By Pat Loeb

PHILADELPHIA (CBS) - A coalition of dental health groups wants to make better brushing part of the “back-to-school” routine. They’ve launched a campaign to get kids brushing twice a day, for two minutes.

To judge by a random sample in Independence Historic Park, kids have already gotten the message.

But according to the “Healthy Mouths, Health Lives Partnership,” 16 million children nationally suffer from untreated tooth decay; in Pennsylvania, that includes 27 percent of 3rd graders. Among their efforts to address these statistics, they posted web videos to www.2min2x.org of exactly two minutes each that kids can watch while they brush, to keep them from cutting corners.

They say tooth decay is the most common chronic childhood disease and it’s entirely preventable.