Why does mouthwash recommend being used after brushing, when it has lower ppm fluoride than toothpaste?

Question

My Listerine mouthwash bottle directions says that for best results use twice a day after brushing. My toothpaste has 1450ppm fluoride, whereas the mouthwash is only 450ppm. Won’t using the mouthwash afterwards simply wash away the higher, more beneficial levels of toothpaste fluoride and replace it with lower mouthwash levels? What’s the reasoning for this advice?

In: Other

Answer 1

My (non-Listerine) mouthwash bottle specifically says to use it *before* brushing, which made no sense until I compared the fluoride levels.