Periodontal treatment is the specialist cleaning of your teeth and gums to help control the bacteria that cause gum disease. Gum disease is caused by the germs (bacteria) which live in your mouth. The bacteria stick to your teeth, irritate the gums and make them bleed.
(Redirected from Ground effect in aircraft) In fixed-wing aircraft, ground effect is the increased lift (force) and decreased aerodynamic drag that an aircraft's wings generate when they are close to a fixed surface. When landing, ground effect can give the pilot the feeling that the aircraft is floating.
The ground is used for common mode rejection. The primary purpose of the ground is to prevent power line noise from interfering with the small biopotential signals of interest. By design, amplifiers should not be affected by large changes in potential at both the active and reference sites. A ground electrode for EEG recordings is often placed on the forehead (but could be placed anywhere else on the body; the location of the ground on the subject is generally irrelevant).