Gingivitis is inflammation of gum tissue. Most common is plaque-induced gingivitis, due to bacterial plaque in close proximity to the gum margin. Plaque is an invisible , sticky film or layer primarily made up of bacteria and residual foods (starch, sugars etc). If not removed properly by effective daily toothbrushing and flossing, it can mineralize into hard calcium deposits( calculus/ tartar) and accumulate on the teeth, restorations, dentures, and gaps between the teeth and gums( gingival crevice).If untreated, it may progress to periodontitis.
Periodontitis is gum disease that causes inflammation of gums and loss of bone that anchors the teeth, and eventually mobility and tooth loss. Most common reason is buildup of bacterial plaque biofilms on the tooth surfaces and close to the gums, over a certain time frame. Periodontal diseases take on many different forms but primarily the cause remains dental plaque combined with a host immunoinflammatory response. This is also modified by certain risk factors like diabetes, smoking, stress, genetics, obesity, infrequent dental visits, osteoporosis, etc.)