Sedation Dentistry

We offer a range of options to make our patients more comfortable to have their dental treatment.  Despite the fact that most people can tolerate standard dental treatment with only local anaesthetic, some patients prefer alternative forms of anaesthesia to make them more comfortable for their procedures.

Beyond local anaesthesia, we offer:

1) Mild and deep oral sedation
2) Nitrous oxide and oxygen conscious sedation
3) Intravenous conscious sedation

Please note that not all forms of sedation are covered by your insurance plan, and that for booking certain forms of sedation, a booking deposit will be required. 

Inhalation Sedation (Laughing Gas or Nitrous)

Inhalation sedation, laughing gas, nitrous oxide, N2O-O2… this has more names than any other sedation technique! Inhalation sedation with nitrous oxide (N2O) and oxygen (O2) has been described as “representing the most nearly ‘ideal’ clinical sedative circumstance”…

What is it? And what does it do?

Nitrous oxide (N2O) is simply a gas which you can breathe in. It has no color, smell, and doesn’t irritate. It was discovered in 1772. Humphrey Davy (1778-1829). Dentists are credited as being the pioneers or founders of modern anaesthesia!

After 5 minutes or so of breathing in the gas, you should feel a euphoric feeling spread throughout your body. It really kind of feels like a ‘happy drunk’ feeling. Some people find that there are auditory or visual effects as well. You will feel a bit light headed and often people get ‘the giggles’ (hence the name laughing gas!). As an interesting aside, nitrous oxide was one of the drugs of choice for young people in the late 1700s and early 1800s, when laughing gas demonstrations were a popular source of entertainment and enjoyment.

How does nitrous oxide work?

Today, we know that nitrous oxide (N2O) on its own can only safely be used for short periods of time (because the lack of oxygen in pure N2O can lead to unconsciousness and even death) – but that it’s safe to use for longer periods of time if you mix it with oxygen (O2). Hence, the “laughing gas” used now is called N2O-O2, and contains at least 30% oxygen (that’s all the machines used nowadays will permit). Usually, the mix is about 70% oxygen to 30% nitrous oxide.

In medicine, sometimes a mix of 50% oxygen to 50% nitrous oxide is used. This is known as entonox or, more commonly, “gas and air”.

Depending on the concentration and length of administration of laughing gas, four levels of sedation can be experienced (after an initial feeling of light-headedness):

1. a tingling sensation, especially in the arms and legs, or a feeling of vibration (“parasthesia”), quickly followed by warm sensations, and
    
2. a feeling of well-being, euphoria and/or floating. During heavier sedation, hearing may dissolve into a constant, electronic-like throbbing.
    
3. At a deeper level of sedation again, sleepiness, difficulty to keep one’s eyes open or speak (“dream”) can occur. Should nausea set in, it means you’re definitely oversedated!If you experience any unpleasant symptoms, let your dentist know so that they can adjust the percentage of N2O. Alternatively, just take the mask off.
    
4. During relative analgesia, you should stay within the first three stages. The “dream” stage means that the N2O concentration is too high, or that the gas has been administered for too long. This stage can be associated with side effects such as nausea and other potentially unpleasant sensations, including flashbacks. N2O concentration should always be gradually increased (“titrated”) at each visit, because people’s tolerance can vary from day to day. If you’ve had bad experiences with laughing gas in the past, it is highly likely that these were due to improper administration and too high a concentration of N2O.
    

What are the advantages of nitrous oxide?

• Nitrous oxide works very rapidly – it reaches the brain within 20 seconds, and relaxation and pain-killing properties develop after 2 or 3 minutes.
• The depth of sedation can be altered from moment to moment, allowing the person who administers the gas to increase or decrease the depth of sedation. Other sedation techniques don’t allow for this. For example, with IV sedation, it’s easy to deepen the level of sedation, but difficult to lessen it. Whereas with laughing gas, the effects are almost instant.
• Other sedation techniques have a fixed duration of action (because the effects of pills or intravenous drugs last for a specific time span), whereas gas can be given for the exact time span it’s needed for. It can also be switched off when not needed and then switched on again (though to avoid a roller-coaster effect, you shouldn’t do this too abruptly).
• There’s no “hangover” effect – the gas is eliminated from the body within 3 to 5 minutes after the gas supply is stopped. You can safely drive home and don’t need an escort.
• With nitrous oxide, it’s easy to give incremental doses until the desired action is obtained (this is called “titration”). So the administrator has virtually absolute control over the action of the drug, preventing the possibility of accidental overdoses. While giving incremental doses is possible with IV sedation, it’s not possible with oral sedation (as a result, oral sedation can be a bit of a hit-and-miss affair).
• For certain procedures – those involving gums rather than teeth (e. g. deep cleaning) – it may be possible to use nitrous instead of local anaesthesia. N2O acts as a painkiller on soft tissues such as gums. However, its pain-relieving effects vary a lot from person to person and can’t be relied upon.
• No injection is required. In cases of very severe needle phobia, getting laughing gas first can help you feel relaxed enough to allow the needle required for IV sedation to be inserted in your arm or hand. The very deep state of sedation achievable through IV sedation will then allow you to accept local anaesthetic.
• Inhalation sedation is very safe. It has very few side effects and the drugs used have no ill effects on the heart, lungs, liver, kidneys, or brain.
• Inhalation sedation has been found to be very effective in eliminating or at least minimizing severe gagging.
   

 

Are there any disadvantages?

• Some people are not comfortable with the effects of laughing gas (either because they’re afraid they might lose control or because it makes them feel nauseous – this is quite rare, though, and usually due to oversedation). If you’re prone to nausea, it’s a good idea to have a meal (not a huge one) about 4 hours before your appointment. If that’s not possible (e. g. an early morning appointment), make sure your stomach isn’t completely empty – but don’t stuff yourself straight beforehand either.
• Some people will not achieve adequate sedation with permissible levels of oxygen.
• If you can’t breathe through your nose (either because you’re a pure mouth breather, or because your nose is blocked), or you feel too claustrophobic when something is put over your nose, it can’t be used.
• Depending on where you live, a dentist who offers nitrous oxide may be hard to come by.
• Apart from that, most of the disadvantages of inhalation sedation don’t affect you, but the dental team: there’s training required, the equipment is quite bulky and takes up a lot of space, and there is a possibility that dental staff who are chronically exposed to nitrous oxide might develop health problems. The cost of the equipment and gases is high, so you’ll have to contribute to the cost – but it’s quite a bit cheaper than IV sedation.
   

 

What about bad experiences with laughing gas?

On rare occasions, people have reported a bad experience with nitrous oxide. Usually this is due to oversedation – getting too much N2O in the mix. This is easily reversible by reducing the amount of N2O. For example, a few people have reported auditory and “physical” hallucinations, dizziness, or vertigo.

Don’t panic if you should experience this. While these symptoms are usually due to the N2O concentration being too high for you, the machines used nowadays have built-in safety features preventing an accidental overdose. Nonetheless, these sensations can be unpleasant – let your dentist know asap about any unpleasant sensations or symptoms so that they can adjust the percentage of N2O. Laughing, becoming giddy, crying, or uncoordinated movements are other signs that the NO2 concentration is too high, but these will easily be spotted by your dentist. Alternatively, just rip the mask off your nose! Don’t confuse “dizziness” with the normal feeling of lightheadedness which many people who’ve never had N2O before experience after maybe 60 or 90 seconds. The feeling of lightheadedness will pass as the concentration of N2O is increased.

Some experts in this field (e. g. Stanley Malamed) argue that nitrous oxide should always be “titrated”. This means gradually increasing the percentage of nitrous oxide in the N2O – O2 mix until a comfortable level is reached. The reason why titration should ideally be used every single time is because of potential adverse effects in the event of oversedation (including flashbacks of traumatic past events, as well as physical ill-effects).

However, other experts (e.g. Fred Quarnstrom) say that it’s ok to use a mix based on prior experience (a concentration which a particular patient has experienced as pleasant during previous appointments). Quite a lot of dentists do this because it’s quicker.

The problem with this approach is that tolerance can vary from visit to visit, depending on both psychological and physiological factors. What is experienced as pleasant varies from person to person and from day to day. And once a person has been oversedated, they may come to dislike nitrous oxide so much that they don’t want to try it again.
 

Are there any contraindications?

There aren’t any major contraindications to relative analgesia, except for M.S., emphysema and some exotic chest problems. It hasn’t been proven to be safe during the first trimester of pregnancy, so you can’t use it then.

Because you have to breathe it in through your nose, it’s not suitable for people who have a cold or some other condition which prevents them from breathing through their nose.

You can’t be allergic to N2O. It’s also safe to use if you suffer from epilepsy, liver disease, heart disease, diabetes, or cerebrovascular disease. It is also used quite successfully in many people with respiratory disease – but it depends on the exact nature of the disease, so check with your dentist!

Intravenous Conscious Sedation (aka “IV sedation”) is when a drug, usually of the anti-anxiety variety, is administered into the blood system during dental treatment.
 

What does it feel like? Will I be asleep?

A lot of dental offices and 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 isn’t commonly used, 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:

1. IV sedation induces a state of deep relaxation and a feeling of not being bothered by what’s going on
    
2. 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.
    

Is it still necessary to be numbed with local anaesthetic? Will my dentist numb my gums before or after I’m sedated?

The drugs which are usually used for IV sedation are not painkillers (although some pain-killing drugs are occasionally added, see below for more info), but anti-anxiety drugs. While they relax you and make you forget what happens, you will still need to be numbed.

If you have a fear of injections, you will not be numbed until the IV sedation has fully kicked in. If you have a phobia of needles, you will very probably be relaxed enough not to care by this stage. Your dentist will then wait until the local anaesthetic has taken effect (i. e. until you’re numb) before starting on any procedure.
 

How is IV sedation given? 

“Intravenous” means that the drug is put into a vein. An extremely thin needle is put into a vein close to the surface of the skin in either the arm or the back of your hand. This needle is wrapped up with a soft plastic tube. It makes the entry into the vein, then is slid out leaving the soft plastic tube in place. The drugs are put in through that tube (which is correctly referred to as an “indwelling catheter”, but more commonly known by the tradename of Venflon). The tube stays in place throughout the procedure.

The venflon to the right is a pinkie, which is one size bigger than the blue one that’s usually used for IV sedation in dentistry.

Throughout the procedure, your pulse and oxygen levels are measured using a “pulse oximeter”. This gadget clips onto a finger or an earlobe and measures pulse and oxygen saturation. It gives a useful early warning sign if you’re getting too low on oxygen, although if your dentist and the nurses are paying attention they should see it way before the machine does. Blood pressure before and after the procedure should be checked with a blood pressure measuring machine (a tongue-twister called “sphygmomanometer”, which for obvious reasons is referred to as “sphyg”).

 

Is it safe? Are there any contraindications?

IV sedation is extremely safe when carried out under the supervision of a specially-trained dentist. Purely statistically speaking, it’s even safer than local anaesthetic on its own!

However, contraindications include:

• pregnancy
• known allergy to benzodiazepines
• alcohol intoxication
• CNS depression, and
• some instances of glaucoma.

Cautions (relative contraindications) include psychosis, impaired lung or kidney or liver function, advanced age, and sleep apnea. Many people who have sleep apnea haven’t been officially diagnosed – if you are overweight and you snore, do mention this.
Heart disease is generally not a contraindication.
If you have been taking benzodiazepines for many years, your tolerance may be very high – so let your dentist know that you’ve been taking them!
 

What are the main advantages of IV sedation?

• IV sedation tends to be the method of choice if you don’t want to be aware of the procedure – you “don’t want to know”. The alternative in the U.S. is oral sedation using Halcion, but oral sedation is not as reliably effective as IV sedation.
• The onset of action is very rapid, and drug dosage and level of sedation can be tailored to meet the individual’s needs. This is a huge advantage compared to oral sedation, where the effects can be very unreliable. IV sedation, on the other hand, is both highly effective and highly reliable.
• The maximum level of sedation which can be reached with IV is deeper than with oral or inhalation sedation.
• Benzodiazepines produce amnesia for the procedure.
• The gag reflex is hugely diminished – people receiving IV sedation rarely experience difficulties with gagging. However, if minimizing a severe gag reflex is the main objective, inhalation sedation is usually tried first. Only if that fails to diminish the gag reflex should IV sedation be used for this purpose.
• Unlike General Anaesthesia or Deep Sedation, conscious IV sedation doesn’t really introduce any compromises per se in terms of carrying out the actual procedures, because people are conscious and they can cooperate with instructions, and there is no airway tube involved.
   

Are there any disadvantages?

• It is possible to experience complications at the site where the needle entered, for example hematoma (a localized swelling filled with blood).
• While IV sedation is desired precisely because of the amnesia effect (i. e. forgetting what happened while under the influence of the drug/s), there can be a downside to this: if you can’t remember that the procedure wasn’t uncomfortable or threatening, you cannot unlearn your fears. However, it depends on the precise nature of your phobia and the underlying causes to which extent this may be a problem. Some people would voice a concern that some patients can’t be “weaned off” IV sedation, as dental anxiety tends to returns to baseline levels. As a result, people who rely on IV sedation may be less likely to seek regular dental care. Other people would argue that this is not a concern if IV sedation is readily available to people.
• Some dentists may resort to IV sedation too quickly, without exploring alternative options such as iatrosedation and psychological techniques in enough detail first. Sedation should not be used as a substitute for these techniques, but as an additional tool if other techniques alone don’t work, or if it is a potentially traumatic procedure.
• Recovery from IV administered drugs is not complete at the end of dental treatment. You need to be escorted by a responsible adult.
• You should want to be sedated. If, for any reason, you’re unwilling to “let go”, for example because you’re terrified of not being in control, it will be more difficult to be successfully sedated.
• Cost is another disadvantage – IV sedation is more expensive than other sedation options.

 

Can I take valium tablets or other benzodiazepines beforehand?

Yes. You must let your dentist know about it though (unless your dentist has prescribed them and knows already). It’s best to do this before you turn up on the day, because you’re likely to forget to mention it.
 

What about eating and drinking before sedation?

Some dentists in Canada prefer to have people have a light meal about an hour before they come in (this is for conscious sedation using midazolam), but it may depend on the drugs used for the IV. In the U.S., the standard advice appears to be no eating or drinking for 8 hours beforehand. Where a GA drug like propofol or ketamine or a barbiturate is used, there is a danger that a person who regurgitates food while anesthetized could get food or liquid into their lungs.
 

After IV Sedation:

1. Have your escort take you home and rest for the remainder of the day.
2. Have an adult stay with you until you’re fully alert.
3. Don’t perform any strenuous or hazardous activities and don’t drive a motor vehicle for the rest of the day.
4. Don’t eat a heavy meal immediately. If you’re hungry, eat something light, e. g. liquids and toast.
5. If you experience nausea, lie down for a while or drink a glass of coke.
6. Don’t drink alcohol or take medications for the rest of the day unless you’ve contacted your dentist first.
7. Take medications as directed by your dentist.
8. If you have any unusual problems, call your dentist.