Gingivitis is usually the very earliest stage of gum disease; that is an inflammation of the gums which is caused by a plaque build-up at the patient's gum line

If daily brushing and flossing do not remove the plaque, it produces toxins (poisons) that can irritate the gum tissue, causing gingivitis. You may notice some bleeding during brushing and flossing. At this early stage in gum disease, damage can be improved, since the bone and connective tissue that hold the teeth in place are not yet affected.