So you've tried good oral hygiene, mints, mouthwashes, and sweet-smelling gum. Nothing's worked, and you wonder what else you can do to sweeten a patient's bad breath. How about magnolia bark?
That's the surprising proposition from researchers at the Wrigley Company. In the November 14 issue of the Journal of Agricultural and Food Chemistry, they report that this traditional Chinese medicine can massacre the bacteria behind halitosis.
In fact, compounds from the herb -- magnolol and honokiol -- were particularly effective against S. mutans, one of the chief caries bacteria.
Magnolia bark may offer advantages over mints that merely cover up the odor of gasses produced by bacteria, or antibacterial rinses containing chlorhexidine, which kill bacteria but stain teeth, the researchers theorize.
After finding that the extract killed bacteria in laboratory solutions, the investigators decided to try it out in human mouths. Nine Wrigley employees spit 1 milliliter of saliva into a test tube. Some sucked on a mint containing 4.2 milligrams of magnolia bark extract while others sucked on a placebo. Then the volunteers spit out another milliliter of saliva.
Finally, they repeated the experiment but chewed gum with 2 milligrams of the extract -- or a placebo gum -- instead of sucking on the mints.
For purposes of comparison, they also donated saliva after rinsing with 20 milligrams of Listerine FreshBurst mouthwash.
The results? After a half hour of sucking, the magnolia mint reduced the total oral bacterial count by 61.6 percent -- approximately the same amount as the Listerine. The placebo mint only reduced the total by 3.6 percent.
After an hour of sucking, the magnolia mint reduced bacteria by 33.8 percent while the placebo mint actually increased the total bacterial count by 47.9 percent.
The magnolia gum wiped out 43 percent of the total oral bacteria after 40 minutes, compared to only 18 percent eliminated by the placebo gum. (Perhaps because of the small number of subjects, this difference was not statistically significant.)
The investigators plan further experiments, but tentatively conclude that magnolia bark extract "may be incorporated in compressed mints and chewing gum to achieve long-lasting breath-freshening and oral-care benefits."