I was surprised to read the recommendation to combat bad breath by gargling with half-strength hydrogen peroxide (Item 99-1). My dental hygienist advised me against this and cited reports of increased oral and throat cancers with regular use of peroxide gargles. Is there anything in the literature regarding this?
—TINA BAUM, RN, CNS, CWOCN, Elyria, Ohio

Full- or high-strength hydrogen peroxide can be cytotoxic and should not be used for routine oral hygiene.

However, the American Dental Association (J Am Dent Assoc. 2003;134:209-214), NIH (www.niehs.nih.gov/external/faq/perox.htm. Accessed February 1, 2007), and others validate the efficacy and safety of using the dilute solution mentioned for halitosis. Several other rinses also are available to oxygenate the oral environment and reduce the noxious gas release from the lingual bacteria.
—Sherril Sego, MSN, FNP (101-24)