Bacteria in your mouth, forms a sticky film on your teeth called ‘plaque’. Brushing and flossing helps to remove much of the plaque. The plaque that is not removed can harden and form ‘calculus’ or ‘tartar’. Plaque and tartar can cause inflammation of the gums called gingivitis. With gingivitis, the gums become red, swollen and bleed easily. Gingivitis is a mild form of gum disease that can usually be reversed with daily brushing and flossing, and regular cleaning by a dentist or dental hygienist.