Sedation dentistry allows
you to be sedated just enough to be pain free and unaware of
the treatment, as if you were relaxing. That is why it is normally
referred to as conscious sedation dentistry. So if you have
sensitive teeth, a fear of dentists, have a bad gag reflex,
hate needles, or have limited time to spend on dental care at
the dentist, Sedation during dentistry procedures can help you.
Whatever the case may
be sedation by your dentists can help you be more anxiety free
during your dentistry treatment. Your dentist's ultimate goal
is to make your visit to the dentist a relaxing and enjoyable
one. Since you are completely comfortable, relaxed, and pain
free your sedation dentist can do years of dental treatments
in one or two dental visits.
With sedation your dentist can restore sore gums to good dental
health, fix a chipped tooth, replace crowns or dentures, whiten
yellow or stained teeth, and more. All pain free.
Laughing Gas ( Nitrous
Oxide )
Inhalation sedation,
laughing gas, relative analgesia, RA, happy gas, gas, nitrous,
nitrous oxide, N2O-O2... this one has more synonyms than any
other sedation technique! And deservedly so. 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's colorless, sweet-smelling,
and nonirritating. It was discovered in 1772. Gordon loves the
stuff! And why wouldn't he... Humphrey Davy (1778-1829), one
of the pioneers of N2O experimentation, described the effects
of N2O on himself following self-administration for a toothache
and gum infection as follows:
"On the day
when the inflammation was the most troublesome, I breathed three
large doses of nitrous oxide. The pain always diminished after
the first four or five inspirations; the thrilling came on as
usual, and uneasiness was for a few minutes swallowed up in
pleasure."
Sounds like fun!! The
extract above pretty much summarizes the effects of nitrous
oxide: it kills pain - and it induces a pleasureable feeling.
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 late1700s
and early 1800s, when "laughing gas demonstrations"
were a popular source of entertainment and enjoyment!
Since those days, it's
been discovered 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 these days 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.
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
(2) warm sensations, and
(3) a feeling of well-being,
euphoria and/or floating ("drift"). During heavier
sedation, hearing may dissolve into a constant, electronic-like
throbbing.
(4) 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!
During relative analgesia,
you should be maintained within the first three stages. The
"dream" stage is indicative of too high an N2O concentration
or too lengthy administration, and is associated with ill side
effects such as nausea and other potentially unpleasant sensations,
including flashbacks of bad experiences. These are definitive
signs of oversedation. N2O concentration should always be gradually
increased ("titrated") at each visit, because people's
tolerance can vary from day to day, depending on both psychological
and physiological factors. 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.
Interestingly, the actual mechanism of action of N2O is still
unknown (it appears that there are quite a few different mechanisms
at work)! However, it's been observed that N2O depresses almost
all forms of sensation - especially hearing, touch and pain,
and that it seems to disinhibit some emotional centers in the
brain. The ability to concentrate or perform intelligent acts
is only minimally affected, as is memory.
How
is it administered?
The equipment used for
delivering "happy gas" is quite simple. It consists
of a supply of compressed gases and an apparatus which delivers
the gases to the client. By turning some knobs and flipping
on/off switches, the administrator can produce the desired mix
of N2O-O2 in the desired quantities. Flowmeters and pressure
gauges allow the administrator to keep an eye on the flow of
gases.
The desired N2O-O2 mix
is fed through a tube to which a nasal hood or cannula is attached.
This hood is put over your nose. All you have to do now is breathe
normally through your nose - bingo!
The white inner mask (sticking out) comes in vanilla, strawberry,
and mint
In modern machines there
is a sort of "double mask" where the outside mask
is connected to a vacuum machine to suck away the waste gas
- you wouldn't want your dentist to get a face full of N2O...
The white inside mask, which is placed over your nose, comes
in lots of yummy scents - vanilla, strawberry, and mint!
The grey "outer mask" ensures that your dentist doesn't
leave work with a headache. The twin tubes running to the mask
are for "gas in" and "gas out". The "gas
out" line is attached to the vacuum machine, while the
"gas in" line is attached to the RA (short for relative
analgesia) machine. The inner mask is attached to the "line
in", you breathe out through a one-way valve in the inner
mask, and the exhaust gas is collected inside the outer grey
mask (pictured below)and sucked into the vacuum machine.
What
are the advantages?
* Happy gas 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 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).
* Unlike IV sedation,
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 may 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.
* For certain procedures,
especially those involving soft tissues (e. g. deep cleaning),
inhalation sedation may be used instead of local anaesthesia.
N2O acts as a painkiller; however, its pain-relieving effects
vary a lot from person to person and can't be relied upon. So
if you're determined to give the needle a miss, you and your
dentist will have to try and see what happens...
* 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.
According to Gordon, who's a bit of an expert in the field,
the normal working concentration of gases is about 70% oxygen
to 30% nitrous oxide: "It's rare to go beyond that because
that's what brings on the nausea, more than 45% N2O and you're
going to have the patient puke on you :-)" Ahh... nothing
like a bit of straight talk!
* Some people will not
achieve adequate sedation with permissible levels of oxygen.
* On rare occasions,
people have a bad experience with N2O. Usually this is due to
oversedation. This is easily reversible by reducing the amount
of N2O in the mix. For example, a few people have reported auditory
and "physical" hallucinations, dizziness, or vertigo:
Don't panic should you experience any symptoms of that nature.
While they're 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 - if you start feeling nauseous
or experience any other unpleasant symptoms, communicate these
to your dentist asap so that he or she 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, and you'll be fine :-) !
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 people are unable
to breathe through their noses (see above on how nitrous oxide
is administered), or they feel too claustrophobic when something
is put over their nose. If you have the snuffles and you can't
breathe through 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
do not affect the client, 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.
When
should I not use it?
There aren't any major
contraindications to RA, except for 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. M.S. is another contraindication.
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!
How
do I know if it's for me?
Why not ask if you can
have a 5 minute 'sample' so that you know what to expect on
the day of your procedure? Some dentists offer that service
to patients to help them with the decision of what to do. Your
dentist may not like the idea of doing this (costs, time, etc.),
but there is no harm in asking!
What
are the advantages? 
