Can my dentist tell if I brush and floss? YES! And so can your Hygienist. If you don't brush and floss regularly and effectively, then what we'll typically see visually are red/swollen/bleeding gums, more root decay, and more plaque/tartar accumulation. On x-rays, we can also detect tartar below the gum line, in-between cavities and bone loss...all indicators of the need to improve home care brushing and flossing.