Although federal regulations prohibit the sale of soft drinks to students during lunch hours in most schools, soft drink machines often line the hallways, which means the goods are accessible to students all day long. Some students are merely thirsty, and others are looking for an early morning caffeine kick. However, none are looking for tooth decay, though that's what many may get.

Soft drink purchases by teens in schools increased 1,100 percent over the past 20 years, while dairy purchases have decreased by 30 percent, according to a report in the January/ February 2003 issue of General Dentistry, the clinical, peer-reviewed journal of the Academy of General Dentistry (AGD).

Since 1995, soda companies have approached schools with lucrative, long-term deals – called "pouring rights" contracts – to exclusively sell their brand in exchange for funding. Citizens' groups and dental care professionals have criticized these companies for pushing their products to kids in school.

Many dentists are worried that the increase in soda consumption is leading to an increase in tooth decay among teenagers. "I think it is easy to lose track of the fact that pop is harmful," says AGD spokesperson William Chase, DDS, FAGD. "A lot of parents just don't ask what their kids are drinking and how much."

Studies show an increase in soda consumption over the last three decades. Soda consumption has increased from approximately 20 gallons of cola per person a year in 1970 to more than 50 gallons per person a year in 2004.

"We are not trying to get schools to ban vending machines...we want to educate people on what soda consumption can do to kids' teeth," says Dr. Chase.