Sedation is now an integral part of dentistry and a valid alternative to treatment under general anaesthesia for controlling pain and anxiety in phobic patients. Among the safest methods available, including for children, is sedation with nitrous oxide.
Nitrous oxide has been used in medicine for over 150 years and is the oldest and best-studied anaesthetic gas. It was in fact a dentist, the American Horace Wells, who in 1844 discovered the anaesthetic effect of this colourless gas with its faintly sweet smell.
At first nitrous oxide was used in its pure form, which caused the patient to lose consciousness temporarily and sometimes also triggered uncontrollable fits of laughter; that is why it is more commonly known as laughing gas.
Today nitrous oxide is only ever administered mixed with at least 30% oxygen; this avoids negative or potentially dangerous side effects, such as loss of consciousness.
Through the lungs, the gas reaches the bloodstream and binds temporarily to certain receptors in the brain, producing essentially three effects:
– Analgesic effect (pain relief): although nitrous oxide sedation cannot replace local anaesthesia, its analgesic effect means that a much smaller amount of local anaesthetic is needed.
– Anxiolytic effect (reduces fear): fear and tension in dental-phobic patients give way to a pleasant trance-like state that makes even long and difficult procedures easy to tolerate.
– Antiemetic effect (prevents vomiting): gagging during dental treatment is a widespread problem. With nitrous oxide this reflex is greatly reduced, so delicate procedures such as taking an impression or an X-ray of the back of the mouth can be carried out without major difficulty.
In paediatric dentistry, nitrous oxide sedation is a valuable aid in treating children who are frightened but cooperative, helping them accept the planned dental treatment more willingly.
The use of nitrous oxide is contraindicated only in the following cases:
– Pregnancy, especially in the first trimester.
– Chronic obstructive pulmonary disease (COPD).
– Vitamin B12 deficiency.
– Difficulty breathing through the nose (including very young children who cannot control their nasal breathing).
A huge advantage of nitrous oxide sedation is how precisely the procedure can be adjusted: the anxiolytic effect begins immediately with the first breaths, and the depth of sedation can be adjusted at any time by changing the nitrous oxide/oxygen ratio.
Because it is not metabolised, nitrous oxide is completely eliminated from the body in a very short time, without the after-effects of other sedatives, which remain in the bloodstream and keep acting for hours.
Another decisive advantage is the safety of the procedure: when correctly administered, it causes practically no side effects apart from occasional nausea.
In the past, when effective local anaesthesia was not available, the pain-relieving effect of nitrous oxide was particularly important; today it is the anxiolytic effect that takes centre stage. Given the large number of Italians who are afraid of the dentist, we believe it is important to inform patients about this option.
Credits: Photo by Caleb Woods on Unsplash
