Here, you can see the periodontal pocket, or missing bone around the root. Debris and bacteria collect in the pocket which is beneath the gum line and hard to clean. Eventually the problem becomes a full blown infection, sore to the touch as is the gum around it. Sometimes, the pus becomes trapped and pressure builds. The area is red and inflamed and bleeds easily. When the gum is pressed, pus may ooze out. See wwwgumdisease.com
