THE TARZAN-LIKE bottle swinging through the jungle is gone from Listerine commercials. So is the tune "Hooked on a Feeling," which helped introduce a new flavor of the mouthwash last year.

Listerine, which holds more than one-third of the U.S. mouthwash market, is shifting its focus from the fun approach it has taken since 1990 to a more sober message. Its makers say consumers want to hear about the serious side of mouth care, whether that means peroxide and baking soda in toothpaste or germ-fighting ingredients in mouthwash.

Instead, the mostly black-and-white ads, which are by agency J. Walter Thompson, focus entirely on germ-killing and prevention of gum disease, which long have been at least part of the brand's message. Instead of swinging bottles or loud music, the new spots feature closeups of a stern-looking man's face, scary dental equipment and computer-animated germs being drowned in Listerine. In one spot, the man warns of "wicked germs hoping to ravage" your "so tender" and "so innocent" gums. In another, he calls them "villainous germs" with such clinical names as leptotrichia that "breed in squalid colonies."