb any area or tooth, the main nerve, called the inferior dental nerve is numbed. This is called an ID block.


Both of the above methods are commonly used for all dental procedure, from fillings to placing dental implants

Cocaine was used as anaesthesia in the 19th century. Novocaine (Procaine) was the next alternative in 1905 and is a cocaine derivative (chemically related to cocaine). It's better than cocaine, without the toxicity, with a longer lasting effect, and without addiction. Lidocaine (Xylocaine) came out in 1947 and was widely used in dental practice, then Prilocaine in the 1950's also widely used in dental practice, then Articaine (Ultracain) in 1976, then Scandicaine (Scandonest).

The most commonly used local anaesthetic is lidocaine (also called xylocaine or lignocaine), a modern replacement for novocaine and procaine. Its half-life in the body is about 1.5-2 hours, but this can vary from patient to patient. Anaesthetic "wears off" by being metabolized. So it takes a few hours. The more you work that muscle (talk, chew, etc) the faster it will wear off. If you went home and took a nap, it would most likely still be numb when you woke up.

Most agents come in two forms: with and without epinephrine.

Intravenous Sedation, this is a conscious sedation that works on the central nervous system to help reduce the anxiety of the patient when undergoing dental treatments.


A drug called midazolam is administered into the vein to help relax the patient. The effects can last for approximately 24 hours after the treatment; although the patient is sedated the use of local anaesthesia is still required to numb the area to be treated.

Some dental practices use terms such as "sleep dentistry" or "twilight sleep" when talking about IV sedation. This is confusing, because it suggests that IV sedation involves being put to sleep. These terms are more descriptive of deep sedation. Deep sedation is not commonly used (in the U.K. at least), and is classified as general anaesthesia (even though sedation occurs on a continuum).

In reality, you remain conscious during conscious IV sedation. You will also be able to understand and respond to requests from your dentist.


However, you may not remember much (or anything at all) about what went on because of two things:


IV sedation induces a state of deep relaxation and a feeling of not being bothered by whats going on

The drugs used for IV sedation produce either partial or full memory loss (amnesia) for the period of time when the drug first kicks in until it wears off. As a result, time will appear to pass very quickly and you will not recall much of what happened. Many people remember nothing at all. So it may, indeed, appear as if you were "asleep" during the procedure.

General anaesthesia, this method is only used in hospitals mainly for complex oral surgery and the extraction of multiple teeth, or impacted wisdom teeth.


General anaesthesia is where one or more general anaesthetic drugs have been administered to render the patient unconsciousness and results in a loss of protective reflexes. Amnesia, analgesia, relaxation of skeletal muscles, and loss of control of reflexes of the autonomic nervous system are some of the side effects associated with general anaesthesia.

GA can be useful or even indicated for certain situations.

Conscious IV sedation works for about 97% of extremely anxious people. But there will always be a few people for whom it doesn't work, either because you find it impossible to cooperate even when sedated and/or because you have a very high tolerance to the drugs used for IV sedation. This appears to be more common if you've been taking similar drugs long-term for other mental health conditions. In this case, GA may be the best option.

For short or longer potentially traumatic procedures, such as the removal of wisdom teeth which are completely covered in bone or certain other types of oral surgery. While there may be alternatives like multiple shorter appointments, in some cases GA may be preferable. If it's extractions that really terrify you, it may be possible to be put to sleep for the extractions and then have fillings etc. done under conscious sedation with local anaesthetic.

Related articles.

Dental Anaesthesia

There are different types of anaesthesia used in dentistry Local anaesthesia, this is the most common, it is given to numb the area or tooth that is to be worked on. On the upper teeth the anaesthetic numbs the nerve as it branches out to the individual tooth or area. This injection is called an .... read more


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