Though the minty freshness of mouthwashes will not last all day, the powerful swish of those with xylitol might present lingering benefits.

According to a report at, fluoride and xylitol rinses aid in cavity prevention because they can help neutralize the acidity of the mouth to lessen the decay process.

Some therapeutic rinses (both over-the-counter and by prescription) work by neutralizing the pH of the mouth, according to Dr. Peter Arsenault, division head of operative dentistry at Tufts University School of Dental Medicine.

He offered this explanation to the Wall Street Journal: When the bacteria in our mouth consume carbohydrates and sugars, their metabolic waste is acid. The acid draws out the minerals, resulting in an acidic mouth that leads to tooth decay.

An important ingredient to look for in such rinses is xylitol, a naturally occurring sugar alcohol which certain bacteria are unable to metabolize. “It kind of results in the bacteria in your mouth choking,” said Dr. Arsenault. Xylitol stimulates salivary function due to its sweetness and taste and helps restore the mouth to a neutral level of acidity.