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.
“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.
Depending on the concentration and length of administration of laughing gas, different levels of sedation may be achieved. Nitrous oxide provides variable analgesia (painkiller), and a feeling of happiness, euphoria or deep relaxation

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 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.
• 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 to achieve sedation. In cases of very severe needle phobia, getting laughing gas first can help you feel relaxed enough to allow the needle required local anesthesia.
• 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.