The plaque bacteria can infect your gums and teeth, and eventually, the gum tissue and bone that support the teeth will be impacted. There are three stages of gum disease: Gingivitis - This is the earliest stage of gum disease. It is the inflammation of the gums, caused by dental plaque buildup at the gum line. You may notice some redness or swelling of the gums, or some bleeding during brushing and flossing. At this early stage gum disease can be reversed since the bone and connective tissue that hold the teeth in place are not yet affected.