Chlorine dioxide is a common ingredient in most mouth rinse and some toothpaste. There are two types of chlorine dioxide rinses: stabilized and active.  

Stabilized Chlorine Dioxide is an excellent bactericide, fungicide, and as an anti-microbial agent, It is very gentle to the delicate tissues of the mouth, yet very aggressive towards bacteria and plaque. It breaks down microscopic food films; these film feeds the bacteria that cause tooth decay and gum disease.  

Active chlorine dioxide smells like chlorine while stabilized chlorine dioxide does not have a distinct odor. Yet Active Chlorine dioxide is not very stable in solutions with normal pH--especially if it is stored for long periods of time between use. This is why most manufacturers use stabilized chlorine dioxide. At the same time chlorine dioxide helps in reducing halitosis (Bad breath) for short periods of time by destroying the sulfur-containing molecules that cause bad breath.  

Chlorine dioxide will react with organic compounds, including flavoring agents. This limits the effectiveness because the deodorizing action of the chlorine dioxide compound is spent reacting with the flavoring agent instead of fighting halitosis!  

Mouth rinses that contain chlorine dioxide are safe to use for bad breath and gum disease as instructed by the dentist.