Nitrous oxide gas better known as the ” laughing gas”. The chemical formula is N2O. Used in medicine for over 150 years, it was first 
used as an anesthetic in surgery, and also by rich people in parties, because of the feeling of floating and joy, and people who aspired and who also laughed after his aspiration was called “laughing gas”. The action of the gas is similar to the oxygen and connects in the same place and forms to the red blood cells and so it’s conducted to the whole-body area. Therefore, their risk in prolonged use and in high concentration can cause irreversible brain damage and even death, as happened a few years ago in pubs when birthday balloons were sold with laughing gas. Damage is caused by lack of oxygen in the cells, therefore is allowed to be used and purchased only by trained medical equipment and requires use with an intelligent System that mixes nitrous gas with oxygen so that it’s safe, mixture gases flows and the mechanism stops the flow of nitrous gas in the absence of oxygen
What is the sensation when inhaling gas? Feeling of tingling, in the hands and feet, feeling warm, pleasant feeling of levitation, the 
audience is distant despite its proximity, produces a deep relaxation giving drowsiness, sometimes with difficulty opening the eyes, or the possibility of talking , a tingling sensation or like butterflies in the belly (due to muscle relaxation of the belly), Therefore, the treatment is performed with the stomach almost empty, and the desired effect is the inability of the brain to feel the pain producing a relaxation and neutralizing the sensation of fear or anxiety.
The treatment process: The equipment used for gas inhalation is quite simple. It consists of a supply of compressed gases in bottles 
containers and a device that transfers the gas to the patient through a tube to a mask placed over the nose. By turning the knobs and activating the switches, the mixture is composed of nitrogen oxide and oxygen in the desired ratio. A pressure flow meter in relation to the mixture allows to choose and control the flow of gas. And also, a device is added on the finger that measures the blood pressure and the level of oxygen in the body.
Advantages: Quick effect in a few minutes, which causes relaxation and pain relief. The level of sedation can be changed at any time by regulating the gas ratios. The removal of gases from the body occurs very quickly after a few minutes of closing the flow and inspiration of pure oxygen, there is no trace in the body, only prolonged a good feeling of TRIP! Recovery of all the senses, without causing damage to any organ in the body and even used after a heart attack, so that the patient can relax and not feel the pain, the patient is fully conscious and responds to the environment.
Disadvantages: additional cost to the treatment calculated every 30 minutes, some people feel uncomfortable for fear of loss of control, the effect is achieved only through inspiration / expiration through the mask over the nose, therefore, the people with obstructed airways, or breathing through the mouth, the gas has no effect. Also, those who suffer from respiratory diseases the use is contraindicated, the equipment is expensive, it requires the placement of bottles containers in the clinic, which occupies large space, not all dentists have training and do not have the necessary equipment, in some cases produces the phenomenon of hallucinations or imaginary scenarios. About to use in pregnancy is not recommended because of relaxation of the abdominal and uterine muscles that can lead to spontaneous abortion or induction to premature birth.
