Dentist will clean your teeth. They may use different tools like hand scalars or ultrasonic scalars to loose and remove deposits from the teeth.
When the gingivitis is left untreated, it can spread to the bone which known as periodontitis, in that case dentist will advise you to go for deep cleaning with or without root planing depending on the severity of gums disease.
Depth of the gum tissue between the teeth and gums are called pockets. When it is more than 5 mm or more, your dentist might prescribe a deep cleaning with root planing. Dentist will use a scaling instrument to remove plaque and tarter from the surface or the roots. Which include smoothing of the root surface and removal of any infected tooth structure. Antibiotics may be prescribed to boost immune system to combat the bacterial infection in gum tissue.