After filling the reservoir with water, point the nozzle close to the gum line at an angle of 90 degrees. Then start the device by setting the appropriate pressure value. It is recommended to start irrigation from the back teeth, slowly following the gum line. The water jet should be directed between the tooth spaces, surfaces above the gum line, stopping momentarily at the area to be cleaned. In the case of hard-to-reach areas such as when using braces, in gum pockets, the angle of the nozzle can be changed.
Read more, here.