Chloride dioxide mouthrinses utilize stabilized chlorine dioxide as the active ingredient in addition to citric acid and water. Chlorine dioxide is essentially a disinfectant that releases oxygen to kill anaerobic bacteria. In theory, this would be beneficial in treating periodontal disease, as most of the pathogens associated with it are anaerobic bacteria. Evaluation of the literature, however, reveals that there are insufficient studies showing chloride dioxide’s clinical efficacy against gingivitis. In contrast, chlorhexidine mouthrinse is well documented in its effectiveness against gingivitis. Unfortunately, discoloration (staining) is a possible side effect associated with chlorhexidine use. Chloride dioxide mouthrinse does not cause staining and has no other reported adverse effects. There is evidence that chlorine dioxide reduces breath malodor caused by sulphur-containing chemicals released by anaerobic bacteria. Chloride dioxide significantly reduces breath malodor by chemically neutralizing the sulphur-containing chemicals that cause the odor. Bottom line, chlorine dioxide is a great option for patients who experience breath malodor, but it should not replace chlorhexidine as a treatment for gingivitis/periodontal disease.