Bacteria: Our mouths are full of bacteria. Plaque: Bacteria constantly form's a sticky, colorless "plaque" on the teeth. Tartar: Plaque that is not removed hardens to form bacteria-harboring "tartar." Inflammation: Inflammation of the gums is called "gingivitis." If left untreated, it can advance to "periodontitis," which is an inflammation around the tooth that affects the bony support. Gums Pull Away from Tooth: In Periodontitis, gums pull away from the teeth and form "pockets" that are infected. Plaque and tartar spread and grow below the gum line and break down the bone and connective tissue.