Abstract: An aqueous composition for the treatment and prevention of malodor of the oral cavity has molecular chlorine dioxide at a concentration of about 1 ppm to about 200 ppm and a pH in the range of about 5.0 to about 7.5. The oral rinse may be used as part of a specific regimen of professional care and/or home use. The oral rinse may be prepared by mixing sodium hypochlorite or other chlorine-releasing agent with sodium chlorite. A convenient kit for preparing the oral rinse treatment contains aqueous sodium chlorite and aqueous sodium hypochlorite in buffered solutions.