It is especially done when during a regular dental check-up, it is not possible for teeth and gums to be properly examined due to it being obscured by the hardened plaque.
Some signs include discolouration of your teeth, as well as teeth, appearing longer than usual due to the infection of gums and is receding.
A full mouth debridement (FMD) would then need to be performed first in order for your teeth and gums to be examined by your dentist.