A periodontal examination involves checking the gums and supporting structures of the teeth. 
First, your dental hygienist will look at the gums for signs of redness or puffiness.She may poke them gently to see how easily they bleed.Bleeding gums is a sign of inflammation and indicate gum disease caused by bacteria. Your hygienist may use a special instrument - probe to measure the depth of the pockets between your teeth and your gums. Pockets deeper than 3 millimeters often indicate periodontal disease. If your hygienist determines that you have periodontal disease, he or she may refer you to a periodontist. This is a specialist who treats diseases of the gums.
Keep in mind that healthy gums help serve as an anchor to keep your teeth in place. If your gums look coral pink (not red) and don't bleed when you brush or floss, those are good signs. If you have bad breath, plaque and tartar accumulation, bleeding and tender gums you should see your dental hygienist. At yearly stages infectious gum disease is reversible.