Sometimes, brushing and flossing don't quite seem to cut it, and bad breath recurs even after a twice-daily scrubbing. Many people in this situation go out and buy alcohol-based mouthwashes, which are often flavored with mint or cinnamon. These rinses may mute halitosis for a little while, but one expert told the UK Daily Mail that over time traditional mouthwashes can actually cause bad breath.
Restorative dentist Robin Seymour told the newspaper that many such products contain alcohol, sometimes as much as 13 percent by volume. This substance is then mixed with menthol and other natural compounds, which collectively target plaque and oral odor.
The problem, said Seymour, is that alcohol dries out the tongue and palate, leaving the oral field open to recolonization by microbes. Over time, the cycle of alcohol-rinsing and bacterial re-multiplication can not only make the mouth's bacterial strains more resilient, but it can allow those microorganisms the chance to produce odor compounds during periods of oral dryness.
Seymour also pointed to a study published in the Dental Journal of Australia linking alcoholic mouthwashes with an increased risk of oral cancer. Additionally, she noted that some mouth rinses stain teeth a pale brown over time.
Rather than risk bad breath or worse, those with oral odor may consider using an alcohol-free specialty breath freshening rinse instead.