The suction unit is known as a dental suction machine,  is designed to provide the suction required during dental surgery. The suction unit could draw an amount of air and saliva into them over a short time. During the treatment process, it could keep the patients’ teeth and mouth dry. The dental suction machine also can be used for infection prevention. In order to aerosolize saliva particles, some countries also require the clinic should use a dental suction unit in any treatment involving fast-moving dental tools. Therefore, pneumatic suction in dental chairs is necessary for some countries.