Hello Your friend need oral prophylaxis Calculus and stains will be removed

Hello madam,            Hope you are doing good. They are just dental calculus in your teeth. They need to be cleaned by professional cleaning (scaling).It is a simple dental treatment and nothing to worry.

Hello dear, It’s calculus deposits underneath. You’ll need a dental cleaning done by a dental professional and a good oral hygiene to prevent in future. This calculus deposits do not get removed from your toothbrush so twice a year dental cleaning is mandatory for that healthy gums and tooth. Regular flossing and brushing twice daily would also be better.

Hello dear It's calculus deposit in the lower back of the teeth and it is difficult to remove from brush it can be removed from scaling only.