“Four out of five dentists surveyed recommend sugarless gum for their patients who chew gum.” The slogan “became strongly associated with the Trident brand.” When it was first used is not certain. Sources date the survey to the early 1960s or to 1976.
The wording is careful. The dentists were “surveyed,” and the advice is for “patients who chew gum.” The fifth dentist “usually recommended no gum at all.”