When the bone tissue starts to deteriorate, this is known as a form of gum disease called Periodontitis. This happens when the byproducts of plaque attack the tissues that hold your teeth to the bone. The gums begin falling away from the teeth and form pockets in the gums which allows more plaque to collect below the gum line. When this occurs, the patient becomes more sensitive to hot and cold and the roots of the teeth are more vulnerable to decay.