Decay: Ozone can be used to kill decay-causing bacteria. Since ozone is a liquid, it can permeate into areas below the gum line, into the grooves of teeth and over the smooth surfaces of the teeth and will kill bacteria on contact. If the decayed area, or cavity, is not too deep, then no restoration may be needed at all and may be treated with ozonated olive oil. If the area of decay is deeply cavitated and the bacteria is killed, then a filling can be placed often times with no need for numbing. Because ozone acts to recalcify tooth structure, areas of the tooth that have been treated with ozone are stronger than what was there before.